renegade-project/linux-next
2
0
Fork 0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-29 15:43:59 +08:00
Code

- Prevent lock contention on the new sigaltstack lock on the common-case

Browse Source 
path, when no changes have been made to the alternative signal stack.
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAmG/NZ0ACgkQEsHwGGHe
 VUqwEQ/8CCQ2KKBbDZOYIr1wnl+FDIycgq7tnz+q9SomzxQODdDWLREBoTPsOtoE
 NZgXZEQxX4Wh/+4rvvdSMCVT3nz2GvSSasVKGrPZyLpDDyL3coRO0Ngx9iRUd1kF
 j67e9oMuNboPC5jJfP9cC4T+GgDQDnXAjjT3jX7aiIXnNjnOCTZ5Z7W8GKw7d2qH
 4L2SJwAPOkuRicdQiRMJhVLsowsDIZtC8q8OZHhwu0dqM3/JVJCIxKKGKV69j5uk
 TUP6M0ZdyR30VrDfKYlm3m5fY0YFsBY/algphP41Hz5sUe9Xsw6F5+8sL3nCqLz1
 BBUFr/00qVruM3jWmIag/OQ8/4cAFZjrx+8ewdF61OEOWya9Mq7VxINjT8R77B0i
 AuA6Bkv1LArJyfvywbbD6JzAj7TQFPuhFPc0BUFwZfn+B1rvxm88JK2mjR9aO/wZ
 ZHgDJ5hOSIKKNJ2W9g2fhW0MTMUELxKqxHZqOmQU/8ydVxYHZtD2GLHLDAU3XBoe
 9PTntBvv7+qxqNQyY70k4jzIRfOFB8XuYxeWCbg10LqkbFFm2otYN2orsjVVBY7u
 9wPQhFvJo6pHBx+dNIV6be56SnIeTCdIWBqlUcAto5mCVbmIxQoIMoNLo6rGBrhA
 7UdhVCFJJki/Bs92aEQxl09volI9Ec7yXvmpU74LfKD+Gc8TxQo=
 =if9T
 -----END PGP SIGNATURE-----

Merge tag 'core_urgent_for_v5.16_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull signal handlign fix from Borislav Petkov:

 - Prevent lock contention on the new sigaltstack lock on the
   common-case path, when no changes have been made to the alternative
   signal stack.

* tag 'core_urgent_for_v5.16_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  signal: Skip the altstack update when not needed
This commit is contained in:
Linus Torvalds 2021-12-19 11:46:54 -08:00
commit c36d891d78
1 changed files with 9 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
kernel/signal.c
View File

@ -4185,6 +4185,15 @@ do_sigaltstack (const stack_t *ss, stack_t *oss, unsigned long sp,
ss_mode != 0))
return -EINVAL;
/*
* Return before taking any locks if no actual
* sigaltstack changes were requested.
*/
if (t->sas_ss_sp == (unsigned long)ss_sp &&
t->sas_ss_size == ss_size &&
t->sas_ss_flags == ss_flags)
return 0;
sigaltstack_lock();
if (ss_mode == SS_DISABLE) {
ss_size = 0;