Fix PR gdb/20505 - Make vDSO detection work with core files
Loading a core dump that was either generated on a system running pristine glibc master, or on a Fedora/RHEL system with LD_DEBUG=unused set in the environment, solib-svr4.c:svr4_current_sos fails to filter out the vDSO, resulting in: (gdb) core-file corefile.core^M [New LWP 2362]^M warning: Could not load shared library symbols for linux-vdso.so.1.^M Do you need "set solib-search-path" or "set sysroot"?^M Core was generated by `build-gdb/gdb/testsuite/outputs/gdb.base/corefile/'.^M ... The problem is that gdbarch_vsyscall_range does not support core inferiors at all. When live debugging, we're finding the vDSO's start address with auxv/AT_SYSINFO_EHDR, and then we find the vDSO's size by look for the corresponding mapping, by parsing /proc/PID/maps. When debugging a core dump, we can also determine the starting address from auxv/AT_SYSINFO_EHDR. However, we obviously can't read the core mappings out of the host's /proc. But we can instead look for a corresponding load segment in the core's bfd. gdb/ChangeLog: 2016-08-22 Pedro Alves <palves@redhat.com> PR gdb/20505 * linux-tdep.c (linux_vsyscall_range_raw): For core inferiors, find the vDSO's start address with AT_SYSINFO_EHDR too, and determine the vDSO's size by finding the PT_LOAD segment that matches AT_SYSINFO_EHDR. gdb/testsuite/ChangeLog: 2016-08-22 Pedro Alves <palves@redhat.com> PR gdb/20505 * gdb.base/vdso-warning.exp: Test core dumps too. Use with_test_prefix. Factor out bits to ... (test_no_vdso): ... this new procedure.
This commit is contained in:
Pedro Alves
parent
5fbe0d878a
commit
6bb90213cb
4 changed files with 98 additions and 30 deletions
|
|
@ -1,3 +1,11 @@
|
|||
2016-08-22 Pedro Alves <palves@redhat.com>
|
||||
|
||||
PR gdb/20505
|
||||
* linux-tdep.c (linux_vsyscall_range_raw): For core inferiors,
|
||||
find the vDSO's start address with AT_SYSINFO_EHDR too, and
|
||||
determine the vDSO's size by finding the PT_LOAD segment that
|
||||
matches AT_SYSINFO_EHDR.
|
||||
|
||||
2016-08-19 Yao Qi <yao.qi@linaro.org>
|
||||
|
||||
* aarch64-tdep.c (aarch64_analyze_prologue): Handle register
|
||||
|
|
|
|||
|
|
@ -2287,17 +2287,42 @@ linux_vsyscall_range_raw (struct gdbarch *gdbarch, struct mem_range *range)
|
|||
long pid;
|
||||
char *data;
|
||||
|
||||
/* Can't access /proc if debugging a core file. */
|
||||
if (!target_has_execution)
|
||||
if (target_auxv_search (¤t_target, AT_SYSINFO_EHDR, &range->start) <= 0)
|
||||
return 0;
|
||||
|
||||
/* It doesn't make sense to access the host's /proc when debugging a
|
||||
core file. Instead, look for the PT_LOAD segment that matches
|
||||
the vDSO. */
|
||||
if (!target_has_execution)
|
||||
{
|
||||
Elf_Internal_Phdr *phdrs;
|
||||
long phdrs_size;
|
||||
int num_phdrs, i;
|
||||
|
||||
phdrs_size = bfd_get_elf_phdr_upper_bound (core_bfd);
|
||||
if (phdrs_size == -1)
|
||||
return 0;
|
||||
|
||||
phdrs = (Elf_Internal_Phdr *) alloca (phdrs_size);
|
||||
num_phdrs = bfd_get_elf_phdrs (core_bfd, phdrs);
|
||||
if (num_phdrs == -1)
|
||||
return 0;
|
||||
|
||||
for (i = 0; i < num_phdrs; i++)
|
||||
if (phdrs[i].p_type == PT_LOAD
|
||||
&& phdrs[i].p_vaddr == range->start)
|
||||
{
|
||||
range->length = phdrs[i].p_memsz;
|
||||
return 1;
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/* We need to know the real target PID to access /proc. */
|
||||
if (current_inferior ()->fake_pid_p)
|
||||
return 0;
|
||||
|
||||
if (target_auxv_search (¤t_target, AT_SYSINFO_EHDR, &range->start) <= 0)
|
||||
return 0;
|
||||
|
||||
pid = current_inferior ()->pid;
|
||||
|
||||
/* Note that reading /proc/PID/task/PID/maps (1) is much faster than
|
||||
|
|
|
|||
|
|
@ -1,3 +1,10 @@
|
|||
2016-08-22 Pedro Alves <palves@redhat.com>
|
||||
|
||||
PR gdb/20505
|
||||
* gdb.base/vdso-warning.exp: Test core dumps too. Use
|
||||
with_test_prefix. Factor out bits to ...
|
||||
(test_no_vdso): ... this new procedure.
|
||||
|
||||
2016-08-19 Carl Love <cel@us.ibm.com>
|
||||
|
||||
* gdb.arch/altivec-regs.exp: Use standard_testfile instead of
|
||||
|
|
|
|||
|
|
@ -13,42 +13,70 @@
|
|||
# You should have received a copy of the GNU General Public License
|
||||
# along with this program. If not, see <http://www.gnu.org/licenses/>.
|
||||
|
||||
# Test that on Linux, we don't warn about not finding the vDSO. E.g.:
|
||||
#
|
||||
# warning: Could not load shared library symbols for linux-vdso.so.1.
|
||||
|
||||
standard_testfile
|
||||
|
||||
if { [prepare_for_testing "failed to prepare" ${testfile} $srcfile] } {
|
||||
return -1
|
||||
}
|
||||
|
||||
gdb_breakpoint "main"
|
||||
with_test_prefix "setup" {
|
||||
gdb_breakpoint "main"
|
||||
|
||||
# At least some versions of Fedora/RHEL glibc have local patches that
|
||||
# hide the vDSO. This lines re-exposes it. See PR libc/13097,
|
||||
# comment 2. There's no support for passing environment variables in
|
||||
# the remote protocol, but that's OK -- if we're testing against a
|
||||
# glibc that doesn't list the vDSO without this, the test should still
|
||||
# pass.
|
||||
gdb_test_no_output "set environment LD_DEBUG=unused"
|
||||
# At least some versions of Fedora/RHEL glibc have local patches that
|
||||
# hide the vDSO. This lines re-exposes it. See PR libc/13097,
|
||||
# comment 2. There's no support for passing environment variables in
|
||||
# the remote protocol, but that's OK -- if we're testing against a
|
||||
# glibc that doesn't list the vDSO without this, the test should still
|
||||
# pass.
|
||||
gdb_test_no_output "set environment LD_DEBUG=unused"
|
||||
}
|
||||
|
||||
gdb_run_cmd
|
||||
proc test_no_vdso {command} {
|
||||
global srcfile
|
||||
global gdb_prompt
|
||||
|
||||
set test "stop without warning"
|
||||
gdb_test_multiple "" $test {
|
||||
-re "Could not load shared library symbols .*\r\n$gdb_prompt $" {
|
||||
fail $test
|
||||
set message "startup"
|
||||
gdb_test_multiple "$command" $message {
|
||||
-re "Could not load shared library symbols .*\r\n$gdb_prompt $" {
|
||||
fail $message
|
||||
}
|
||||
-re "main \\(\\) at .*$srcfile.*\r\n$gdb_prompt $" {
|
||||
pass $message
|
||||
}
|
||||
}
|
||||
-re "\r\nBreakpoint \[0-9\]+, main .*\r\n$gdb_prompt $" {
|
||||
pass $test
|
||||
|
||||
# Extra testing in case the warning changes and we miss updating
|
||||
# the above.
|
||||
set test "no vdso without symbols is listed"
|
||||
gdb_test_multiple "info shared" $test {
|
||||
-re "No\[^\r\n\]+linux-(vdso|gate).*$gdb_prompt $" {
|
||||
fail $test
|
||||
}
|
||||
-re "$gdb_prompt $" {
|
||||
pass $test
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
# Extra testing in case the warning changes and we miss updating the
|
||||
# above.
|
||||
set test "no vdso without symbols is listed"
|
||||
gdb_test_multiple "info shared" $test {
|
||||
-re "No\[^\r\n\]+linux-(vdso|gate).*$gdb_prompt $" {
|
||||
fail $test
|
||||
}
|
||||
-re "$gdb_prompt $" {
|
||||
pass $test
|
||||
}
|
||||
# First, try a live process.
|
||||
with_test_prefix "run" {
|
||||
gdb_run_cmd
|
||||
test_no_vdso ""
|
||||
}
|
||||
|
||||
# Now, dump a core, and reload it.
|
||||
with_test_prefix "core" {
|
||||
set corefile [standard_output_file $testfile.core]
|
||||
set core_supported [gdb_gcore_cmd "$corefile" "save a corefile"]
|
||||
if {!$core_supported} {
|
||||
return -1
|
||||
}
|
||||
|
||||
clean_restart ${testfile}
|
||||
|
||||
test_no_vdso "core-file $corefile"
|
||||
}
|
||||
|
|
|
|||
Loading…
Reference in a new issue