[RFC 6/9] HWPOISON: Handle hwpoison in current process

From: Luck, Tony
Date: Mon May 23 2011 - 18:14:24 EST


From: Andi Kleen <andi@xxxxxxxxxxxxxx>

When hardware poison handles the current process use
a forced signal with _AR severity.

Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx>
---
mm/memory-failure.c | 28 ++++++++++++++++------------
1 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 2b9a5ee..a203113 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -184,8 +184,7 @@ int hwpoison_filter(struct page *p)
EXPORT_SYMBOL_GPL(hwpoison_filter);

/*
- * Send all the processes who have the page mapped an ``action optional''
- * signal.
+ * Send all the processes who have the page mapped a SIGBUS.
*/
static int kill_proc_ao(struct task_struct *t, unsigned long addr, int trapno,
unsigned long pfn, struct page *page)
@@ -194,23 +193,28 @@ static int kill_proc_ao(struct task_struct *t, unsigned long addr, int trapno,
int ret;

printk(KERN_ERR
- "MCE %#lx: Killing %s:%d early due to hardware memory corruption\n",
- pfn, t->comm, t->pid);
+ "MCE %#lx: Killing %s:%d due to hardware memory corruption\n",
+ pfn, t->comm, t->pid);
si.si_signo = SIGBUS;
si.si_errno = 0;
- si.si_code = BUS_MCEERR_AO;
si.si_addr = (void *)addr;
#ifdef __ARCH_SI_TRAPNO
si.si_trapno = trapno;
#endif
si.si_addr_lsb = compound_trans_order(compound_head(page)) + PAGE_SHIFT;
- /*
- * Don't use force here, it's convenient if the signal
- * can be temporarily blocked.
- * This could cause a loop when the user sets SIGBUS
- * to SIG_IGN, but hopefully no one will do that?
- */
- ret = send_sig_info(SIGBUS, &si, t); /* synchronous? */
+ if (t == current) {
+ si.si_code = BUS_MCEERR_AR;
+ ret = force_sig_info(SIGBUS, &si, t);
+ } else {
+ /*
+ * Don't use force here, it's convenient if the signal
+ * can be temporarily blocked.
+ * This could cause a loop when the user sets SIGBUS
+ * to SIG_IGN, but hopefully noone will do that?
+ */
+ si.si_code = BUS_MCEERR_AO;
+ ret = send_sig_info(SIGBUS, &si, t);
+ }
if (ret < 0)
printk(KERN_INFO "MCE: Error sending signal to %s:%d: %d\n",
t->comm, t->pid, ret);
--
1.7.3.1

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