[tip: core/entry] microblaze: Snapshot thread flags

From: tip-bot2 for Mark Rutland
Date: Tue Nov 30 2021 - 18:08:56 EST


The following commit has been merged into the core/entry branch of tip:

Commit-ID: e538c5849143a7f0aa97006cd45ce4c0c26d0744
Gitweb: https://git.kernel.org/tip/e538c5849143a7f0aa97006cd45ce4c0c26d0744
Author: Mark Rutland <mark.rutland@xxxxxxx>
AuthorDate: Mon, 29 Nov 2021 13:06:49
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Wed, 01 Dec 2021 00:06:44 +01:00

microblaze: 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@xxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Tested-by: Michal Simek <michal.simek@xxxxxxxxxx>
Acked-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20211129130653.2037928-8-mark.rutland@xxxxxxx

---
arch/microblaze/kernel/signal.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/microblaze/kernel/signal.c b/arch/microblaze/kernel/signal.c
index fc61eb0..23e8a93 100644
--- a/arch/microblaze/kernel/signal.c
+++ b/arch/microblaze/kernel/signal.c
@@ -283,7 +283,7 @@ static void do_signal(struct pt_regs *regs, int in_syscall)
#ifdef DEBUG_SIG
pr_info("do signal: %p %d\n", regs, in_syscall);
pr_info("do signal2: %lx %lx %ld [%lx]\n", regs->pc, regs->r1,
- regs->r12, current_thread_info()->flags);
+ regs->r12, read_thread_flags());
#endif

if (get_signal(&ksig)) {