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| author | Mark Rutland <mark.rutland@arm.com> | 2021-11-29 14:06:44 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2021-12-01 00:06:43 +0100 |
| commit | 6ce895128b3bff738fe8d9dd74747a03e319e466 (patch) | |
| tree | d8585eb931fe75bba40f3cbaf0edc85ab40edd7e /kernel/entry/common.c | |
| parent | x86: Snapshot thread flags (diff) | |
| download | linux-6ce895128b3bff738fe8d9dd74747a03e319e466.tar.xz linux-6ce895128b3bff738fe8d9dd74747a03e319e466.zip | |
entry: Snapshot thread flags
Some thread flags can be set remotely, and so even when IRQs are disabled,
the flags can change under our feet. Generally this is unlikely to cause a
problem in practice, but it is somewhat unsound, and KCSAN will
legitimately warn that there is a data race.
To avoid such issues, a snapshot of the flags has to be taken prior to
using them. Some places already use READ_ONCE() for that, others do not.
Convert them all to the new flag accessor helpers.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/20211129130653.2037928-3-mark.rutland@arm.com
Diffstat (limited to 'kernel/entry/common.c')
| -rw-r--r-- | kernel/entry/common.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/entry/common.c b/kernel/entry/common.c index d5a61d565ad5..bad713684c2e 100644 --- a/kernel/entry/common.c +++ b/kernel/entry/common.c @@ -187,7 +187,7 @@ static unsigned long exit_to_user_mode_loop(struct pt_regs *regs, /* Check if any of the above work has queued a deferred wakeup */ tick_nohz_user_enter_prepare(); - ti_work = READ_ONCE(current_thread_info()->flags); + ti_work = read_thread_flags(); } /* Return the latest work state for arch_exit_to_user_mode() */ @@ -196,7 +196,7 @@ static unsigned long exit_to_user_mode_loop(struct pt_regs *regs, static void exit_to_user_mode_prepare(struct pt_regs *regs) { - unsigned long ti_work = READ_ONCE(current_thread_info()->flags); + unsigned long ti_work = read_thread_flags(); lockdep_assert_irqs_disabled(); |