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| author | Stefan Liebler <stli@linux.vnet.ibm.com> | 2016-04-28 10:26:35 +0200 |
|---|---|---|
| committer | Stefan Liebler <stli@linux.vnet.ibm.com> | 2016-04-28 10:26:35 +0200 |
| commit | edbab2450a084a275d418fba871a8c7b48001a71 (patch) | |
| tree | a309a07424af137f236a05a4dc61c13c3cef780d /ChangeLog | |
| parent | ee35f1cb547e21538b4c6ef0ed7515635552baa6 (diff) | |
| download | glibc-edbab2450a084a275d418fba871a8c7b48001a71.tar.gz | |
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 $(libdl).
* stdlib/tst-makecontext.c (cf): Test if _Unwind_Backtrace
is not called infinitely times.
(backtrace_helper): New function.
(trace_arg): New struct.
(st1): Enlarge stack size.
* sysdeps/unix/sysv/linux/s390/s390-32/__makecontext_ret.S:
(__makecontext_ret): Omit cfi_startproc and cfi_endproc.
* sysdeps/unix/sysv/linux/s390/s390-64/__makecontext_ret.S:
Likewise.
(cherry picked from commit 890b7a4b33d482b5c768ab47d70758b80227e9bc)
Diffstat (limited to 'ChangeLog')
| -rw-r--r-- | ChangeLog | 15 |
1 files changed, 15 insertions, 0 deletions
@@ -1,5 +1,20 @@ 2016-04-28 Stefan Liebler <stli@linux.vnet.ibm.com> + [BZ #18508] + * stdlib/Makefile ($(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. + +2016-04-28 Stefan Liebler <stli@linux.vnet.ibm.com> + [BZ #18080] * sysdeps/unix/sysv/linux/s390/s390-32/setcontext.S (__setcontext): Use SIG_SETMASK instead of SIG_BLOCK. |