Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752108AbaL3IqG (ORCPT ); Tue, 30 Dec 2014 03:46:06 -0500 Received: from lgeamrelo02.lge.com ([156.147.1.126]:51565 "EHLO lgeamrelo02.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752080AbaL3IqE (ORCPT ); Tue, 30 Dec 2014 03:46:04 -0500 X-Original-SENDERIP: 10.177.222.235 X-Original-MAILFROM: namhyung@kernel.org Date: Tue, 30 Dec 2014 17:47:08 +0900 From: Namhyung Kim To: David Ahern Cc: Masami Hiramatsu , Arnaldo Carvalho de Melo , LKML , Mark Wielaard Subject: Re: perf-probe crash in dwarf_getcfi_elf Message-ID: <20141230084708.GG6081@sejong> References: <54A22C76.9000403@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <54A22C76.9000403@gmail.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 29, 2014 at 09:39:18PM -0700, David Ahern wrote: > Hi Namhyung: > > Using perf-probe from top of Linus' tree I get a segfault on both Fedora 16 > and 18 (does not crash on Fedora 20). Command used is: > > perf probe -x /lib64/libc-2.14.90.so -a 'malloc size=%di' > > git bisect points to: > > commit 03d89412981a7681971bc77edba1669595763030 > Author: Namhyung Kim > Date: Mon Apr 7 16:05:48 2014 +0900 > > perf probe: Use dwarf_getcfi_elf() instead of dwarf_getcfi() > It seems to be related to below commit in elfutils. We might need to check .eh_frame section has SHT_PROGBITS. Will send a patch soon. Thanks, Namhyung commit 5704c8c4fa717b6e9c2d2e4304dfbc810ad42e4b Author: Mark Wielaard Date: Tue Jul 2 11:22:35 2013 +0200 getcfi_scn_eh_frame: Don't crash and burn when .eh_frame bits aren't there. Trying to read non-existing bits sometimes works and normally a sanity check will fail. But it could also lead to an unexpected crash much later when trying to use the non-existing data. Signed-off-by: Mark Wielaard diff --git a/libdw/ChangeLog b/libdw/ChangeLog index 700c166..22f8b0c 100644 --- a/libdw/ChangeLog +++ b/libdw/ChangeLog @@ -1,3 +1,7 @@ +2013-07-02 Mark Wielaard + + * dwarf_getcfi_elf.c (getcfi_shdr): Check sh_type == SHT_PROGBITS. + 2013-06-26 Mark Wielaard * libdw_visit_scopes.c (__libdw_visit_scopes): Don't reject root diff --git a/libdw/dwarf_getcfi_elf.c b/libdw/dwarf_getcfi_elf.c index ba00e05..a423ef3 100644 --- a/libdw/dwarf_getcfi_elf.c +++ b/libdw/dwarf_getcfi_elf.c @@ -280,8 +280,13 @@ getcfi_shdr (Elf *elf, const GElf_Ehdr *ehdr) hdr_vaddr = shdr->sh_addr; } else if (!strcmp (name, ".eh_frame")) - return getcfi_scn_eh_frame (elf, ehdr, scn, shdr, - hdr_scn, hdr_vaddr); + { + if (shdr->sh_type == SHT_PROGBITS) + return getcfi_scn_eh_frame (elf, ehdr, scn, shdr, + hdr_scn, hdr_vaddr); + else + return NULL; + } } } > Backtrace at time of crash is: > > (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=, 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=, tevs=0x880f88, > max_tevs=) 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=, 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=, > argv=0x7fffffffe2f0, prefix=Unhandled dwarf expression opcode 0xfa > ) > at builtin-probe.c:488 > #10 0x0000000000440313 in cmd_probe (argc=5, argv=0x7fffffffe2f0, > prefix=) 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=, > argc=) at perf.c:400 > #13 run_argv (argv=, argcp=) at perf.c:444 > #14 main (argc=5, argv=0x7fffffffe2f0) at perf.c:559 > > David > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/