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. diff --git a/gdb/amd64-linux-tdep.c b/gdb/amd64-linux-tdep.c --- a/gdb/amd64-linux-tdep.c +++ b/gdb/amd64-linux-tdep.c @@ -291,6 +291,80 @@ amd64_linux_register_reggroup_p (struct gdbarch *gdbarch, int regnum, /* 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) { @@ -1808,6 +1882,8 @@ amd64_linux_init_abi_common(struct gdbarch_info info, struct gdbarch *gdbarch) tdep->xsave_xcr0_offset = I386_LINUX_XSAVE_XCR0_OFFSET; + tdep->outermost_frame_p = amd64_linux_outermost_frame; + /* Add the %orig_rax register used for syscall restarting. */ set_gdbarch_write_pc (gdbarch, amd64_linux_write_pc); diff --git a/gdb/amd64-tdep.c b/gdb/amd64-tdep.c --- a/gdb/amd64-tdep.c +++ b/gdb/amd64-tdep.c @@ -2595,6 +2595,7 @@ amd64_frame_unwind_stop_reason (struct frame_info *this_frame, { 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; @@ -2603,6 +2604,10 @@ amd64_frame_unwind_stop_reason (struct frame_info *this_frame, 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; } @@ -2737,6 +2742,7 @@ amd64_sigtramp_frame_this_id (struct frame_info *this_frame, { struct amd64_frame_cache *cache = amd64_sigtramp_frame_cache (this_frame, this_cache); + struct gdbarch_tdep *tdep = gdbarch_tdep (get_frame_arch (this_frame)); if (!cache->base_p) (*this_id) = frame_id_build_unavailable_stack (get_frame_pc (this_frame)); @@ -2745,6 +2751,11 @@ amd64_sigtramp_frame_this_id (struct frame_info *this_frame, /* This marks the outermost frame. */ return; } + else if (tdep->outermost_frame_p && tdep->outermost_frame_p (this_frame)) + { + /* Detect OS dependent outermost frames; such as `clone'. */ + return; + } else (*this_id) = frame_id_build (cache->base + 16, get_frame_pc (this_frame)); } diff --git a/gdb/i386-tdep.c b/gdb/i386-tdep.c --- a/gdb/i386-tdep.c +++ b/gdb/i386-tdep.c @@ -8406,6 +8406,9 @@ i386_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches) tdep->xsave_xcr0_offset = -1; + /* Unwinding stops on i386 automatically. */ + tdep->outermost_frame_p = NULL; + tdep->record_regmap = i386_record_regmap; set_gdbarch_type_align (gdbarch, i386_type_align); diff --git a/gdb/i386-tdep.h b/gdb/i386-tdep.h --- a/gdb/i386-tdep.h +++ b/gdb/i386-tdep.h @@ -251,6 +251,9 @@ struct gdbarch_tdep /* Regsets. */ const struct regset *fpregset; + + /* Detect OS dependent outermost frames; such as `clone'. */ + int (*outermost_frame_p) (struct frame_info *this_frame); }; /* Floating-point registers. */