fix off-by-one bug in siglongjmp that caused unpredictable behavior

[musl] / src / signal / siglongjmp.c

diff --git a/src/signal/siglongjmp.c b/src/signal/siglongjmp.c
index 1712917..600d560 100644 (file)
--- a/src/signal/siglongjmp.c
+++ b/src/signal/siglongjmp.c
@@ -4,7 +4,7 @@
 
 void siglongjmp(sigjmp_buf buf, int ret)
 {
-       unsigned long *flag = buf + sizeof(jmp_buf)/sizeof(long);
+       unsigned long *flag = buf + sizeof(jmp_buf)/sizeof(long) - 1;
        sigset_t *mask = (void *)(flag + 1);
        if (*flag)
                sigprocmask (SIG_SETMASK, mask, NULL);