2021-05-06 14:50:37

by Christophe Leroy

Subject: [PATCH] powerpc/interrupts: Fix kuep_unlock() call

Same as kuap_user_restore(), kuep_unlock() has to be called when
really returning to user, that is in interrupt_exit_user_prepare(),
not in interrupt_exit_prepare().

Fixes: b5efec00b671 ("powerpc/32s: Move KUEP locking/unlocking in C")
Signed-off-by: Christophe Leroy <[email protected]>
---
arch/powerpc/include/asm/interrupt.h | 2 --
arch/powerpc/kernel/interrupt.c | 1 +
2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
index 44cde2e129b8..c77e8f57ff06 100644
--- a/arch/powerpc/include/asm/interrupt.h
+++ b/arch/powerpc/include/asm/interrupt.h
@@ -153,8 +153,6 @@ static inline void interrupt_enter_prepare(struct pt_regs *regs, struct interrup
*/
static inline void interrupt_exit_prepare(struct pt_regs *regs, struct interrupt_state *state)
{
- if (user_mode(regs))
- kuep_unlock();
}

static inline void interrupt_async_enter_prepare(struct pt_regs *regs, struct interrupt_state *state)
diff --git a/arch/powerpc/kernel/interrupt.c b/arch/powerpc/kernel/interrupt.c
index 30a596182baa..e0938ba298f2 100644
--- a/arch/powerpc/kernel/interrupt.c
+++ b/arch/powerpc/kernel/interrupt.c
@@ -424,6 +424,7 @@ notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs, unsigned

/* Restore user access locks last */
kuap_user_restore(regs);
+ kuep_unlock();

return ret;
}
--
2.25.0

2021-05-16 09:40:21

by Michael Ellerman

Subject: Re: [PATCH] powerpc/interrupts: Fix kuep_unlock() call

On Thu, 6 May 2021 14:49:45 +0000 (UTC), Christophe Leroy wrote:
> Same as kuap_user_restore(), kuep_unlock() has to be called when
> really returning to user, that is in interrupt_exit_user_prepare(),
> not in interrupt_exit_prepare().

Applied to powerpc/fixes.

[1/1] powerpc/interrupts: Fix kuep_unlock() call
https://git.kernel.org/powerpc/c/a78339698ab1f43435fbe67fcd6de8f4f6eb9eec

cheers