diff options
| author |   Linus Torvalds <torvalds@linux-foundation.org> | 2022-01-10 11:34:10 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-01-10 11:34:10 -0800 |
| commit | 48a60bdb2be807767eba6878fdf2fe5bea5d8d27 (patch) | |
| tree | b6fa5a6c11dc3e5d98b0724d344ae62f368de82a /include | |
| parent | Merge tag 'core_core_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip (diff) | |
| parent | powerpc: Snapshot thread flags (diff) | |
| download | linux-dev-48a60bdb2be807767eba6878fdf2fe5bea5d8d27.tar.xz linux-dev-48a60bdb2be807767eba6878fdf2fe5bea5d8d27.zip | |
Merge tag 'core_entry_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull thread_info flag accessor helper updates from Borislav Petkov:
"Add a set of thread_info.flags accessors which snapshot it before
accesing it in order to prevent any potential data races, and convert
all users to those new accessors"
* tag 'core_entry_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
powerpc: Snapshot thread flags
powerpc: Avoid discarding flags in system_call_exception()
openrisc: Snapshot thread flags
microblaze: Snapshot thread flags
arm64: Snapshot thread flags
ARM: Snapshot thread flags
alpha: Snapshot thread flags
sched: Snapshot thread flags
entry: Snapshot thread flags
x86: Snapshot thread flags
thread_info: Add helpers to snapshot thread flags
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/entry-kvm.h | 2 | ||||
| -rw-r--r-- | include/linux/thread_info.h | 14 |
2 files changed, 15 insertions, 1 deletions
diff --git a/include/linux/entry-kvm.h b/include/linux/entry-kvm.h index 0d7865a0731c..07c878d6e323 100644 --- a/include/linux/entry-kvm.h +++ b/include/linux/entry-kvm.h @@ -75,7 +75,7 @@ static inline void xfer_to_guest_mode_prepare(void) */ static inline bool __xfer_to_guest_mode_work_pending(void) { - unsigned long ti_work = READ_ONCE(current_thread_info()->flags); + unsigned long ti_work = read_thread_flags(); return !!(ti_work & XFER_TO_GUEST_MODE_WORK); } diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h index ad0c4e041030..73a6f34b3847 100644 --- a/include/linux/thread_info.h +++ b/include/linux/thread_info.h @@ -118,6 +118,15 @@ static inline int test_ti_thread_flag(struct thread_info *ti, int flag) return test_bit(flag, (unsigned long *)&ti->flags); } +/* + * This may be used in noinstr code, and needs to be __always_inline to prevent + * inadvertent instrumentation. + */ +static __always_inline unsigned long read_ti_thread_flags(struct thread_info *ti) +{ + return READ_ONCE(ti->flags); +} + #define set_thread_flag(flag) \ set_ti_thread_flag(current_thread_info(), flag) #define clear_thread_flag(flag) \ @@ -130,6 +139,11 @@ static inline int test_ti_thread_flag(struct thread_info *ti, int flag) test_and_clear_ti_thread_flag(current_thread_info(), flag) #define test_thread_flag(flag) \ test_ti_thread_flag(current_thread_info(), flag) +#define read_thread_flags() \ + read_ti_thread_flags(current_thread_info()) + +#define read_task_thread_flags(t) \ + read_ti_thread_flags(task_thread_info(t)) #ifdef CONFIG_GENERIC_ENTRY #define set_syscall_work(fl) \ |