463 lines
16 KiB
Diff
463 lines
16 KiB
Diff
commit 5d7a77ede3e91948ee125bd82533d7e692543fff
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Author: Jeff Law <law@redhat.com>
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Date: Mon Oct 2 13:43:01 2017 -0600
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aarch64 support
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diff --git a/gcc/config/aarch64/.aarch64.c.rej.swp b/gcc/config/aarch64/.aarch64.c.rej.swp
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new file mode 100644
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index 00000000000..b899e21b855
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Binary files /dev/null and b/gcc/config/aarch64/.aarch64.c.rej.swp differ
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diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
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index cadf193cfcf..e08632ffa88 100644
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--- a/gcc/config/aarch64/aarch64.c
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+++ b/gcc/config/aarch64/aarch64.c
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@@ -45,6 +45,8 @@
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#include "gimple.h"
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#include "optabs.h"
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#include "dwarf2.h"
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+#include "params.h"
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+#include "dumpfile.h"
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/* Classifies an address.
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@@ -1696,7 +1698,14 @@ aarch64_output_probe_stack_range (rtx reg1, rtx reg2)
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output_asm_insn ("sub\t%0, %0, %1", xops);
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/* Probe at TEST_ADDR. */
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- output_asm_insn ("str\txzr, [%0]", xops);
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+ if (flag_stack_clash_protection)
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+ {
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+ gcc_assert (xops[0] == stack_pointer_rtx);
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+ xops[1] = GEN_INT (PROBE_INTERVAL - 8);
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+ output_asm_insn ("str\txzr, [%0, %1]", xops);
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+ }
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+ else
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+ output_asm_insn ("str\txzr, [%0]", xops);
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/* Test if TEST_ADDR == LAST_ADDR. */
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xops[1] = reg2;
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@@ -2001,6 +2010,123 @@ aarch64_save_or_restore_callee_save_registers (HOST_WIDE_INT offset,
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base_rtx, cfi_ops);
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}
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+/* Allocate SIZE bytes of stack space using SCRATCH_REG as a scratch
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+ register. */
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+
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+static void
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+aarch64_allocate_and_probe_stack_space (int scratchreg, HOST_WIDE_INT size)
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+{
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+ HOST_WIDE_INT probe_interval
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+ = 1 << PARAM_VALUE (PARAM_STACK_CLASH_PROTECTION_PROBE_INTERVAL);
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+ HOST_WIDE_INT guard_size
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+ = 1 << PARAM_VALUE (PARAM_STACK_CLASH_PROTECTION_GUARD_SIZE);
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+ HOST_WIDE_INT guard_used_by_caller = 1024;
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+
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+ /* SIZE should be large enough to require probing here. ie, it
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+ must be larger than GUARD_SIZE - GUARD_USED_BY_CALLER.
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+
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+ We can allocate GUARD_SIZE - GUARD_USED_BY_CALLER as a single chunk
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+ without any probing. */
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+ gcc_assert (size >= guard_size - guard_used_by_caller);
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+ aarch64_sub_sp (scratchreg, guard_size - guard_used_by_caller, true);
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+ HOST_WIDE_INT orig_size = size;
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+ size -= (guard_size - guard_used_by_caller);
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+
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+ HOST_WIDE_INT rounded_size = size & -probe_interval;
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+ HOST_WIDE_INT residual = size - rounded_size;
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+
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+ /* We can handle a small number of allocations/probes inline. Otherwise
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+ punt to a loop. */
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+ if (rounded_size && rounded_size <= 4 * probe_interval)
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+ {
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+ /* We don't use aarch64_sub_sp here because we don't want to
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+ repeatedly load SCRATCHREG. */
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+ rtx scratch_rtx = gen_rtx_REG (Pmode, scratchreg);
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+ if (probe_interval > ARITH_FACTOR)
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+ emit_move_insn (scratch_rtx, GEN_INT (-probe_interval));
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+ else
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+ scratch_rtx = GEN_INT (-probe_interval);
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+
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+ for (HOST_WIDE_INT i = 0; i < rounded_size; i += probe_interval)
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+ {
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+ rtx insn = emit_insn (gen_add2_insn (stack_pointer_rtx, scratch_rtx));
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+ add_reg_note (insn, REG_STACK_CHECK, const0_rtx);
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+
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+ if (probe_interval > ARITH_FACTOR)
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+ {
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+ RTX_FRAME_RELATED_P (insn) = 1;
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+ rtx adj = plus_constant (Pmode, stack_pointer_rtx, -probe_interval);
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+ add_reg_note (insn, REG_CFA_ADJUST_CFA,
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+ gen_rtx_SET (VOIDmode, stack_pointer_rtx, adj));
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+ }
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+
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+ emit_stack_probe (plus_constant (Pmode, stack_pointer_rtx,
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+ (probe_interval
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+ - GET_MODE_SIZE (word_mode))));
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+ emit_insn (gen_blockage ());
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+ }
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+ dump_stack_clash_frame_info (PROBE_INLINE, size != rounded_size);
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+ }
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+ else if (rounded_size)
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+ {
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+ /* Compute the ending address. */
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+ rtx temp = gen_rtx_REG (word_mode, scratchreg);
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+ emit_move_insn (temp, GEN_INT (-rounded_size));
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+ rtx insn = emit_insn (gen_add3_insn (temp, stack_pointer_rtx, temp));
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+
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+ /* For the initial allocation, we don't have a frame pointer
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+ set up, so we always need CFI notes. If we're doing the
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+ final allocation, then we may have a frame pointer, in which
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+ case it is the CFA, otherwise we need CFI notes.
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+
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+ We can determine which allocation we are doing by looking at
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+ the temporary register. IP0 is the initial allocation, IP1
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+ is the final allocation. */
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+ if (scratchreg == IP0_REGNUM || !frame_pointer_needed)
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+ {
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+ /* We want the CFA independent of the stack pointer for the
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+ duration of the loop. */
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+ add_reg_note (insn, REG_CFA_DEF_CFA,
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+ plus_constant (Pmode, temp,
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+ (rounded_size + (orig_size - size))));
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+ RTX_FRAME_RELATED_P (insn) = 1;
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+ }
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+
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+ /* This allocates and probes the stack.
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+
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+ It also probes at a 4k interval regardless of the value of
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+ PARAM_STACK_CLASH_PROTECTION_PROBE_INTERVAL. */
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+ insn = emit_insn (gen_probe_stack_range (stack_pointer_rtx,
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+ stack_pointer_rtx, temp));
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+
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+ /* Now reset the CFA register if needed. */
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+ if (scratchreg == IP0_REGNUM || !frame_pointer_needed)
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+ {
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+ add_reg_note (insn, REG_CFA_DEF_CFA,
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+ plus_constant (Pmode, stack_pointer_rtx,
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+ (rounded_size + (orig_size - size))));
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+ RTX_FRAME_RELATED_P (insn) = 1;
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+ }
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+
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+ emit_insn (gen_blockage ());
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+ dump_stack_clash_frame_info (PROBE_LOOP, size != rounded_size);
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+ }
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+ else
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+ dump_stack_clash_frame_info (PROBE_INLINE, size != rounded_size);
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+
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+ /* Handle any residuals.
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+ Note that any residual must be probed. */
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+ if (residual)
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+ {
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+ aarch64_sub_sp (scratchreg, residual, true);
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+ add_reg_note (get_last_insn (), REG_STACK_CHECK, const0_rtx);
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+ emit_stack_probe (plus_constant (Pmode, stack_pointer_rtx,
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+ (residual - GET_MODE_SIZE (word_mode))));
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+ emit_insn (gen_blockage ());
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+ }
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+ return;
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+}
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+
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/* AArch64 stack frames generated by this compiler look like:
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+-------------------------------+
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@@ -2073,6 +2199,44 @@ aarch64_expand_prologue (void)
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- original_frame_size
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- cfun->machine->frame.saved_regs_size);
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+ /* We do not fully protect aarch64 against stack clash style attacks
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+ as doing so would be prohibitively expensive with less utility over
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+ time as newer compilers are deployed.
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+
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+ We assume the guard is at least 64k. Furthermore, we assume that
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+ the caller has not pushed the stack pointer more than 1k into
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+ the guard. A caller that pushes the stack pointer than 1k into
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+ the guard is considered invalid.
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+
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+ Note that the caller's ability to push the stack pointer into the
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+ guard is a function of the number and size of outgoing arguments and/or
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+ dynamic stack allocations due to the mandatory save of the link register
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+ in the caller's frame.
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+
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+ With those assumptions the callee can allocate up to 63k of stack
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+ space without probing.
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+
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+ When probing is needed, we emit a probe at the start of the prologue
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+ and every PARAM_STACK_CLASH_PROTECTION_PROBE_INTERVAL bytes thereafter.
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+
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+ We have to track how much space has been allocated, but we do not
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+ track stores into the stack as implicit probes except for the
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+ fp/lr store. */
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+ HOST_WIDE_INT guard_size
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+ = 1 << PARAM_VALUE (PARAM_STACK_CLASH_PROTECTION_GUARD_SIZE);
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+ HOST_WIDE_INT guard_used_by_caller = 1024;
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+ HOST_WIDE_INT final_adjust = crtl->outgoing_args_size;
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+ HOST_WIDE_INT initial_adjust = frame_size;
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+
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+ if (flag_stack_clash_protection)
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+ {
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+ if (initial_adjust == 0)
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+ dump_stack_clash_frame_info (NO_PROBE_NO_FRAME, false);
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+ else if (offset < guard_size - guard_used_by_caller
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+ && final_adjust < guard_size - guard_used_by_caller)
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+ dump_stack_clash_frame_info (NO_PROBE_SMALL_FRAME, true);
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+ }
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+
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/* Store pairs and load pairs have a range only -512 to 504. */
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if (offset >= 512)
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{
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@@ -2089,7 +2253,10 @@ aarch64_expand_prologue (void)
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frame_size -= (offset + crtl->outgoing_args_size);
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fp_offset = 0;
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- if (frame_size >= 0x1000000)
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+ if (flag_stack_clash_protection
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+ && frame_size >= guard_size - guard_used_by_caller)
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+ aarch64_allocate_and_probe_stack_space (IP0_REGNUM, frame_size);
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+ else if (frame_size >= 0x1000000)
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{
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rtx op0 = gen_rtx_REG (Pmode, IP0_REGNUM);
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emit_move_insn (op0, GEN_INT (-frame_size));
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@@ -2206,10 +2373,30 @@ aarch64_expand_prologue (void)
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{
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if (crtl->outgoing_args_size > 0)
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{
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- insn = emit_insn (gen_add2_insn
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- (stack_pointer_rtx,
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- GEN_INT (- crtl->outgoing_args_size)));
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- RTX_FRAME_RELATED_P (insn) = 1;
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+ if (flag_stack_clash_protection)
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+ {
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+ /* First probe if the final adjustment is larger than the
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+ guard size less the amount of guard reserved for use by
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+ the caller's outgoing args. */
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+ if (final_adjust >= guard_size - guard_used_by_caller)
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+ aarch64_allocate_and_probe_stack_space (IP1_REGNUM,
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+ final_adjust);
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+ else
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+ aarch64_sub_sp (IP1_REGNUM, final_adjust, !frame_pointer_needed);
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+
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+ /* We must also probe if the final adjustment is larger than the
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+ guard that is assumed used by the caller. This may be
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+ sub-optimal. */
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+ if (final_adjust >= guard_used_by_caller)
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+ {
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+ if (dump_file)
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+ fprintf (dump_file,
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+ "Stack clash aarch64 large outgoing arg, probing\n");
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+ emit_stack_probe (stack_pointer_rtx);
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+ }
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+ }
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+ else
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+ aarch64_sub_sp (IP1_REGNUM, final_adjust, !frame_pointer_needed);
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}
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}
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}
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@@ -5088,6 +5275,12 @@ aarch64_override_options (void)
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#endif
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}
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+ /* We assume the guard page is 64k. */
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+ maybe_set_param_value (PARAM_STACK_CLASH_PROTECTION_GUARD_SIZE,
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+ 16,
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+ global_options.x_param_values,
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+ global_options_set.x_param_values);
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+
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aarch64_override_options_after_change ();
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}
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@@ -8161,6 +8354,28 @@ aarch64_vectorize_vec_perm_const_ok (enum machine_mode vmode,
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return ret;
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}
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+/* It has been decided that to allow up to 1kb of outgoing argument
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+ space to be allocated w/o probing. If more than 1kb of outgoing
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+ argment space is allocated, then it must be probed and the last
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+ probe must occur no more than 1kbyte away from the end of the
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+ allocated space.
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+
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+ This implies that the residual part of an alloca allocation may
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+ need probing in cases where the generic code might not otherwise
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+ think a probe is needed.
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+
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+ This target hook returns TRUE when allocating RESIDUAL bytes of
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+ alloca space requires an additional probe, otherwise FALSE is
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+ returned. */
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+
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+static bool
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+aarch64_stack_clash_protection_final_dynamic_probe (rtx residual)
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+{
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+ return (residual == CONST0_RTX (Pmode)
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+ || GET_CODE (residual) != CONST_INT
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+ || INTVAL (residual) >= 1024);
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+}
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+
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#undef TARGET_ADDRESS_COST
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#define TARGET_ADDRESS_COST aarch64_address_cost
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@@ -8378,6 +8593,10 @@ aarch64_vectorize_vec_perm_const_ok (enum machine_mode vmode,
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#undef TARGET_FIXED_CONDITION_CODE_REGS
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#define TARGET_FIXED_CONDITION_CODE_REGS aarch64_fixed_condition_code_regs
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+#undef TARGET_STACK_CLASH_PROTECTION_FINAL_DYNAMIC_PROBE
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+#define TARGET_STACK_CLASH_PROTECTION_FINAL_DYNAMIC_PROBE \
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+ aarch64_stack_clash_protection_final_dynamic_probe
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+
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struct gcc_target targetm = TARGET_INITIALIZER;
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#include "gt-aarch64.h"
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diff --git a/gcc/config/aarch64/aarch64.md b/gcc/config/aarch64/aarch64.md
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index a085c6acaf5..5485a5f70b1 100644
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--- a/gcc/config/aarch64/aarch64.md
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+++ b/gcc/config/aarch64/aarch64.md
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@@ -3401,7 +3401,7 @@
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)
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(define_insn "probe_stack_range"
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- [(set (match_operand:DI 0 "register_operand" "=r")
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+ [(set (match_operand:DI 0 "register_operand" "=rk")
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(unspec_volatile:DI [(match_operand:DI 1 "register_operand" "0")
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(match_operand:DI 2 "register_operand" "r")]
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UNSPECV_PROBE_STACK_RANGE))]
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diff --git a/gcc/testsuite/gcc.target/aarch64/stack-check-12.c b/gcc/testsuite/gcc.target/aarch64/stack-check-12.c
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new file mode 100644
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index 00000000000..2ce38483b6b
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--- /dev/null
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+++ b/gcc/testsuite/gcc.target/aarch64/stack-check-12.c
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@@ -0,0 +1,20 @@
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+/* { dg-do compile } */
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+/* { dg-options "-O2 -fstack-clash-protection --param stack-clash-protection-guard-size=12" } */
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+/* { dg-require-effective-target supports_stack_clash_protection } */
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+
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+extern void arf (unsigned long int *, unsigned long int *);
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+void
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+frob ()
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+{
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+ unsigned long int num[1000];
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+ unsigned long int den[1000];
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+ arf (den, num);
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+}
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+
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+/* This verifies that the scheduler did not break the dependencies
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+ by adjusting the offsets within the probe and that the scheduler
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+ did not reorder around the stack probes. */
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+/* { dg-final { scan-assembler-times "sub\\tsp, sp, #4096\\n\\tstr\\txzr, .sp, 4088." 3 } } */
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+
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+
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+
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diff --git a/gcc/testsuite/gcc.target/aarch64/stack-check-13.c b/gcc/testsuite/gcc.target/aarch64/stack-check-13.c
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new file mode 100644
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index 00000000000..d8886835989
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--- /dev/null
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+++ b/gcc/testsuite/gcc.target/aarch64/stack-check-13.c
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@@ -0,0 +1,28 @@
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+/* { dg-do compile } */
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+/* { dg-options "-O2 -fstack-clash-protection --param stack-clash-protection-guard-size=12" } */
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+/* { dg-require-effective-target supports_stack_clash_protection } */
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+
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+#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
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+#define ARG192(X) ARG32(X),ARG32(X),ARG32(X),ARG32(X),ARG32(X),ARG32(X)
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+void out1(ARG192(__int128));
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+int t1(int);
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+
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+int t3(int x)
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+{
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+ if (x < 1000)
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+ return t1 (x) + 1;
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+
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+ out1 (ARG192(1));
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+ return 0;
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+}
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+
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+
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+
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+/* This test creates a large (> 1k) outgoing argument area that needs
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+ to be probed. We don't test the exact size of the space or the
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+ exact offset to make the test a little less sensitive to trivial
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+ output changes. */
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+/* { dg-final { scan-assembler-times "sub\\tsp, sp, #....\\n\\tstr\\txzr, \\\[sp" 1 } } */
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+
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+
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+
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diff --git a/gcc/testsuite/gcc.target/aarch64/stack-check-14.c b/gcc/testsuite/gcc.target/aarch64/stack-check-14.c
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new file mode 100644
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index 00000000000..59ffe01376d
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--- /dev/null
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+++ b/gcc/testsuite/gcc.target/aarch64/stack-check-14.c
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@@ -0,0 +1,25 @@
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+/* { dg-do compile } */
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+/* { dg-options "-O2 -fstack-clash-protection --param stack-clash-protection-guard-size=12" } */
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+/* { dg-require-effective-target supports_stack_clash_protection } */
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+
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+int t1(int);
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+
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+int t2(int x)
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+{
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+ char *p = __builtin_alloca (4050);
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+ x = t1 (x);
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+ return p[x];
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+}
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+
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+
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+/* This test has a constant sized alloca that is smaller than the
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+ probe interval. But it actually requires two probes instead
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+ of one because of the optimistic assumptions we made in the
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+ aarch64 prologue code WRT probing state.
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+
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+ The form can change quite a bit so we just check for two
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+ probes without looking at the actual address. */
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+/* { dg-final { scan-assembler-times "str\\txzr," 2 } } */
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+
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+
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+
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diff --git a/gcc/testsuite/gcc.target/aarch64/stack-check-15.c b/gcc/testsuite/gcc.target/aarch64/stack-check-15.c
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new file mode 100644
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index 00000000000..e06db6dc2f0
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--- /dev/null
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+++ b/gcc/testsuite/gcc.target/aarch64/stack-check-15.c
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|
@@ -0,0 +1,24 @@
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|
+/* { dg-do compile } */
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|
+/* { dg-options "-O2 -fstack-clash-protection --param stack-clash-protection-guard-size=12" } */
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+/* { 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 aba99513ed0..a8451c98b08 100644
|
|
--- a/gcc/testsuite/lib/target-supports.exp
|
|
+++ b/gcc/testsuite/lib/target-supports.exp
|
|
@@ -5420,14 +5420,9 @@ proc check_effective_target_autoincdec { } {
|
|
#
|
|
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
|