Files
binutils-gdb/gdb/testsuite/gdb.base/vdso-warning.exp
Pedro Alves 6bb90213cb 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.
2016-08-22 20:05:09 +01:00

83 lines
2.4 KiB
Plaintext

# Copyright 2012-2016 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 3 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, 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} $srcfile] } {
return -1
}
with_test_prefix "setup" {
gdb_breakpoint "main"
# At least some versions of Fedora/RHEL glibc have local patches that
# hide the vDSO. This lines re-exposes it. See PR libc/13097,
# comment 2. There's no support for passing environment variables in
# the remote protocol, but that's OK -- if we're testing against a
# glibc that doesn't list the vDSO without this, the test should still
# pass.
gdb_test_no_output "set environment LD_DEBUG=unused"
}
proc test_no_vdso {command} {
global srcfile
global gdb_prompt
set message "startup"
gdb_test_multiple "$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
}
}
# 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"
}