Anshuman Khandual <[email protected]> writes: > On 07/10/2013 06:32 PM, Mahesh J Salgaonkar wrote: >> 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); > > We need to replace this "62" with a shift macro specifying the significance > of these top two address bits in the real mode.
huh?? (gdb) p/t 0x3ull << 62 $4 = 1100000000000000000000000000000000000000000000000000000000000000 Why you need an extra comment to explain 62. But yes, we can possibly write that this is an RTAS bug -aneesh _______________________________________________ Linuxppc-dev mailing list [email protected] https://lists.ozlabs.org/listinfo/linuxppc-dev
