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 <jan.kratochvil@redhat.com>
* 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 <jan.kratochvil@redhat.com>
* gdb.threads/bt-clone-stop.exp, gdb.threads/bt-clone-stop.c:
New file.
2007-10-16 Jan Kratochvil <jan.kratochvil@redhat.com>
Port to GDB-6.7.
Index: gdb-7.10.90.20160211/gdb/amd64-linux-tdep.c
===================================================================
--- gdb-7.10.90.20160211.orig/gdb/amd64-linux-tdep.c 2016-02-15 23:37:06.936501443 +0100
+++ gdb-7.10.90.20160211/gdb/amd64-linux-tdep.c 2016-02-15 23:37:39.928735691 +0100
@@ -292,6 +292,80 @@
/* 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)
{
@@ -1800,6 +1874,8 @@
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);
Index: gdb-7.10.90.20160211/gdb/amd64-tdep.c
===================================================================
--- gdb-7.10.90.20160211.orig/gdb/amd64-tdep.c 2016-02-15 23:37:06.936501443 +0100
+++ gdb-7.10.90.20160211/gdb/amd64-tdep.c 2016-02-15 23:37:39.929735698 +0100
@@ -2494,6 +2494,7 @@
{
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;
@@ -2502,6 +2503,10 @@
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;
}
@@ -2636,6 +2641,7 @@
{
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));
@@ -2644,6 +2650,11 @@
/* 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));
}
Index: gdb-7.10.90.20160211/gdb/i386-tdep.c
===================================================================
--- gdb-7.10.90.20160211.orig/gdb/i386-tdep.c 2016-02-15 23:37:06.936501443 +0100
+++ gdb-7.10.90.20160211/gdb/i386-tdep.c 2016-02-15 23:37:39.931735713 +0100
@@ -8305,6 +8305,9 @@
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-7.10.90.20160211/gdb/i386-tdep.h
===================================================================
--- gdb-7.10.90.20160211.orig/gdb/i386-tdep.h 2016-02-15 23:37:06.936501443 +0100
+++ gdb-7.10.90.20160211/gdb/i386-tdep.h 2016-02-15 23:37:39.932735720 +0100
@@ -240,6 +240,9 @@
/* 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. */
Index: gdb-7.10.90.20160211/gdb/testsuite/gdb.threads/bt-clone-stop.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ gdb-7.10.90.20160211/gdb/testsuite/gdb.threads/bt-clone-stop.c 2016-02-15 23:37:39.932735720 +0100
@@ -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 <pthread.h>
+#include <unistd.h>
+#include <assert.h>
+
+
+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-7.10.90.20160211/gdb/testsuite/gdb.threads/bt-clone-stop.exp
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ gdb-7.10.90.20160211/gdb/testsuite/gdb.threads/bt-clone-stop.exp 2016-02-15 23:37:56.197851204 +0100
@@ -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 [standard_output_file ${testfile}]
+if { [gdb_compile_pthreads "${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" \
+ {Thread 2 "bt-clone-stop" 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"
+ }
+}