diff options
Diffstat (limited to 'util/oslib-posix.c')
| -rw-r--r-- | util/oslib-posix.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/util/oslib-posix.c b/util/oslib-posix.c index fbd0dc8c57..c1bee2a581 100644 --- a/util/oslib-posix.c +++ b/util/oslib-posix.c @@ -596,6 +596,7 @@ pid_t qemu_fork(Error **errp) void *qemu_alloc_stack(size_t *sz) { void *ptr, *guardpage; + int flags; #ifdef CONFIG_DEBUG_STACK_USAGE void *ptr2; #endif @@ -610,8 +611,18 @@ void *qemu_alloc_stack(size_t *sz) /* allocate one extra page for the guard page */ *sz += pagesz; - ptr = mmap(NULL, *sz, PROT_READ | PROT_WRITE, - MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + flags = MAP_PRIVATE | MAP_ANONYMOUS; +#if defined(MAP_STACK) && defined(__OpenBSD__) + /* Only enable MAP_STACK on OpenBSD. Other OS's such as + * Linux/FreeBSD/NetBSD have a flag with the same name + * but have differing functionality. OpenBSD will SEGV + * if it spots execution with a stack pointer pointing + * at memory that was not allocated with MAP_STACK. + */ + flags |= MAP_STACK; +#endif + + ptr = mmap(NULL, *sz, PROT_READ | PROT_WRITE, flags, -1, 0); if (ptr == MAP_FAILED) { perror("failed to allocate memory for stack"); abort(); |