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| author | Eric Blake <ebb9@byu.net> | 2008-09-23 08:56:10 -0600 |
|---|---|---|
| committer | Eric Blake <ebb9@byu.net> | 2008-09-23 08:56:10 -0600 |
| commit | 91a109c0426e8b8cd8b317e29c8a91bd99757f0a (patch) | |
| tree | f44402b438aba9a554b02392d32e33536d3df5e5 /m4 | |
| parent | ad73682838ae0e66832aad97a8fbc5fb935130c6 (diff) | |
| download | gnulib-91a109c0426e8b8cd8b317e29c8a91bd99757f0a.tar.gz | |
c-stack: avoid compiler optimizations when provoking overflow
* m4/c-stack.m4 (AC_SYS_XSI_STACK_OVERFLOW_HEURISTIC): Make
recursion harder to optimize, to ensure a stack overflow occurs.
* tests/test-c-stack.c (recurse): Likewise.
Borrowed from libsigsegv.
Signed-off-by: Eric Blake <ebb9@byu.net>
Diffstat (limited to 'm4')
| -rw-r--r-- | m4/c-stack.m4 | 36 |
1 files changed, 22 insertions, 14 deletions
diff --git a/m4/c-stack.m4 b/m4/c-stack.m4 index f1bda7bb70..50693331a3 100644 --- a/m4/c-stack.m4 +++ b/m4/c-stack.m4 @@ -64,15 +64,19 @@ AC_DEFUN([AC_SYS_XSI_STACK_OVERFLOW_HEURISTIC], act.sa_handler = segv_handler; return sigaction (SIGSEGV, &act, 0); } - + static volatile int * + recurse_1 (volatile int n, volatile int *p) + { + if (n >= 0) + *recurse_1 (n + 1, p) += n; + return p; + } static int - recurse (char *p) + recurse (volatile int n) { - char array[500]; - array[0] = 1; - return *p + recurse (array); + int sum = 0; + return *recurse_1 (n, &sum); } - int main () { @@ -86,7 +90,7 @@ AC_DEFUN([AC_SYS_XSI_STACK_OVERFLOW_HEURISTIC], setrlimit (RLIMIT_STACK, &rl); #endif - return c_stack_action () || recurse ("\1"); + return c_stack_action () || recurse (0); } ], [ac_cv_sys_stack_overflow_works=yes], @@ -242,15 +246,19 @@ int main () act.sa_sigaction = segv_handler; return sigaction (SIGSEGV, &act, 0); } - + static volatile int * + recurse_1 (volatile int n, volatile int *p) + { + if (n >= 0) + *recurse_1 (n + 1, p) += n; + return p; + } static int - recurse (char *p) + recurse (volatile int n) { - char array[500]; - array[0] = 1; - return *p + recurse (array); + int sum = 0; + return *recurse_1 (n, &sum); } - int main () { @@ -264,7 +272,7 @@ int main () setrlimit (RLIMIT_STACK, &rl); #endif - return c_stack_action () || recurse ("\1"); + return c_stack_action () || recurse (0); } ], [ac_cv_sys_xsi_stack_overflow_heuristic=yes], |