diff options
| -rw-r--r-- | arch/x86/kernel/shstk.c | 38 |
1 files changed, 17 insertions, 21 deletions
diff --git a/arch/x86/kernel/shstk.c b/arch/x86/kernel/shstk.c index 47f5204b0fa9..cd10d074a444 100644 --- a/arch/x86/kernel/shstk.c +++ b/arch/x86/kernel/shstk.c @@ -134,28 +134,24 @@ static unsigned long adjust_shstk_size(unsigned long size) static void unmap_shadow_stack(u64 base, u64 size) { - while (1) { - int r; - - r = vm_munmap(base, size); - - /* - * vm_munmap() returns -EINTR when mmap_lock is held by - * something else, and that lock should not be held for a - * long time. Retry it for the case. - */ - if (r == -EINTR) { - cond_resched(); - continue; - } + int r; - /* - * For all other types of vm_munmap() failure, either the - * system is out of memory or there is bug. - */ - WARN_ON_ONCE(r); - break; - } + r = vm_munmap(base, size); + + /* + * mmap_write_lock_killable() failed with -EINTR. This means + * the process is about to die and have it's MM cleaned up. + * This task shouldn't ever make it back to userspace. In this + * case it is ok to leak a shadow stack, so just exit out. + */ + if (r == -EINTR) + return; + + /* + * For all other types of vm_munmap() failure, either the + * system is out of memory or there is bug. + */ + WARN_ON_ONCE(r); } static int shstk_setup(void) |