From: Mahesh Salgaonkar <[email protected]> During Machine Check interrupt on pseries platform, R3 generally points to memory region inside RTAS (FWNMI) area. We see r3 corruption because when RTAS delivers the machine check exception it passes the address inside FWNMI area with the top most bit set. This patch fixes this issue by masking top two bit in machine check exception handler.
Signed-off-by: Mahesh Salgaonkar <[email protected]> --- arch/powerpc/platforms/pseries/ras.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/powerpc/platforms/pseries/ras.c b/arch/powerpc/platforms/pseries/ras.c index 7b3cbde..721c058 100644 --- a/arch/powerpc/platforms/pseries/ras.c +++ b/arch/powerpc/platforms/pseries/ras.c @@ -287,6 +287,9 @@ static struct rtas_error_log *fwnmi_get_errinfo(struct pt_regs *regs) unsigned long *savep; struct rtas_error_log *h, *errhdr = NULL; + /* Mask top two bits */ + regs->gpr[3] &= ~(0x3UL << 62); + if (!VALID_FWNMI_BUFFER(regs->gpr[3])) { printk(KERN_ERR "FWNMI: corrupt r3 0x%016lx\n", regs->gpr[3]); return NULL; _______________________________________________ Linuxppc-dev mailing list [email protected] https://lists.ozlabs.org/listinfo/linuxppc-dev
