| Message ID | 55345AD3.3000403@redhat.com |
|---|---|
| State | New |
| Headers | show |
On 04/19/2015 07:48 PM, Martin Sebor wrote: > The attached patch resolves the failures in a number of address > sanitizer tests on powerpc64*-*-*-* discussed in bug 65479 (the > failures in c-c++-common/asan/swapcontext-test-1.c reported in > pr65643 remain unresolved). > > The patch has been tested on powerpc64*-*-*-* and x86_64 with > no regressions. > > Is this okay for trunk? For 5.1? > > Martin > > gcc-65479.patch > > > diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog > index b4052ef..18eede3 100644 > --- a/gcc/testsuite/ChangeLog > +++ b/gcc/testsuite/ChangeLog > @@ -1,3 +1,12 @@ > +2015-04-19 Martin Sebor<msebor@redhat.com> > + > + PR sanitizer/65479 > + * gcc/testsuite/c-c++-common/asan/misalign-1.c [powerpc*-*-*-*]: > + Use -fno-omit-frame-pointer. Adjust line numbers and expect exact > + matches. > + * gcc/testsuite/c-c++-common/asan/misalign-2.c: Ditto. > + * gcc/testsuite/c-c++-common/asan/null-deref-1.c: Ditto. So the ChangeLog doesn't match the patch. The changelog references "-fno-omit-frame-pointer", but in the patch you actually add "-fasynchronous-unwind-tables". I also wonder if other targets need -fasynchronous-unwind-tables and whether or not we should just add it unconditionally. > diff --git a/libbacktrace/ChangeLog b/libbacktrace/ChangeLog > index e385d8f..9348321 100644 > --- a/libbacktrace/ChangeLog > +++ b/libbacktrace/ChangeLog > @@ -1,3 +1,11 @@ > +2015-04-19 Martin Sebor<msebor@redhat.com> > + > + PR sanitizer/65479 > + * libbacktrace/dwarf.c (struct line): Add idx data member. > + (line_compare): Use struct line idx member. > + (add_line): Set ln->idx. > + (read_line_info): Clear ln->idx. Seems OK. > diff --git a/libsanitizer/ChangeLog b/libsanitizer/ChangeLog > index 6f44dcf..7b82378 100644 > --- a/libsanitizer/ChangeLog > +++ b/libsanitizer/ChangeLog > @@ -1,3 +1,15 @@ > +2015-04-19 Martin Sebor<msebor@redhat.com> > + > + PR sanitizer/65479 > + * libsanitizer/sanitizer_common/sanitizer_stacktrace.h > + (StackTrace::signaled, StackTrace::min_insn_bytes): New data members. > + (StackTrace::StackTrace): Initialize signaled. > + * libsanitizer/sanitizer_common/sanitizer_stacktrace.cc > + (StackTrace::GetPreviousInstructionPc): Rewrite. > + * libsanitizer/sanitizer_common/sanitizer_stacktrace_libcdep.cc > + (StackTrace::Print): Use min_insn_bytes to adjust PC value. > + (BufferedStackTrace::Unwind): Set signaled. Is libsanitizer maintained in LLVM? If so, we want to minimize divergence, so it may be better to get this approved in LLVM then pick it up via a merge. Given this hits 3 distinct pieces of code, do any of them make sense in isolation or do they have to land together as a unit? Jeff
On 04/20/2015 09:23 PM, Jeff Law wrote: > On 04/19/2015 07:48 PM, Martin Sebor wrote: >> The attached patch resolves the failures in a number of address >> sanitizer tests on powerpc64*-*-*-* discussed in bug 65479 (the >> failures in c-c++-common/asan/swapcontext-test-1.c reported in >> pr65643 remain unresolved). >> >> The patch has been tested on powerpc64*-*-*-* and x86_64 with >> no regressions. >> >> Is this okay for trunk? For 5.1? >> >> Martin >> >> gcc-65479.patch >> >> >> diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog >> index b4052ef..18eede3 100644 >> --- a/gcc/testsuite/ChangeLog >> +++ b/gcc/testsuite/ChangeLog >> @@ -1,3 +1,12 @@ >> +2015-04-19 Martin Sebor<msebor@redhat.com> >> + >> + PR sanitizer/65479 >> + * gcc/testsuite/c-c++-common/asan/misalign-1.c [powerpc*-*-*-*]: >> + Use -fno-omit-frame-pointer. Adjust line numbers and expect exact >> + matches. >> + * gcc/testsuite/c-c++-common/asan/misalign-2.c: Ditto. >> + * gcc/testsuite/c-c++-common/asan/null-deref-1.c: Ditto. > So the ChangeLog doesn't match the patch. The changelog references > "-fno-omit-frame-pointer", but in the patch you actually add > "-fasynchronous-unwind-tables". > > I also wonder if other targets need -fasynchronous-unwind-tables and > whether or not we should just add it unconditionally. Perhaps enable unwind tables in GCC spec if -fsanitize=address is present? Sanitizer backtraces typically won't work without unwind tables anyway so IMHO this makes sense. BTW why do we need asynchronous tables? Wouldn't simple -funwind-tables be enough? -Y
On 04/20/2015 12:38 PM, Yury Gribov wrote: > Perhaps enable unwind tables in GCC spec if -fsanitize=address is > present? Sanitizer backtraces typically won't work without unwind tables > anyway so IMHO this makes sense. > > BTW why do we need asynchronous tables? Wouldn't simple -funwind-tables > be enough? I haven't thought much about it. I'd kind of expect with the instrumentation for the sanitizers that it wouldn't make much, if any difference. But I've never been inside the sanitizer instrumentation :) jeff
On Mon, Apr 20, 2015 at 09:38:03PM +0300, Yury Gribov wrote: > >>--- a/gcc/testsuite/ChangeLog > >>+++ b/gcc/testsuite/ChangeLog > >>@@ -1,3 +1,12 @@ > >>+2015-04-19 Martin Sebor<msebor@redhat.com> > >>+ > >>+ PR sanitizer/65479 > >>+ * gcc/testsuite/c-c++-common/asan/misalign-1.c [powerpc*-*-*-*]: > >>+ Use -fno-omit-frame-pointer. Adjust line numbers and expect exact > >>+ matches. > >>+ * gcc/testsuite/c-c++-common/asan/misalign-2.c: Ditto. > >>+ * gcc/testsuite/c-c++-common/asan/null-deref-1.c: Ditto. > >So the ChangeLog doesn't match the patch. The changelog references > >"-fno-omit-frame-pointer", but in the patch you actually add > >"-fasynchronous-unwind-tables". > > > >I also wonder if other targets need -fasynchronous-unwind-tables and > >whether or not we should just add it unconditionally. PowerPC really should use the "fast" unwinding unconditionally, as it always works there reliably due to the ABI requirements. So IMHO we shouldn't change the tests this way. > Perhaps enable unwind tables in GCC spec if -fsanitize=address is present? No. That is orthogonal to that, most targets enable them by default anyway and if somebody for some reason asks for something different, we should honor that. > Sanitizer backtraces typically won't work without unwind tables anyway so > IMHO this makes sense. > > BTW why do we need asynchronous tables? Wouldn't simple -funwind-tables be > enough? -funwind-tables enables them only for functions that can throw, while you really want it for all functions. Jakub
On 04/20/2015 09:43 PM, Jakub Jelinek wrote: > On Mon, Apr 20, 2015 at 09:38:03PM +0300, Yury Gribov wrote: >>>> --- a/gcc/testsuite/ChangeLog >>>> +++ b/gcc/testsuite/ChangeLog >>>> @@ -1,3 +1,12 @@ >>>> +2015-04-19 Martin Sebor<msebor@redhat.com> >>>> + >>>> + PR sanitizer/65479 >>>> + * gcc/testsuite/c-c++-common/asan/misalign-1.c [powerpc*-*-*-*]: >>>> + Use -fno-omit-frame-pointer. Adjust line numbers and expect exact >>>> + matches. >>>> + * gcc/testsuite/c-c++-common/asan/misalign-2.c: Ditto. >>>> + * gcc/testsuite/c-c++-common/asan/null-deref-1.c: Ditto. >>> So the ChangeLog doesn't match the patch. The changelog references >>> "-fno-omit-frame-pointer", but in the patch you actually add >>> "-fasynchronous-unwind-tables". >>> >>> I also wonder if other targets need -fasynchronous-unwind-tables and >>> whether or not we should just add it unconditionally. > > PowerPC really should use the "fast" unwinding unconditionally, as it always > works there reliably due to the ABI requirements. > So IMHO we shouldn't change the tests this way. Agreed, I think Martin just wanted a temp workaround until he gets to fix PowerPC unwinder in LLVM. >> Perhaps enable unwind tables in GCC spec if -fsanitize=address is present? > > No. That is orthogonal to that, most targets enable them by default anyway > and if somebody for some reason asks for something different, we should > honor that. > >> Sanitizer backtraces typically won't work without unwind tables anyway so >> IMHO this makes sense. >> >> BTW why do we need asynchronous tables? Wouldn't simple -funwind-tables be >> enough? > > -funwind-tables enables them only for functions that can throw, while you > really want it for all functions. Right but asynchronous tables also enable them for all instructions which is quite an overkill. -Y
Hi! Note, the changes aren't acceptable for 5.1 at this point (release is tomorrow), and for 5.2 backport they should be tested for a while on the trunk, so there is no rush now. > --- a/libsanitizer/ChangeLog > +++ b/libsanitizer/ChangeLog > @@ -1,3 +1,15 @@ > +2015-04-19 Martin Sebor <msebor@redhat.com> > + > + PR sanitizer/65479 > + * libsanitizer/sanitizer_common/sanitizer_stacktrace.h > + (StackTrace::signaled, StackTrace::min_insn_bytes): New data members. > + (StackTrace::StackTrace): Initialize signaled. > + * libsanitizer/sanitizer_common/sanitizer_stacktrace.cc > + (StackTrace::GetPreviousInstructionPc): Rewrite. > + * libsanitizer/sanitizer_common/sanitizer_stacktrace_libcdep.cc > + (StackTrace::Print): Use min_insn_bytes to adjust PC value. > + (BufferedStackTrace::Unwind): Set signaled. libsanitizer/ should not show up in the ChangeLog entry. But as somebody said earlier, the libsanitizer changes really should go to LLVM compiler-rt repo first and then be just backported, either cherry-picked (probably the case for the 5 branch backport later on) or go in full merge from compiler-rt. > --- a/libsanitizer/sanitizer_common/sanitizer_stacktrace.cc > +++ b/libsanitizer/sanitizer_common/sanitizer_stacktrace.cc > @@ -15,19 +15,33 @@ > > namespace __sanitizer { > > -uptr StackTrace::GetPreviousInstructionPc(uptr pc) { > -#if defined(__arm__) > - // Cancel Thumb bit. > - pc = pc & (~1); > -#endif Your code loses this, which is undesirable. > -#if defined(__powerpc__) || defined(__powerpc64__) > - // PCs are always 4 byte aligned. > - return pc - 4; > -#elif defined(__sparc__) || defined(__mips__) > - return pc - 8; The SPARC/MIPS case is of course needed, because on these architectures the call is followed by a delay slot. But I wonder why you need anything special on any other architecture, why pc - 1 isn't good enough for those. The point isn't to find a PC of the call instruction, on some targets that is very hard and you need to disassemble, but to just find some byte in the call instruction. > +const unsigned StackTrace::min_insn_bytes = > +#if defined __ia64__ > + // Intel Itanium has 5 byte instructions. > + 5 E.g. this is wrong, ia64 doesn't have 5 byte instructions, but has VLIW bundles, where in the 16 byte bundle there are up to 3 41-bit instructions plus template. But, ia64 isn't supported by libsanitizer and I doubt there are enough users that would be interested in writing support for a dead architecture. Jakub
On Tue, 2015-04-21 at 08:22 +0200, Jakub Jelinek wrote: > > -#if defined(__powerpc__) || defined(__powerpc64__) > > - // PCs are always 4 byte aligned. > > - return pc - 4; > > -#elif defined(__sparc__) || defined(__mips__) > > - return pc - 8; > > The SPARC/MIPS case is of course needed, because on these architectures > the call is followed by a delay slot. But I wonder why you need anything > special on any other architecture, why pc - 1 isn't good enough for those. > The point isn't to find a PC of the call instruction, on some targets that > is very hard and you need to disassemble, but to just find some byte in the > call instruction. I wrote the "pc - 4" code for powerpc* and I guess I was just being pedantic on returning the first address of the instruction. If using "pc - 1" works, then I'm fine with that. Peter
>> --- a/libsanitizer/ChangeLog >> +++ b/libsanitizer/ChangeLog >> @@ -1,3 +1,15 @@ >> +2015-04-19 Martin Sebor <msebor@redhat.com> >> + >> + PR sanitizer/65479 >> + * libsanitizer/sanitizer_common/sanitizer_stacktrace.h >> + (StackTrace::signaled, StackTrace::min_insn_bytes): New data members. >> + (StackTrace::StackTrace): Initialize signaled. >> + * libsanitizer/sanitizer_common/sanitizer_stacktrace.cc >> + (StackTrace::GetPreviousInstructionPc): Rewrite. >> + * libsanitizer/sanitizer_common/sanitizer_stacktrace_libcdep.cc >> + (StackTrace::Print): Use min_insn_bytes to adjust PC value. >> + (BufferedStackTrace::Unwind): Set signaled. > > libsanitizer/ should not show up in the ChangeLog entry. > But as somebody said earlier, the libsanitizer changes really should go > to LLVM compiler-rt repo first and then be just backported, either > cherry-picked (probably the case for the 5 branch backport later on) or go in > full merge from compiler-rt. Okay, let me submit the sanitizer changes there. Since the tests will continue to fail without it, the libbacktrace change can go in later if that's preferable. > >> --- a/libsanitizer/sanitizer_common/sanitizer_stacktrace.cc >> +++ b/libsanitizer/sanitizer_common/sanitizer_stacktrace.cc >> @@ -15,19 +15,33 @@ >> >> namespace __sanitizer { >> >> -uptr StackTrace::GetPreviousInstructionPc(uptr pc) { >> -#if defined(__arm__) >> - // Cancel Thumb bit. >> - pc = pc & (~1); >> -#endif > > Your code loses this, which is undesirable. The original function fails to return the pc value on ARM so I just took it out. I didn't look into what the intent was but all the tests pass with the patch on aarch64 (after applying the Fedora gcc 5 patch you mentioned yesterday). > >> -#if defined(__powerpc__) || defined(__powerpc64__) >> - // PCs are always 4 byte aligned. >> - return pc - 4; >> -#elif defined(__sparc__) || defined(__mips__) >> - return pc - 8; > > The SPARC/MIPS case is of course needed, because on these architectures > the call is followed by a delay slot. But I wonder why you need anything > special on any other architecture, why pc - 1 isn't good enough for those. > The point isn't to find a PC of the call instruction, on some targets that > is very hard and you need to disassemble, but to just find some byte in the > call instruction. I forgot about the delay slot. Thanks for the reminder. > >> +const unsigned StackTrace::min_insn_bytes = >> +#if defined __ia64__ >> + // Intel Itanium has 5 byte instructions. >> + 5 > > E.g. this is wrong, ia64 doesn't have 5 byte instructions, but has VLIW > bundles, where in the 16 byte bundle there are up to 3 41-bit instructions > plus template. But, ia64 isn't supported by libsanitizer and I doubt there > are enough users that would be interested in writing support for a dead > architecture. I suppose with the sanitizer output referencing the unmodified PC values on the stack the computation can be simplified to just subtract (and later add) 1 on all targets. Let me change that. Martin
On 04/21/2015 06:39 AM, Peter Bergner wrote: > On Tue, 2015-04-21 at 08:22 +0200, Jakub Jelinek wrote: >>> -#if defined(__powerpc__) || defined(__powerpc64__) >>> - // PCs are always 4 byte aligned. >>> - return pc - 4; >>> -#elif defined(__sparc__) || defined(__mips__) >>> - return pc - 8; >> >> The SPARC/MIPS case is of course needed, because on these architectures >> the call is followed by a delay slot. But I wonder why you need anything >> special on any other architecture, why pc - 1 isn't good enough for those. >> The point isn't to find a PC of the call instruction, on some targets that >> is very hard and you need to disassemble, but to just find some byte in the >> call instruction. > > I wrote the "pc - 4" code for powerpc* and I guess I was just > being pedantic on returning the first address of the instruction. > If using "pc - 1" works, then I'm fine with that. It works fine with the patch and produces sensible output because the decremented address is only used to look up the debug info and restored before it's output. Otherwise (with the unpatched code) we'd end up with odd PC addresses in the stack trace. Martin > > Peter >
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index b4052ef..18eede3 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,12 @@ +2015-04-19 Martin Sebor <msebor@redhat.com> + + PR sanitizer/65479 + * gcc/testsuite/c-c++-common/asan/misalign-1.c [powerpc*-*-*-*]: + Use -fno-omit-frame-pointer. Adjust line numbers and expect exact + matches. + * gcc/testsuite/c-c++-common/asan/misalign-2.c: Ditto. + * gcc/testsuite/c-c++-common/asan/null-deref-1.c: Ditto. + 2015-04-18 Martin Sebor <msebor@redhat.com> * gfortran.dg/pr32627.f03 (strptr): Change size to match the number diff --git a/gcc/testsuite/c-c++-common/asan/misalign-1.c b/gcc/testsuite/c-c++-common/asan/misalign-1.c index f1cca16..833b82a 100644 --- a/gcc/testsuite/c-c++-common/asan/misalign-1.c +++ b/gcc/testsuite/c-c++-common/asan/misalign-1.c @@ -1,5 +1,6 @@ /* { dg-do run { target { ilp32 || lp64 } } } */ /* { dg-options "-O2" } */ +/* { dg-additional-options "-fasynchronous-unwind-tables" { target powerpc*-*-*-* } } */ /* { dg-additional-options "-fno-omit-frame-pointer" { target *-*-darwin* } } */ /* { dg-shouldfail "asan" } */ @@ -39,5 +40,5 @@ main () /* { dg-output "ERROR: AddressSanitizer:\[^\n\r]*on address\[^\n\r]*" } */ /* { dg-output "0x\[0-9a-f\]+ at pc 0x\[0-9a-f\]+ bp 0x\[0-9a-f\]+ sp 0x\[0-9a-f\]+\[^\n\r]*(\n|\r\n|\r)" } */ /* { dg-output "\[^\n\r]*READ of size 4 at 0x\[0-9a-f\]+ thread T0\[^\n\r]*(\n|\r\n|\r)" } */ -/* { dg-output " #0 0x\[0-9a-f\]+ +(in _*foo(\[^\n\r]*misalign-1.c:1\[01]|\[^\n\r]*:0)|\[(\])\[^\n\r]*(\n|\r\n|\r)" } */ -/* { dg-output " #1 0x\[0-9a-f\]+ +(in _*main (\[^\n\r]*misalign-1.c:3\[45]|\[^\n\r]*:0)|\[(\]).*(\n|\r\n|\r)" } */ +/* { dg-output " #0 0x\[0-9a-f\]+ +(in _*foo(\[^\n\r]*misalign-1.c:12|\[^\n\r]*:0)|\[(\])\[^\n\r]*(\n|\r\n|\r)" } */ +/* { dg-output " #1 0x\[0-9a-f\]+ +(in _*main (\[^\n\r]*misalign-1.c:36|\[^\n\r]*:0)|\[(\]).*(\n|\r\n|\r)" } */ diff --git a/gcc/testsuite/c-c++-common/asan/misalign-2.c b/gcc/testsuite/c-c++-common/asan/misalign-2.c index 9f400b4..923d26b 100644 --- a/gcc/testsuite/c-c++-common/asan/misalign-2.c +++ b/gcc/testsuite/c-c++-common/asan/misalign-2.c @@ -1,5 +1,6 @@ /* { dg-do run { target { ilp32 || lp64 } } } */ /* { dg-options "-O2" } */ +/* { dg-additional-options "-fasynchronous-unwind-tables" { target powerpc*-*-*-* } } */ /* { dg-additional-options "-fno-omit-frame-pointer" { target *-*-darwin* } } */ /* { dg-shouldfail "asan" } */ @@ -39,5 +40,5 @@ main () /* { dg-output "ERROR: AddressSanitizer:\[^\n\r]*on address\[^\n\r]*" } */ /* { dg-output "0x\[0-9a-f\]+ at pc 0x\[0-9a-f\]+ bp 0x\[0-9a-f\]+ sp 0x\[0-9a-f\]+\[^\n\r]*(\n|\r\n|\r)" } */ /* { dg-output "\[^\n\r]*READ of size 4 at 0x\[0-9a-f\]+ thread T0\[^\n\r]*(\n|\r\n|\r)" } */ -/* { dg-output " #0 0x\[0-9a-f\]+ +(in _*baz(\[^\n\r]*misalign-2.c:2\[23]|\[^\n\r]*:0)|\[(\])\[^\n\r]*(\n|\r\n|\r)" } */ -/* { dg-output " #1 0x\[0-9a-f\]+ +(in _*main (\[^\n\r]*misalign-2.c:3\[45]|\[^\n\r]*:0)|\[(\]).*(\n|\r\n|\r)" } */ +/* { dg-output " #0 0x\[0-9a-f\]+ +(in _*baz(\[^\n\r]*misalign-2.c:24|\[^\n\r]*:0)|\[(\])\[^\n\r]*(\n|\r\n|\r)" } */ +/* { dg-output " #1 0x\[0-9a-f\]+ +(in _*main (\[^\n\r]*misalign-2.c:36|\[^\n\r]*:0)|\[(\]).*(\n|\r\n|\r)" } */ diff --git a/gcc/testsuite/c-c++-common/asan/null-deref-1.c b/gcc/testsuite/c-c++-common/asan/null-deref-1.c index 45d35ac..b9bc3e5 100644 --- a/gcc/testsuite/c-c++-common/asan/null-deref-1.c +++ b/gcc/testsuite/c-c++-common/asan/null-deref-1.c @@ -1,5 +1,6 @@ /* { dg-do run } */ /* { dg-options "-fno-omit-frame-pointer -fno-shrink-wrap" } */ +/* { dg-additional-options "-fasynchronous-unwind-tables" { target { powerpc*-*-*-*} } } */ /* { dg-additional-options "-mno-omit-leaf-frame-pointer" { target { i?86-*-* x86_64-*-* } } } */ /* { dg-shouldfail "asan" } */ @@ -18,5 +19,5 @@ int main() /* { dg-output "ERROR: AddressSanitizer:? SEGV on unknown address\[^\n\r]*" } */ /* { dg-output "0x\[0-9a-f\]+ \[^\n\r]*pc 0x\[0-9a-f\]+\[^\n\r]*(\n|\r\n|\r)" } */ -/* { dg-output "\[^\n\r]* #0 0x\[0-9a-f\]+ +(in \[^\n\r]*NullDeref\[^\n\r]* (\[^\n\r]*null-deref-1.c:10|\[^\n\r]*:0)|\[(\])\[^\n\r]*(\n|\r\n|\r)" } */ -/* { dg-output " #1 0x\[0-9a-f\]+ +(in _*main (\[^\n\r]*null-deref-1.c:15|\[^\n\r]*:0)|\[(\])\[^\n\r]*(\n|\r\n|\r)" } */ +/* { dg-output "\[^\n\r]* #0 0x\[0-9a-f\]+ +(in \[^\n\r]*NullDeref\[^\n\r]* (\[^\n\r]*null-deref-1.c:11|\[^\n\r]*:0)|\[(\])\[^\n\r]*(\n|\r\n|\r)" } */ +/* { dg-output " #1 0x\[0-9a-f\]+ +(in _*main (\[^\n\r]*null-deref-1.c:16|\[^\n\r]*:0)|\[(\])\[^\n\r]*(\n|\r\n|\r)" } */ diff --git a/libbacktrace/ChangeLog b/libbacktrace/ChangeLog index e385d8f..9348321 100644 --- a/libbacktrace/ChangeLog +++ b/libbacktrace/ChangeLog @@ -1,3 +1,11 @@ +2015-04-19 Martin Sebor <msebor@redhat.com> + + PR sanitizer/65479 + * libbacktrace/dwarf.c (struct line): Add idx data member. + (line_compare): Use struct line idx member. + (add_line): Set ln->idx. + (read_line_info): Clear ln->idx. + 2015-01-24 Matthias Klose <doko@ubuntu.com> * configure.ac: Move AM_ENABLE_MULTILIB before AC_PROG_CC. diff --git a/libbacktrace/dwarf.c b/libbacktrace/dwarf.c index 919b568..e32c468 100644 --- a/libbacktrace/dwarf.c +++ b/libbacktrace/dwarf.c @@ -211,6 +211,10 @@ struct line const char *filename; /* Line number. */ int lineno; + /* Index of the object in the original array read from the DWARF + section, before it has been sorted. The index makes it possible + to use Quicksort and maintain stability. */ + int idx; }; /* A growable vector of line number information. This is used while @@ -940,9 +944,10 @@ unit_addrs_search (const void *vkey, const void *ventry) return 0; } -/* Sort the line vector by PC. We want a stable sort here. We know - that the pointers are into the same array, so it is safe to compare - them directly. */ +/* Sort the line vector by PC. We want a stable sort here to maintain + the order of lines for the same PC values. Since the sequence is + being sorted in place, their addresses cannot be relied on to + maintain stability. That is the purpose of the index member. */ static int line_compare (const void *v1, const void *v2) @@ -954,9 +959,9 @@ line_compare (const void *v1, const void *v2) return -1; else if (ln1->pc > ln2->pc) return 1; - else if (ln1 < ln2) + else if (ln1->idx < ln2->idx) return -1; - else if (ln1 > ln2) + else if (ln1->idx > ln2->idx) return 1; else return 0; @@ -1551,6 +1556,7 @@ add_line (struct backtrace_state *state, struct dwarf_data *ddata, ln->filename = filename; ln->lineno = lineno; + ln->idx = vec->count; ++vec->count; @@ -2011,6 +2017,7 @@ read_line_info (struct backtrace_state *state, struct dwarf_data *ddata, ln->pc = (uintptr_t) -1; ln->filename = NULL; ln->lineno = 0; + ln->idx = 0; if (!backtrace_vector_release (state, &vec.vec, error_callback, data)) goto fail; diff --git a/libsanitizer/ChangeLog b/libsanitizer/ChangeLog index 6f44dcf..7b82378 100644 --- a/libsanitizer/ChangeLog +++ b/libsanitizer/ChangeLog @@ -1,3 +1,15 @@ +2015-04-19 Martin Sebor <msebor@redhat.com> + + PR sanitizer/65479 + * libsanitizer/sanitizer_common/sanitizer_stacktrace.h + (StackTrace::signaled, StackTrace::min_insn_bytes): New data members. + (StackTrace::StackTrace): Initialize signaled. + * libsanitizer/sanitizer_common/sanitizer_stacktrace.cc + (StackTrace::GetPreviousInstructionPc): Rewrite. + * libsanitizer/sanitizer_common/sanitizer_stacktrace_libcdep.cc + (StackTrace::Print): Use min_insn_bytes to adjust PC value. + (BufferedStackTrace::Unwind): Set signaled. + 2015-04-13 Yury Gribov <y.gribov@samsung.com> PR sanitizer/64839 diff --git a/libsanitizer/sanitizer_common/sanitizer_stacktrace.cc b/libsanitizer/sanitizer_common/sanitizer_stacktrace.cc index 9b99b5b..9b61b85 100644 --- a/libsanitizer/sanitizer_common/sanitizer_stacktrace.cc +++ b/libsanitizer/sanitizer_common/sanitizer_stacktrace.cc @@ -15,19 +15,33 @@ namespace __sanitizer { -uptr StackTrace::GetPreviousInstructionPc(uptr pc) { -#if defined(__arm__) - // Cancel Thumb bit. - pc = pc & (~1); -#endif -#if defined(__powerpc__) || defined(__powerpc64__) - // PCs are always 4 byte aligned. - return pc - 4; -#elif defined(__sparc__) || defined(__mips__) - return pc - 8; +const unsigned StackTrace::min_insn_bytes = +#if defined __ia64__ + // Intel Itanium has 5 byte instructions. + 5 +#elif defined AVR + 2 +#elif defined __i386__ || defined __x86_64__ || defined mc68000 + // Intel x86 and Motorola 68000 have variable instruction sets. + 1 +#elif defined __s390__ || defined __sh__ + // System 390 has 2 or 4 byte instructions. + // Hitachi SuperH is a 32-bit CPU with 16-bit instructions. + 2 #else - return pc - 1; + // Most instruction sets define instructions whose size in bytes + // matches that of the int type. I.e., 32-bit and 64-bit RISC + // CPUs typically have 32-bit instructions, while 16-bit RISC CPUs + // have 16 bit instructions. + sizeof (int) #endif + ; + +uptr StackTrace::GetPreviousInstructionPc(uptr pc) { + // Return a value that represents the address of either the first + // byte or some byte past the first byte of the instruction before + // the argument. + return pc - min_insn_bytes; } uptr StackTrace::GetCurrentPc() { diff --git a/libsanitizer/sanitizer_common/sanitizer_stacktrace.h b/libsanitizer/sanitizer_common/sanitizer_stacktrace.h index 31495cf..a01f676 100644 --- a/libsanitizer/sanitizer_common/sanitizer_stacktrace.h +++ b/libsanitizer/sanitizer_common/sanitizer_stacktrace.h @@ -39,9 +39,18 @@ static const uptr kStackTraceMax = 256; struct StackTrace { const uptr *trace; uptr size; - - StackTrace() : trace(nullptr), size(0) {} - StackTrace(const uptr *trace, uptr size) : trace(trace), size(size) {} + // Greater than zero of the stack trace was generated in response + // to a signal, -1 otherwise. + int signaled; + + // Minimum instruction size in bytes. Typically 4 on RISC processors + // and 1 on CISC. Used to advance the PC to the previous instruction + // in a stack trace and back. + static const unsigned min_insn_bytes; + + StackTrace() : trace(nullptr), size(0), signaled(-1) {} + StackTrace(const uptr *trace, uptr size, int signaled = -1) + : trace(trace), size(size), signaled(signaled) {} // Prints a symbolized stacktrace, followed by an empty line. void Print() const; diff --git a/libsanitizer/sanitizer_common/sanitizer_stacktrace_libcdep.cc b/libsanitizer/sanitizer_common/sanitizer_stacktrace_libcdep.cc index 2d55b73..7282d4b 100644 --- a/libsanitizer/sanitizer_common/sanitizer_stacktrace_libcdep.cc +++ b/libsanitizer/sanitizer_common/sanitizer_stacktrace_libcdep.cc @@ -29,9 +29,16 @@ void StackTrace::Print() const { InternalScopedString frame_desc(GetPageSizeCached() * 2); uptr frame_num = 0; for (uptr i = 0; i < size && trace[i]; i++) { - // PCs in stack traces are actually the return addresses, that is, - // addresses of the next instructions after the call. - uptr pc = GetPreviousInstructionPc(trace[i]); + // Except when the stack trace was generated in response to a signal + // and the frame is #0, decrementing the PC in the stack trace by + // the size of the smallest instruction helps find the expected + // corresponding line number in the debug info. This is because + // with the exception of frame #0 the PC saved on the stack is + // the return address, that is, the address of the next instructions + // after a branch and link or call instruction. + const uptr pc = (0 == i) && signaled ? + trace[i] : trace[i] - StackTrace::min_insn_bytes; + uptr addr_frames_num = Symbolizer::GetOrInit()->SymbolizePC( pc, addr_frames.data(), kMaxAddrFrames); if (addr_frames_num == 0) { @@ -40,6 +47,10 @@ void StackTrace::Print() const { } for (uptr j = 0; j < addr_frames_num; j++) { AddressInfo &info = addr_frames[j]; + if (i || !signaled) { + // Restore the PC to match the stack trace (see also PR65749). + info.address += StackTrace::min_insn_bytes; + } frame_desc.clear(); RenderFrame(&frame_desc, common_flags()->stack_trace_format, frame_num++, info, common_flags()->strip_path_prefix); @@ -54,6 +65,9 @@ void StackTrace::Print() const { void BufferedStackTrace::Unwind(uptr max_depth, uptr pc, uptr bp, void *context, uptr stack_top, uptr stack_bottom, bool request_fast_unwind) { + // Record that the stack trace was generated as a result of a signal. + signaled = 0 != context; + top_frame_bp = (max_depth > 0) ? bp : 0; // Avoid doing any work for small max_depth. if (max_depth == 0) {