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- Backport -fstack-clash-protection from development trunk (#1512529)

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This commit is contained in:
Jeff Law 2017-11-28 09:00:50 -07:00
parent 553b93f777
commit e987aff0a2
19 changed files with 6313 additions and 1 deletions
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43
gcc.spec
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@ -4,7 +4,7 @@
%global gcc_major 7
# Note, gcc_release must be integer, if you want to add suffixes to
# %{release}, append them after %{gcc_release} on Release: line.
%global gcc_release 2
%global gcc_release 3
%global nvptx_tools_gitrev c28050f60193b3b95a18866a96f03334e874e78f
%global nvptx_newlib_gitrev aadc8eb0ec43b7cd0dd2dfb484bae63c8b05ef24
%global _unpackaged_files_terminate_build 0
@ -242,6 +242,25 @@ Patch1000: nvptx-tools-no-ptxas.patch
Patch1001: nvptx-tools-build.patch
Patch1002: nvptx-tools-glibc.patch
Patch2001: gcc7-rh1512529-1.patch
Patch2002: gcc7-rh1512529-2.patch
Patch2003: gcc7-rh1512529-3.patch
Patch2004: gcc7-rh1512529-4.patch
Patch2005: gcc7-rh1512529-5.patch
Patch2006: gcc7-rh1512529-6.patch
Patch2007: gcc7-rh1512529-7.patch
Patch2008: gcc7-rh1512529-8.patch
Patch2009: gcc7-rh1512529-9.patch
Patch2010: gcc7-rh1512529-10.patch
Patch2011: gcc7-rh1512529-11.patch
Patch2012: gcc7-rh1512529-12.patch
Patch2013: gcc7-rh1512529-13.patch
Patch2014: gcc7-rh1512529-14.patch
Patch2015: gcc7-rh1512529-15.patch
Patch2016: gcc7-rh1512529-16.patch
Patch2017: gcc7-rh1512529-17.patch
Patch2018: gcc7-rh1512529-18.patch
# On ARM EABI systems, we do want -gnueabi to be part of the
# target triple.
%ifnarch %{arm}
@ -838,6 +857,25 @@ cd nvptx-tools-%{nvptx_tools_gitrev}
%patch1002 -p1 -b .nvptx-tools-glibc~
cd ..
%patch2001 -p1
%patch2002 -p1
%patch2003 -p1
%patch2004 -p1
%patch2005 -p1
%patch2006 -p1
%patch2007 -p1
%patch2008 -p1
%patch2009 -p1
%patch2010 -p1
%patch2011 -p1
%patch2012 -p1
%patch2013 -p1
%patch2014 -p1
%patch2015 -p1
%patch2016 -p1
%patch2017 -p1
%patch2018 -p1
%if 0%{?_enable_debug_packages}
mkdir dwz-wrapper
if [ -f /usr/bin/dwz ]; then
@ -3248,6 +3286,9 @@ fi
%endif
%changelog
* Tue Nov 28 2017 Jeff Law <law@redhat.com> 7.2.1-3
- Backport -fstack-clash-protection from development trunk (#1512529)
* Fri Sep 15 2017 Jakub Jelinek <jakub@redhat.com> 7.2.1-2
- update from the 7 branch
- PRs ada/62235, ada/79441, ada/79542, bootstrap/81926, c++/81355,

340
gcc7-rh1512529-1.patch Normal file
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@ -0,0 +1,340 @@
commit cc3586c7f4704acbbd3f2f99de5b82bcc8f6fe36
Author: law <law@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Wed Sep 20 04:56:54 2017 +0000
* common.opt (-fstack-clash-protection): New option.
* flag-types.h (enum stack_check_type): Note difference between
-fstack-check= and -fstack-clash-protection.
* params.def (PARAM_STACK_CLASH_PROTECTION_GUARD_SIZE): New PARAM.
(PARAM_STACK_CLASH_PROTECTION_PROBE_INTERVAL): Likewise.
* toplev.c (process_options): Issue warnings/errors for cases
not handled with -fstack-clash-protection.
* doc/invoke.texi (-fstack-clash-protection): Document new option.
(-fstack-check): Note additional problem with -fstack-check=generic.
Note that -fstack-check is primarily for Ada and refer users
to -fstack-clash-protection for stack-clash-protection.
Document new params for stack clash protection.
* gcc.dg/stack-check-2.c: New test.
* lib/target-supports.exp
(check_effective_target_supports_stack_clash_protection): New function.
(check_effective_target_frame_pointer_for_non_leaf): Likewise.
(check_effective_target_caller_implicit_probes): Likewise.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@252994 138bc75d-0d04-0410-961f-82ee72b054a4
diff --git a/gcc/common.opt b/gcc/common.opt
index 592bbd15309..bcaea91c130 100644
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -2291,13 +2291,18 @@ Common Report Var(flag_variable_expansion_in_unroller) Optimization
Apply variable expansion when loops are unrolled.
fstack-check=
-Common Report RejectNegative Joined
+Common Report RejectNegative Joined Optimization
-fstack-check=[no|generic|specific] Insert stack checking code into the program.
fstack-check
Common Alias(fstack-check=, specific, no)
Insert stack checking code into the program. Same as -fstack-check=specific.
+fstack-clash-protection
+Common Report Var(flag_stack_clash_protection) Optimization
+Insert code to probe each page of stack space as it is allocated to protect
+from stack-clash style attacks.
+
fstack-limit
Common Var(common_deferred_options) Defer
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index a0fb09eb9e1..f77035571a1 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -10026,6 +10026,21 @@ compilation without. The value for compilation with profile feedback
needs to be more conservative (higher) in order to make tracer
effective.
+@item stack-clash-protection-guard-size
+Specify the size of the operating system provided stack guard as
+2 raised to @var{num} bytes. The default value is 12 (4096 bytes).
+Acceptable values are between 12 and 30. Higher values may reduce the
+number of explicit probes, but a value larger than the operating system
+provided guard will leave code vulnerable to stack clash style attacks.
+
+@item stack-clash-protection-probe-interval
+Stack clash protection involves probing stack space as it is allocated. This
+param controls the maximum distance between probes into the stack as 2 raised
+to @var{num} bytes. Acceptable values are between 10 and 16 and defaults to
+12. Higher values may reduce the number of explicit probes, but a value
+larger than the operating system provided guard will leave code vulnerable to
+stack clash style attacks.
+
@item max-cse-path-length
The maximum number of basic blocks on path that CSE considers.
@@ -11218,7 +11233,8 @@ target support in the compiler but comes with the following drawbacks:
@enumerate
@item
Modified allocation strategy for large objects: they are always
-allocated dynamically if their size exceeds a fixed threshold.
+allocated dynamically if their size exceeds a fixed threshold. Note this
+may change the semantics of some code.
@item
Fixed limit on the size of the static frame of functions: when it is
@@ -11233,6 +11249,25 @@ generic implementation, code performance is hampered.
Note that old-style stack checking is also the fallback method for
@samp{specific} if no target support has been added in the compiler.
+@samp{-fstack-check=} is designed for Ada's needs to detect infinite recursion
+and stack overflows. @samp{specific} is an excellent choice when compiling
+Ada code. It is not generally sufficient to protect against stack-clash
+attacks. To protect against those you want @samp{-fstack-clash-protection}.
+
+@item -fstack-clash-protection
+@opindex fstack-clash-protection
+Generate code to prevent stack clash style attacks. When this option is
+enabled, the compiler will only allocate one page of stack space at a time
+and each page is accessed immediately after allocation. Thus, it prevents
+allocations from jumping over any stack guard page provided by the
+operating system.
+
+Most targets do not fully support stack clash protection. However, on
+those targets @option{-fstack-clash-protection} will protect dynamic stack
+allocations. @option{-fstack-clash-protection} may also provide limited
+protection for static stack allocations if the target supports
+@option{-fstack-check=specific}.
+
@item -fstack-limit-register=@var{reg}
@itemx -fstack-limit-symbol=@var{sym}
@itemx -fno-stack-limit
diff --git a/gcc/flag-types.h b/gcc/flag-types.h
index 27a38efdc8e..4e5a4e58119 100644
--- a/gcc/flag-types.h
+++ b/gcc/flag-types.h
@@ -166,7 +166,14 @@ enum permitted_flt_eval_methods
PERMITTED_FLT_EVAL_METHODS_C11
};
-/* Type of stack check. */
+/* Type of stack check.
+
+ Stack checking is designed to detect infinite recursion and stack
+ overflows for Ada programs. Furthermore stack checking tries to ensure
+ in that scenario that enough stack space is left to run a signal handler.
+
+ -fstack-check= does not prevent stack-clash style attacks. For that
+ you want -fstack-clash-protection. */
enum stack_check_type
{
/* Do not check the stack. */
diff --git a/gcc/params.def b/gcc/params.def
index 6b07518a34b..ce66e393eb1 100644
--- a/gcc/params.def
+++ b/gcc/params.def
@@ -213,6 +213,16 @@ DEFPARAM(PARAM_STACK_FRAME_GROWTH,
"Maximal stack frame growth due to inlining (in percent).",
1000, 0, 0)
+DEFPARAM(PARAM_STACK_CLASH_PROTECTION_GUARD_SIZE,
+ "stack-clash-protection-guard-size",
+ "Size of the stack guard expressed as a power of two.",
+ 12, 12, 30)
+
+DEFPARAM(PARAM_STACK_CLASH_PROTECTION_PROBE_INTERVAL,
+ "stack-clash-protection-probe-interval",
+ "Interval in which to probe the stack expressed as a power of two.",
+ 12, 10, 16)
+
/* The GCSE optimization will be disabled if it would require
significantly more memory than this value. */
DEFPARAM(PARAM_MAX_GCSE_MEMORY,
diff --git a/gcc/testsuite/gcc.dg/stack-check-2.c b/gcc/testsuite/gcc.dg/stack-check-2.c
new file mode 100644
index 00000000000..196c4bbfbdd
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/stack-check-2.c
@@ -0,0 +1,66 @@
+/* The goal here is to ensure that we never consider a call to a noreturn
+ function as a potential tail call.
+
+ Right now GCC discovers potential tail calls by looking at the
+ predecessors of the exit block. A call to a non-return function
+ has no successors and thus can never match that first filter.
+
+ But that could change one day and we want to catch it. The problem
+ is the compiler could potentially optimize a tail call to a nonreturn
+ function, even if the caller has a frame. That breaks the assumption
+ that calls probe *sp when saving the return address that some targets
+ depend on to elide stack probes. */
+
+/* { dg-do compile } */
+/* { dg-options "-O2 -fstack-clash-protection -fdump-tree-tailc -fdump-tree-optimized" } */
+/* { dg-require-effective-target supports_stack_clash_protection } */
+
+extern void foo (void) __attribute__ ((__noreturn__));
+
+
+void
+test_direct_1 (void)
+{
+ foo ();
+}
+
+void
+test_direct_2 (void)
+{
+ return foo ();
+}
+
+void (*indirect)(void)__attribute__ ((noreturn));
+
+
+void
+test_indirect_1 ()
+{
+ (*indirect)();
+}
+
+void
+test_indirect_2 (void)
+{
+ return (*indirect)();;
+}
+
+
+typedef void (*pvfn)() __attribute__ ((noreturn));
+
+void (*indirect_casted)(void);
+
+void
+test_indirect_casted_1 ()
+{
+ (*(pvfn)indirect_casted)();
+}
+
+void
+test_indirect_casted_2 (void)
+{
+ return (*(pvfn)indirect_casted)();
+}
+/* { dg-final { scan-tree-dump-not "tail call" "tailc" } } */
+/* { dg-final { scan-tree-dump-not "tail call" "optimized" } } */
+
diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp
index 57caec74836..1000f15358b 100644
--- a/gcc/testsuite/lib/target-supports.exp
+++ b/gcc/testsuite/lib/target-supports.exp
@@ -8371,3 +8371,80 @@ proc check_effective_target_arm_coproc4_ok { } {
return [check_cached_effective_target arm_coproc4_ok \
check_effective_target_arm_coproc4_ok_nocache]
}
+
+# Return 1 if the target has support for stack probing designed
+# to avoid stack-clash style attacks.
+#
+# This is used to restrict the stack-clash mitigation tests to
+# just those targets that have been explicitly supported.
+#
+# In addition to the prologue work on those targets, each target's
+# properties should be described in the functions below so that
+# tests do not become a mess of unreadable target conditions.
+#
+proc check_effective_target_supports_stack_clash_protection { } {
+
+ # Temporary until the target bits are fully ACK'd.
+# if { [istarget aarch*-*-*] || [istarget x86_64-*-*]
+# || [istarget i?86-*-*] || [istarget s390*-*-*]
+# || [istarget powerpc*-*-*] || [istarget rs6000*-*-*] } {
+# return 1
+# }
+ return 0
+}
+
+# Return 1 if the target creates a frame pointer for non-leaf functions
+# Note we ignore cases where we apply tail call optimization here.
+proc check_effective_target_frame_pointer_for_non_leaf { } {
+ if { [istarget aarch*-*-*] } {
+ return 1
+ }
+ return 0
+}
+
+# Return 1 if the target's calling sequence or its ABI
+# create implicit stack probes at or prior to function entry.
+proc check_effective_target_caller_implicit_probes { } {
+
+ # On x86/x86_64 the call instruction itself pushes the return
+ # address onto the stack. That is an implicit probe of *sp.
+ if { [istarget x86_64-*-*] || [istarget i?86-*-*] } {
+ return 1
+ }
+
+ # On PPC, the ABI mandates that the address of the outer
+ # frame be stored at *sp. Thus each allocation of stack
+ # space is itself an implicit probe of *sp.
+ if { [istarget powerpc*-*-*] || [istarget rs6000*-*-*] } {
+ return 1
+ }
+
+ # s390's ABI has a register save area allocated by the
+ # caller for use by the callee. The mere existence does
+ # not constitute a probe by the caller, but when the slots
+ # used by the callee those stores are implicit probes.
+ if { [istarget s390*-*-*] } {
+ return 1
+ }
+
+ # Not strictly true on aarch64, but we have agreed that we will
+ # consider any function that pushes SP more than 3kbytes into
+ # the guard page as broken. This essentially means that we can
+ # consider the aarch64 as having a caller implicit probe at
+ # *(sp + 1k).
+ if { [istarget aarch64*-*-*] } {
+ return 1;
+ }
+
+ return 0
+}
+
+# Targets that potentially realign the stack pointer often cause residual
+# stack allocations and make it difficult to elimination loops or residual
+# allocations for dynamic stack allocations
+proc check_effective_target_callee_realigns_stack { } {
+ if { [istarget x86_64-*-*] || [istarget i?86-*-*] } {
+ return 1
+ }
+ return 0
+}
diff --git a/gcc/toplev.c b/gcc/toplev.c
index e7a5d487313..a7da7964fbb 100644
--- a/gcc/toplev.c
+++ b/gcc/toplev.c
@@ -1574,6 +1574,26 @@ process_options (void)
flag_associative_math = 0;
}
+ /* -fstack-clash-protection is not currently supported on targets
+ where the stack grows up. */
+ if (flag_stack_clash_protection && !STACK_GROWS_DOWNWARD)
+ {
+ warning_at (UNKNOWN_LOCATION, 0,
+ "%<-fstack-clash-protection%> is not supported on targets "
+ "where the stack grows from lower to higher addresses");
+ flag_stack_clash_protection = 0;
+ }
+
+ /* We can not support -fstack-check= and -fstack-clash-protection at
+ the same time. */
+ if (flag_stack_check != NO_STACK_CHECK && flag_stack_clash_protection)
+ {
+ warning_at (UNKNOWN_LOCATION, 0,
+ "%<-fstack-check=%> and %<-fstack-clash_protection%> are "
+ "mutually exclusive. Disabling %<-fstack-check=%>");
+ flag_stack_check = NO_STACK_CHECK;
+ }
+
/* With -fcx-limited-range, we do cheap and quick complex arithmetic. */
if (flag_cx_limited_range)
flag_complex_method = 0;

605
gcc7-rh1512529-10.patch Normal file
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@ -0,0 +1,605 @@
commit b552ddab57a34fe1acb8d714b5f556082600b9e0
Author: law <law@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Mon Sep 25 23:13:55 2017 +0000
* config/rs6000/rs6000-protos.h (output_probe_stack_range): Update
prototype for new argument.
* config/rs6000/rs6000.c (rs6000_emit_allocate_stack_1): New function,
mostly extracted from rs6000_emit_allocate_stack.
(rs6000_emit_probe_stack_range_stack_clash): New function.
(rs6000_emit_allocate_stack): Call
rs6000_emit_probe_stack_range_stack_clash as needed.
(rs6000_emit_probe_stack_range): Add additional argument
to call to gen_probe_stack_range{si,di}.
(output_probe_stack_range): New.
(output_probe_stack_range_1): Renamed from output_probe_stack_range.
(output_probe_stack_range_stack_clash): New.
(rs6000_emit_prologue): Emit notes into dump file as requested.
* rs6000.md (allocate_stack): Handle -fstack-clash-protection.
(probe_stack_range<P:mode>): Operand 0 is now early-clobbered.
Add additional operand and pass it to output_probe_stack_range.
* lib/target-supports.exp
(check_effective_target_supports_stack_clash_protection): Enable for
rs6000 and powerpc targets.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@253179 138bc75d-0d04-0410-961f-82ee72b054a4
diff --git a/gcc/config/rs6000/rs6000-protos.h b/gcc/config/rs6000/rs6000-protos.h
index 74ad733d1b9..d48aa88f4b1 100644
--- a/gcc/config/rs6000/rs6000-protos.h
+++ b/gcc/config/rs6000/rs6000-protos.h
@@ -134,7 +134,7 @@ extern void rs6000_emit_sCOND (machine_mode, rtx[]);
extern void rs6000_emit_cbranch (machine_mode, rtx[]);
extern char * output_cbranch (rtx, const char *, int, rtx_insn *);
extern char * output_e500_flip_gt_bit (rtx, rtx);
-extern const char * output_probe_stack_range (rtx, rtx);
+extern const char * output_probe_stack_range (rtx, rtx, rtx);
extern bool rs6000_emit_set_const (rtx, rtx);
extern int rs6000_emit_cmove (rtx, rtx, rtx, rtx);
extern int rs6000_emit_vector_cond_expr (rtx, rtx, rtx, rtx, rtx, rtx);
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index 1836e1d147d..8235bff2469 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -28133,6 +28133,221 @@ rs6000_emit_stack_tie (rtx fp, bool hard_frame_needed)
emit_insn (gen_stack_tie (gen_rtx_PARALLEL (VOIDmode, p)));
}
+/* Allocate SIZE_INT bytes on the stack using a store with update style insn
+ and set the appropriate attributes for the generated insn. Return the
+ first insn which adjusts the stack pointer or the last insn before
+ the stack adjustment loop.
+
+ SIZE_INT is used to create the CFI note for the allocation.
+
+ SIZE_RTX is an rtx containing the size of the adjustment. Note that
+ since stacks grow to lower addresses its runtime value is -SIZE_INT.
+
+ ORIG_SP contains the backchain value that must be stored at *sp. */
+
+static rtx_insn *
+rs6000_emit_allocate_stack_1 (HOST_WIDE_INT size_int, rtx orig_sp)
+{
+ rtx_insn *insn;
+
+ rtx size_rtx = GEN_INT (-size_int);
+ if (size_int > 32767)
+ {
+ rtx tmp_reg = gen_rtx_REG (Pmode, 0);
+ /* Need a note here so that try_split doesn't get confused. */
+ if (get_last_insn () == NULL_RTX)
+ emit_note (NOTE_INSN_DELETED);
+ insn = emit_move_insn (tmp_reg, size_rtx);
+ try_split (PATTERN (insn), insn, 0);
+ size_rtx = tmp_reg;
+ }
+
+ if (Pmode == SImode)
+ insn = emit_insn (gen_movsi_update_stack (stack_pointer_rtx,
+ stack_pointer_rtx,
+ size_rtx,
+ orig_sp));
+ else
+ insn = emit_insn (gen_movdi_di_update_stack (stack_pointer_rtx,
+ stack_pointer_rtx,
+ size_rtx,
+ orig_sp));
+ rtx par = PATTERN (insn);
+ gcc_assert (GET_CODE (par) == PARALLEL);
+ rtx set = XVECEXP (par, 0, 0);
+ gcc_assert (GET_CODE (set) == SET);
+ rtx mem = SET_DEST (set);
+ gcc_assert (MEM_P (mem));
+ MEM_NOTRAP_P (mem) = 1;
+ set_mem_alias_set (mem, get_frame_alias_set ());
+
+ RTX_FRAME_RELATED_P (insn) = 1;
+ add_reg_note (insn, REG_FRAME_RELATED_EXPR,
+ gen_rtx_SET (stack_pointer_rtx,
+ gen_rtx_PLUS (Pmode,
+ stack_pointer_rtx,
+ GEN_INT (-size_int))));
+
+ /* Emit a blockage to ensure the allocation/probing insns are
+ not optimized, combined, removed, etc. Add REG_STACK_CHECK
+ note for similar reasons. */
+ if (flag_stack_clash_protection)
+ {
+ add_reg_note (insn, REG_STACK_CHECK, const0_rtx);
+ emit_insn (gen_blockage ());
+ }
+
+ return insn;
+}
+
+static HOST_WIDE_INT
+get_stack_clash_protection_probe_interval (void)
+{
+ return (HOST_WIDE_INT_1U
+ << PARAM_VALUE (PARAM_STACK_CLASH_PROTECTION_PROBE_INTERVAL));
+}
+
+static HOST_WIDE_INT
+get_stack_clash_protection_guard_size (void)
+{
+ return (HOST_WIDE_INT_1U
+ << PARAM_VALUE (PARAM_STACK_CLASH_PROTECTION_GUARD_SIZE));
+}
+
+/* Allocate ORIG_SIZE bytes on the stack and probe the newly
+ allocated space every STACK_CLASH_PROTECTION_PROBE_INTERVAL bytes.
+
+ COPY_REG, if non-null, should contain a copy of the original
+ stack pointer at exit from this function.
+
+ This is subtly different than the Ada probing in that it tries hard to
+ prevent attacks that jump the stack guard. Thus it is never allowed to
+ allocate more than STACK_CLASH_PROTECTION_PROBE_INTERVAL bytes of stack
+ space without a suitable probe. */
+static rtx_insn *
+rs6000_emit_probe_stack_range_stack_clash (HOST_WIDE_INT orig_size,
+ rtx copy_reg)
+{
+ rtx orig_sp = copy_reg;
+
+ HOST_WIDE_INT probe_interval = get_stack_clash_protection_probe_interval ();
+
+ /* Round the size down to a multiple of PROBE_INTERVAL. */
+ HOST_WIDE_INT rounded_size = ROUND_DOWN (orig_size, probe_interval);
+
+ /* If explicitly requested,
+ or the rounded size is not the same as the original size
+ or the the rounded size is greater than a page,
+ then we will need a copy of the original stack pointer. */
+ if (rounded_size != orig_size
+ || rounded_size > probe_interval
+ || copy_reg)
+ {
+ /* If the caller did not request a copy of the incoming stack
+ pointer, then we use r0 to hold the copy. */
+ if (!copy_reg)
+ orig_sp = gen_rtx_REG (Pmode, 0);
+ emit_move_insn (orig_sp, stack_pointer_rtx);
+ }
+
+ /* There's three cases here.
+
+ One is a single probe which is the most common and most efficiently
+ implemented as it does not have to have a copy of the original
+ stack pointer if there are no residuals.
+
+ Second is unrolled allocation/probes which we use if there's just
+ a few of them. It needs to save the original stack pointer into a
+ temporary for use as a source register in the allocation/probe.
+
+ Last is a loop. This is the most uncommon case and least efficient. */
+ rtx_insn *retval = NULL;
+ if (rounded_size == probe_interval)
+ {
+ retval = rs6000_emit_allocate_stack_1 (probe_interval, stack_pointer_rtx);
+
+ dump_stack_clash_frame_info (PROBE_INLINE, rounded_size != orig_size);
+ }
+ else if (rounded_size <= 8 * probe_interval)
+ {
+ /* The ABI requires using the store with update insns to allocate
+ space and store the backchain into the stack
+
+ So we save the current stack pointer into a temporary, then
+ emit the store-with-update insns to store the saved stack pointer
+ into the right location in each new page. */
+ for (int i = 0; i < rounded_size; i += probe_interval)
+ {
+ rtx_insn *insn
+ = rs6000_emit_allocate_stack_1 (probe_interval, orig_sp);
+
+ /* Save the first stack adjustment in RETVAL. */
+ if (i == 0)
+ retval = insn;
+ }
+
+ dump_stack_clash_frame_info (PROBE_INLINE, rounded_size != orig_size);
+ }
+ else
+ {
+ /* Compute the ending address. */
+ rtx end_addr
+ = copy_reg ? gen_rtx_REG (Pmode, 0) : gen_rtx_REG (Pmode, 12);
+ rtx rs = GEN_INT (-rounded_size);
+ rtx_insn *insn;
+ if (add_operand (rs, Pmode))
+ insn = emit_insn (gen_add3_insn (end_addr, stack_pointer_rtx, rs));
+ else
+ {
+ emit_move_insn (end_addr, GEN_INT (-rounded_size));
+ insn = emit_insn (gen_add3_insn (end_addr, end_addr,
+ stack_pointer_rtx));
+ /* Describe the effect of INSN to the CFI engine. */
+ add_reg_note (insn, REG_FRAME_RELATED_EXPR,
+ gen_rtx_SET (end_addr,
+ gen_rtx_PLUS (Pmode, stack_pointer_rtx,
+ rs)));
+ }
+ RTX_FRAME_RELATED_P (insn) = 1;
+
+ /* Emit the loop. */
+ if (TARGET_64BIT)
+ retval = emit_insn (gen_probe_stack_rangedi (stack_pointer_rtx,
+ stack_pointer_rtx, orig_sp,
+ end_addr));
+ else
+ retval = emit_insn (gen_probe_stack_rangesi (stack_pointer_rtx,
+ stack_pointer_rtx, orig_sp,
+ end_addr));
+ RTX_FRAME_RELATED_P (retval) = 1;
+ /* Describe the effect of INSN to the CFI engine. */
+ add_reg_note (retval, REG_FRAME_RELATED_EXPR,
+ gen_rtx_SET (stack_pointer_rtx, end_addr));
+
+ /* Emit a blockage to ensure the allocation/probing insns are
+ not optimized, combined, removed, etc. Other cases handle this
+ within their call to rs6000_emit_allocate_stack_1. */
+ emit_insn (gen_blockage ());
+
+ dump_stack_clash_frame_info (PROBE_LOOP, rounded_size != orig_size);
+ }
+
+ if (orig_size != rounded_size)
+ {
+ /* Allocate (and implicitly probe) any residual space. */
+ HOST_WIDE_INT residual = orig_size - rounded_size;
+
+ rtx_insn *insn = rs6000_emit_allocate_stack_1 (residual, orig_sp);
+
+ /* If the residual was the only allocation, then we can return the
+ allocating insn. */
+ if (!retval)
+ retval = insn;
+ }
+
+ return retval;
+}
+
/* Emit the correct code for allocating stack space, as insns.
If COPY_REG, make sure a copy of the old frame is left there.
The generated code may use hard register 0 as a temporary. */
@@ -28144,7 +28359,6 @@ rs6000_emit_allocate_stack (HOST_WIDE_INT size, rtx copy_reg, int copy_off)
rtx stack_reg = gen_rtx_REG (Pmode, STACK_POINTER_REGNUM);
rtx tmp_reg = gen_rtx_REG (Pmode, 0);
rtx todec = gen_int_mode (-size, Pmode);
- rtx par, set, mem;
if (INTVAL (todec) != -size)
{
@@ -28184,6 +28398,23 @@ rs6000_emit_allocate_stack (HOST_WIDE_INT size, rtx copy_reg, int copy_off)
warning (0, "stack limit expression is not supported");
}
+ if (flag_stack_clash_protection)
+ {
+ if (size < get_stack_clash_protection_guard_size ())
+ dump_stack_clash_frame_info (NO_PROBE_SMALL_FRAME, true);
+ else
+ {
+ rtx_insn *insn = rs6000_emit_probe_stack_range_stack_clash (size,
+ copy_reg);
+
+ /* If we asked for a copy with an offset, then we still need add in
+ the offset. */
+ if (copy_reg && copy_off)
+ emit_insn (gen_add3_insn (copy_reg, copy_reg, GEN_INT (copy_off)));
+ return insn;
+ }
+ }
+
if (copy_reg)
{
if (copy_off != 0)
@@ -28192,38 +28423,11 @@ rs6000_emit_allocate_stack (HOST_WIDE_INT size, rtx copy_reg, int copy_off)
emit_move_insn (copy_reg, stack_reg);
}
- if (size > 32767)
- {
- /* Need a note here so that try_split doesn't get confused. */
- if (get_last_insn () == NULL_RTX)
- emit_note (NOTE_INSN_DELETED);
- insn = emit_move_insn (tmp_reg, todec);
- try_split (PATTERN (insn), insn, 0);
- todec = tmp_reg;
- }
-
- insn = emit_insn (TARGET_32BIT
- ? gen_movsi_update_stack (stack_reg, stack_reg,
- todec, stack_reg)
- : gen_movdi_di_update_stack (stack_reg, stack_reg,
- todec, stack_reg));
/* Since we didn't use gen_frame_mem to generate the MEM, grab
it now and set the alias set/attributes. The above gen_*_update
calls will generate a PARALLEL with the MEM set being the first
operation. */
- par = PATTERN (insn);
- gcc_assert (GET_CODE (par) == PARALLEL);
- set = XVECEXP (par, 0, 0);
- gcc_assert (GET_CODE (set) == SET);
- mem = SET_DEST (set);
- gcc_assert (MEM_P (mem));
- MEM_NOTRAP_P (mem) = 1;
- set_mem_alias_set (mem, get_frame_alias_set ());
-
- RTX_FRAME_RELATED_P (insn) = 1;
- add_reg_note (insn, REG_FRAME_RELATED_EXPR,
- gen_rtx_SET (stack_reg, gen_rtx_PLUS (Pmode, stack_reg,
- GEN_INT (-size))));
+ insn = rs6000_emit_allocate_stack_1 (size, stack_reg);
return insn;
}
@@ -28305,9 +28509,9 @@ rs6000_emit_probe_stack_range (HOST_WIDE_INT first, HOST_WIDE_INT size)
until it is equal to ROUNDED_SIZE. */
if (TARGET_64BIT)
- emit_insn (gen_probe_stack_rangedi (r12, r12, r0));
+ emit_insn (gen_probe_stack_rangedi (r12, r12, stack_pointer_rtx, r0));
else
- emit_insn (gen_probe_stack_rangesi (r12, r12, r0));
+ emit_insn (gen_probe_stack_rangesi (r12, r12, stack_pointer_rtx, r0));
/* Step 4: probe at FIRST + SIZE if we cannot assert at compile-time
@@ -28319,10 +28523,10 @@ rs6000_emit_probe_stack_range (HOST_WIDE_INT first, HOST_WIDE_INT size)
}
/* Probe a range of stack addresses from REG1 to REG2 inclusive. These are
- absolute addresses. */
+ addresses, not offsets. */
-const char *
-output_probe_stack_range (rtx reg1, rtx reg2)
+static const char *
+output_probe_stack_range_1 (rtx reg1, rtx reg2)
{
static int labelno = 0;
char loop_lab[32];
@@ -28357,6 +28561,95 @@ output_probe_stack_range (rtx reg1, rtx reg2)
return "";
}
+/* This function is called when rs6000_frame_related is processing
+ SETs within a PARALLEL, and returns whether the REGNO save ought to
+ be marked RTX_FRAME_RELATED_P. The PARALLELs involved are those
+ for out-of-line register save functions, store multiple, and the
+ Darwin world_save. They may contain registers that don't really
+ need saving. */
+
+static bool
+interesting_frame_related_regno (unsigned int regno)
+{
+ /* Saves apparently of r0 are actually saving LR. It doesn't make
+ sense to substitute the regno here to test save_reg_p (LR_REGNO).
+ We *know* LR needs saving, and dwarf2cfi.c is able to deduce that
+ (set (mem) (r0)) is saving LR from a prior (set (r0) (lr)) marked
+ as frame related. */
+ if (regno == 0)
+ return true;
+ /* If we see CR2 then we are here on a Darwin world save. Saves of
+ CR2 signify the whole CR is being saved. This is a long-standing
+ ABI wart fixed by ELFv2. As for r0/lr there is no need to check
+ that CR needs to be saved. */
+ if (regno == CR2_REGNO)
+ return true;
+ /* Omit frame info for any user-defined global regs. If frame info
+ is supplied for them, frame unwinding will restore a user reg.
+ Also omit frame info for any reg we don't need to save, as that
+ bloats frame info and can cause problems with shrink wrapping.
+ Since global regs won't be seen as needing to be saved, both of
+ these conditions are covered by save_reg_p. */
+ return save_reg_p (regno);
+}
+
+/* Probe a range of stack addresses from REG1 to REG3 inclusive. These are
+ addresses, not offsets.
+
+ REG2 contains the backchain that must be stored into *sp at each allocation.
+
+ This is subtly different than the Ada probing above in that it tries hard
+ to prevent attacks that jump the stack guard. Thus, it is never allowed
+ to allocate more than PROBE_INTERVAL bytes of stack space without a
+ suitable probe. */
+
+static const char *
+output_probe_stack_range_stack_clash (rtx reg1, rtx reg2, rtx reg3)
+{
+ static int labelno = 0;
+ char loop_lab[32];
+ rtx xops[3];
+
+ HOST_WIDE_INT probe_interval = get_stack_clash_protection_probe_interval ();
+
+ ASM_GENERATE_INTERNAL_LABEL (loop_lab, "LPSRL", labelno++);
+
+ ASM_OUTPUT_INTERNAL_LABEL (asm_out_file, loop_lab);
+
+ /* This allocates and probes. */
+ xops[0] = reg1;
+ xops[1] = reg2;
+ xops[2] = GEN_INT (-probe_interval);
+ if (TARGET_64BIT)
+ output_asm_insn ("stdu %1,%2(%0)", xops);
+ else
+ output_asm_insn ("stwu %1,%2(%0)", xops);
+
+ /* Jump to LOOP_LAB if TEST_ADDR != LAST_ADDR. */
+ xops[0] = reg1;
+ xops[1] = reg3;
+ if (TARGET_64BIT)
+ output_asm_insn ("cmpd 0,%0,%1", xops);
+ else
+ output_asm_insn ("cmpw 0,%0,%1", xops);
+
+ fputs ("\tbne 0,", asm_out_file);
+ assemble_name_raw (asm_out_file, loop_lab);
+ fputc ('\n', asm_out_file);
+
+ return "";
+}
+
+/* Wrapper around the output_probe_stack_range routines. */
+const char *
+output_probe_stack_range (rtx reg1, rtx reg2, rtx reg3)
+{
+ if (flag_stack_clash_protection)
+ return output_probe_stack_range_stack_clash (reg1, reg2, reg3);
+ else
+ return output_probe_stack_range_1 (reg1, reg3);
+}
+
/* Add to 'insn' a note which is PATTERN (INSN) but with REG replaced
with (plus:P (reg 1) VAL), and with REG2 replaced with REPL2 if REG2
is not NULL. It would be nice if dwarf2out_frame_debug_expr could
@@ -29951,6 +30244,13 @@ rs6000_emit_prologue (void)
}
}
+ /* If we are emitting stack probes, but allocate no stack, then
+ just note that in the dump file. */
+ if (flag_stack_clash_protection
+ && dump_file
+ && !info->push_p)
+ dump_stack_clash_frame_info (NO_PROBE_NO_FRAME, false);
+
/* Update stack and set back pointer unless this is V.4,
for which it was done previously. */
if (!WORLD_SAVE_P (info) && info->push_p
diff --git a/gcc/config/rs6000/rs6000.md b/gcc/config/rs6000/rs6000.md
index 3323976a35d..843148e9703 100644
--- a/gcc/config/rs6000/rs6000.md
+++ b/gcc/config/rs6000/rs6000.md
@@ -10386,10 +10386,20 @@
;;
;; First, an insn to allocate new stack space for dynamic use (e.g., alloca).
;; We move the back-chain and decrement the stack pointer.
-
+;;
+;; Operand1 is more naturally reg_or_short_operand. However, for a large
+;; constant alloca, using that predicate will force the generic code to put
+;; the constant size into a register before calling the expander.
+;;
+;; As a result the expander would not have the constant size information
+;; in those cases and would have to generate less efficient code.
+;;
+;; Thus we allow reg_or_cint_operand instead so that the expander can see
+;; the constant size. The value is forced into a register if necessary.
+;;
(define_expand "allocate_stack"
[(set (match_operand 0 "gpc_reg_operand" "")
- (minus (reg 1) (match_operand 1 "reg_or_short_operand" "")))
+ (minus (reg 1) (match_operand 1 "reg_or_cint_operand" "")))
(set (reg 1)
(minus (reg 1) (match_dup 1)))]
""
@@ -10399,6 +10409,15 @@
rtx neg_op0;
rtx insn, par, set, mem;
+ /* By allowing reg_or_cint_operand as the predicate we can get
+ better code for stack-clash-protection because we do not lose
+ size information. But the rest of the code expects the operand
+ to be reg_or_short_operand. If it isn't, then force it into
+ a register. */
+ rtx orig_op1 = operands[1];
+ if (!reg_or_short_operand (operands[1], Pmode))
+ operands[1] = force_reg (Pmode, operands[1]);
+
emit_move_insn (chain, stack_bot);
/* Check stack bounds if necessary. */
@@ -10411,6 +10430,51 @@
emit_insn (gen_cond_trap (LTU, available, operands[1], const0_rtx));
}
+ /* Allocate and probe if requested.
+ This may look similar to the loop we use for prologue allocations,
+ but it is critically different. For the former we know the loop
+ will iterate, but do not know that generally here. The former
+ uses that knowledge to rotate the loop. Combining them would be
+ possible with some performance cost. */
+ if (flag_stack_clash_protection)
+ {
+ rtx rounded_size, last_addr, residual;
+ HOST_WIDE_INT probe_interval;
+ compute_stack_clash_protection_loop_data (&rounded_size, &last_addr,
+ &residual, &probe_interval,
+ orig_op1);
+
+ /* We do occasionally get in here with constant sizes, we might
+ as well do a reasonable job when we obviously can. */
+ if (rounded_size != const0_rtx)
+ {
+ rtx loop_lab, end_loop;
+ bool rotated = CONST_INT_P (rounded_size);
+
+ emit_stack_clash_protection_probe_loop_start (&loop_lab, &end_loop,
+ last_addr, rotated);
+
+ if (Pmode == SImode)
+ emit_insn (gen_movsi_update_stack (stack_pointer_rtx,
+ stack_pointer_rtx,
+ GEN_INT (-probe_interval),
+ chain));
+ else
+ emit_insn (gen_movdi_di_update_stack (stack_pointer_rtx,
+ stack_pointer_rtx,
+ GEN_INT (-probe_interval),
+ chain));
+ emit_stack_clash_protection_probe_loop_end (loop_lab, end_loop,
+ last_addr, rotated);
+ }
+
+ /* Now handle residuals. We just have to set operands[1] correctly
+ and let the rest of the expander run. */
+ operands[1] = residual;
+ if (!CONST_INT_P (residual))
+ operands[1] = force_reg (Pmode, operands[1]);
+ }
+
if (GET_CODE (operands[1]) != CONST_INT
|| INTVAL (operands[1]) < -32767
|| INTVAL (operands[1]) > 32768)
@@ -11549,12 +11613,13 @@
(set_attr "length" "4")])
(define_insn "probe_stack_range<P:mode>"
- [(set (match_operand:P 0 "register_operand" "=r")
+ [(set (match_operand:P 0 "register_operand" "=&r")
(unspec_volatile:P [(match_operand:P 1 "register_operand" "0")
- (match_operand:P 2 "register_operand" "r")]
+ (match_operand:P 2 "register_operand" "r")
+ (match_operand:P 3 "register_operand" "r")]
UNSPECV_PROBE_STACK_RANGE))]
""
- "* return output_probe_stack_range (operands[0], operands[2]);"
+ "* return output_probe_stack_range (operands[0], operands[2], operands[3]);"
[(set_attr "type" "three")])
;; Compare insns are next. Note that the RS/6000 has two types of compares,
diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp
index cb58a2be35f..02eb2066393 100644
--- a/gcc/testsuite/lib/target-supports.exp
+++ b/gcc/testsuite/lib/target-supports.exp
@@ -8385,12 +8385,12 @@ proc check_effective_target_arm_coproc4_ok { } {
proc check_effective_target_supports_stack_clash_protection { } {
# Temporary until the target bits are fully ACK'd.
-# if { [istarget aarch*-*-*]
-# || [istarget powerpc*-*-*] || [istarget rs6000*-*-*] } {
+# if { [istarget aarch*-*-*] } {
# return 1
# }
if { [istarget x86_64-*-*] || [istarget i?86-*-*]
+ || [istarget powerpc*-*-*] || [istarget rs6000*-*-*]
|| [istarget s390*-*-*] } {
return 1
}

28
gcc7-rh1512529-11.patch Normal file
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@ -0,0 +1,28 @@
commit eecbe7ada9a8ab913e779a27c0e90ec736eedc78
Author: law <law@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Fri Nov 3 17:14:23 2017 +0000
* config/i386/i386.c (ix86_expand_prologue): Tighten assert
for int_registers_saved.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@254386 138bc75d-0d04-0410-961f-82ee72b054a4
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 086848b2c73..fd74f1f6c0c 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -14172,8 +14172,12 @@ ix86_expand_prologue (void)
&& (flag_stack_check == STATIC_BUILTIN_STACK_CHECK
|| flag_stack_clash_protection))
{
- /* We expect the registers to be saved when probes are used. */
- gcc_assert (int_registers_saved);
+ /* This assert wants to verify that integer registers were saved
+ prior to probing. This is necessary when probing may be implemented
+ as a function call (Windows). It is not necessary for stack clash
+ protection probing. */
+ if (!flag_stack_clash_protection)
+ gcc_assert (int_registers_saved);
if (flag_stack_clash_protection)
{

81
gcc7-rh1512529-12.patch Normal file
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@ -0,0 +1,81 @@
commit 75179275ecc35724a058676199188e0d13e65054
Author: law <law@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Fri Nov 3 20:30:53 2017 +0000
* config/i386/i386.c (ix86_emit_restore_reg_using_pop): Prototype.
(ix86_adjust_stack_and_probe_stack_clash): Use a push/pop sequence
to probe at the start of a noreturn function.
* gcc.target/i386/stack-check-12.c: New test.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@254396 138bc75d-0d04-0410-961f-82ee72b054a4
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index fd74f1f6c0c..3c828ba492d 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -96,6 +96,7 @@ static rtx legitimize_dllimport_symbol (rtx, bool);
static rtx legitimize_pe_coff_extern_decl (rtx, bool);
static rtx legitimize_pe_coff_symbol (rtx, bool);
static void ix86_print_operand_address_as (FILE *, rtx, addr_space_t, bool);
+static void ix86_emit_restore_reg_using_pop (rtx);
#ifndef CHECK_STACK_LIMIT
#define CHECK_STACK_LIMIT (-1)
@@ -13287,10 +13288,13 @@ ix86_adjust_stack_and_probe_stack_clash (const HOST_WIDE_INT size)
no probes are needed. */
if (!size)
{
+ struct ix86_frame frame;
+ ix86_compute_frame_layout (&frame);
+
/* However, the allocation of space via pushes for register
saves could be viewed as allocating space, but without the
need to probe. */
- if (m->frame.nregs || m->frame.nsseregs || frame_pointer_needed)
+ if (frame.nregs || frame.nsseregs || frame_pointer_needed)
dump_stack_clash_frame_info (NO_PROBE_SMALL_FRAME, true);
else
dump_stack_clash_frame_info (NO_PROBE_NO_FRAME, false);
@@ -13312,8 +13316,14 @@ ix86_adjust_stack_and_probe_stack_clash (const HOST_WIDE_INT size)
we just probe when we cross PROBE_INTERVAL. */
if (TREE_THIS_VOLATILE (cfun->decl))
{
- emit_stack_probe (plus_constant (Pmode, stack_pointer_rtx,
- -GET_MODE_SIZE (word_mode)));
+ /* We can safely use any register here since we're just going to push
+ its value and immediately pop it back. But we do try and avoid
+ argument passing registers so as not to introduce dependencies in
+ the pipeline. For 32 bit we use %esi and for 64 bit we use %rax. */
+ rtx dummy_reg = gen_rtx_REG (word_mode, TARGET_64BIT ? AX_REG : SI_REG);
+ rtx_insn *insn = emit_insn (gen_push (dummy_reg));
+ RTX_FRAME_RELATED_P (insn) = 1;
+ ix86_emit_restore_reg_using_pop (dummy_reg);
emit_insn (gen_blockage ());
}
diff --git a/gcc/testsuite/gcc.target/i386/stack-check-12.c b/gcc/testsuite/gcc.target/i386/stack-check-12.c
new file mode 100644
index 00000000000..cb69bb08086
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/stack-check-12.c
@@ -0,0 +1,19 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fstack-clash-protection -mtune=generic" } */
+/* { dg-require-effective-target supports_stack_clash_protection } */
+
+__attribute__ ((noreturn)) void exit (int);
+
+__attribute__ ((noreturn)) void
+f (void)
+{
+ asm volatile ("nop" ::: "edi");
+ exit (1);
+}
+
+/* { dg-final { scan-assembler-not "or\[ql\]" } } */
+/* { dg-final { scan-assembler "pushl %esi" { target ia32 } } } */
+/* { dg-final { scan-assembler "popl %esi" { target ia32 } } }*/
+/* { dg-final { scan-assembler "pushq %rax" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler "popq %rax" { target { ! ia32 } } } }*/
+

228
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@ -0,0 +1,228 @@
commit 2f97a7844f2211bbd4fd869c18e26801bb795aa9
Author: law <law@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Mon Nov 6 15:51:16 2017 +0000
PR target/82788
* config/i386/i386.c (PROBE_INTERVAL): Remove.
(get_probe_interval): New functions.
(ix86_adjust_stack_and_probe_stack_clash): Use get_probe_interval.
(ix86_adjust_stack_and_probe): Likewise.
(output_adjust_stack_and_probe): Likewise.
(ix86_emit_probe_stack_range): Likewise.
(ix86_expand_prologue): Likewise.
PR target/82788
* gcc.dg/pr82788.c: New test.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@254456 138bc75d-0d04-0410-961f-82ee72b054a4
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index acd192a98c5..a904afe828d 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -13270,7 +13270,17 @@ release_scratch_register_on_entry (struct scratch_reg *sr)
}
}
-#define PROBE_INTERVAL (1 << STACK_CHECK_PROBE_INTERVAL_EXP)
+/* Return the probing interval for -fstack-clash-protection. */
+
+static HOST_WIDE_INT
+get_probe_interval (void)
+{
+ if (flag_stack_clash_protection)
+ return (HOST_WIDE_INT_1U
+ << PARAM_VALUE (PARAM_STACK_CLASH_PROTECTION_PROBE_INTERVAL));
+ else
+ return (HOST_WIDE_INT_1U << STACK_CHECK_PROBE_INTERVAL_EXP);
+}
/* Emit code to adjust the stack pointer by SIZE bytes while probing it.
@@ -13339,8 +13349,7 @@ ix86_adjust_stack_and_probe_stack_clash (const HOST_WIDE_INT size)
/* We're allocating a large enough stack frame that we need to
emit probes. Either emit them inline or in a loop depending
on the size. */
- HOST_WIDE_INT probe_interval
- = 1 << PARAM_VALUE (PARAM_STACK_CLASH_PROTECTION_PROBE_INTERVAL);
+ HOST_WIDE_INT probe_interval = get_probe_interval ();
if (size <= 4 * probe_interval)
{
HOST_WIDE_INT i;
@@ -13349,7 +13358,7 @@ ix86_adjust_stack_and_probe_stack_clash (const HOST_WIDE_INT size)
/* Allocate PROBE_INTERVAL bytes. */
rtx insn
= pro_epilogue_adjust_stack (stack_pointer_rtx, stack_pointer_rtx,
- GEN_INT (-PROBE_INTERVAL), -1,
+ GEN_INT (-probe_interval), -1,
m->fs.cfa_reg == stack_pointer_rtx);
add_reg_note (insn, REG_STACK_CHECK, const0_rtx);
@@ -13442,7 +13451,7 @@ ix86_adjust_stack_and_probe (const HOST_WIDE_INT size)
that's the easy case. The run-time loop is made up of 9 insns in the
generic case while the compile-time loop is made up of 3+2*(n-1) insns
for n # of intervals. */
- if (size <= 4 * PROBE_INTERVAL)
+ if (size <= 4 * get_probe_interval ())
{
HOST_WIDE_INT i, adjust;
bool first_probe = true;
@@ -13451,15 +13460,15 @@ ix86_adjust_stack_and_probe (const HOST_WIDE_INT size)
values of N from 1 until it exceeds SIZE. If only one probe is
needed, this will not generate any code. Then adjust and probe
to PROBE_INTERVAL + SIZE. */
- for (i = PROBE_INTERVAL; i < size; i += PROBE_INTERVAL)
+ for (i = get_probe_interval (); i < size; i += get_probe_interval ())
{
if (first_probe)
{
- adjust = 2 * PROBE_INTERVAL + dope;
+ adjust = 2 * get_probe_interval () + dope;
first_probe = false;
}
else
- adjust = PROBE_INTERVAL;
+ adjust = get_probe_interval ();
emit_insn (gen_rtx_SET (stack_pointer_rtx,
plus_constant (Pmode, stack_pointer_rtx,
@@ -13468,9 +13477,9 @@ ix86_adjust_stack_and_probe (const HOST_WIDE_INT size)
}
if (first_probe)
- adjust = size + PROBE_INTERVAL + dope;
+ adjust = size + get_probe_interval () + dope;
else
- adjust = size + PROBE_INTERVAL - i;
+ adjust = size + get_probe_interval () - i;
emit_insn (gen_rtx_SET (stack_pointer_rtx,
plus_constant (Pmode, stack_pointer_rtx,
@@ -13480,7 +13489,8 @@ ix86_adjust_stack_and_probe (const HOST_WIDE_INT size)
/* Adjust back to account for the additional first interval. */
last = emit_insn (gen_rtx_SET (stack_pointer_rtx,
plus_constant (Pmode, stack_pointer_rtx,
- PROBE_INTERVAL + dope)));
+ (get_probe_interval ()
+ + dope))));
}
/* Otherwise, do the same as above, but in a loop. Note that we must be
@@ -13498,7 +13508,7 @@ ix86_adjust_stack_and_probe (const HOST_WIDE_INT size)
/* Step 1: round SIZE to the previous multiple of the interval. */
- rounded_size = ROUND_DOWN (size, PROBE_INTERVAL);
+ rounded_size = ROUND_DOWN (size, get_probe_interval ());
/* Step 2: compute initial and final value of the loop counter. */
@@ -13506,7 +13516,7 @@ ix86_adjust_stack_and_probe (const HOST_WIDE_INT size)
/* SP = SP_0 + PROBE_INTERVAL. */
emit_insn (gen_rtx_SET (stack_pointer_rtx,
plus_constant (Pmode, stack_pointer_rtx,
- - (PROBE_INTERVAL + dope))));
+ - (get_probe_interval () + dope))));
/* LAST_ADDR = SP_0 + PROBE_INTERVAL + ROUNDED_SIZE. */
if (rounded_size <= (HOST_WIDE_INT_1 << 31))
@@ -13551,7 +13561,8 @@ ix86_adjust_stack_and_probe (const HOST_WIDE_INT size)
/* Adjust back to account for the additional first interval. */
last = emit_insn (gen_rtx_SET (stack_pointer_rtx,
plus_constant (Pmode, stack_pointer_rtx,
- PROBE_INTERVAL + dope)));
+ (get_probe_interval ()
+ + dope))));
release_scratch_register_on_entry (&sr);
}
@@ -13568,7 +13579,7 @@ ix86_adjust_stack_and_probe (const HOST_WIDE_INT size)
XVECEXP (expr, 0, 1)
= gen_rtx_SET (stack_pointer_rtx,
plus_constant (Pmode, stack_pointer_rtx,
- PROBE_INTERVAL + dope + size));
+ get_probe_interval () + dope + size));
add_reg_note (last, REG_FRAME_RELATED_EXPR, expr);
RTX_FRAME_RELATED_P (last) = 1;
@@ -13595,7 +13606,7 @@ output_adjust_stack_and_probe (rtx reg)
/* SP = SP + PROBE_INTERVAL. */
xops[0] = stack_pointer_rtx;
- xops[1] = GEN_INT (PROBE_INTERVAL);
+ xops[1] = GEN_INT (get_probe_interval ());
output_asm_insn ("sub%z0\t{%1, %0|%0, %1}", xops);
/* Probe at SP. */
@@ -13625,14 +13636,14 @@ ix86_emit_probe_stack_range (HOST_WIDE_INT first, HOST_WIDE_INT size)
that's the easy case. The run-time loop is made up of 6 insns in the
generic case while the compile-time loop is made up of n insns for n #
of intervals. */
- if (size <= 6 * PROBE_INTERVAL)
+ if (size <= 6 * get_probe_interval ())
{
HOST_WIDE_INT i;
/* Probe at FIRST + N * PROBE_INTERVAL for values of N from 1 until
it exceeds SIZE. If only one probe is needed, this will not
generate any code. Then probe at FIRST + SIZE. */
- for (i = PROBE_INTERVAL; i < size; i += PROBE_INTERVAL)
+ for (i = get_probe_interval (); i < size; i += get_probe_interval ())
emit_stack_probe (plus_constant (Pmode, stack_pointer_rtx,
-(first + i)));
@@ -13655,7 +13666,7 @@ ix86_emit_probe_stack_range (HOST_WIDE_INT first, HOST_WIDE_INT size)
/* Step 1: round SIZE to the previous multiple of the interval. */
- rounded_size = ROUND_DOWN (size, PROBE_INTERVAL);
+ rounded_size = ROUND_DOWN (size, get_probe_interval ());
/* Step 2: compute initial and final value of the loop counter. */
@@ -13716,7 +13727,7 @@ output_probe_stack_range (rtx reg, rtx end)
/* TEST_ADDR = TEST_ADDR + PROBE_INTERVAL. */
xops[0] = reg;
- xops[1] = GEN_INT (PROBE_INTERVAL);
+ xops[1] = GEN_INT (get_probe_interval ());
output_asm_insn ("sub%z0\t{%1, %0|%0, %1}", xops);
/* Probe at TEST_ADDR. */
@@ -14194,7 +14205,7 @@ ix86_expand_prologue (void)
else if (STACK_CHECK_MOVING_SP)
{
if (!(crtl->is_leaf && !cfun->calls_alloca
- && allocate <= PROBE_INTERVAL))
+ && allocate <= get_probe_interval ()))
{
ix86_adjust_stack_and_probe (allocate);
allocate = 0;
@@ -14211,7 +14222,7 @@ ix86_expand_prologue (void)
{
if (crtl->is_leaf && !cfun->calls_alloca)
{
- if (size > PROBE_INTERVAL)
+ if (size > get_probe_interval ())
ix86_emit_probe_stack_range (0, size);
}
else
@@ -14222,7 +14233,7 @@ ix86_expand_prologue (void)
{
if (crtl->is_leaf && !cfun->calls_alloca)
{
- if (size > PROBE_INTERVAL
+ if (size > get_probe_interval ()
&& size > get_stack_check_protect ())
ix86_emit_probe_stack_range (get_stack_check_protect (),
size - get_stack_check_protect ());
diff --git a/gcc/testsuite/gcc.dg/pr82788.c b/gcc/testsuite/gcc.dg/pr82788.c
new file mode 100644
index 00000000000..a8f628fd7f6
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr82788.c
@@ -0,0 +1,4 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -fstack-clash-protection --param stack-clash-protection-probe-interval=10 --param stack-clash-protection-guard-size=12" } */
+/* { dg-require-effective-target supports_stack_clash_protection } */
+int main() { int a[1442]; return 0;}

43
gcc7-rh1512529-14.patch Normal file
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@ -0,0 +1,43 @@
commit 799fb6fee433891510ab613a024450c926cdb4b3
Author: law <law@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Wed Nov 15 06:30:31 2017 +0000
* explow.c (anti_adjust_stack_and_probe_stack_clash): Avoid probing
the red zone for stack_clash_protection_final_dynamic_probe targets
when the total dynamic stack size is zero bytes.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@254753 138bc75d-0d04-0410-961f-82ee72b054a4
diff --git a/gcc/explow.c b/gcc/explow.c
index 6af6355fe30..53c4a6d7db9 100644
--- a/gcc/explow.c
+++ b/gcc/explow.c
@@ -1978,6 +1978,13 @@ anti_adjust_stack_and_probe_stack_clash (rtx size)
if (size != CONST0_RTX (Pmode)
&& targetm.stack_clash_protection_final_dynamic_probe (residual))
{
+ /* SIZE could be zero at runtime and in that case *sp could hold
+ live data. Furthermore, we don't want to probe into the red
+ zone.
+
+ Go ahead and just guard a probe at *sp on SIZE != 0 at runtime
+ if SIZE is not a compile time constant. */
+
/* Ideally we would just probe at *sp. However, if SIZE is not
a compile-time constant, but is zero at runtime, then *sp
might hold live data. So probe at *sp if we know that
@@ -1990,9 +1997,12 @@ anti_adjust_stack_and_probe_stack_clash (rtx size)
}
else
{
- emit_stack_probe (plus_constant (Pmode, stack_pointer_rtx,
- -GET_MODE_SIZE (word_mode)));
+ rtx label = gen_label_rtx ();
+ emit_cmp_and_jump_insns (size, CONST0_RTX (GET_MODE (size)),
+ EQ, NULL_RTX, Pmode, 1, label);
+ emit_stack_probe (stack_pointer_rtx);
emit_insn (gen_blockage ());
+ emit_label (label);
}
}
}

46
gcc7-rh1512529-15.patch Normal file
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@ -0,0 +1,46 @@
commit df7f99d5297f3c592401d7312c481578a8a62991
Author: Jeff Law <law@redhat.com>
Date: Wed Nov 22 11:55:10 2017 -0700
* gcc.dg/stack-check-5.c: Skip with -fstack-protector.
* gcc.dg/stack-check-6.c: Likewise.
* gcc.dg/stack-check-6a.c: Likewise.
diff --git a/gcc/testsuite/gcc.dg/stack-check-5.c b/gcc/testsuite/gcc.dg/stack-check-5.c
index 3178f5d8ce5..dd9f8dbf607 100644
--- a/gcc/testsuite/gcc.dg/stack-check-5.c
+++ b/gcc/testsuite/gcc.dg/stack-check-5.c
@@ -1,6 +1,8 @@
/* { dg-do compile } */
/* { dg-options "-O2 -fstack-clash-protection -fdump-rtl-pro_and_epilogue -fno-optimize-sibling-calls --param stack-clash-protection-probe-interval=12 --param stack-clash-protection-guard-size=12" } */
/* { dg-require-effective-target supports_stack_clash_protection } */
+/* { dg-skip-if "" { *-*-* } { "-fstack-protector" } { "" } } */
+
/* Otherwise the S/390 back-end might save the stack pointer in f2 ()
diff --git a/gcc/testsuite/gcc.dg/stack-check-6.c b/gcc/testsuite/gcc.dg/stack-check-6.c
index ad2021c9037..83559c5533c 100644
--- a/gcc/testsuite/gcc.dg/stack-check-6.c
+++ b/gcc/testsuite/gcc.dg/stack-check-6.c
@@ -1,6 +1,8 @@
/* { dg-do compile } */
/* { dg-options "-O2 -fstack-clash-protection -fdump-rtl-pro_and_epilogue -fno-optimize-sibling-calls --param stack-clash-protection-probe-interval=12 --param stack-clash-protection-guard-size=12" } */
/* { dg-require-effective-target supports_stack_clash_protection } */
+/* { dg-skip-if "" { *-*-* } { "-fstack-protector" } { "" } } */
+
extern void foo (char *);
diff --git a/gcc/testsuite/gcc.dg/stack-check-6a.c b/gcc/testsuite/gcc.dg/stack-check-6a.c
index 6f8e7128921..a1a2acbd6bd 100644
--- a/gcc/testsuite/gcc.dg/stack-check-6a.c
+++ b/gcc/testsuite/gcc.dg/stack-check-6a.c
@@ -4,6 +4,7 @@
/* { dg-do compile } */
/* { dg-options "-O2 -fstack-clash-protection -fdump-rtl-pro_and_epilogue -fno-optimize-sibling-calls --param stack-clash-protection-probe-interval=12 --param stack-clash-protection-guard-size=16" } */
/* { dg-require-effective-target supports_stack_clash_protection } */
+/* { dg-skip-if "" { *-*-* } { "-fstack-protector" } { "" } } */
#include "stack-check-6.c"

473
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@ -0,0 +1,473 @@
commit dafbd9e0c347cde6d8192f374787f5dbee4aed89
Author: Jeff Law <law@redhat.com>
Date: Wed Nov 22 12:01:56 2017 -0700
aarch64 support
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index 75c12f1de65..d7100c36664 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -2747,7 +2747,14 @@ aarch64_output_probe_stack_range (rtx reg1, rtx reg2)
output_asm_insn ("sub\t%0, %0, %1", xops);
/* Probe at TEST_ADDR. */
- output_asm_insn ("str\txzr, [%0]", xops);
+ if (flag_stack_clash_protection)
+ {
+ gcc_assert (xops[0] == stack_pointer_rtx);
+ xops[1] = GEN_INT (PROBE_INTERVAL - 8);
+ output_asm_insn ("str\txzr, [%0, %1]", xops);
+ }
+ else
+ output_asm_insn ("str\txzr, [%0]", xops);
/* Test if TEST_ADDR == LAST_ADDR. */
xops[1] = reg2;
@@ -3511,6 +3518,125 @@ aarch64_set_handled_components (sbitmap components)
cfun->machine->reg_is_wrapped_separately[regno] = true;
}
+/* Allocate SIZE bytes of stack space using SCRATCH_REG as a scratch
+ register. */
+
+static void
+aarch64_allocate_and_probe_stack_space (int scratchreg, HOST_WIDE_INT size)
+{
+ HOST_WIDE_INT probe_interval
+ = 1 << PARAM_VALUE (PARAM_STACK_CLASH_PROTECTION_PROBE_INTERVAL);
+ HOST_WIDE_INT guard_size
+ = 1 << PARAM_VALUE (PARAM_STACK_CLASH_PROTECTION_GUARD_SIZE);
+ HOST_WIDE_INT guard_used_by_caller = 1024;
+
+ /* SIZE should be large enough to require probing here. ie, it
+ must be larger than GUARD_SIZE - GUARD_USED_BY_CALLER.
+
+ We can allocate GUARD_SIZE - GUARD_USED_BY_CALLER as a single chunk
+ without any probing. */
+ gcc_assert (size >= guard_size - guard_used_by_caller);
+ aarch64_sub_sp (scratchreg, guard_size - guard_used_by_caller, true);
+ HOST_WIDE_INT orig_size = size;
+ size -= (guard_size - guard_used_by_caller);
+
+ HOST_WIDE_INT rounded_size = size & -probe_interval;
+ HOST_WIDE_INT residual = size - rounded_size;
+
+ /* We can handle a small number of allocations/probes inline. Otherwise
+ punt to a loop. */
+ if (rounded_size && rounded_size <= 4 * probe_interval)
+ {
+ /* We don't use aarch64_sub_sp here because we don't want to
+ repeatedly load SCRATCHREG. */
+ rtx scratch_rtx = gen_rtx_REG (Pmode, scratchreg);
+ if (probe_interval > ARITH_FACTOR)
+ emit_move_insn (scratch_rtx, GEN_INT (-probe_interval));
+ else
+ scratch_rtx = GEN_INT (-probe_interval);
+
+ for (HOST_WIDE_INT i = 0; i < rounded_size; i += probe_interval)
+ {
+ rtx_insn *insn = emit_insn (gen_add2_insn (stack_pointer_rtx,
+ scratch_rtx));
+ add_reg_note (insn, REG_STACK_CHECK, const0_rtx);
+
+ if (probe_interval > ARITH_FACTOR)
+ {
+ RTX_FRAME_RELATED_P (insn) = 1;
+ rtx adj = plus_constant (Pmode, stack_pointer_rtx, -probe_interval);
+ add_reg_note (insn, REG_CFA_ADJUST_CFA,
+ gen_rtx_SET (stack_pointer_rtx, adj));
+ }
+
+ emit_stack_probe (plus_constant (Pmode, stack_pointer_rtx,
+ (probe_interval
+ - GET_MODE_SIZE (word_mode))));
+ emit_insn (gen_blockage ());
+ }
+ dump_stack_clash_frame_info (PROBE_INLINE, size != rounded_size);
+ }
+ else if (rounded_size)
+ {
+ /* Compute the ending address. */
+ rtx temp = gen_rtx_REG (word_mode, scratchreg);
+ emit_move_insn (temp, GEN_INT (-rounded_size));
+ rtx_insn *insn
+ = emit_insn (gen_add3_insn (temp, stack_pointer_rtx, temp));
+
+ /* For the initial allocation, we don't have a frame pointer
+ set up, so we always need CFI notes. If we're doing the
+ final allocation, then we may have a frame pointer, in which
+ case it is the CFA, otherwise we need CFI notes.
+
+ We can determine which allocation we are doing by looking at
+ the temporary register. IP0 is the initial allocation, IP1
+ is the final allocation. */
+ if (scratchreg == IP0_REGNUM || !frame_pointer_needed)
+ {
+ /* We want the CFA independent of the stack pointer for the
+ duration of the loop. */
+ add_reg_note (insn, REG_CFA_DEF_CFA,
+ plus_constant (Pmode, temp,
+ (rounded_size + (orig_size - size))));
+ RTX_FRAME_RELATED_P (insn) = 1;
+ }
+
+ /* This allocates and probes the stack.
+
+ It also probes at a 4k interval regardless of the value of
+ PARAM_STACK_CLASH_PROTECTION_PROBE_INTERVAL. */
+ insn = emit_insn (gen_probe_stack_range (stack_pointer_rtx,
+ stack_pointer_rtx, temp));
+
+ /* Now reset the CFA register if needed. */
+ if (scratchreg == IP0_REGNUM || !frame_pointer_needed)
+ {
+ add_reg_note (insn, REG_CFA_DEF_CFA,
+ plus_constant (Pmode, stack_pointer_rtx,
+ (rounded_size + (orig_size - size))));
+ RTX_FRAME_RELATED_P (insn) = 1;
+ }
+
+ emit_insn (gen_blockage ());
+ dump_stack_clash_frame_info (PROBE_LOOP, size != rounded_size);
+ }
+ else
+ dump_stack_clash_frame_info (PROBE_INLINE, size != rounded_size);
+
+ /* Handle any residuals.
+ Note that any residual must be probed. */
+ if (residual)
+ {
+ aarch64_sub_sp (scratchreg, residual, true);
+ add_reg_note (get_last_insn (), REG_STACK_CHECK, const0_rtx);
+ emit_stack_probe (plus_constant (Pmode, stack_pointer_rtx,
+ (residual - GET_MODE_SIZE (word_mode))));
+ emit_insn (gen_blockage ());
+ }
+ return;
+}
+
/* AArch64 stack frames generated by this compiler look like:
+-------------------------------+
@@ -3592,7 +3718,54 @@ aarch64_expand_prologue (void)
aarch64_emit_probe_stack_range (get_stack_check_protect (), frame_size);
}
- aarch64_sub_sp (IP0_REGNUM, initial_adjust, true);
+ /* We do not fully protect aarch64 against stack clash style attacks
+ as doing so would be prohibitively expensive with less utility over
+ time as newer compilers are deployed.
+
+ We assume the guard is at least 64k. Furthermore, we assume that
+ the caller has not pushed the stack pointer more than 1k into
+ the guard. A caller that pushes the stack pointer than 1k into
+ the guard is considered invalid.
+
+ Note that the caller's ability to push the stack pointer into the
+ guard is a function of the number and size of outgoing arguments and/or
+ dynamic stack allocations due to the mandatory save of the link register
+ in the caller's frame.
+
+ With those assumptions the callee can allocate up to 63k of stack
+ space without probing.
+
+ When probing is needed, we emit a probe at the start of the prologue
+ and every PARAM_STACK_CLASH_PROTECTION_PROBE_INTERVAL bytes thereafter.
+
+ We have to track how much space has been allocated, but we do not
+ track stores into the stack as implicit probes except for the
+ fp/lr store. */
+ HOST_WIDE_INT guard_size
+ = 1 << PARAM_VALUE (PARAM_STACK_CLASH_PROTECTION_GUARD_SIZE);
+ HOST_WIDE_INT guard_used_by_caller = 1024;
+ if (flag_stack_clash_protection)
+ {
+ if (frame_size == 0)
+ dump_stack_clash_frame_info (NO_PROBE_NO_FRAME, false);
+ else if (initial_adjust < guard_size - guard_used_by_caller
+ && final_adjust < guard_size - guard_used_by_caller)
+ dump_stack_clash_frame_info (NO_PROBE_SMALL_FRAME, true);
+ }
+
+ /* In theory we should never have both an initial adjustment
+ and a callee save adjustment. Verify that is the case since the
+ code below does not handle it for -fstack-clash-protection. */
+ gcc_assert (initial_adjust == 0 || callee_adjust == 0);
+
+ /* Only probe if the initial adjustment is larger than the guard
+ less the amount of the guard reserved for use by the caller's
+ outgoing args. */
+ if (flag_stack_clash_protection
+ && initial_adjust >= guard_size - guard_used_by_caller)
+ aarch64_allocate_and_probe_stack_space (IP0_REGNUM, initial_adjust);
+ else
+ aarch64_sub_sp (IP0_REGNUM, initial_adjust, true);
if (callee_adjust != 0)
aarch64_push_regs (reg1, reg2, callee_adjust);
@@ -3613,7 +3786,30 @@ aarch64_expand_prologue (void)
callee_adjust != 0 || frame_pointer_needed);
aarch64_save_callee_saves (DFmode, callee_offset, V0_REGNUM, V31_REGNUM,
callee_adjust != 0 || frame_pointer_needed);
- aarch64_sub_sp (IP1_REGNUM, final_adjust, !frame_pointer_needed);
+
+ /* We may need to probe the final adjustment as well. */
+ if (flag_stack_clash_protection && final_adjust != 0)
+ {
+ /* First probe if the final adjustment is larger than the guard size
+ less the amount of the guard reserved for use by the caller's
+ outgoing args. */
+ if (final_adjust >= guard_size - guard_used_by_caller)
+ aarch64_allocate_and_probe_stack_space (IP1_REGNUM, final_adjust);
+ else
+ aarch64_sub_sp (IP1_REGNUM, final_adjust, !frame_pointer_needed);
+
+ /* We must also probe if the final adjustment is larger than the guard
+ that is assumed used by the caller. This may be sub-optimal. */
+ if (final_adjust >= guard_used_by_caller)
+ {
+ if (dump_file)
+ fprintf (dump_file,
+ "Stack clash aarch64 large outgoing arg, probing\n");
+ emit_stack_probe (stack_pointer_rtx);
+ }
+ }
+ else
+ aarch64_sub_sp (IP1_REGNUM, final_adjust, !frame_pointer_needed);
}
/* Return TRUE if we can use a simple_return insn.
@@ -3679,7 +3875,11 @@ aarch64_expand_epilogue (bool for_sibcall)
RTX_FRAME_RELATED_P (insn) = callee_adjust == 0;
}
else
- aarch64_add_sp (IP1_REGNUM, final_adjust, df_regs_ever_live_p (IP1_REGNUM));
+ aarch64_add_sp (IP1_REGNUM, final_adjust,
+ /* A stack clash protection prologue may not have
+ left IP1_REGNUM in a usable state. */
+ (flag_stack_clash_protection
+ || df_regs_ever_live_p (IP1_REGNUM)));
aarch64_restore_callee_saves (DImode, callee_offset, R0_REGNUM, R30_REGNUM,
callee_adjust != 0, &cfi_ops);
@@ -3702,7 +3902,11 @@ aarch64_expand_epilogue (bool for_sibcall)
cfi_ops = NULL;
}
- aarch64_add_sp (IP0_REGNUM, initial_adjust, df_regs_ever_live_p (IP0_REGNUM));
+ /* A stack clash protection prologue may not have left IP0_REGNUM
+ in a usable state. */
+ aarch64_add_sp (IP0_REGNUM, initial_adjust,
+ (flag_stack_clash_protection
+ || df_regs_ever_live_p (IP0_REGNUM)));
if (cfi_ops)
{
@@ -8696,6 +8900,12 @@ aarch64_override_options_internal (struct gcc_options *opts)
opts->x_param_values,
global_options_set.x_param_values);
+ /* We assume the guard page is 64k. */
+ maybe_set_param_value (PARAM_STACK_CLASH_PROTECTION_GUARD_SIZE,
+ 16,
+ opts->x_param_values,
+ global_options_set.x_param_values);
+
aarch64_override_options_after_change_1 (opts);
}
@@ -14726,6 +14936,28 @@ aarch64_sched_can_speculate_insn (rtx_insn *insn)
}
}
+/* It has been decided that to allow up to 1kb of outgoing argument
+ space to be allocated w/o probing. If more than 1kb of outgoing
+ argment space is allocated, then it must be probed and the last
+ probe must occur no more than 1kbyte away from the end of the
+ allocated space.
+
+ This implies that the residual part of an alloca allocation may
+ need probing in cases where the generic code might not otherwise
+ think a probe is needed.
+
+ This target hook returns TRUE when allocating RESIDUAL bytes of
+ alloca space requires an additional probe, otherwise FALSE is
+ returned. */
+
+static bool
+aarch64_stack_clash_protection_final_dynamic_probe (rtx residual)
+{
+ return (residual == CONST0_RTX (Pmode)
+ || GET_CODE (residual) != CONST_INT
+ || INTVAL (residual) >= 1024);
+}
+
/* Target-specific selftests. */
#if CHECKING_P
@@ -15154,6 +15386,10 @@ aarch64_libgcc_floating_mode_supported_p
#undef TARGET_CUSTOM_FUNCTION_DESCRIPTORS
#define TARGET_CUSTOM_FUNCTION_DESCRIPTORS 4
+#undef TARGET_STACK_CLASH_PROTECTION_FINAL_DYNAMIC_PROBE
+#define TARGET_STACK_CLASH_PROTECTION_FINAL_DYNAMIC_PROBE \
+ aarch64_stack_clash_protection_final_dynamic_probe
+
#if CHECKING_P
#undef TARGET_RUN_TARGET_SELFTESTS
#define TARGET_RUN_TARGET_SELFTESTS selftest::aarch64_run_selftests
diff --git a/gcc/config/aarch64/aarch64.md b/gcc/config/aarch64/aarch64.md
index 51368e29f2d..09b353d7470 100644
--- a/gcc/config/aarch64/aarch64.md
+++ b/gcc/config/aarch64/aarch64.md
@@ -5413,7 +5413,7 @@
)
(define_insn "probe_stack_range"
- [(set (match_operand:DI 0 "register_operand" "=r")
+ [(set (match_operand:DI 0 "register_operand" "=rk")
(unspec_volatile:DI [(match_operand:DI 1 "register_operand" "0")
(match_operand:DI 2 "register_operand" "r")]
UNSPECV_PROBE_STACK_RANGE))]
diff --git a/gcc/testsuite/gcc.target/aarch64/stack-check-12.c b/gcc/testsuite/gcc.target/aarch64/stack-check-12.c
new file mode 100644
index 00000000000..2ce38483b6b
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/stack-check-12.c
@@ -0,0 +1,20 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fstack-clash-protection --param stack-clash-protection-guard-size=12" } */
+/* { dg-require-effective-target supports_stack_clash_protection } */
+
+extern void arf (unsigned long int *, unsigned long int *);
+void
+frob ()
+{
+ unsigned long int num[1000];
+ unsigned long int den[1000];
+ arf (den, num);
+}
+
+/* This verifies that the scheduler did not break the dependencies
+ by adjusting the offsets within the probe and that the scheduler
+ did not reorder around the stack probes. */
+/* { dg-final { scan-assembler-times "sub\\tsp, sp, #4096\\n\\tstr\\txzr, .sp, 4088." 3 } } */
+
+
+
diff --git a/gcc/testsuite/gcc.target/aarch64/stack-check-13.c b/gcc/testsuite/gcc.target/aarch64/stack-check-13.c
new file mode 100644
index 00000000000..d8886835989
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/stack-check-13.c
@@ -0,0 +1,28 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fstack-clash-protection --param stack-clash-protection-guard-size=12" } */
+/* { dg-require-effective-target supports_stack_clash_protection } */
+
+#define ARG32(X) X,X,X,X,X,X,X,X,X,X,X,X,X,X,X,X,X,X,X,X,X,X,X,X,X,X,X,X,X,X,X,X
+#define ARG192(X) ARG32(X),ARG32(X),ARG32(X),ARG32(X),ARG32(X),ARG32(X)
+void out1(ARG192(__int128));
+int t1(int);
+
+int t3(int x)
+{
+ if (x < 1000)
+ return t1 (x) + 1;
+
+ out1 (ARG192(1));
+ return 0;
+}
+
+
+
+/* This test creates a large (> 1k) outgoing argument area that needs
+ to be probed. We don't test the exact size of the space or the
+ exact offset to make the test a little less sensitive to trivial
+ output changes. */
+/* { dg-final { scan-assembler-times "sub\\tsp, sp, #....\\n\\tstr\\txzr, \\\[sp" 1 } } */
+
+
+
diff --git a/gcc/testsuite/gcc.target/aarch64/stack-check-14.c b/gcc/testsuite/gcc.target/aarch64/stack-check-14.c
new file mode 100644
index 00000000000..59ffe01376d
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/stack-check-14.c
@@ -0,0 +1,25 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fstack-clash-protection --param stack-clash-protection-guard-size=12" } */
+/* { dg-require-effective-target supports_stack_clash_protection } */
+
+int t1(int);
+
+int t2(int x)
+{
+ char *p = __builtin_alloca (4050);
+ x = t1 (x);
+ return p[x];
+}
+
+
+/* This test has a constant sized alloca that is smaller than the
+ probe interval. But it actually requires two probes instead
+ of one because of the optimistic assumptions we made in the
+ aarch64 prologue code WRT probing state.
+
+ The form can change quite a bit so we just check for two
+ probes without looking at the actual address. */
+/* { dg-final { scan-assembler-times "str\\txzr," 2 } } */
+
+
+
diff --git a/gcc/testsuite/gcc.target/aarch64/stack-check-15.c b/gcc/testsuite/gcc.target/aarch64/stack-check-15.c
new file mode 100644
index 00000000000..e06db6dc2f0
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/stack-check-15.c
@@ -0,0 +1,24 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fstack-clash-protection --param stack-clash-protection-guard-size=12" } */
+/* { dg-require-effective-target supports_stack_clash_protection } */
+
+int t1(int);
+
+int t2(int x)
+{
+ char *p = __builtin_alloca (x);
+ x = t1 (x);
+ return p[x];
+}
+
+
+/* This test has a variable sized alloca. It requires 3 probes.
+ One in the loop, one for the residual and at the end of the
+ alloca area.
+
+ The form can change quite a bit so we just check for two
+ probes without looking at the actual address. */
+/* { dg-final { scan-assembler-times "str\\txzr," 3 } } */
+
+
+
diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp
index 02eb2066393..5431c236aa1 100644
--- a/gcc/testsuite/lib/target-supports.exp
+++ b/gcc/testsuite/lib/target-supports.exp
@@ -8384,14 +8384,9 @@ proc check_effective_target_arm_coproc4_ok { } {
#
proc check_effective_target_supports_stack_clash_protection { } {
- # Temporary until the target bits are fully ACK'd.
-# if { [istarget aarch*-*-*] } {
-# return 1
-# }
-
if { [istarget x86_64-*-*] || [istarget i?86-*-*]
|| [istarget powerpc*-*-*] || [istarget rs6000*-*-*]
- || [istarget s390*-*-*] } {
+ || [istarget aarch64*-**] || [istarget s390*-*-*] } {
return 1
}
return 0

40
gcc7-rh1512529-17.patch Normal file
View File

@ -0,0 +1,40 @@
commit 5ed5d56d36fc50627edf537c75afa0fdf6ba4f5d
Author: Jeff Law <law@redhat.com>
Date: Wed Nov 22 12:02:50 2017 -0700
2017-10-31 Segher Boessenkool <segher@kernel.crsahing.org>
PR target/82674
* config/rs6000/rs6000.md (allocate_stack): Force update interval
into a register if it does not fit into an immediate offset field.
diff --git a/gcc/config/rs6000/rs6000.md b/gcc/config/rs6000/rs6000.md
index 843148e9703..4b9732a78ec 100644
--- a/gcc/config/rs6000/rs6000.md
+++ b/gcc/config/rs6000/rs6000.md
@@ -10450,6 +10450,9 @@
{
rtx loop_lab, end_loop;
bool rotated = CONST_INT_P (rounded_size);
+ rtx update = GEN_INT (-probe_interval);
+ if (probe_interval > 32768)
+ update = force_reg (Pmode, update);
emit_stack_clash_protection_probe_loop_start (&loop_lab, &end_loop,
last_addr, rotated);
@@ -10457,13 +10460,11 @@
if (Pmode == SImode)
emit_insn (gen_movsi_update_stack (stack_pointer_rtx,
stack_pointer_rtx,
- GEN_INT (-probe_interval),
- chain));
+ update, chain));
else
emit_insn (gen_movdi_di_update_stack (stack_pointer_rtx,
stack_pointer_rtx,
- GEN_INT (-probe_interval),
- chain));
+ update, chain));
emit_stack_clash_protection_probe_loop_end (loop_lab, end_loop,
last_addr, rotated);
}

13
gcc7-rh1512529-18.patch Normal file
View File

@ -0,0 +1,13 @@
diff --git a/libsanitizer/sanitizer_common/sanitizer_linux.cc b/libsanitizer/sanitizer_common/sanitizer_linux.cc
index 5b6f18602e7..b5e96a1a0e4 100644
--- a/libsanitizer/sanitizer_common/sanitizer_linux.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_linux.cc
@@ -1262,7 +1262,7 @@ struct __sanitizer_esr_context {
static bool Aarch64GetESR(ucontext_t *ucontext, u64 *esr) {
static const u32 kEsrMagic = 0x45535201;
- u8 *aux = ucontext->uc_mcontext.__reserved;
+ u8 *aux = ucontext->uc_mcontext.__glibc_reserved1;
while (true) {
_aarch64_ctx *ctx = (_aarch64_ctx *)aux;
if (ctx->size == 0) break;

735
gcc7-rh1512529-2.patch Normal file
View File

@ -0,0 +1,735 @@
commit bed27844b80e17ad786028a0a82c7d47990d15bb
Author: law <law@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Wed Sep 20 05:05:12 2017 +0000
2017-09-18 Jeff Law <law@redhat.com>
* explow.c: Include "params.h".
(anti_adjust_stack_and_probe_stack_clash): New function.
(get_stack_check_protect): Likewise.
(compute_stack_clash_protection_loop_data): Likewise.
(emit_stack_clash_protection_loop_start): Likewise.
(emit_stack_clash_protection_loop_end): Likewise.
(allocate_dynamic_stack_space): Use get_stack_check_protect.
Use anti_adjust_stack_and_probe_stack_clash.
* explow.h (compute_stack_clash_protection_loop_data): Prototype.
(emit_stack_clash_protection_loop_start): Likewise.
(emit_stack_clash_protection_loop_end): Likewise.
* rtl.h (get_stack_check_protect): Prototype.
* target.def (stack_clash_protection_final_dynamic_probe): New hook.
* targhooks.c (default_stack_clash_protection_final_dynamic_probe): New.
* targhooks.h (default_stack_clash_protection_final_dynamic_probe):
Prototype.
* doc/tm.texi.in (TARGET_STACK_CLASH_PROTECTION_FINAL_DYNAMIC_PROBE):
Add @hook.
* doc/tm.texi: Rebuilt.
* config/aarch64/aarch64.c (aarch64_expand_prologue): Use
get_stack_check_protect.
* config/alpha/alpha.c (alpha_expand_prologue): Likewise.
* config/arm/arm.c (arm_expand_prologue): Likewise.
(arm_frame_pointer_required): Likewise.
* config/i386/i386.c (ix86_expand_prologue): Likewise.
* config/ia64/ia64.c (ia64_expand_prologue): Likewise.
* config/mips/mips.c (mips_expand_prologue): Likewise.
* config/powerpcspe/powerpcspe.c (rs6000_emit_prologue): Likewise.
* config/rs6000/rs6000.c (rs6000_emit_prologue): Likewise.
* config/sparc/sparc.c (sparc_expand_prologue): Likewise.
(sparc_flat_expand_prologue): Likewise.
* gcc.dg/stack-check-3.c: New test.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@252995 138bc75d-0d04-0410-961f-82ee72b054a4
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index 1bd010be756..75c12f1de65 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -3582,12 +3582,14 @@ aarch64_expand_prologue (void)
{
if (crtl->is_leaf && !cfun->calls_alloca)
{
- if (frame_size > PROBE_INTERVAL && frame_size > STACK_CHECK_PROTECT)
- aarch64_emit_probe_stack_range (STACK_CHECK_PROTECT,
- frame_size - STACK_CHECK_PROTECT);
+ if (frame_size > PROBE_INTERVAL
+ && frame_size > get_stack_check_protect ())
+ aarch64_emit_probe_stack_range (get_stack_check_protect (),
+ (frame_size
+ - get_stack_check_protect ()));
}
else if (frame_size > 0)
- aarch64_emit_probe_stack_range (STACK_CHECK_PROTECT, frame_size);
+ aarch64_emit_probe_stack_range (get_stack_check_protect (), frame_size);
}
aarch64_sub_sp (IP0_REGNUM, initial_adjust, true);
diff --git a/gcc/config/alpha/alpha.c b/gcc/config/alpha/alpha.c
index 00a69c1a08d..91f3d7cfbeb 100644
--- a/gcc/config/alpha/alpha.c
+++ b/gcc/config/alpha/alpha.c
@@ -7741,7 +7741,7 @@ alpha_expand_prologue (void)
probed_size = frame_size;
if (flag_stack_check)
- probed_size += STACK_CHECK_PROTECT;
+ probed_size += get_stack_check_protect ();
if (probed_size <= 32768)
{
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index 1ded0d2a17d..242d7c792fe 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -21604,13 +21604,13 @@ arm_expand_prologue (void)
if (crtl->is_leaf && !cfun->calls_alloca)
{
- if (size > PROBE_INTERVAL && size > STACK_CHECK_PROTECT)
- arm_emit_probe_stack_range (STACK_CHECK_PROTECT,
- size - STACK_CHECK_PROTECT,
+ if (size > PROBE_INTERVAL && size > get_stack_check_protect ())
+ arm_emit_probe_stack_range (get_stack_check_protect (),
+ size - get_stack_check_protect (),
regno, live_regs_mask);
}
else if (size > 0)
- arm_emit_probe_stack_range (STACK_CHECK_PROTECT, size,
+ arm_emit_probe_stack_range (get_stack_check_protect (), size,
regno, live_regs_mask);
}
@@ -27751,7 +27751,7 @@ arm_frame_pointer_required (void)
{
/* We don't have the final size of the frame so adjust. */
size += 32 * UNITS_PER_WORD;
- if (size > PROBE_INTERVAL && size > STACK_CHECK_PROTECT)
+ if (size > PROBE_INTERVAL && size > get_stack_check_protect ())
return true;
}
else
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 2d163797ba0..60bab9a26a6 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -14037,7 +14037,7 @@ ix86_expand_prologue (void)
HOST_WIDE_INT size = allocate;
if (TARGET_64BIT && size >= HOST_WIDE_INT_C (0x80000000))
- size = 0x80000000 - STACK_CHECK_PROTECT - 1;
+ size = 0x80000000 - get_stack_check_protect () - 1;
if (TARGET_STACK_PROBE)
{
@@ -14047,18 +14047,20 @@ ix86_expand_prologue (void)
ix86_emit_probe_stack_range (0, size);
}
else
- ix86_emit_probe_stack_range (0, size + STACK_CHECK_PROTECT);
+ ix86_emit_probe_stack_range (0,
+ size + get_stack_check_protect ());
}
else
{
if (crtl->is_leaf && !cfun->calls_alloca)
{
- if (size > PROBE_INTERVAL && size > STACK_CHECK_PROTECT)
- ix86_emit_probe_stack_range (STACK_CHECK_PROTECT,
- size - STACK_CHECK_PROTECT);
+ if (size > PROBE_INTERVAL
+ && size > get_stack_check_protect ())
+ ix86_emit_probe_stack_range (get_stack_check_protect (),
+ size - get_stack_check_protect ());
}
else
- ix86_emit_probe_stack_range (STACK_CHECK_PROTECT, size);
+ ix86_emit_probe_stack_range (get_stack_check_protect (), size);
}
}
}
diff --git a/gcc/config/ia64/ia64.c b/gcc/config/ia64/ia64.c
index a9f479b6e5c..17d6b3318a6 100644
--- a/gcc/config/ia64/ia64.c
+++ b/gcc/config/ia64/ia64.c
@@ -3476,15 +3476,16 @@ ia64_expand_prologue (void)
if (crtl->is_leaf && !cfun->calls_alloca)
{
- if (size > PROBE_INTERVAL && size > STACK_CHECK_PROTECT)
- ia64_emit_probe_stack_range (STACK_CHECK_PROTECT,
- size - STACK_CHECK_PROTECT,
+ if (size > PROBE_INTERVAL && size > get_stack_check_protect ())
+ ia64_emit_probe_stack_range (get_stack_check_protect (),
+ size - get_stack_check_protect (),
bs_size);
- else if (size + bs_size > STACK_CHECK_PROTECT)
- ia64_emit_probe_stack_range (STACK_CHECK_PROTECT, 0, bs_size);
+ else if (size + bs_size > get_stack_check_protect ())
+ ia64_emit_probe_stack_range (get_stack_check_protect (),
+ 0, bs_size);
}
else if (size + bs_size > 0)
- ia64_emit_probe_stack_range (STACK_CHECK_PROTECT, size, bs_size);
+ ia64_emit_probe_stack_range (get_stack_check_protect (), size, bs_size);
}
if (dump_file)
diff --git a/gcc/config/mips/mips.c b/gcc/config/mips/mips.c
index 6bfd86a07af..7d85ce7055a 100644
--- a/gcc/config/mips/mips.c
+++ b/gcc/config/mips/mips.c
@@ -12081,12 +12081,12 @@ mips_expand_prologue (void)
{
if (crtl->is_leaf && !cfun->calls_alloca)
{
- if (size > PROBE_INTERVAL && size > STACK_CHECK_PROTECT)
- mips_emit_probe_stack_range (STACK_CHECK_PROTECT,
- size - STACK_CHECK_PROTECT);
+ if (size > PROBE_INTERVAL && size > get_stack_check_protect ())
+ mips_emit_probe_stack_range (get_stack_check_protect (),
+ size - get_stack_check_protect ());
}
else if (size > 0)
- mips_emit_probe_stack_range (STACK_CHECK_PROTECT, size);
+ mips_emit_probe_stack_range (get_stack_check_protect (), size);
}
/* Save the registers. Allocate up to MIPS_MAX_FIRST_STACK_STEP
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index 66496a1f80f..1836e1d147d 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -29294,12 +29294,12 @@ rs6000_emit_prologue (void)
if (crtl->is_leaf && !cfun->calls_alloca)
{
- if (size > PROBE_INTERVAL && size > STACK_CHECK_PROTECT)
- rs6000_emit_probe_stack_range (STACK_CHECK_PROTECT,
- size - STACK_CHECK_PROTECT);
+ if (size > PROBE_INTERVAL && size > get_stack_check_protect ())
+ rs6000_emit_probe_stack_range (get_stack_check_protect (),
+ size - get_stack_check_protect ());
}
else if (size > 0)
- rs6000_emit_probe_stack_range (STACK_CHECK_PROTECT, size);
+ rs6000_emit_probe_stack_range (get_stack_check_protect (), size);
}
if (TARGET_FIX_AND_CONTINUE)
diff --git a/gcc/config/sparc/sparc.c b/gcc/config/sparc/sparc.c
index 83ca1dcc617..b32bb9859e1 100644
--- a/gcc/config/sparc/sparc.c
+++ b/gcc/config/sparc/sparc.c
@@ -5695,12 +5695,12 @@ sparc_expand_prologue (void)
{
if (crtl->is_leaf && !cfun->calls_alloca)
{
- if (size > PROBE_INTERVAL && size > STACK_CHECK_PROTECT)
- sparc_emit_probe_stack_range (STACK_CHECK_PROTECT,
- size - STACK_CHECK_PROTECT);
+ if (size > PROBE_INTERVAL && size > get_stack_check_protect ())
+ sparc_emit_probe_stack_range (get_stack_check_protect (),
+ size - get_stack_check_protect ());
}
else if (size > 0)
- sparc_emit_probe_stack_range (STACK_CHECK_PROTECT, size);
+ sparc_emit_probe_stack_range (get_stack_check_protect (), size);
}
if (size == 0)
@@ -5806,12 +5806,12 @@ sparc_flat_expand_prologue (void)
{
if (crtl->is_leaf && !cfun->calls_alloca)
{
- if (size > PROBE_INTERVAL && size > STACK_CHECK_PROTECT)
- sparc_emit_probe_stack_range (STACK_CHECK_PROTECT,
- size - STACK_CHECK_PROTECT);
+ if (size > PROBE_INTERVAL && size > get_stack_check_protect ())
+ sparc_emit_probe_stack_range (get_stack_check_protect (),
+ size - get_stack_check_protect ());
}
else if (size > 0)
- sparc_emit_probe_stack_range (STACK_CHECK_PROTECT, size);
+ sparc_emit_probe_stack_range (get_stack_check_protect (), size);
}
if (sparc_save_local_in_regs_p)
diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
index c4f2c893c8e..0ba2925a1bd 100644
--- a/gcc/doc/tm.texi
+++ b/gcc/doc/tm.texi
@@ -3419,6 +3419,10 @@ GCC computed the default from the values of the above macros and you will
normally not need to override that default.
@end defmac
+@deftypefn {Target Hook} bool TARGET_STACK_CLASH_PROTECTION_FINAL_DYNAMIC_PROBE (rtx @var{residual})
+Some targets make optimistic assumptions about the state of stack probing when they emit their prologues. On such targets a probe into the end of any dynamically allocated space is likely required for safety against stack clash style attacks. Define this variable to return nonzero if such a probe is required or zero otherwise. You need not define this macro if it would always have the value zero.
+@end deftypefn
+
@need 2000
@node Frame Registers
@subsection Registers That Address the Stack Frame
diff --git a/gcc/doc/tm.texi.in b/gcc/doc/tm.texi.in
index 1c471d8da35..d31255e86cb 100644
--- a/gcc/doc/tm.texi.in
+++ b/gcc/doc/tm.texi.in
@@ -2999,6 +2999,8 @@ GCC computed the default from the values of the above macros and you will
normally not need to override that default.
@end defmac
+@hook TARGET_STACK_CLASH_PROTECTION_FINAL_DYNAMIC_PROBE
+
@need 2000
@node Frame Registers
@subsection Registers That Address the Stack Frame
diff --git a/gcc/explow.c b/gcc/explow.c
index 67cb6ff1513..e7db438b1ec 100644
--- a/gcc/explow.c
+++ b/gcc/explow.c
@@ -39,8 +39,11 @@ along with GCC; see the file COPYING3. If not see
#include "expr.h"
#include "common/common-target.h"
#include "output.h"
+#include "params.h"
+#include "dumpfile.h"
static rtx break_out_memory_refs (rtx);
+static void anti_adjust_stack_and_probe_stack_clash (rtx);
/* Truncate and perhaps sign-extend C as appropriate for MODE. */
@@ -1271,6 +1274,29 @@ get_dynamic_stack_size (rtx *psize, unsigned size_align,
*psize = size;
}
+/* Return the number of bytes to "protect" on the stack for -fstack-check.
+
+ "protect" in the context of -fstack-check means how many bytes we
+ should always ensure are available on the stack. More importantly
+ this is how many bytes are skipped when probing the stack.
+
+ On some targets we want to reuse the -fstack-check prologue support
+ to give a degree of protection against stack clashing style attacks.
+
+ In that scenario we do not want to skip bytes before probing as that
+ would render the stack clash protections useless.
+
+ So we never use STACK_CHECK_PROTECT directly. Instead we indirect though
+ this helper which allows us to provide different values for
+ -fstack-check and -fstack-clash-protection. */
+HOST_WIDE_INT
+get_stack_check_protect (void)
+{
+ if (flag_stack_clash_protection)
+ return 0;
+ return STACK_CHECK_PROTECT;
+}
+
/* Return an rtx representing the address of an area of memory dynamically
pushed on the stack.
@@ -1429,7 +1455,7 @@ allocate_dynamic_stack_space (rtx size, unsigned size_align,
probe_stack_range (STACK_OLD_CHECK_PROTECT + STACK_CHECK_MAX_FRAME_SIZE,
size);
else if (flag_stack_check == STATIC_BUILTIN_STACK_CHECK)
- probe_stack_range (STACK_CHECK_PROTECT, size);
+ probe_stack_range (get_stack_check_protect (), size);
/* Don't let anti_adjust_stack emit notes. */
suppress_reg_args_size = true;
@@ -1482,6 +1508,8 @@ allocate_dynamic_stack_space (rtx size, unsigned size_align,
if (flag_stack_check && STACK_CHECK_MOVING_SP)
anti_adjust_stack_and_probe (size, false);
+ else if (flag_stack_clash_protection)
+ anti_adjust_stack_and_probe_stack_clash (size);
else
anti_adjust_stack (size);
@@ -1757,6 +1785,219 @@ probe_stack_range (HOST_WIDE_INT first, rtx size)
emit_insn (gen_blockage ());
}
+/* Compute parameters for stack clash probing a dynamic stack
+ allocation of SIZE bytes.
+
+ We compute ROUNDED_SIZE, LAST_ADDR, RESIDUAL and PROBE_INTERVAL.
+
+ Additionally we conditionally dump the type of probing that will
+ be needed given the values computed. */
+
+void
+compute_stack_clash_protection_loop_data (rtx *rounded_size, rtx *last_addr,
+ rtx *residual,
+ HOST_WIDE_INT *probe_interval,
+ rtx size)
+{
+ /* Round SIZE down to STACK_CLASH_PROTECTION_PROBE_INTERVAL */
+ *probe_interval
+ = 1 << PARAM_VALUE (PARAM_STACK_CLASH_PROTECTION_PROBE_INTERVAL);
+ *rounded_size = simplify_gen_binary (AND, Pmode, size,
+ GEN_INT (-*probe_interval));
+
+ /* Compute the value of the stack pointer for the last iteration.
+ It's just SP + ROUNDED_SIZE. */
+ rtx rounded_size_op = force_operand (*rounded_size, NULL_RTX);
+ *last_addr = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
+ stack_pointer_rtx,
+ rounded_size_op),
+ NULL_RTX);
+
+ /* Compute any residuals not allocated by the loop above. Residuals
+ are just the ROUNDED_SIZE - SIZE. */
+ *residual = simplify_gen_binary (MINUS, Pmode, size, *rounded_size);
+
+ /* Dump key information to make writing tests easy. */
+ if (dump_file)
+ {
+ if (*rounded_size == CONST0_RTX (Pmode))
+ fprintf (dump_file,
+ "Stack clash skipped dynamic allocation and probing loop.\n");
+ else if (GET_CODE (*rounded_size) == CONST_INT
+ && INTVAL (*rounded_size) <= 4 * *probe_interval)
+ fprintf (dump_file,
+ "Stack clash dynamic allocation and probing inline.\n");
+ else if (GET_CODE (*rounded_size) == CONST_INT)
+ fprintf (dump_file,
+ "Stack clash dynamic allocation and probing in "
+ "rotated loop.\n");
+ else
+ fprintf (dump_file,
+ "Stack clash dynamic allocation and probing in loop.\n");
+
+ if (*residual != CONST0_RTX (Pmode))
+ fprintf (dump_file,
+ "Stack clash dynamic allocation and probing residuals.\n");
+ else
+ fprintf (dump_file,
+ "Stack clash skipped dynamic allocation and "
+ "probing residuals.\n");
+ }
+}
+
+/* Emit the start of an allocate/probe loop for stack
+ clash protection.
+
+ LOOP_LAB and END_LAB are returned for use when we emit the
+ end of the loop.
+
+ LAST addr is the value for SP which stops the loop. */
+void
+emit_stack_clash_protection_probe_loop_start (rtx *loop_lab,
+ rtx *end_lab,
+ rtx last_addr,
+ bool rotated)
+{
+ /* Essentially we want to emit any setup code, the top of loop
+ label and the comparison at the top of the loop. */
+ *loop_lab = gen_label_rtx ();
+ *end_lab = gen_label_rtx ();
+
+ emit_label (*loop_lab);
+ if (!rotated)
+ emit_cmp_and_jump_insns (stack_pointer_rtx, last_addr, EQ, NULL_RTX,
+ Pmode, 1, *end_lab);
+}
+
+/* Emit the end of a stack clash probing loop.
+
+ This consists of just the jump back to LOOP_LAB and
+ emitting END_LOOP after the loop. */
+
+void
+emit_stack_clash_protection_probe_loop_end (rtx loop_lab, rtx end_loop,
+ rtx last_addr, bool rotated)
+{
+ if (rotated)
+ emit_cmp_and_jump_insns (stack_pointer_rtx, last_addr, NE, NULL_RTX,
+ Pmode, 1, loop_lab);
+ else
+ emit_jump (loop_lab);
+
+ emit_label (end_loop);
+
+}
+
+/* Adjust the stack pointer by minus SIZE (an rtx for a number of bytes)
+ while probing it. This pushes when SIZE is positive. SIZE need not
+ be constant.
+
+ This is subtly different than anti_adjust_stack_and_probe to try and
+ prevent stack-clash attacks
+
+ 1. It must assume no knowledge of the probing state, any allocation
+ must probe.
+
+ Consider the case of a 1 byte alloca in a loop. If the sum of the
+ allocations is large, then this could be used to jump the guard if
+ probes were not emitted.
+
+ 2. It never skips probes, whereas anti_adjust_stack_and_probe will
+ skip probes on the first couple PROBE_INTERVALs on the assumption
+ they're done elsewhere.
+
+ 3. It only allocates and probes SIZE bytes, it does not need to
+ allocate/probe beyond that because this probing style does not
+ guarantee signal handling capability if the guard is hit. */
+
+static void
+anti_adjust_stack_and_probe_stack_clash (rtx size)
+{
+ /* First ensure SIZE is Pmode. */
+ if (GET_MODE (size) != VOIDmode && GET_MODE (size) != Pmode)
+ size = convert_to_mode (Pmode, size, 1);
+
+ /* We can get here with a constant size on some targets. */
+ rtx rounded_size, last_addr, residual;
+ HOST_WIDE_INT probe_interval;
+ compute_stack_clash_protection_loop_data (&rounded_size, &last_addr,
+ &residual, &probe_interval, size);
+
+ if (rounded_size != CONST0_RTX (Pmode))
+ {
+ if (INTVAL (rounded_size) <= 4 * probe_interval)
+ {
+ for (HOST_WIDE_INT i = 0;
+ i < INTVAL (rounded_size);
+ i += probe_interval)
+ {
+ anti_adjust_stack (GEN_INT (probe_interval));
+
+ /* The prologue does not probe residuals. Thus the offset
+ here to probe just beyond what the prologue had already
+ allocated. */
+ emit_stack_probe (plus_constant (Pmode, stack_pointer_rtx,
+ (probe_interval
+ - GET_MODE_SIZE (word_mode))));
+ emit_insn (gen_blockage ());
+ }
+ }
+ else
+ {
+ rtx loop_lab, end_loop;
+ bool rotate_loop = GET_CODE (rounded_size) == CONST_INT;
+ emit_stack_clash_protection_probe_loop_start (&loop_lab, &end_loop,
+ last_addr, rotate_loop);
+
+ anti_adjust_stack (GEN_INT (probe_interval));
+
+ /* The prologue does not probe residuals. Thus the offset here
+ to probe just beyond what the prologue had already allocated. */
+ emit_stack_probe (plus_constant (Pmode, stack_pointer_rtx,
+ (probe_interval
+ - GET_MODE_SIZE (word_mode))));
+
+ emit_stack_clash_protection_probe_loop_end (loop_lab, end_loop,
+ last_addr, rotate_loop);
+ emit_insn (gen_blockage ());
+ }
+ }
+
+ if (residual != CONST0_RTX (Pmode))
+ {
+ rtx x = force_reg (Pmode, plus_constant (Pmode, residual,
+ -GET_MODE_SIZE (word_mode)));
+ anti_adjust_stack (residual);
+ emit_stack_probe (gen_rtx_PLUS (Pmode, stack_pointer_rtx, x));
+ emit_insn (gen_blockage ());
+ }
+
+ /* Some targets make optimistic assumptions in their prologues about
+ how the caller may have probed the stack. Make sure we honor
+ those assumptions when needed. */
+ if (size != CONST0_RTX (Pmode)
+ && targetm.stack_clash_protection_final_dynamic_probe (residual))
+ {
+ /* Ideally we would just probe at *sp. However, if SIZE is not
+ a compile-time constant, but is zero at runtime, then *sp
+ might hold live data. So probe at *sp if we know that
+ an allocation was made, otherwise probe into the red zone
+ which is obviously undesirable. */
+ if (GET_CODE (size) == CONST_INT)
+ {
+ emit_stack_probe (stack_pointer_rtx);
+ emit_insn (gen_blockage ());
+ }
+ else
+ {
+ emit_stack_probe (plus_constant (Pmode, stack_pointer_rtx,
+ -GET_MODE_SIZE (word_mode)));
+ emit_insn (gen_blockage ());
+ }
+ }
+}
+
+
/* Adjust the stack pointer by minus SIZE (an rtx for a number of bytes)
while probing it. This pushes when SIZE is positive. SIZE need not
be constant. If ADJUST_BACK is true, adjust back the stack pointer
diff --git a/gcc/explow.h b/gcc/explow.h
index 217a3226adb..b85c051e8ce 100644
--- a/gcc/explow.h
+++ b/gcc/explow.h
@@ -69,6 +69,15 @@ extern void anti_adjust_stack (rtx);
/* Add some bytes to the stack while probing it. An rtx says how many. */
extern void anti_adjust_stack_and_probe (rtx, bool);
+/* Support for building allocation/probing loops for stack-clash
+ protection of dyamically allocated stack space. */
+extern void compute_stack_clash_protection_loop_data (rtx *, rtx *, rtx *,
+ HOST_WIDE_INT *, rtx);
+extern void emit_stack_clash_protection_probe_loop_start (rtx *, rtx *,
+ rtx, bool);
+extern void emit_stack_clash_protection_probe_loop_end (rtx, rtx,
+ rtx, bool);
+
/* This enum is used for the following two functions. */
enum save_level {SAVE_BLOCK, SAVE_FUNCTION, SAVE_NONLOCAL};
diff --git a/gcc/rtl.h b/gcc/rtl.h
index 93330425c00..98f993a95a5 100644
--- a/gcc/rtl.h
+++ b/gcc/rtl.h
@@ -2707,6 +2707,7 @@ get_full_set_src_cost (rtx x, machine_mode mode, struct full_rtx_costs *c)
/* In explow.c */
extern HOST_WIDE_INT trunc_int_for_mode (HOST_WIDE_INT, machine_mode);
extern rtx plus_constant (machine_mode, rtx, HOST_WIDE_INT, bool = false);
+extern HOST_WIDE_INT get_stack_check_protect (void);
/* In rtl.c */
extern rtx rtx_alloc_stat (RTX_CODE MEM_STAT_DECL);
diff --git a/gcc/target.def b/gcc/target.def
index 6bebfd5b9d6..8b8ad1f4938 100644
--- a/gcc/target.def
+++ b/gcc/target.def
@@ -5473,6 +5473,13 @@ these registers when the target switches are opposed to them.)",
void, (void),
hook_void_void)
+DEFHOOK
+(stack_clash_protection_final_dynamic_probe,
+ "Some targets make optimistic assumptions about the state of stack probing when they emit their prologues. On such targets a probe into the end of any dynamically allocated space is likely required for safety against stack clash style attacks. Define this variable to return nonzero if such a probe is required or zero otherwise. You need not define this macro if it would always have the value zero.",
+ bool, (rtx residual),
+ default_stack_clash_protection_final_dynamic_probe)
+
+
/* Functions specific to the C family of frontends. */
#undef HOOK_PREFIX
#define HOOK_PREFIX "TARGET_C_"
diff --git a/gcc/targhooks.c b/gcc/targhooks.c
index 1cdec068ed8..225048e7518 100644
--- a/gcc/targhooks.c
+++ b/gcc/targhooks.c
@@ -2107,4 +2107,10 @@ default_excess_precision (enum excess_precision_type ATTRIBUTE_UNUSED)
return FLT_EVAL_METHOD_PROMOTE_TO_FLOAT;
}
+HOST_WIDE_INT
+default_stack_clash_protection_final_dynamic_probe (rtx residual ATTRIBUTE_UNUSED)
+{
+ return 0;
+}
+
#include "gt-targhooks.h"
diff --git a/gcc/targhooks.h b/gcc/targhooks.h
index 18070df7839..32ae9d88050 100644
--- a/gcc/targhooks.h
+++ b/gcc/targhooks.h
@@ -263,5 +263,6 @@ extern unsigned int default_min_arithmetic_precision (void);
extern enum flt_eval_method
default_excess_precision (enum excess_precision_type ATTRIBUTE_UNUSED);
+extern bool default_stack_clash_protection_final_dynamic_probe (rtx);
#endif /* GCC_TARGHOOKS_H */
diff --git a/gcc/testsuite/gcc.dg/stack-check-3.c b/gcc/testsuite/gcc.dg/stack-check-3.c
new file mode 100644
index 00000000000..58fb65649ee
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/stack-check-3.c
@@ -0,0 +1,86 @@
+/* The goal here is to ensure that dynamic allocations via vlas or
+ alloca calls receive probing.
+
+ Scanning the RTL or assembly code seems like insanity here as does
+ checking for particular allocation sizes and probe offsets. For
+ now we just verify that there's an allocation + probe loop and
+ residual allocation + probe for f?. */
+
+/* { dg-do compile } */
+/* { dg-options "-O2 -fstack-clash-protection -fdump-rtl-expand -fno-optimize-sibling-calls --param stack-clash-protection-probe-interval=4096 --param stack-clash-protection-guard-size=4096" } */
+/* { dg-require-effective-target supports_stack_clash_protection } */
+
+__attribute__((noinline, noclone)) void
+foo (char *p)
+{
+ asm volatile ("" : : "r" (p) : "memory");
+}
+
+/* Simple VLA, no other locals. */
+__attribute__((noinline, noclone)) void
+f0 (int x)
+{
+ char vla[x];
+ foo (vla);
+}
+
+/* Simple VLA, small local frame. */
+__attribute__((noinline, noclone)) void
+f1 (int x)
+{
+ char locals[128];
+ char vla[x];
+ foo (vla);
+}
+
+/* Small constant alloca, no other locals. */
+__attribute__((noinline, noclone)) void
+f2 (int x)
+{
+ char *vla = __builtin_alloca (128);
+ foo (vla);
+}
+
+/* Big constant alloca, small local frame. */
+__attribute__((noinline, noclone)) void
+f3 (int x)
+{
+ char locals[128];
+ char *vla = __builtin_alloca (16384);
+ foo (vla);
+}
+
+/* Big constant alloca, small local frame. */
+__attribute__((noinline, noclone)) void
+f3a (int x)
+{
+ char locals[128];
+ char *vla = __builtin_alloca (32768);
+ foo (vla);
+}
+
+/* Nonconstant alloca, no other locals. */
+__attribute__((noinline, noclone)) void
+f4 (int x)
+{
+ char *vla = __builtin_alloca (x);
+ foo (vla);
+}
+
+/* Nonconstant alloca, small local frame. */
+__attribute__((noinline, noclone)) void
+f5 (int x)
+{
+ char locals[128];
+ char *vla = __builtin_alloca (x);
+ foo (vla);
+}
+
+/* { dg-final { scan-rtl-dump-times "allocation and probing residuals" 7 "expand" } } */
+
+
+/* { dg-final { scan-rtl-dump-times "allocation and probing in loop" 7 "expand" { target callee_realigns_stack } } } */
+/* { dg-final { scan-rtl-dump-times "allocation and probing in loop" 4 "expand" { target { ! callee_realigns_stack } } } } */
+/* { dg-final { scan-rtl-dump-times "allocation and probing in rotated loop" 1 "expand" { target { ! callee_realigns_stack } } } } */
+/* { dg-final { scan-rtl-dump-times "allocation and probing inline" 1 "expand" { target { ! callee_realigns_stack } } } } */
+/* { dg-final { scan-rtl-dump-times "skipped dynamic allocation and probing loop" 1 "expand" { target { ! callee_realigns_stack } } } } */

199
gcc7-rh1512529-3.patch Normal file
View File

@ -0,0 +1,199 @@
commit 640ca5ef08a3ade8fe3f32d8c412008410de989c
Author: law <law@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Wed Sep 20 05:21:09 2017 +0000
* config/alpha/alpha.c (alpha_expand_prologue): Also check
flag_stack_clash_protection.
* config/arm/arm.c (arm_compute_static_chain_stack_bytes): Likewise.
(arm_expand_prologue, thumb1_expand_prologue): Likewise.
(arm_frame_pointer_required): Likewise.
* config/ia64/ia64.c (ia64_compute_frame_size): Likewise.
(ia64_expand_prologue): Likewise.
* config/mips/mips.c (mips_expand_prologue): Likewise.
* config/powerpcspe/powerpcspe.c (rs6000_expand_prologue): Likewise.
* config/sparc/sparc.c (sparc_expand_prologue): Likewise.
(sparc_flat_expand_prologue): Likewise.
* config/spu/spu.c (spu_expand_prologue): Likewise.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@252996 138bc75d-0d04-0410-961f-82ee72b054a4
diff --git a/gcc/config/alpha/alpha.c b/gcc/config/alpha/alpha.c
index 91f3d7cfbeb..36e78a0caf7 100644
--- a/gcc/config/alpha/alpha.c
+++ b/gcc/config/alpha/alpha.c
@@ -7740,7 +7740,7 @@ alpha_expand_prologue (void)
Note that we are only allowed to adjust sp once in the prologue. */
probed_size = frame_size;
- if (flag_stack_check)
+ if (flag_stack_check || flag_stack_clash_protection)
probed_size += get_stack_check_protect ();
if (probed_size <= 32768)
@@ -7755,7 +7755,7 @@ alpha_expand_prologue (void)
/* We only have to do this probe if we aren't saving registers or
if we are probing beyond the frame because of -fstack-check. */
if ((sa_size == 0 && probed_size > probed - 4096)
- || flag_stack_check)
+ || flag_stack_check || flag_stack_clash_protection)
emit_insn (gen_probe_stack (GEN_INT (-probed_size)));
}
@@ -7785,7 +7785,8 @@ alpha_expand_prologue (void)
late in the compilation, generate the loop as a single insn. */
emit_insn (gen_prologue_stack_probe_loop (count, ptr));
- if ((leftover > 4096 && sa_size == 0) || flag_stack_check)
+ if ((leftover > 4096 && sa_size == 0)
+ || flag_stack_check || flag_stack_clash_protection)
{
rtx last = gen_rtx_MEM (DImode,
plus_constant (Pmode, ptr, -leftover));
@@ -7793,7 +7794,7 @@ alpha_expand_prologue (void)
emit_move_insn (last, const0_rtx);
}
- if (flag_stack_check)
+ if (flag_stack_check || flag_stack_clash_protection)
{
/* If -fstack-check is specified we have to load the entire
constant into a register and subtract from the sp in one go,
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index 242d7c792fe..4f85a061753 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -19083,7 +19083,8 @@ arm_compute_static_chain_stack_bytes (void)
/* See the defining assertion in arm_expand_prologue. */
if (IS_NESTED (arm_current_func_type ())
&& ((TARGET_APCS_FRAME && frame_pointer_needed && TARGET_ARM)
- || (flag_stack_check == STATIC_BUILTIN_STACK_CHECK
+ || ((flag_stack_check == STATIC_BUILTIN_STACK_CHECK
+ || flag_stack_clash_protection)
&& !df_regs_ever_live_p (LR_REGNUM)))
&& arm_r3_live_at_start_p ()
&& crtl->args.pretend_args_size == 0)
@@ -21377,7 +21378,8 @@ arm_expand_prologue (void)
clobbered when creating the frame, we need to save and restore it. */
clobber_ip = IS_NESTED (func_type)
&& ((TARGET_APCS_FRAME && frame_pointer_needed && TARGET_ARM)
- || (flag_stack_check == STATIC_BUILTIN_STACK_CHECK
+ || ((flag_stack_check == STATIC_BUILTIN_STACK_CHECK
+ || flag_stack_clash_protection)
&& !df_regs_ever_live_p (LR_REGNUM)
&& arm_r3_live_at_start_p ()));
@@ -21591,7 +21593,8 @@ arm_expand_prologue (void)
stack checking. We use IP as the first scratch register, except for the
non-APCS nested functions if LR or r3 are available (see clobber_ip). */
if (!IS_INTERRUPT (func_type)
- && flag_stack_check == STATIC_BUILTIN_STACK_CHECK)
+ && (flag_stack_check == STATIC_BUILTIN_STACK_CHECK
+ || flag_stack_clash_protection))
{
unsigned int regno;
@@ -24875,7 +24878,9 @@ thumb1_expand_prologue (void)
current_function_static_stack_size = size;
/* If we have a frame, then do stack checking. FIXME: not implemented. */
- if (flag_stack_check == STATIC_BUILTIN_STACK_CHECK && size)
+ if ((flag_stack_check == STATIC_BUILTIN_STACK_CHECK
+ || flag_stack_clash_protection)
+ && size)
sorry ("-fstack-check=specific for Thumb-1");
amount = offsets->outgoing_args - offsets->saved_regs;
@@ -27736,7 +27741,8 @@ arm_frame_pointer_required (void)
instruction prior to the stack adjustment and this requires a frame
pointer if we want to catch the exception using the EABI unwinder. */
if (!IS_INTERRUPT (arm_current_func_type ())
- && flag_stack_check == STATIC_BUILTIN_STACK_CHECK
+ && (flag_stack_check == STATIC_BUILTIN_STACK_CHECK
+ || flag_stack_clash_protection)
&& arm_except_unwind_info (&global_options) == UI_TARGET
&& cfun->can_throw_non_call_exceptions)
{
diff --git a/gcc/config/ia64/ia64.c b/gcc/config/ia64/ia64.c
index 17d6b3318a6..8acb92fd32b 100644
--- a/gcc/config/ia64/ia64.c
+++ b/gcc/config/ia64/ia64.c
@@ -2685,7 +2685,8 @@ ia64_compute_frame_size (HOST_WIDE_INT size)
mark_reg_gr_used_mask (cfun->machine->ia64_eh_epilogue_bsp, NULL);
/* Static stack checking uses r2 and r3. */
- if (flag_stack_check == STATIC_BUILTIN_STACK_CHECK)
+ if (flag_stack_check == STATIC_BUILTIN_STACK_CHECK
+ || flag_stack_clash_protection)
current_frame_info.gr_used_mask |= 0xc;
/* Find the size of the register stack frame. We have only 80 local
@@ -3468,7 +3469,8 @@ ia64_expand_prologue (void)
if (flag_stack_usage_info)
current_function_static_stack_size = current_frame_info.total_size;
- if (flag_stack_check == STATIC_BUILTIN_STACK_CHECK)
+ if (flag_stack_check == STATIC_BUILTIN_STACK_CHECK
+ || flag_stack_clash_protection)
{
HOST_WIDE_INT size = current_frame_info.total_size;
int bs_size = BACKING_STORE_SIZE (current_frame_info.n_input_regs
diff --git a/gcc/config/mips/mips.c b/gcc/config/mips/mips.c
index 7d85ce7055a..b2d3c737b34 100644
--- a/gcc/config/mips/mips.c
+++ b/gcc/config/mips/mips.c
@@ -12077,7 +12077,8 @@ mips_expand_prologue (void)
if (flag_stack_usage_info)
current_function_static_stack_size = size;
- if (flag_stack_check == STATIC_BUILTIN_STACK_CHECK)
+ if (flag_stack_check == STATIC_BUILTIN_STACK_CHECK
+ || flag_stack_clash_protection)
{
if (crtl->is_leaf && !cfun->calls_alloca)
{
diff --git a/gcc/config/sparc/sparc.c b/gcc/config/sparc/sparc.c
index b32bb9859e1..498bd04f5c2 100644
--- a/gcc/config/sparc/sparc.c
+++ b/gcc/config/sparc/sparc.c
@@ -5691,7 +5691,8 @@ sparc_expand_prologue (void)
if (flag_stack_usage_info)
current_function_static_stack_size = size;
- if (flag_stack_check == STATIC_BUILTIN_STACK_CHECK)
+ if (flag_stack_check == STATIC_BUILTIN_STACK_CHECK
+ || flag_stack_clash_protection)
{
if (crtl->is_leaf && !cfun->calls_alloca)
{
@@ -5802,7 +5803,8 @@ sparc_flat_expand_prologue (void)
if (flag_stack_usage_info)
current_function_static_stack_size = size;
- if (flag_stack_check == STATIC_BUILTIN_STACK_CHECK)
+ if (flag_stack_check == STATIC_BUILTIN_STACK_CHECK
+ || flag_stack_clash_protection)
{
if (crtl->is_leaf && !cfun->calls_alloca)
{
diff --git a/gcc/config/spu/spu.c b/gcc/config/spu/spu.c
index fcb85c0ee16..22745fa32c3 100644
--- a/gcc/config/spu/spu.c
+++ b/gcc/config/spu/spu.c
@@ -1760,7 +1760,7 @@ spu_expand_prologue (void)
if (total_size > 0)
{
- if (flag_stack_check)
+ if (flag_stack_check || flag_stack_clash_protection)
{
/* We compare against total_size-1 because
($sp >= total_size) <=> ($sp > total_size-1) */
@@ -5364,7 +5364,7 @@ spu_allocate_stack (rtx op0, rtx op1)
emit_insn (gen_spu_convert (sp, stack_pointer_rtx));
emit_insn (gen_subv4si3 (sp, sp, splatted));
- if (flag_stack_check)
+ if (flag_stack_check || flag_stack_clash_protection)
{
rtx avail = gen_reg_rtx(SImode);
rtx result = gen_reg_rtx(SImode);

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commit 7f0d332f992c3b51c8aff3ed79e2233ed2498863
Author: law <law@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Wed Sep 20 05:23:51 2017 +0000
* function.c (dump_stack_clash_frame_info): New function.
* function.h (dump_stack_clash_frame_info): Prototype.
(enum stack_clash_probes): New enum.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@252997 138bc75d-0d04-0410-961f-82ee72b054a4
diff --git a/gcc/function.c b/gcc/function.c
index 21eb586a8f7..6d0f462a262 100644
--- a/gcc/function.c
+++ b/gcc/function.c
@@ -5695,6 +5695,58 @@ get_arg_pointer_save_area (void)
return ret;
}
+
+/* If debugging dumps are requested, dump information about how the
+ target handled -fstack-check=clash for the prologue.
+
+ PROBES describes what if any probes were emitted.
+
+ RESIDUALS indicates if the prologue had any residual allocation
+ (i.e. total allocation was not a multiple of PROBE_INTERVAL). */
+
+void
+dump_stack_clash_frame_info (enum stack_clash_probes probes, bool residuals)
+{
+ if (!dump_file)
+ return;
+
+ switch (probes)
+ {
+ case NO_PROBE_NO_FRAME:
+ fprintf (dump_file,
+ "Stack clash no probe no stack adjustment in prologue.\n");
+ break;
+ case NO_PROBE_SMALL_FRAME:
+ fprintf (dump_file,
+ "Stack clash no probe small stack adjustment in prologue.\n");
+ break;
+ case PROBE_INLINE:
+ fprintf (dump_file, "Stack clash inline probes in prologue.\n");
+ break;
+ case PROBE_LOOP:
+ fprintf (dump_file, "Stack clash probe loop in prologue.\n");
+ break;
+ }
+
+ if (residuals)
+ fprintf (dump_file, "Stack clash residual allocation in prologue.\n");
+ else
+ fprintf (dump_file, "Stack clash no residual allocation in prologue.\n");
+
+ if (frame_pointer_needed)
+ fprintf (dump_file, "Stack clash frame pointer needed.\n");
+ else
+ fprintf (dump_file, "Stack clash no frame pointer needed.\n");
+
+ if (TREE_THIS_VOLATILE (cfun->decl))
+ fprintf (dump_file,
+ "Stack clash noreturn prologue, assuming no implicit"
+ " probes in caller.\n");
+ else
+ fprintf (dump_file,
+ "Stack clash not noreturn prologue.\n");
+}
+
/* Add a list of INSNS to the hash HASHP, possibly allocating HASHP
for the first time. */
diff --git a/gcc/function.h b/gcc/function.h
index 0f34bcd6123..87dac803622 100644
--- a/gcc/function.h
+++ b/gcc/function.h
@@ -553,6 +553,14 @@ do { \
((TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_pfn) \
? MAX (FUNCTION_BOUNDARY, 2 * BITS_PER_UNIT) : FUNCTION_BOUNDARY)
+enum stack_clash_probes {
+ NO_PROBE_NO_FRAME,
+ NO_PROBE_SMALL_FRAME,
+ PROBE_INLINE,
+ PROBE_LOOP
+};
+
+extern void dump_stack_clash_frame_info (enum stack_clash_probes, bool);
extern void push_function_context (void);

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commit e7519110827a59eb7275591db640bdbdfd31ba15
Author: law <law@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Wed Sep 20 05:43:28 2017 +0000
* combine-stack-adj.c (combine_stack_adjustments_for_block): Do
nothing for stack adjustments with REG_STACK_CHECK.
* sched-deps.c (parse_add_or_inc): Reject insns with
REG_STACK_CHECK from dependency breaking.
* config/i386/i386.c (pro_epilogue_adjust_stack): Return insn.
(ix86_adjust_satck_and_probe_stack_clash): Add REG_STACK_NOTEs.
* reg-notes.def (STACK_CHECK): New note.
* gcc.target/i386/stack-check-11.c: New test.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@252999 138bc75d-0d04-0410-961f-82ee72b054a4
diff --git a/gcc/combine-stack-adj.c b/gcc/combine-stack-adj.c
index 9ec14a3e443..82d6dba856f 100644
--- a/gcc/combine-stack-adj.c
+++ b/gcc/combine-stack-adj.c
@@ -508,6 +508,8 @@ combine_stack_adjustments_for_block (basic_block bb)
continue;
set = single_set_for_csa (insn);
+ if (set && find_reg_note (insn, REG_STACK_CHECK, NULL_RTX))
+ set = NULL_RTX;
if (set)
{
rtx dest = SET_DEST (set);
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 088dca2001f..5aff9b9d113 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -12900,7 +12900,7 @@ ix86_add_queued_cfa_restore_notes (rtx insn)
zero if %r11 register is live and cannot be freely used and positive
otherwise. */
-static void
+static rtx
pro_epilogue_adjust_stack (rtx dest, rtx src, rtx offset,
int style, bool set_cfa)
{
@@ -12987,6 +12987,7 @@ pro_epilogue_adjust_stack (rtx dest, rtx src, rtx offset,
m->fs.sp_offset = ooffset - INTVAL (offset);
m->fs.sp_valid = valid;
}
+ return insn;
}
/* Find an available register to be used as dynamic realign argument
@@ -13333,9 +13334,11 @@ ix86_adjust_stack_and_probe_stack_clash (const HOST_WIDE_INT size)
for (i = probe_interval; i <= size; i += probe_interval)
{
/* Allocate PROBE_INTERVAL bytes. */
- pro_epilogue_adjust_stack (stack_pointer_rtx, stack_pointer_rtx,
- GEN_INT (-probe_interval), -1,
- m->fs.cfa_reg == stack_pointer_rtx);
+ rtx insn
+ = pro_epilogue_adjust_stack (stack_pointer_rtx, stack_pointer_rtx,
+ GEN_INT (-PROBE_INTERVAL), -1,
+ m->fs.cfa_reg == stack_pointer_rtx);
+ add_reg_note (insn, REG_STACK_CHECK, const0_rtx);
/* And probe at *sp. */
emit_stack_probe (stack_pointer_rtx);
diff --git a/gcc/reg-notes.def b/gcc/reg-notes.def
index 8734d26e5b4..18cf7e3cfc0 100644
--- a/gcc/reg-notes.def
+++ b/gcc/reg-notes.def
@@ -223,6 +223,10 @@ REG_NOTE (ARGS_SIZE)
pseudo reg. */
REG_NOTE (RETURNED)
+/* Indicates the instruction is a stack check probe that should not
+ be combined with other stack adjustments. */
+REG_NOTE (STACK_CHECK)
+
/* Used to mark a call with the function decl called by the call.
The decl might not be available in the call due to splitting of the call
insn. This note is a SYMBOL_REF. */
diff --git a/gcc/sched-deps.c b/gcc/sched-deps.c
index b2393bf28fb..564f3fb1559 100644
--- a/gcc/sched-deps.c
+++ b/gcc/sched-deps.c
@@ -4717,6 +4717,11 @@ parse_add_or_inc (struct mem_inc_info *mii, rtx_insn *insn, bool before_mem)
if (RTX_FRAME_RELATED_P (insn) || !pat)
return false;
+ /* Do not allow breaking data dependencies for insns that are marked
+ with REG_STACK_CHECK. */
+ if (find_reg_note (insn, REG_STACK_CHECK, NULL))
+ return false;
+
/* Result must be single reg. */
if (!REG_P (SET_DEST (pat)))
return false;
diff --git a/gcc/testsuite/gcc.target/i386/stack-check-11.c b/gcc/testsuite/gcc.target/i386/stack-check-11.c
new file mode 100644
index 00000000000..183103f01e5
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/stack-check-11.c
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fstack-clash-protection" } */
+/* { dg-require-effective-target supports_stack_clash_protection } */
+
+extern void arf (unsigned long int *, unsigned long int *);
+void
+frob ()
+{
+ unsigned long int num[859];
+ unsigned long int den[859];
+ arf (den, num);
+}
+
+/* { dg-final { scan-assembler-times "subq" 4 } } */
+/* { dg-final { scan-assembler-times "orq" 3 } } */
+

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commit 919262bedfe78b0d4f9fddbd980b85243a83bf28
Author: law <law@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Wed Sep 20 21:59:50 2017 +0000
* explow.c (compute_stack_clash_protection_loop_data): Use
CONST_INT_P instead of explicit test. Verify object is a
CONST_INT_P before looking at INTVAL.
(anti_adjust_stack_and_probe_stack_clash): Use CONST_INT_P
instead of explicit test.
* gcc.target/i386/stack-check-11.c: Update test and regexp
so that it works for both i?86 and x86_64.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@253034 138bc75d-0d04-0410-961f-82ee72b054a4
diff --git a/gcc/explow.c b/gcc/explow.c
index 2a73414ab22..6af6355fe30 100644
--- a/gcc/explow.c
+++ b/gcc/explow.c
@@ -1822,11 +1822,11 @@ compute_stack_clash_protection_loop_data (rtx *rounded_size, rtx *last_addr,
if (*rounded_size == CONST0_RTX (Pmode))
fprintf (dump_file,
"Stack clash skipped dynamic allocation and probing loop.\n");
- else if (GET_CODE (*rounded_size) == CONST_INT
+ else if (CONST_INT_P (*rounded_size)
&& INTVAL (*rounded_size) <= 4 * *probe_interval)
fprintf (dump_file,
"Stack clash dynamic allocation and probing inline.\n");
- else if (GET_CODE (*rounded_size) == CONST_INT)
+ else if (CONST_INT_P (*rounded_size))
fprintf (dump_file,
"Stack clash dynamic allocation and probing in "
"rotated loop.\n");
@@ -1924,7 +1924,8 @@ anti_adjust_stack_and_probe_stack_clash (rtx size)
if (rounded_size != CONST0_RTX (Pmode))
{
- if (INTVAL (rounded_size) <= 4 * probe_interval)
+ if (CONST_INT_P (rounded_size)
+ && INTVAL (rounded_size) <= 4 * probe_interval)
{
for (HOST_WIDE_INT i = 0;
i < INTVAL (rounded_size);
@@ -1944,7 +1945,7 @@ anti_adjust_stack_and_probe_stack_clash (rtx size)
else
{
rtx loop_lab, end_loop;
- bool rotate_loop = GET_CODE (rounded_size) == CONST_INT;
+ bool rotate_loop = CONST_INT_P (rounded_size);
emit_stack_clash_protection_probe_loop_start (&loop_lab, &end_loop,
last_addr, rotate_loop);
@@ -1982,7 +1983,7 @@ anti_adjust_stack_and_probe_stack_clash (rtx size)
might hold live data. So probe at *sp if we know that
an allocation was made, otherwise probe into the red zone
which is obviously undesirable. */
- if (GET_CODE (size) == CONST_INT)
+ if (CONST_INT_P (size))
{
emit_stack_probe (stack_pointer_rtx);
emit_insn (gen_blockage ());
diff --git a/gcc/testsuite/gcc.target/i386/stack-check-11.c b/gcc/testsuite/gcc.target/i386/stack-check-11.c
index 183103f01e5..fe5b2c2b844 100644
--- a/gcc/testsuite/gcc.target/i386/stack-check-11.c
+++ b/gcc/testsuite/gcc.target/i386/stack-check-11.c
@@ -2,15 +2,17 @@
/* { dg-options "-O2 -fstack-clash-protection" } */
/* { dg-require-effective-target supports_stack_clash_protection } */
-extern void arf (unsigned long int *, unsigned long int *);
+#include <stdint.h>
+
+extern void arf (uint64_t *, uint64_t *);
void
frob ()
{
- unsigned long int num[859];
- unsigned long int den[859];
+ uint64_t num[859];
+ uint64_t den[859];
arf (den, num);
}
-/* { dg-final { scan-assembler-times "subq" 4 } } */
-/* { dg-final { scan-assembler-times "orq" 3 } } */
+/* { dg-final { scan-assembler-times "sub\[ql\]" 4 } } */
+/* { dg-final { scan-assembler-times "or\[ql\]" 3 } } */

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@ -0,0 +1,388 @@
commit a63af926db1d6109011e4dd81c750ecf784ab6c1
Author: law <law@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Thu Sep 21 04:30:16 2017 +0000
* config/s390/s390.c (MIN_UNROLL_PROBES): Define.
(allocate_stack_space): New function, partially extracted from
s390_emit_prologue.
(s390_emit_prologue): Track offset to most recent stack probe.
Code to allocate space moved into allocate_stack_space.
Dump actions when no stack is allocated.
(s390_prologue_plus_offset): New function.
(s390_emit_stack_probe): Likewise.
* gcc.dg/stack-check-5.c: Add argument for s390.
* lib/target-supports.exp:
(check_effective_target_supports_stack_clash_protection): Enable for
s390/s390x targets.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@253049 138bc75d-0d04-0410-961f-82ee72b054a4
diff --git a/gcc/config/s390/s390.c b/gcc/config/s390/s390.c
index c408d59efd2..c78f1456daa 100644
--- a/gcc/config/s390/s390.c
+++ b/gcc/config/s390/s390.c
@@ -10974,6 +10974,183 @@ pass_s390_early_mach::execute (function *fun)
} // anon namespace
+/* Calculate TARGET = REG + OFFSET as s390_emit_prologue would do it.
+ - push too big immediates to the literal pool and annotate the refs
+ - emit frame related notes for stack pointer changes. */
+
+static rtx
+s390_prologue_plus_offset (rtx target, rtx reg, rtx offset, bool frame_related_p)
+{
+ rtx insn;
+ rtx orig_offset = offset;
+
+ gcc_assert (REG_P (target));
+ gcc_assert (REG_P (reg));
+ gcc_assert (CONST_INT_P (offset));
+
+ if (offset == const0_rtx) /* lr/lgr */
+ {
+ insn = emit_move_insn (target, reg);
+ }
+ else if (DISP_IN_RANGE (INTVAL (offset))) /* la */
+ {
+ insn = emit_move_insn (target, gen_rtx_PLUS (Pmode, reg,
+ offset));
+ }
+ else
+ {
+ if (!satisfies_constraint_K (offset) /* ahi/aghi */
+ && (!TARGET_EXTIMM
+ || (!satisfies_constraint_Op (offset) /* alfi/algfi */
+ && !satisfies_constraint_On (offset)))) /* slfi/slgfi */
+ offset = force_const_mem (Pmode, offset);
+
+ if (target != reg)
+ {
+ insn = emit_move_insn (target, reg);
+ RTX_FRAME_RELATED_P (insn) = frame_related_p ? 1 : 0;
+ }
+
+ insn = emit_insn (gen_add2_insn (target, offset));
+
+ if (!CONST_INT_P (offset))
+ {
+ annotate_constant_pool_refs (&PATTERN (insn));
+
+ if (frame_related_p)
+ add_reg_note (insn, REG_FRAME_RELATED_EXPR,
+ gen_rtx_SET (target,
+ gen_rtx_PLUS (Pmode, target,
+ orig_offset)));
+ }
+ }
+
+ RTX_FRAME_RELATED_P (insn) = frame_related_p ? 1 : 0;
+
+ /* If this is a stack adjustment and we are generating a stack clash
+ prologue, then add a REG_STACK_CHECK note to signal that this insn
+ should be left alone. */
+ if (flag_stack_clash_protection && target == stack_pointer_rtx)
+ add_reg_note (insn, REG_STACK_CHECK, const0_rtx);
+
+ return insn;
+}
+
+/* Emit a compare instruction with a volatile memory access as stack
+ probe. It does not waste store tags and does not clobber any
+ registers apart from the condition code. */
+static void
+s390_emit_stack_probe (rtx addr)
+{
+ rtx tmp = gen_rtx_MEM (Pmode, addr);
+ MEM_VOLATILE_P (tmp) = 1;
+ s390_emit_compare (EQ, gen_rtx_REG (Pmode, 0), tmp);
+ emit_insn (gen_blockage ());
+}
+
+/* Use a runtime loop if we have to emit more probes than this. */
+#define MIN_UNROLL_PROBES 3
+
+/* Allocate SIZE bytes of stack space, using TEMP_REG as a temporary
+ if necessary. LAST_PROBE_OFFSET contains the offset of the closest
+ probe relative to the stack pointer.
+
+ Note that SIZE is negative.
+
+ The return value is true if TEMP_REG has been clobbered. */
+static bool
+allocate_stack_space (rtx size, HOST_WIDE_INT last_probe_offset,
+ rtx temp_reg)
+{
+ bool temp_reg_clobbered_p = false;
+ HOST_WIDE_INT probe_interval
+ = 1 << PARAM_VALUE (PARAM_STACK_CLASH_PROTECTION_PROBE_INTERVAL);
+ HOST_WIDE_INT guard_size
+ = 1 << PARAM_VALUE (PARAM_STACK_CLASH_PROTECTION_GUARD_SIZE);
+
+ if (flag_stack_clash_protection)
+ {
+ if (last_probe_offset + -INTVAL (size) < guard_size)
+ dump_stack_clash_frame_info (NO_PROBE_SMALL_FRAME, true);
+ else
+ {
+ rtx offset = GEN_INT (probe_interval - UNITS_PER_LONG);
+ HOST_WIDE_INT rounded_size = -INTVAL (size) & -probe_interval;
+ HOST_WIDE_INT num_probes = rounded_size / probe_interval;
+ HOST_WIDE_INT residual = -INTVAL (size) - rounded_size;
+
+ if (num_probes < MIN_UNROLL_PROBES)
+ {
+ /* Emit unrolled probe statements. */
+
+ for (unsigned int i = 0; i < num_probes; i++)
+ {
+ s390_prologue_plus_offset (stack_pointer_rtx,
+ stack_pointer_rtx,
+ GEN_INT (-probe_interval), true);
+ s390_emit_stack_probe (gen_rtx_PLUS (Pmode,
+ stack_pointer_rtx,
+ offset));
+ }
+ dump_stack_clash_frame_info (PROBE_INLINE, residual != 0);
+ }
+ else
+ {
+ /* Emit a loop probing the pages. */
+
+ rtx_code_label *loop_start_label = gen_label_rtx ();
+
+ /* From now on temp_reg will be the CFA register. */
+ s390_prologue_plus_offset (temp_reg, stack_pointer_rtx,
+ GEN_INT (-rounded_size), true);
+ emit_label (loop_start_label);
+
+ s390_prologue_plus_offset (stack_pointer_rtx,
+ stack_pointer_rtx,
+ GEN_INT (-probe_interval), false);
+ s390_emit_stack_probe (gen_rtx_PLUS (Pmode,
+ stack_pointer_rtx,
+ offset));
+ emit_cmp_and_jump_insns (stack_pointer_rtx, temp_reg,
+ GT, NULL_RTX,
+ Pmode, 1, loop_start_label);
+
+ /* Without this make_edges ICEes. */
+ JUMP_LABEL (get_last_insn ()) = loop_start_label;
+ LABEL_NUSES (loop_start_label) = 1;
+
+ /* That's going to be a NOP since stack pointer and
+ temp_reg are supposed to be the same here. We just
+ emit it to set the CFA reg back to r15. */
+ s390_prologue_plus_offset (stack_pointer_rtx, temp_reg,
+ const0_rtx, true);
+ temp_reg_clobbered_p = true;
+ dump_stack_clash_frame_info (PROBE_LOOP, residual != 0);
+ }
+
+ /* Handle any residual allocation request. */
+ s390_prologue_plus_offset (stack_pointer_rtx,
+ stack_pointer_rtx,
+ GEN_INT (-residual), true);
+ last_probe_offset += residual;
+ if (last_probe_offset >= probe_interval)
+ s390_emit_stack_probe (gen_rtx_PLUS (Pmode,
+ stack_pointer_rtx,
+ GEN_INT (residual
+ - UNITS_PER_LONG)));
+
+ return temp_reg_clobbered_p;
+ }
+ }
+
+ /* Subtract frame size from stack pointer. */
+ s390_prologue_plus_offset (stack_pointer_rtx,
+ stack_pointer_rtx,
+ size, true);
+
+ return temp_reg_clobbered_p;
+}
+
/* Expand the prologue into a bunch of separate insns. */
void
@@ -10998,6 +11175,19 @@ s390_emit_prologue (void)
else
temp_reg = gen_rtx_REG (Pmode, 1);
+ /* When probing for stack-clash mitigation, we have to track the distance
+ between the stack pointer and closest known reference.
+
+ Most of the time we have to make a worst cast assumption. The
+ only exception is when TARGET_BACKCHAIN is active, in which case
+ we know *sp (offset 0) was written. */
+ HOST_WIDE_INT probe_interval
+ = 1 << PARAM_VALUE (PARAM_STACK_CLASH_PROTECTION_PROBE_INTERVAL);
+ HOST_WIDE_INT last_probe_offset
+ = (TARGET_BACKCHAIN
+ ? (TARGET_PACKED_STACK ? STACK_POINTER_OFFSET - UNITS_PER_LONG : 0)
+ : probe_interval - (STACK_BOUNDARY / UNITS_PER_WORD));
+
s390_save_gprs_to_fprs ();
/* Save call saved gprs. */
@@ -11009,6 +11199,14 @@ s390_emit_prologue (void)
- cfun_frame_layout.first_save_gpr_slot),
cfun_frame_layout.first_save_gpr,
cfun_frame_layout.last_save_gpr);
+
+ /* This is not 100% correct. If we have more than one register saved,
+ then LAST_PROBE_OFFSET can move even closer to sp. */
+ last_probe_offset
+ = (cfun_frame_layout.gprs_offset +
+ UNITS_PER_LONG * (cfun_frame_layout.first_save_gpr
+ - cfun_frame_layout.first_save_gpr_slot));
+
emit_insn (insn);
}
@@ -11025,6 +11223,8 @@ s390_emit_prologue (void)
if (cfun_fpr_save_p (i))
{
save_fpr (stack_pointer_rtx, offset, i);
+ if (offset < last_probe_offset)
+ last_probe_offset = offset;
offset += 8;
}
else if (!TARGET_PACKED_STACK || cfun->stdarg)
@@ -11038,6 +11238,8 @@ s390_emit_prologue (void)
if (cfun_fpr_save_p (i))
{
insn = save_fpr (stack_pointer_rtx, offset, i);
+ if (offset < last_probe_offset)
+ last_probe_offset = offset;
offset += 8;
/* If f4 and f6 are call clobbered they are saved due to
@@ -11060,6 +11262,8 @@ s390_emit_prologue (void)
if (cfun_fpr_save_p (i))
{
insn = save_fpr (stack_pointer_rtx, offset, i);
+ if (offset < last_probe_offset)
+ last_probe_offset = offset;
RTX_FRAME_RELATED_P (insn) = 1;
offset -= 8;
@@ -11079,10 +11283,11 @@ s390_emit_prologue (void)
if (cfun_frame_layout.frame_size > 0)
{
rtx frame_off = GEN_INT (-cfun_frame_layout.frame_size);
- rtx real_frame_off;
+ rtx_insn *stack_pointer_backup_loc;
+ bool temp_reg_clobbered_p;
if (s390_stack_size)
- {
+ {
HOST_WIDE_INT stack_guard;
if (s390_stack_guard)
@@ -11148,35 +11353,36 @@ s390_emit_prologue (void)
if (s390_warn_dynamicstack_p && cfun->calls_alloca)
warning (0, "%qs uses dynamic stack allocation", current_function_name ());
- /* Save incoming stack pointer into temp reg. */
- if (TARGET_BACKCHAIN || next_fpr)
- insn = emit_insn (gen_move_insn (temp_reg, stack_pointer_rtx));
+ /* Save the location where we could backup the incoming stack
+ pointer. */
+ stack_pointer_backup_loc = get_last_insn ();
- /* Subtract frame size from stack pointer. */
+ temp_reg_clobbered_p = allocate_stack_space (frame_off, last_probe_offset,
+ temp_reg);
- if (DISP_IN_RANGE (INTVAL (frame_off)))
- {
- insn = gen_rtx_SET (stack_pointer_rtx,
- gen_rtx_PLUS (Pmode, stack_pointer_rtx,
- frame_off));
- insn = emit_insn (insn);
- }
- else
+ if (TARGET_BACKCHAIN || next_fpr)
{
- if (!CONST_OK_FOR_K (INTVAL (frame_off)))
- frame_off = force_const_mem (Pmode, frame_off);
-
- insn = emit_insn (gen_add2_insn (stack_pointer_rtx, frame_off));
- annotate_constant_pool_refs (&PATTERN (insn));
+ if (temp_reg_clobbered_p)
+ {
+ /* allocate_stack_space had to make use of temp_reg and
+ we need it to hold a backup of the incoming stack
+ pointer. Calculate back that value from the current
+ stack pointer. */
+ s390_prologue_plus_offset (temp_reg, stack_pointer_rtx,
+ GEN_INT (cfun_frame_layout.frame_size),
+ false);
+ }
+ else
+ {
+ /* allocate_stack_space didn't actually required
+ temp_reg. Insert the stack pointer backup insn
+ before the stack pointer decrement code - knowing now
+ that the value will survive. */
+ emit_insn_after (gen_move_insn (temp_reg, stack_pointer_rtx),
+ stack_pointer_backup_loc);
+ }
}
- RTX_FRAME_RELATED_P (insn) = 1;
- real_frame_off = GEN_INT (-cfun_frame_layout.frame_size);
- add_reg_note (insn, REG_FRAME_RELATED_EXPR,
- gen_rtx_SET (stack_pointer_rtx,
- gen_rtx_PLUS (Pmode, stack_pointer_rtx,
- real_frame_off)));
-
/* Set backchain. */
if (TARGET_BACKCHAIN)
@@ -11200,6 +11406,8 @@ s390_emit_prologue (void)
emit_clobber (addr);
}
}
+ else if (flag_stack_clash_protection)
+ dump_stack_clash_frame_info (NO_PROBE_NO_FRAME, false);
/* Save fprs 8 - 15 (64 bit ABI). */
diff --git a/gcc/testsuite/gcc.dg/stack-check-5.c b/gcc/testsuite/gcc.dg/stack-check-5.c
index 2171d9b6c23..3178f5d8ce5 100644
--- a/gcc/testsuite/gcc.dg/stack-check-5.c
+++ b/gcc/testsuite/gcc.dg/stack-check-5.c
@@ -3,6 +3,10 @@
/* { dg-require-effective-target supports_stack_clash_protection } */
+/* Otherwise the S/390 back-end might save the stack pointer in f2 ()
+ into an FPR. */
+/* { dg-additional-options "-msoft-float" { target { s390x-*-* } } } */
+
extern void foo (char *);
extern void bar (void);
diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp
index 8dbec663b18..e9f03886ca6 100644
--- a/gcc/testsuite/lib/target-supports.exp
+++ b/gcc/testsuite/lib/target-supports.exp
@@ -8386,12 +8386,12 @@ proc check_effective_target_supports_stack_clash_protection { } {
# Temporary until the target bits are fully ACK'd.
# if { [istarget aarch*-*-*]
-# || [istarget s390*-*-*]
# || [istarget powerpc*-*-*] || [istarget rs6000*-*-*] } {
# return 1
# }
- if { [istarget x86_64-*-*] || [istarget i?86-*-*] } {
+ if { [istarget x86_64-*-*] || [istarget i?86-*-*]
+ || [istarget s390*-*-*] } {
return 1
}
return 0

49
gcc7-rh1512529-9.patch Normal file
View File

@ -0,0 +1,49 @@
commit 233a9def5cd0b70f1288ff57ce67d9d5d5d7f845
Author: law <law@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Thu Sep 21 22:03:59 2017 +0000
* config/i386/i386.c (ix86_adjust_stack_and_probe_stack_clash):
Fix dump output if the only stack space is for pushed registers.
* lib/target-supports.exp
(check_effective_target_frame_pointer_for_non_leaf): Add
case for x86 Solaris.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@253082 138bc75d-0d04-0410-961f-82ee72b054a4
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 5aff9b9d113..086848b2c73 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -13287,7 +13287,13 @@ ix86_adjust_stack_and_probe_stack_clash (const HOST_WIDE_INT size)
no probes are needed. */
if (!size)
{
- dump_stack_clash_frame_info (NO_PROBE_NO_FRAME, false);
+ /* However, the allocation of space via pushes for register
+ saves could be viewed as allocating space, but without the
+ need to probe. */
+ if (m->frame.nregs || m->frame.nsseregs || frame_pointer_needed)
+ dump_stack_clash_frame_info (NO_PROBE_SMALL_FRAME, true);
+ else
+ dump_stack_clash_frame_info (NO_PROBE_NO_FRAME, false);
return;
}
diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp
index e9f03886ca6..cb58a2be35f 100644
--- a/gcc/testsuite/lib/target-supports.exp
+++ b/gcc/testsuite/lib/target-supports.exp
@@ -8403,6 +8403,12 @@ proc check_effective_target_frame_pointer_for_non_leaf { } {
if { [istarget aarch*-*-*] } {
return 1
}
+
+ # Solaris/x86 defaults to -fno-omit-frame-pointer.
+ if { [istarget i?86-*-solaris*] || [istarget x86_64-*-solaris*] } {
+ return 1
+ }
+
return 0
}