From: Mahesh Salgaonkar <mah...@linux.vnet.ibm.com>
The current code extracts the physical address for UE errors and then
hooks it up into memory failure infrastructure. On successful extraction
of physical address it wrongly sets "handled = 1" which means this UE error
has been recovered. Since MCE handler gets return value as handled = 1, it
assumes that error has been recovered and goes back to same NIP. This causes
MCE interrupt again and again in a loop leading to hard lockup.
Also, initialize phys_addr to ULONG_MAX so that we don't end up queuing
undesired page to hwpoison.
Without this patch we see:
[ 1476.541984] Severe Machine check interrupt [Recovered]
[ 1476.541985] NIP: [000000001002588c] PID: 7109 Comm: find
[ 1476.541986] Initiator: CPU
[ 1476.541987] Error type: UE [Load/Store]
[ 1476.541988] Effective address: 00007fffd2755940
[ 1476.541989] Physical address: 000020181a080000
[...]
[ 1476.542003] Severe Machine check interrupt [Recovered]
[ 1476.542004] NIP: [000000001002588c] PID: 7109 Comm: find
[ 1476.542005] Initiator: CPU
[ 1476.542006] Error type: UE [Load/Store]
[ 1476.542006] Effective address: 00007fffd2755940
[ 1476.542007] Physical address: 000020181a080000
[ 1476.542010] Severe Machine check interrupt [Recovered]
[ 1476.542012] NIP: [000000001002588c] PID: 7109 Comm: find
[ 1476.542013] Initiator: CPU
[ 1476.542014] Error type: UE [Load/Store]
[ 1476.542015] Effective address: 00007fffd2755940
[ 1476.542016] Physical address: 000020181a080000
[ 1476.542448] Memory failure: 0x20181a08: recovery action for dirty LRU page:
Recovered
[ 1476.542452] Memory failure: 0x20181a08: already hardware poisoned
[ 1476.542453] Memory failure: 0x20181a08: already hardware poisoned
[ 1476.542454] Memory failure: 0x20181a08: already hardware poisoned
[ 1476.542455] Memory failure: 0x20181a08: already hardware poisoned
[ 1476.542456] Memory failure: 0x20181a08: already hardware poisoned
[ 1476.542457] Memory failure: 0x20181a08: already hardware poisoned
[...]
[ 1490.972174] Watchdog CPU:38 Hard LOCKUP
After this patch we see:
[ 325.384336] Severe Machine check interrupt [Not recovered]
[ 325.384338] NIP: [00007fffaae585f4] PID: 7168 Comm: find
[ 325.384339] Initiator: CPU
[ 325.384341] Error type: UE [Load/Store]
[ 325.384343] Effective address: 00007fffaafe28ac
[ 325.384345] Physical address: 00002017c0bd0000
[ 325.384350] find[7168]: unhandled signal 7 at 00007fffaae585f4 nip
00007fffaae585f4 lr 00007fffaae585e0 code 4
[ 325.388574] Memory failure: 0x2017c0bd: recovery action for dirty LRU page:
Recovered
Fixes: 01eaac2b0591 ("powerpc/mce: Hookup ierror (instruction) UE errors")
Fixes: ba41e1e1ccb9 ("powerpc/mce: Hookup derror (load/store) UE errors")
Signed-off-by: Mahesh Salgaonkar <mah...@linux.vnet.ibm.com>
---
arch/powerpc/kernel/mce_power.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/kernel/mce_power.c b/arch/powerpc/kernel/mce_power.c
index fe6fc63251fe..63b58ae5d601 100644
--- a/arch/powerpc/kernel/mce_power.c
+++ b/arch/powerpc/kernel/mce_power.c
@@ -441,7 +441,6 @@ static int mce_handle_ierror(struct pt_regs *regs,
if (pfn != ULONG_MAX) {
*phys_addr =
(pfn << PAGE_SHIFT);
- handled = 1;
}
}
}
@@ -532,9 +531,8 @@ static int mce_handle_derror(struct pt_regs *regs,
* kernel/exception-64s.h
*/
if (get_paca()->in_mce < MAX_MCE_DEPTH)
- if (!mce_find_instr_ea_and_pfn(regs, addr,
- phys_addr))
- handled = 1;
+ mce_find_instr_ea_and_pfn(regs, addr,
+ phys_addr);
}
found = 1;
}
@@ -572,7 +570,7 @@ static long mce_handle_error(struct pt_regs *regs,
const struct mce_ierror_table itable[])
{
struct mce_error_info mce_err = { 0 };
- uint64_t addr, phys_addr;
+ uint64_t addr, phys_addr = ULONG_MAX;
uint64_t srr1 = regs->msr;
long handled;
