[PATCH 08/13] powerpc: Unpoison pt_regs

From: Nicholas Miehlbradt
Date: Thu Dec 14 2023 - 00:56:57 EST


pt_regs is initialized ppc_save_regs which is implemented in assembly
and therefore does not mark the struct as initialized. Unpoison it so
that it will not generate false positives.

Signed-off-by: Nicholas Miehlbradt <nicholas@xxxxxxxxxxxxx>
---
arch/powerpc/include/asm/interrupt.h | 2 ++
arch/powerpc/kernel/irq_64.c | 2 ++
2 files changed, 4 insertions(+)

diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
index a4196ab1d016..a9bb09633689 100644
--- a/arch/powerpc/include/asm/interrupt.h
+++ b/arch/powerpc/include/asm/interrupt.h
@@ -68,6 +68,7 @@

#include <linux/context_tracking.h>
#include <linux/hardirq.h>
+#include <linux/kmsan.h>
#include <asm/cputime.h>
#include <asm/firmware.h>
#include <asm/ftrace.h>
@@ -170,6 +171,7 @@ static inline void interrupt_enter_prepare(struct pt_regs *regs)
__hard_RI_enable();
}
/* Enable MSR[RI] early, to support kernel SLB and hash faults */
+ kmsan_unpoison_entry_regs(regs);
#endif

if (!arch_irq_disabled_regs(regs))
diff --git a/arch/powerpc/kernel/irq_64.c b/arch/powerpc/kernel/irq_64.c
index 938e66829eae..3d441f1b8c49 100644
--- a/arch/powerpc/kernel/irq_64.c
+++ b/arch/powerpc/kernel/irq_64.c
@@ -45,6 +45,7 @@
#include <linux/vmalloc.h>
#include <linux/pgtable.h>
#include <linux/static_call.h>
+#include <linux/kmsan.h>

#include <linux/uaccess.h>
#include <asm/interrupt.h>
@@ -117,6 +118,7 @@ static __no_kcsan void __replay_soft_interrupts(void)
local_paca->irq_happened |= PACA_IRQ_REPLAYING;

ppc_save_regs(&regs);
+ kmsan_unpoison_entry_regs(&regs);
regs.softe = IRQS_ENABLED;
regs.msr |= MSR_EE;

--
2.40.1