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| author | Paul Eggert <eggert@cs.ucla.edu> | 2021-03-09 11:22:59 -0800 |
|---|---|---|
| committer | Stefan Kangas <stefan@marxist.se> | 2022-07-15 13:37:40 +0200 |
| commit | 647a9353a35bb6f97a8494f1765400f8a34081ea (patch) | |
| tree | f869e16440cf0bc67d491d2a416c4d669670ce58 | |
| parent | d7f4cc0974645cc6a295740afe85c6e21d956119 (diff) | |
| download | emacs-647a9353a35bb6f97a8494f1765400f8a34081ea.tar.gz | |
Port alternate signal stack to upcoming glibc 2.34emacs-27
* src/sysdep.c (sigsegv_stack): Increase size to 64 KiB and align
it to max_align_t. This copies from Gnulib’s c-stack.c, and works
around a portability bug in draft glibc 2.34, which no longer
defines SIGSTKSZ when _GNU_SOURCE is defined.
(cherry picked from commit f97e07ea807cc6d38774a3888a15091b20645ac6)
| -rw-r--r-- | src/sysdep.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/src/sysdep.c b/src/sysdep.c index d100a5cb50b..f0b97767ba4 100644 --- a/src/sysdep.c +++ b/src/sysdep.c @@ -1818,7 +1818,15 @@ handle_arith_signal (int sig) /* Alternate stack used by SIGSEGV handler below. */ -static unsigned char sigsegv_stack[SIGSTKSZ]; +/* Storage for the alternate signal stack. + 64 KiB is not too large for Emacs, and is large enough + for all known platforms. Smaller sizes may run into trouble. + For example, libsigsegv 2.6 through 2.8 have a bug where some + architectures use more than the Linux default of an 8 KiB alternate + stack when deciding if a fault was caused by stack overflow. */ +static max_align_t sigsegv_stack[(64 * 1024 + + sizeof (max_align_t) - 1) + / sizeof (max_align_t)]; /* Return true if SIGINFO indicates a stack overflow. */ |