From 836e2fa92cf99191a4975bf601b823c1e5b70e5c Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Fri, 8 May 2020 14:33:59 +1000 Subject: [PATCH] powerpc/pseries/ras: fwnmi avoid modifying r3 in error case If there is some error with the fwnmi save area, r3 has already been modified which doesn't help with debugging. Only update r3 when to restore the saved value. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200508043408.886394-8-npiggin@gmail.com --- arch/powerpc/platforms/pseries/ras.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/platforms/pseries/ras.c b/arch/powerpc/platforms/pseries/ras.c index a5bd0f747bb16..fe14186a8cef2 100644 --- a/arch/powerpc/platforms/pseries/ras.c +++ b/arch/powerpc/platforms/pseries/ras.c @@ -423,18 +423,19 @@ static inline struct rtas_error_log *fwnmi_get_errlog(void) */ static struct rtas_error_log *fwnmi_get_errinfo(struct pt_regs *regs) { + unsigned long savep_ra; unsigned long *savep; struct rtas_error_log *h; /* Mask top two bits */ - regs->gpr[3] &= ~(0x3UL << 62); + savep_ra = regs->gpr[3] & ~(0x3UL << 62); - if (!VALID_FWNMI_BUFFER(regs->gpr[3])) { + if (!VALID_FWNMI_BUFFER(savep_ra)) { printk(KERN_ERR "FWNMI: corrupt r3 0x%016lx\n", regs->gpr[3]); return NULL; } - savep = __va(regs->gpr[3]); + savep = __va(savep_ra); regs->gpr[3] = be64_to_cpu(savep[0]); /* restore original r3 */ h = (struct rtas_error_log *)&savep[1]; -- 2.39.5