Messages in this thread | | | Date | Tue, 30 Dec 2014 10:13:40 -0700 | From | David Ahern <> | Subject | Re: perf-probe crash in dwarf_getcfi_elf |
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On 12/30/14 2:05 AM, Namhyung Kim wrote: > From f56964e74d60a9921214d0e2e5c3d082f5a910c1 Mon Sep 17 00:00:00 2001 > From: Namhyung Kim <namhyung@kernel.org> > Date: Tue, 30 Dec 2014 17:47:47 +0900 > Subject: [PATCH] perf probe: Fix a segfault on old libdw > > David reported that perf can segfault when adding an uprobe event like > this: > > $ perf probe -x /lib64/libc-2.14.90.so -a 'malloc size=%di' > > (gdb) bt > #0 parse_eh_frame_hdr (hdr=0x0, hdr_size=2596, hdr_vaddr=71788, > ehdr=0x7fffffffd390, eh_frame_vaddr= > 0x7fffffffd378, table_entries=0x8808d8, table_encoding=0x8808e0 "") at > dwarf_getcfi_elf.c:79 > #1 0x000000385f81615a in getcfi_scn_eh_frame (hdr_vaddr=71788, > hdr_scn=0x8839b0, shdr=0x7fffffffd2f0, scn=<optimized out>, > ehdr=0x7fffffffd390, elf=0x882b30) at dwarf_getcfi_elf.c:231 > #2 getcfi_shdr (ehdr=0x7fffffffd390, elf=0x882b30) at dwarf_getcfi_elf.c:283 > #3 dwarf_getcfi_elf (elf=0x882b30) at dwarf_getcfi_elf.c:309 > #4 0x00000000004d5bac in debuginfo__find_probes (pf=0x7fffffffd4f0, > dbg=Unhandled dwarf expression opcode 0xfa) at util/probe-finder.c:993 > #5 0x00000000004d634a in debuginfo__find_trace_events (dbg=0x880840, > pev=<optimized out>, tevs=0x880f88, max_tevs=<optimized out>) at > util/probe-finder.c:1200 > #6 0x00000000004aed6b in try_to_find_probe_trace_events (target=0x881b20 > "/lib64/libpthread-2.14.90.so", > max_tevs=128, tevs=0x880f88, pev=0x859b30) at util/probe-event.c:482 > #7 convert_to_probe_trace_events (target=0x881b20 > "/lib64/libpthread-2.14.90.so", max_tevs=128, tevs=0x880f88, > pev=0x859b30) at util/probe-event.c:2356 > #8 add_perf_probe_events (pevs=<optimized out>, npevs=1, max_tevs=128, > target=0x881b20 "/lib64/libpthread-2.14.90.so", force_add=false) at > util/probe-event.c:2391 > #9 0x000000000044014f in __cmd_probe (argc=<optimized out>, > argv=0x7fffffffe2f0, prefix=Unhandled dwarf expression opcode 0xfa) at > at builtin-probe.c:488 > #10 0x0000000000440313 in cmd_probe (argc=5, argv=0x7fffffffe2f0, > prefix=<optimized out>) at builtin-probe.c:506 > #11 0x000000000041d133 in run_builtin (p=0x805680, argc=5, > argv=0x7fffffffe2f0) at perf.c:341 > #12 0x000000000041c8b2 in handle_internal_command (argv=<optimized out>, > argc=<optimized out>) at perf.c:400 > #13 run_argv (argv=<optimized out>, argcp=<optimized out>) at perf.c:444 > #14 main (argc=5, argv=0x7fffffffe2f0) at perf.c:559 > > And I found a related commit (5704c8c4fa71 "getcfi_scn_eh_frame: Don't > crash and burn when .eh_frame bits aren't there.") in elfutils that > can lead to a unexpected crash like this. To safely use the function, > it needs to check the .eh_frame section is a PROGBITS type. > > Reported-by: David Ahern <dsahern@gmail.com> > Cc: Mark Wielaard <mjw@redhat.com> > Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Solves the crash for me.
Tested-by: David Ahern <dsahern@gmail.com>
Thanks for the quick response, Namhyung.
David
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