Thanks Vishal and Naoya!
-jane
On 5/20/2019 3:21 AM, Naoya Horiguchi wrote:
On Fri, May 17, 2019 at 10:18:02AM +0530, Anshuman Khandual wrote:
On 05/17/2019 09:38 AM, Jane Chu wrote:
Some user who install SIGBUS handler that does longjmp out
What the longjmp about ? Are you referring to the mechanism of catching the
signal which was registered ?
AFAIK, longjmp() might be useful for signal-based retrying, so highly
optimized applications like Oracle DB might want to utilize it to handle
memory errors in application level, I guess.
therefore keeping the process alive is confused by the error
message
"[188988.765862] Memory failure: 0x1840200: Killing
cellsrv:33395 due to hardware memory corruption"
Its a valid point because those are two distinct actions.
Slightly modify the error message to improve clarity.
Signed-off-by: Jane Chu <jane.chu@xxxxxxxxxx>
---
mm/memory-failure.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index fc8b517..14de5e2 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -216,10 +216,9 @@ static int kill_proc(struct to_kill *tk, unsigned long pfn, int flags)
short addr_lsb = tk->size_shift;
int ret;
- pr_err("Memory failure: %#lx: Killing %s:%d due to hardware memory corruption\n",
- pfn, t->comm, t->pid);
-
if ((flags & MF_ACTION_REQUIRED) && t->mm == current->mm) {
+ pr_err("Memory failure: %#lx: Killing %s:%d due to hardware memory "
+ "corruption\n", pfn, t->comm, t->pid);
ret = force_sig_mceerr(BUS_MCEERR_AR, (void __user *)tk->addr,
addr_lsb, current);
} else {
@@ -229,6 +228,8 @@ static int kill_proc(struct to_kill *tk, unsigned long pfn, int flags)
* This could cause a loop when the user sets SIGBUS
* to SIG_IGN, but hopefully no one will do that?
*/
+ pr_err("Memory failure: %#lx: Sending SIGBUS to %s:%d due to hardware "
+ "memory corruption\n", pfn, t->comm, t->pid);
ret = send_sig_mceerr(BUS_MCEERR_AO, (void __user *)tk->addr,
addr_lsb, t); /* synchronous? */
As both the pr_err() messages are very similar, could not we just switch between "Killing"
and "Sending SIGBUS to" based on a variable e.g action_[kill|sigbus] evaluated previously
with ((flags & MF_ACTION_REQUIRED) && t->mm == current->mm).
That might need additional if sentence, which I'm not sure worth doing.
I think that the simplest fix for the reported problem (a confusing message)
is like below:
- pr_err("Memory failure: %#lx: Killing %s:%d due to hardware memory corruption\n",
+ pr_err("Memory failure: %#lx: Sending SIGBUS to %s:%d due to hardware memory corruption\n",
pfn, t->comm, t->pid);
Or, if we have a good reason to separate the message for MF_ACTION_REQUIRED and
MF_ACTION_OPTIONAL, that might be OK.
Thanks,
Naoya Horiguchi
