https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=216711 FIXME: This workaround should be dropped and glibc/sysdeps/unix/sysv/linux/x86_64/clone.S should get CFI for the child instead. 2006-12-17 Jan Kratochvil * gdb/amd64-linux-tdep.c (linux_clone_code): New variable. (LINUX_CLONE_LEN): New definition. (amd64_linux_clone_running, amd64_linux_outermost_frame): New function. (amd64_linux_init_abi): Initialize `outermost_frame_p'. * gdb/i386-tdep.c (i386_gdbarch_init): Likewise. * gdb/i386-tdep.h (gdbarch_tdep): Add `outermost_frame_p' member. * gdb/amd64-tdep.c (amd64_frame_this_id): Call `outermost_frame_p'. 2006-12-17 Jan Kratochvil * gdb.threads/bt-clone-stop.exp, gdb.threads/bt-clone-stop.c: New file. 2007-10-16 Jan Kratochvil Port to GDB-6.7. Index: gdb-7.4.50.20120602/gdb/amd64-linux-tdep.c =================================================================== --- gdb-7.4.50.20120602.orig/gdb/amd64-linux-tdep.c 2012-06-02 21:05:45.352280128 +0200 +++ gdb-7.4.50.20120602/gdb/amd64-linux-tdep.c 2012-06-02 21:06:25.536265325 +0200 @@ -271,6 +271,80 @@ amd64_linux_register_reggroup_p (struct /* Set the program counter for process PTID to PC. */ +/* Detect the outermost frame; during unwind of + #5 0x000000305cec68c3 in clone () from /lib64/tls/libc.so.6 + avoid the additional bogus frame + #6 0x0000000000000000 in ?? + We compare if the `linux_clone_code' block is _before_ unwound PC. */ + +static const unsigned char linux_clone_code[] = +{ +/* libc/sysdeps/unix/sysv/linux/x86_64/clone.S */ +/* #ifdef RESET_PID */ +/* ... */ +/* mov $SYS_ify(getpid), %eax */ +/* 0xb8, 0x27, 0x00, 0x00, 0x00 */ +/* OR */ +/* mov $SYS_ify(getpid), %rax */ +/* 0x48, 0xc7, 0xc0, 0x27, 0x00, 0x00, 0x00 */ +/* so just: */ + 0x27, 0x00, 0x00, 0x00, +/* syscall */ + 0x0f, 0x05, +/* movl %eax, %fs:PID */ + 0x64, 0x89, 0x04, 0x25, 0x94, 0x00, 0x00, 0x00, +/* movl %eax, %fs:TID */ + 0x64, 0x89, 0x04, 0x25, 0x90, 0x00, 0x00, 0x00, +/* #endif */ +/* |* Set up arguments for the function call. *| */ +/* popq %rax |* Function to call. *| */ + 0x58, +/* popq %rdi |* Argument. *| */ + 0x5f, +/* call *%rax$ */ + 0xff, 0xd0 +}; + +#define LINUX_CLONE_LEN (sizeof linux_clone_code) + +static int +amd64_linux_clone_running (struct frame_info *this_frame) +{ + CORE_ADDR pc = get_frame_pc (this_frame); + unsigned char buf[LINUX_CLONE_LEN]; + + if (!safe_frame_unwind_memory (this_frame, pc - LINUX_CLONE_LEN, buf, + LINUX_CLONE_LEN)) + return 0; + + if (memcmp (buf, linux_clone_code, LINUX_CLONE_LEN) != 0) + return 0; + + return 1; +} + +static int +amd64_linux_outermost_frame (struct frame_info *this_frame) +{ + CORE_ADDR pc = get_frame_pc (this_frame); + const char *name; + + find_pc_partial_function (pc, &name, NULL, NULL); + + /* If we have NAME, we can optimize the search. + `clone' NAME still needs to have the code checked as its name may be + present in the user code. + `__clone' NAME should not be present in the user code but in the initial + parts of the `__clone' implementation the unwind still makes sense. + More detailed unwinding decision would be too much sensitive to possible + subtle changes in specific glibc revisions. */ + if (name == NULL || strcmp (name, "clone") == 0 + || strcmp ("__clone", name) == 0) + return (amd64_linux_clone_running (this_frame) != 0); + + return 0; +} + static void amd64_linux_write_pc (struct regcache *regcache, CORE_ADDR pc) { @@ -1330,6 +1404,8 @@ amd64_linux_init_abi (struct gdbarch_inf tdep->xsave_xcr0_offset = I386_LINUX_XSAVE_XCR0_OFFSET; + tdep->outermost_frame_p = amd64_linux_outermost_frame; + /* GNU/Linux uses SVR4-style shared libraries. */ set_solib_svr4_fetch_link_map_offsets (gdbarch, svr4_lp64_fetch_link_map_offsets); Index: gdb-7.4.50.20120602/gdb/amd64-tdep.c =================================================================== --- gdb-7.4.50.20120602.orig/gdb/amd64-tdep.c 2012-06-02 21:05:45.352280128 +0200 +++ gdb-7.4.50.20120602/gdb/amd64-tdep.c 2012-06-02 21:06:00.437274574 +0200 @@ -2138,6 +2138,7 @@ amd64_frame_unwind_stop_reason (struct f { struct amd64_frame_cache *cache = amd64_frame_cache (this_frame, this_cache); + struct gdbarch_tdep *tdep = gdbarch_tdep (get_frame_arch (this_frame)); if (!cache->base_p) return UNWIND_UNAVAILABLE; @@ -2146,6 +2147,10 @@ amd64_frame_unwind_stop_reason (struct f if (cache->base == 0) return UNWIND_OUTERMOST; + /* Detect OS dependent outermost frames; such as `clone'. */ + if (tdep->outermost_frame_p && tdep->outermost_frame_p (this_frame)) + return UNWIND_OUTERMOST; + return UNWIND_NO_REASON; } @@ -2155,6 +2160,7 @@ amd64_frame_this_id (struct frame_info * { struct amd64_frame_cache *cache = amd64_frame_cache (this_frame, this_cache); + struct gdbarch_tdep *tdep = gdbarch_tdep (get_frame_arch (this_frame)); if (!cache->base_p) return; @@ -2163,6 +2169,10 @@ amd64_frame_this_id (struct frame_info * if (cache->base == 0) return; + /* Detect OS dependent outermost frames; such as `clone'. */ + if (tdep->outermost_frame_p && tdep->outermost_frame_p (this_frame)) + return; + (*this_id) = frame_id_build (cache->base + 16, cache->pc); } Index: gdb-7.4.50.20120602/gdb/i386-tdep.c =================================================================== --- gdb-7.4.50.20120602.orig/gdb/i386-tdep.c 2012-06-02 21:05:45.352280128 +0200 +++ gdb-7.4.50.20120602/gdb/i386-tdep.c 2012-06-02 21:06:00.466274562 +0200 @@ -7639,6 +7639,9 @@ i386_gdbarch_init (struct gdbarch_info i tdep->xsave_xcr0_offset = -1; + /* Unwinding stops on i386 automatically. */ + tdep->outermost_frame_p = NULL; + tdep->record_regmap = i386_record_regmap; set_gdbarch_long_long_align_bit (gdbarch, 32); Index: gdb-7.4.50.20120602/gdb/i386-tdep.h =================================================================== --- gdb-7.4.50.20120602.orig/gdb/i386-tdep.h 2012-06-02 21:05:45.352280128 +0200 +++ gdb-7.4.50.20120602/gdb/i386-tdep.h 2012-06-02 21:06:00.486274568 +0200 @@ -219,6 +219,9 @@ struct gdbarch_tdep int (*i386_sysenter_record) (struct regcache *regcache); /* Parse syscall args. */ int (*i386_syscall_record) (struct regcache *regcache); + + /* Detect OS dependent outermost frames; such as `clone'. */ + int (*outermost_frame_p) (struct frame_info *this_frame); }; /* Floating-point registers. */ Index: gdb-7.4.50.20120602/gdb/ia64-tdep.c =================================================================== --- gdb-7.4.50.20120602.orig/gdb/ia64-tdep.c 2012-06-02 21:05:45.352280128 +0200 +++ gdb-7.4.50.20120602/gdb/ia64-tdep.c 2012-06-02 21:06:00.490274552 +0200 @@ -2176,6 +2176,138 @@ static const struct frame_unwind ia64_fr default_frame_sniffer }; +/* Detect the outermost frame; during unwind of + #6 0x2000000000347100 in __clone2 () from /lib/libc.so.6.1 + avoid the additional bogus frame + #7 0x0000000000000000 in ?? () */ + +static char linux_clone2_code[] = +{ +/* libc/sysdeps/unix/sysv/linux/ia64/clone2.S */ + 0x09, 0x00, 0x20, 0x12, 0x90, 0x11, 0x00, 0x40, + 0x28, 0x20, 0x23, 0x00, 0x00, 0x00, 0x04, 0x00, +/* st4 [r9]=r8 */ +/* st4 [r10]=r8 */ +/* ;; */ +/* #endif */ + 0x02, 0x50, 0x21, 0x40, 0x18, 0x14, 0x90, 0x02, + 0x90, 0x00, 0x42, 0x00, 0x00, 0x00, 0x04, 0x00, +/* 1: ld8 out1=[in0],8 |* Retrieve code pointer. *| */ +/* mov out0=in4 |* Pass proper argument to fn *| */ +/* ;; */ + 0x11, 0x08, 0x00, 0x40, 0x18, 0x10, 0x60, 0x50, + 0x05, 0x80, 0x03, 0x00, 0x68, 0x00, 0x80, 0x12, +/* ld8 gp=[in0] |* Load function gp. *| */ +/* mov b6=out1 */ +/* br.call.dptk.many rp=b6 |* Call fn(arg) in the child *| */ +/* ;; */ + 0x10, 0x48, 0x01, 0x10, 0x00, 0x21, 0x10, 0x00, + 0xa0, 0x00, 0x42, 0x00, 0x98, 0xdf, 0xf7, 0x5b, +/* mov out0=r8 |* Argument to _exit *| */ +/* mov gp=loc0 */ +/* .globl HIDDEN_JUMPTARGET(_exit) */ +/* br.call.dpnt.many rp=HIDDEN_JUMPTARGET(_exit) */ +/* |* call _exit with result from fn. *| */ + 0x11, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, + 0x00, 0x02, 0x00, 0x80, 0x00, 0x00, 0x84, 0x00 +/* ret |* Not reached. *| */ +}; + +#define LINUX_CLONE_PRE_SLOTS 3 /* Number of slots before PC. */ +#define LINUX_CLONE_LEN (sizeof linux_clone2_code) + +static int +ia64_linux_clone2_running (struct frame_info *this_frame) +{ + CORE_ADDR pc = get_frame_pc (this_frame); + char buf[LINUX_CLONE_LEN]; + struct minimal_symbol *minsym; + long long instr; + + if (!safe_frame_unwind_memory (this_frame, pc - LINUX_CLONE_PRE_SLOTS * 16, + buf, LINUX_CLONE_LEN)) + return 0; + + if (memcmp (buf, linux_clone2_code, LINUX_CLONE_PRE_SLOTS * 16) != 0) + return 0; + + /* Adjust the expected "_exit" address. */ + minsym = lookup_minimal_symbol_text ("_exit", NULL); + if (minsym == NULL) + return 0; + + instr = slotN_contents (&linux_clone2_code[LINUX_CLONE_PRE_SLOTS * 16], 2); + instr &= ~(((1L << 20) - 1) << 13); + /* Address is relative to the jump instruction slot, not the next one. */ + instr |= (((SYMBOL_VALUE_ADDRESS (minsym) - (pc & ~0xfL)) >> 4) + & ((1L << 20) - 1)) << 13; + replace_slotN_contents (&linux_clone2_code[LINUX_CLONE_PRE_SLOTS * 16], instr, + 2); + + if (memcmp (&buf[LINUX_CLONE_PRE_SLOTS * 16], + &linux_clone2_code[LINUX_CLONE_PRE_SLOTS * 16], + LINUX_CLONE_LEN - (LINUX_CLONE_PRE_SLOTS * 16)) != 0) + return 0; + + return 1; +} + +static int +ia64_outermost_frame (struct frame_info *this_frame) +{ + CORE_ADDR pc = get_frame_pc (this_frame); + char *name; + + find_pc_partial_function (pc, &name, NULL, NULL); + + /* If we have NAME, we can optimize the search. + `clone' NAME still needs to have the code checked as its name may be + present in the user code. + `__clone' NAME should not be present in the user code but in the initial + parts of the `__clone' implementation the unwind still makes sense. + More detailed unwinding decision would be too much sensitive to possible + subtle changes in specific glibc revisions. */ + if (name == NULL || strcmp (name, "clone2") == 0 + || strcmp ("__clone2", name) == 0) + return (ia64_linux_clone2_running (this_frame) != 0); + + return 0; +} + +static void +ia64_clone2_frame_this_id (struct frame_info *this_frame, void **this_cache, + struct frame_id *this_id) +{ + /* Leave the default outermost frame at *THIS_ID. */ +} + +static struct value * +ia64_clone2_frame_prev_register (struct frame_info *this_frame, + void **this_cache, int regnum) +{ + return frame_unwind_got_register (this_frame, regnum, regnum); +} + +static int +ia64_clone2_frame_sniffer (const struct frame_unwind *self, + struct frame_info *this_frame, + void **this_prologue_cache) +{ + if (ia64_outermost_frame (this_frame)) + return 1; + + return 0; +} + +static const struct frame_unwind ia64_clone2_frame_unwind = +{ + NORMAL_FRAME, + &ia64_clone2_frame_this_id, + &ia64_clone2_frame_prev_register, + NULL, + &ia64_clone2_frame_sniffer +}; + /* Signal trampolines. */ static void @@ -4146,6 +4278,7 @@ ia64_gdbarch_init (struct gdbarch_info i set_gdbarch_dummy_id (gdbarch, ia64_dummy_id); set_gdbarch_unwind_pc (gdbarch, ia64_unwind_pc); + frame_unwind_append_unwinder (gdbarch, &ia64_clone2_frame_unwind); #ifdef HAVE_LIBUNWIND_IA64_H frame_unwind_append_unwinder (gdbarch, &ia64_libunwind_sigtramp_frame_unwind); Index: gdb-7.4.50.20120602/gdb/testsuite/gdb.threads/bt-clone-stop.c =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ gdb-7.4.50.20120602/gdb/testsuite/gdb.threads/bt-clone-stop.c 2012-06-02 21:06:00.514274544 +0200 @@ -0,0 +1,39 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2006 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, + MA 02110-1301, USA. */ + + +#include +#include +#include + + +void *threader (void *arg) +{ + assert (0); + return NULL; +} + +int main (void) +{ + pthread_t t1; + + pthread_create (&t1, NULL, threader, (void *) NULL); + for (;;) + pause(); +} Index: gdb-7.4.50.20120602/gdb/testsuite/gdb.threads/bt-clone-stop.exp =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ gdb-7.4.50.20120602/gdb/testsuite/gdb.threads/bt-clone-stop.exp 2012-06-02 21:06:00.515274547 +0200 @@ -0,0 +1,61 @@ +# Copyright 2006 Free Software Foundation, Inc. + +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 2 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program; if not, write to the Free Software +# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + +# Backtraced `clone' must not have `PC == 0' as its previous frame. + +if $tracelevel then { + strace $tracelevel +} + +set testfile bt-clone-stop +set srcfile ${testfile}.c +set binfile ${objdir}/${subdir}/${testfile} +if { [gdb_compile_pthreads "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable {debug}] != "" } { + untested "Couldn't compile test program" + return -1 +} + +# Get things started. + +gdb_exit +gdb_start +gdb_reinitialize_dir $srcdir/$subdir +gdb_load ${binfile} + +# threader: threader.c:8: threader: Assertion `0' failed. +# Program received signal SIGABRT, Aborted. + +gdb_test "run" \ + "Program received signal SIGABRT.*" \ + "run" + +# Former gdb unwind (the first function is `clone'): +# #5 0x0000003421ecd62d in ?? () from /lib64/libc.so.6 +# #6 0x0000000000000000 in ?? () +# (gdb) +# Tested `amd64_linux_outermost_frame' functionality should omit the line `#6'. +# +# Two `-re' cases below must be in this order (1st is a subset of the 2nd one). +# Unhandled case below should not happen and it is fortunately handled by +# `amd64_linux_outermost_frame' as FAIL (and result `0x0 entry output invalid'). +gdb_test_multiple "bt" "0x0 entry output invalid" { + -re "in threader \\(.*\n#\[0-9\]* *0x0* in .*$gdb_prompt $" { + fail "0x0 entry found" + } + -re "in threader \\(.*$gdb_prompt $" { + pass "0x0 entry not found" + } +}