[PATCH 06/15] HWPOISON: x86: Add VM_FAULT_HWPOISON handling to x86 page fault handler v2

From: Wu Fengguang
Date: Fri Jun 19 2009 - 23:22:45 EST


From: Andi Kleen <ak@xxxxxxxxxxxxxxx>

Add VM_FAULT_HWPOISON handling to the x86 page fault handler. This is
very similar to VM_FAULT_OOM, the only difference is that a different
si_code is passed to user space and the new addr_lsb field is initialized.

v2: Make the printk more verbose/unique

Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>

---
arch/x86/mm/fault.c | 19 +++++++++++++++----
1 file changed, 15 insertions(+), 4 deletions(-)

--- sound-2.6.orig/arch/x86/mm/fault.c
+++ sound-2.6/arch/x86/mm/fault.c
@@ -167,6 +167,7 @@ force_sig_info_fault(int si_signo, int s
info.si_errno = 0;
info.si_code = si_code;
info.si_addr = (void __user *)address;
+ info.si_addr_lsb = si_code == BUS_MCEERR_AR ? PAGE_SHIFT : 0;

force_sig_info(si_signo, &info, tsk);
}
@@ -798,10 +799,12 @@ out_of_memory(struct pt_regs *regs, unsi
}

static void
-do_sigbus(struct pt_regs *regs, unsigned long error_code, unsigned long address)
+do_sigbus(struct pt_regs *regs, unsigned long error_code, unsigned long address,
+ unsigned int fault)
{
struct task_struct *tsk = current;
struct mm_struct *mm = tsk->mm;
+ int code = BUS_ADRERR;

up_read(&mm->mmap_sem);

@@ -817,7 +820,15 @@ do_sigbus(struct pt_regs *regs, unsigned
tsk->thread.error_code = error_code;
tsk->thread.trap_no = 14;

- force_sig_info_fault(SIGBUS, BUS_ADRERR, address, tsk);
+#ifdef CONFIG_MEMORY_FAILURE
+ if (fault & VM_FAULT_HWPOISON) {
+ printk(KERN_ERR
+ "MCE: Killing %s:%d due to hardware memory corruption fault at %lx\n",
+ tsk->comm, tsk->pid, address);
+ code = BUS_MCEERR_AR;
+ }
+#endif
+ force_sig_info_fault(SIGBUS, code, address, tsk);
}

static noinline void
@@ -827,8 +838,8 @@ mm_fault_error(struct pt_regs *regs, uns
if (fault & VM_FAULT_OOM) {
out_of_memory(regs, error_code, address);
} else {
- if (fault & VM_FAULT_SIGBUS)
- do_sigbus(regs, error_code, address);
+ if (fault & (VM_FAULT_SIGBUS|VM_FAULT_HWPOISON))
+ do_sigbus(regs, error_code, address, fault);
else
BUG();
}

--

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