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| author | Stefan Liebler <stli@linux.vnet.ibm.com> | 2016-04-28 10:30:09 +0200 |
|---|---|---|
| committer | Stefan Liebler <stli@linux.vnet.ibm.com> | 2016-04-28 10:30:09 +0200 |
| commit | 94dc51ad841ba5a019680f7fd48decf7f23e964e (patch) | |
| tree | 441ea1d4a12c6a2f477ddb8fead8e7c666381467 /NEWS | |
| parent | 50d2d4bb0e473528d425aba608620b5e0dad891e (diff) | |
| download | glibc-94dc51ad841ba5a019680f7fd48decf7f23e964e.zip glibc-94dc51ad841ba5a019680f7fd48decf7f23e964e.tar.gz glibc-94dc51ad841ba5a019680f7fd48decf7f23e964e.tar.bz2 | |
S390: Fix "backtrace() returns infinitely deep stack frames with makecontext()" [BZ #18508].
On s390/s390x backtrace(buffer, size) returns the series of called functions until
"makecontext_ret" and additional entries (up to "size") with "makecontext_ret".
GDB-backtrace is also warning:
"Backtrace stopped: previous frame identical to this frame (corrupt stack?)"
To reproduce this scenario you have to setup a new context with makecontext()
and activate it with setcontext(). See e.g. cf() function in testcase stdlib/tst-makecontext.c.
Or see bug in libgo "Bug 66303 - runtime.Caller() returns infinitely deep stack frames
on s390x " (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66303).
This patch omits the cfi_startproc/cfi_endproc directives in ENTRY/END macro of
__makecontext_ret. Thus no frame information is generated in .eh_frame and backtrace
stops after __makecontext_ret. There is also no .eh_frame info for _start or
thread_start functions.
ChangeLog:
[BZ #18508]
* stdlib/Makefile ($(objpfx)tst-makecontext3):
Depend on $(libdl).
* stdlib/tst-makecontext.c (cf): Test if _Unwind_Backtrace
is not called infinitely times.
(backtrace_helper): New function.
(trace_arg): New struct.
(st1): Enlarge stack size.
* sysdeps/unix/sysv/linux/s390/s390-32/__makecontext_ret.S:
(__makecontext_ret): Omit cfi_startproc and cfi_endproc.
* sysdeps/unix/sysv/linux/s390/s390-64/__makecontext_ret.S:
Likewise.
(cherry picked from commit 890b7a4b33d482b5c768ab47d70758b80227e9bc)
Diffstat (limited to 'NEWS')
| -rw-r--r-- | NEWS | 4 |
1 files changed, 2 insertions, 2 deletions
@@ -9,8 +9,8 @@ Version 2.21.1 * The following bugs are resolved with this release: - 17269, 17905, 17949, 18007, 18032, 18080, 18240, 18287, 18694, 18887, - 18985, 19682. + 17269, 17905, 17949, 18007, 18032, 18080, 18240, 18287, 18508, 18694, + 18887, 18985, 19682. * A stack-based buffer overflow was found in libresolv when invoked from libnss_dns, allowing specially crafted DNS responses to seize control |