mirrors
/
linux-stable
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
1
0
Fork 0
Code Issues Releases Wiki Activity

ARM: 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>
Cc: Russell King <linux@armlinux.org.uk>
Link: https://lore.kernel.org/r/20211129130653.2037928-6-mark.rutland@arm.com
This commit is contained in:
Mark Rutland 2021-11-29 13:06:47 +00:00 committed by Thomas Gleixner
parent 7fb2b24bb5
commit 050e22bfc4
2 changed files with 2 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/arm/kernel/signal.c
View File

@ -631,7 +631,7 @@ do_work_pending(struct pt_regs *regs, unsigned int thread_flags, int syscall)
}
}
local_irq_disable();
thread_flags = current_thread_info()->flags;
thread_flags = read_thread_flags();
} while (thread_flags & _TIF_WORK_MASK);
return 0;
}

2
arch/arm/mm/alignment.c
View File

@ -990,7 +990,7 @@ do_alignment(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
* there is no work pending for this thread.
*/
raw_local_irq_disable();
if (!(current_thread_info()->flags & _TIF_WORK_MASK))
if (!(read_thread_flags() & _TIF_WORK_MASK))
set_cr(cr_no_alignment);
}