Commit 4f8e0910 authored by Rohan McLure's avatar Rohan McLure Committed by Michael Ellerman
Browse files

powerpc/kcsan: Prevent recursive instrumentation with IRQ save/restores 



Instrumented memory accesses provided by KCSAN will access core-local
memories (which will save and restore IRQs) as well as restoring IRQs
directly. Avoid recursive instrumentation by applying __no_kcsan
annotation to IRQ restore routines.

Signed-off-by: default avatarRohan McLure <rmclure@linux.ibm.com>
[mpe: Resolve merge conflict with IRQ replay recursion changes]
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230206021801.105268-5-rmclure@linux.ibm.com
parent b6e25929

arch/powerpc/kernel/irq_64.c

+4 −4
Original line number Diff line number Diff line
@@ -94,7 +94,7 @@ static inline bool irq_happened_test_and_clear(u8 irq) 
	return false;

}



static void __replay_soft_interrupts(void)

static __no_kcsan void __replay_soft_interrupts(void)

{

	struct pt_regs regs;
@@ -171,7 +171,7 @@ static void __replay_soft_interrupts(void) 
	local_paca->irq_happened &= ~PACA_IRQ_REPLAYING;

}



void replay_soft_interrupts(void)

__no_kcsan void replay_soft_interrupts(void)

{

	irq_enter(); /* See comment in arch_local_irq_restore */

	__replay_soft_interrupts();
@@ -179,7 +179,7 @@ void replay_soft_interrupts(void) 
}



#if defined(CONFIG_PPC_BOOK3S_64) && defined(CONFIG_PPC_KUAP)

static inline void replay_soft_interrupts_irqrestore(void)

static inline __no_kcsan void replay_soft_interrupts_irqrestore(void)

{

	unsigned long kuap_state = get_kuap();
@@ -203,7 +203,7 @@ static inline void replay_soft_interrupts_irqrestore(void) 
#define replay_soft_interrupts_irqrestore() __replay_soft_interrupts()

#endif



notrace void arch_local_irq_restore(unsigned long mask)

notrace __no_kcsan void arch_local_irq_restore(unsigned long mask)

{

	unsigned char irq_happened;