Bug 1080656
| Summary: | [RHEL6] Can't access TLS variables in statically linked binaries | ||||||
|---|---|---|---|---|---|---|---|
| Product: | Red Hat Enterprise Linux 6 | Reporter: | Ben Woodard <woodard> | ||||
| Component: | gdb | Assignee: | Sergio Durigan Junior <sergiodj> | ||||
| Status: | CLOSED ERRATA | QA Contact: | qe-baseos-tools-bugs | ||||
| Severity: | medium | Docs Contact: | |||||
| Priority: | unspecified | ||||||
| Version: | 6.6 | CC: | jan.kratochvil, mcermak, mfranc, patrickm, tgummels | ||||
| Target Milestone: | rc | ||||||
| Target Release: | --- | ||||||
| Hardware: | x86_64 | ||||||
| OS: | Linux | ||||||
| Whiteboard: | |||||||
| Fixed In Version: | gdb-7.2-72.el6 | Doc Type: | Bug Fix | ||||
| Doc Text: |
Cause: GDB could not correctly access TLS (Thread Local Storage) data on statically linked binaries.
Consequence: The user was not able to inspect TLS data on the program being debugged, if this program was linked statically.
Fix: GDB now correctly accesses TLS data on statically linked binaries.
Result: The user can now inspect the TLS data on a statically linked binary.
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Story Points: | --- | ||||
| Clone Of: | |||||||
| : | 1080657 1080660 (view as bug list) | Environment: | |||||
| Last Closed: | 2014-10-14 07:28:13 UTC | Type: | Bug | ||||
| Regression: | --- | Mount Type: | --- | ||||
| Documentation: | --- | CRM: | |||||
| Verified Versions: | Category: | --- | |||||
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |||||
| Cloudforms Team: | --- | Target Upstream Version: | |||||
| Embargoed: | |||||||
| Bug Depends On: | |||||||
| Bug Blocks: | 1005265 | ||||||
| Attachments: |
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Created attachment 878704 [details]
reproducer
The way that we arrived at this problem was trying to diagnose a suspected problem with libthread_db's calculation of the address to TLS for OpenMP C/C++ threadprivate variables in statically linked binaries. Therefore, once GDB is able to properly load libthread_db there may be another problem with libthread_db's ability to return a correct address. glibc-RFC patch for GDB: TLS variables access for -static -lpthread executables https://sourceware.org/ml/libc-help/2014-03/msg00024.html [patch] Fix gdbserver qGetTLSAddr for x86_64 -m32 https://sourceware.org/ml/gdb-patches/2014-04/msg00154.html Message-ID: <20140410114901.GA16411.net> [patch] Fix TLS access for -static -pthread https://sourceware.org/ml/gdb-patches/2014-04/msg00155.html Message-ID: <20140410115204.GB16411.net> commit 9e0aa64f5510861b2517c5841b59adde8e423540
Author: Jan Kratochvil <jan.kratochvil>
Fix gdbserver qGetTLSAddr for x86_64 -m32
commit 5876f5032f60c45c4bd19e7ea7d0c14d0346b93e
Author: Jan Kratochvil <jan.kratochvil>
Fix TLS access for -static -pthread
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. http://rhn.redhat.com/errata/RHBA-2014-1534.html |
Description of problem: When you have a statically linked binary you can't access the tls data through gdb Version-Release number of selected component (if applicable): All. This problem exists in 6.4, 6.5, rhel7, F20 and even the upstream trunk version GDB How reproducible: always everywhere Steps to Reproduce: sierra648{jdelsign}82: gcc -g -o tls tls.c -pthread -static /usr/lib/gcc/x86_64-redhat-linux/4.4.7/../../../../lib64/libpthread.a(libpthread.o): In function `sem_open': (.text+0x764d): warning: the use of `mktemp' is dangerous, better use `mkstemp' sierra648{jdelsign}83: gdb tls GNU gdb (GDB) Red Hat Enterprise Linux (7.2-60.el6_4.1) ... Reading symbols from /g/g0/jdelsign/tls...done. (gdb) b 12 Breakpoint 1 at 0x400511: file tls.c, line 12. (gdb) run Starting program: /g/g0/jdelsign/tls [Thread debugging using libthread_db enabled] [New Thread 0x2aaaaacac700 (LWP 6735)] thread_local_p: & == 00002aaaaacac6c0, . == 00002aaaaacabd1c, * == 1 [Switching to Thread 0x2aaaaacac700 (LWP 6735)] Breakpoint 1, start_routine (arg=0x1) at tls.c:12 12 return arg; Actual results: (gdb) p thread_local_p Cannot find executable file `/g/g0/jdelsign/tls' in dynamic linker's load module list Expected results: It print's the variable Additional info: