Bug 1172766
| Summary: | ppc64: segv in libbfd | ||||||
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| Product: | Red Hat Enterprise Linux 7 | Reporter: | Martin Cermak <mcermak> | ||||
| Component: | binutils | Assignee: | Jeff Law <law> | ||||
| Status: | CLOSED ERRATA | QA Contact: | Miloš Prchlík <mprchlik> | ||||
| Severity: | medium | Docs Contact: | |||||
| Priority: | medium | ||||||
| Version: | 7.1 | CC: | mnewsome, mprchlik, msebor, nickc, ohudlick | ||||
| Target Milestone: | rc | ||||||
| Target Release: | --- | ||||||
| Hardware: | ppc64 | ||||||
| OS: | Linux | ||||||
| Whiteboard: | |||||||
| Fixed In Version: | binutils-2.23.52.0.1-41.el7 | Doc Type: | Bug Fix | ||||
| Doc Text: |
Objdump on PowerPC no longer fails when accessing the symbol table
Previously, objdump on 64-bit PowerPC incorrectly deallocated an important variable that held the symbol table for the binary being debugged, which caused a segmentation fault when objdump tried to access that symbol table. To solve this issue, this specific variable has been made persistent, and objdump can now access the needed information later during the debugging session, without reading an invalid memory region.
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Story Points: | --- | ||||
| Clone Of: | |||||||
| : | 1190506 (view as bug list) | Environment: | |||||
| Last Closed: | 2015-11-19 03:34:58 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: | 1110700, 1191021, 1205796 | ||||||
| Attachments: |
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Description
Martin Cermak
2014-12-10 17:13:09 UTC
Similarly using gdb: 7.1 S ppc64 # rpm -q gdb gdb-7.6.1-64.el7.ppc64 7.1 S ppc64 # gdb -q /lib/modules/3.10.0-215.el7.ppc64/kernel/fs/nfsd/nfsd.ko Reading symbols from /usr/lib/modules/3.10.0-215.el7.ppc64/kernel/fs/nfsd/nfsd.ko...Reading symbols from /usr/lib/debug/lib/modules/3.10.0-215.el7.ppc64/kernel/fs/nfsd/nfsd.ko.debug...Segmentation fault 7.1 S ppc64 # 7.1 S ppc64 # gdb -q --args gdb -q /lib/modules/3.10.0-215.el7.ppc64/kernel/fs/nfsd/nfsd.ko Reading symbols from /usr/bin/gdb...Reading symbols from /usr/lib/debug/usr/bin/gdb.debug...done. done. (gdb) r Starting program: /usr/bin/gdb -q /lib/modules/3.10.0-215.el7.ppc64/kernel/fs/nfsd/nfsd.ko [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib64/power8/libthread_db.so.1". Detaching after fork from child process 40699. Reading symbols from /usr/lib/modules/3.10.0-215.el7.ppc64/kernel/fs/nfsd/nfsd.ko...Reading symbols from /usr/lib/debug/lib/modules/3.10.0-215.el7.ppc64/kernel/fs/nfsd/nfsd.ko.debug... Program received signal SIGSEGV, Segmentation fault. 0x0000000010393bf0 in ppc64_elf_get_synthetic_symtab (abfd=<optimized out>, static_count=<optimized out>, static_syms=<optimized out>, dyn_count=<optimized out>, dyn_syms=<optimized out>, ret=0x3fffffffdd40) at ../../bfd/elf64-ppc.c:3138 3138 if (!sym_exists_at (syms, opdsymend, symcount, Missing separate debuginfos, use: debuginfo-install pcre-8.32-14.el7.ppc64 (gdb) (gdb) bt #0 0x0000000010393bf0 in ppc64_elf_get_synthetic_symtab (abfd=<optimized out>, static_count=<optimized out>, static_syms=<optimized out>, dyn_count=<optimized out>, dyn_syms=<optimized out>, ret=0x3fffffffdd40) at ../../bfd/elf64-ppc.c:3138 #1 0x000000001014803c in elf_symfile_read (objfile=0x10999260, symfile_flags=<optimized out>) at ../../gdb/elfread.c:2369 #2 0x00000000101e3698 in read_symbols (objfile=<optimized out>, objfile@entry=0x10999260, add_flags=<optimized out>, add_flags@entry=6) at ../../gdb/symfile.c:827 #3 0x00000000101e2678 in syms_from_objfile_1 (objfile=objfile@entry=0x10999260, addrs=addrs@entry=0x10955ac0, offsets=offsets@entry=0x0, num_offsets=num_offsets@entry=0, add_flags=add_flags@entry=6) at ../../gdb/symfile.c:1027 #4 0x00000000101e2cac in syms_from_objfile (add_flags=6, num_offsets=0, offsets=0x0, addrs=0x10955ac0, objfile=0x10999260) at ../../gdb/symfile.c:1045 #5 symbol_file_add_with_addrs_or_offsets (abfd=abfd@entry=0x10938750, add_flags=<optimized out>, addrs=addrs@entry=0x10955ac0, flags=<optimized out>, parent=parent@entry=0x1093a800, num_offsets=0, offsets=0x0) at ../../gdb/symfile.c:1144 #6 0x00000000101e360c in symbol_file_add_separate (bfd=0x10938750, symfile_flags=<optimized out>, objfile=0x1093a800) at ../../gdb/symfile.c:1214 #7 0x00000000101482d0 in elf_symfile_read (objfile=0x1093a800, symfile_flags=<optimized out>) at ../../gdb/elfread.c:2490 #8 0x00000000101e3698 in read_symbols (objfile=<optimized out>, objfile@entry=0x1093a800, add_flags=<optimized out>, add_flags@entry=6) at ../../gdb/symfile.c:827 #9 0x00000000101e2678 in syms_from_objfile_1 (objfile=objfile@entry=0x1093a800, addrs=0x108a4740, addrs@entry=0x0, offsets=offsets@entry=0x0, num_offsets=num_offsets@entry=0, add_flags=add_flags@entry=6) at ../../gdb/symfile.c:1027 #10 0x00000000101e2cac in syms_from_objfile (add_flags=6, num_offsets=0, offsets=0x0, addrs=0x0, objfile=0x1093a800) at ../../gdb/symfile.c:1045 #11 symbol_file_add_with_addrs_or_offsets (abfd=abfd@entry=0x1089a9b0, add_flags=<optimized out>, addrs=0x0, flags=<optimized out>, parent=parent@entry=0x0, num_offsets=0, offsets=0x0) at ../../gdb/symfile.c:1144 #12 0x00000000101e2ebc in symbol_file_add_from_bfd (parent=0x0, flags=<optimized out>, addrs=<optimized out>, add_flags=<optimized out>, abfd=0x1089a9b0) at ../../gdb/symfile.c:1234 #13 symbol_file_add (name=name@entry=0x3ffffffff1d8 "/lib/modules/3.10.0-215.el7.ppc64/kernel/fs/nfsd/nfsd.ko", add_flags=<optimized out>, addrs=addrs@entry=0x0, flags=flags@entry=0) at ../../gdb/symfile.c:1250 #14 0x00000000101e2f5c in symbol_file_add_main_1 (args=0x3ffffffff1d8 "/lib/modules/3.10.0-215.el7.ppc64/kernel/fs/nfsd/nfsd.ko", from_tty=<optimized out>, flags=<optimized out>) at ../../gdb/symfile.c:1276 #15 0x00000000102127b4 in catch_command_errors (command=@0x10637480: 0x101e2fc0 <symbol_file_add_main>, arg=0x3ffffffff1d8 "/lib/modules/3.10.0-215.el7.ppc64/kernel/fs/nfsd/nfsd.ko", from_tty=<optimized out>, mask=<optimized out>) at ../../gdb/exceptions.c:573 #16 0x00000000102165a8 in captured_main (data=<optimized out>) at ../../gdb/main.c:1013 #17 0x0000000010212660 in catch_errors (func=@0x10639420: 0x102153a0 <captured_main>, func_args=0x3fffffffe978, errstring=0x10452028 "", mask=<optimized out>) at ../../gdb/exceptions.c:546 #18 0x0000000010216c84 in gdb_main (args=<optimized out>) at ../../gdb/main.c:1144 #19 0x0000000010056c64 in main (argc=<error reading variable: value has been optimized out>, argv=<optimized out>) at ../../gdb/gdb.c:34 (gdb) Created attachment 989450 [details] Proposed patch. The attached patch fixes the SIGSEGV in libbfd in RHEL 7.1 binutils by backporting upstream commit b53dfeb26: PowerPC64 ELFv1 function symbol definition vs LTO and discarded sections on top of the enabled ppc64le patches (bug #1183838) and also adjusting the changes made in that commit to avoid failures in the ifunc.exp test that it otherwise triggers. The patch is for binutils only (namely the private-rh1183838-rhel-7.1 branch) and doesn't contain a fix the GDB problem mentioned in the report. Verified for build binutils-2.23.52.0.1-54.el7. 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. https://rhn.redhat.com/errata/RHSA-2015-2079.html |