diff options
| author | Konstantin Belousov <kib@FreeBSD.org> | 2026-05-06 22:53:59 +0000 |
|---|---|---|
| committer | Konstantin Belousov <kib@FreeBSD.org> | 2026-05-07 17:00:14 +0000 |
| commit | 18c5a26f8a747583b9bca3a6a1ae9db1ed4591a3 (patch) | |
| tree | a9e4fc73f9e4ce4c2dcc59814d6ad20c55f6343e | |
| parent | 642dd17ee94377c3d5533d05d0d9a58b88f60387 (diff) | |
vm_map_growstack(): give a hint to user that stack was blown out
Reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D56863
| -rw-r--r-- | sys/vm/vm_map.c | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/sys/vm/vm_map.c b/sys/vm/vm_map.c index 0a81e62d2d63..7ead7d7e6472 100644 --- a/sys/vm/vm_map.c +++ b/sys/vm/vm_map.c @@ -4723,6 +4723,11 @@ vm_map_stack_locked(vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize, return (rv); } +static bool report_stackoverflow = true; +SYSCTL_BOOL(_vm, OID_AUTO, report_stackoverflow, CTLFLAG_RWTUN, + &report_stackoverflow, 0, + "uprintf() on stack overflow"); + /* * Attempts to grow a vm stack entry. Returns KERN_SUCCESS if we * successfully grow the stack. @@ -4787,8 +4792,12 @@ retry: if (guard > max_grow) return (KERN_NO_SPACE); max_grow -= guard; - if (grow_amount > max_grow) + if (grow_amount > max_grow) { + if (report_stackoverflow) + uprintf("pid %d comm %s tid %d stack overflow\n", + p->p_pid, p->p_comm, td->td_tid); return (KERN_NO_SPACE); + } /* * If this is the main process stack, see if we're over the stack @@ -4796,8 +4805,12 @@ retry: */ is_procstack = addr >= (vm_offset_t)vm->vm_maxsaddr && addr < (vm_offset_t)vm->vm_stacktop; - if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > stacklim)) + if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > stacklim)) { + if (report_stackoverflow) + uprintf("pid %d comm %s tid %d stack overflow\n", + p->p_pid, p->p_comm, td->td_tid); return (KERN_NO_SPACE); + } #ifdef RACCT if (racct_enable) { |