[PATCH] [9/16] POISON: x86: Add VM_FAULT_POISON handling to x86 page fault handler

Andi Kleen
2009-04-07T15:22:29Z

Add VM_FAULT_POISON 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.

Signed-off-by: Andi Kleen <ak@linux.intel.com>

---
arch/x86/mm/fault.c | 18 ++++++++++++++----
1 file changed, 14 insertions(+), 4 deletions(-)

Index: linux/arch/x86/mm/fault.c
===================================================================
--- linux.orig/arch/x86/mm/fault.c 2009-04-07 16:39:23.000000000 +0200
+++ linux/arch/x86/mm/fault.c 2009-04-07 16:39:39.000000000 +0200
@@ -189,6 +189,7 @@
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);
}
@@ -827,10 +828,12 @@
}

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);

@@ -846,7 +849,14 @@
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_POISON) {
+ printk(KERN_ERR "MCE: Killing %s:%d due to hardware memory corruption\n",
+ tsk->comm, tsk->pid);
+ code = BUS_MCEERR_AR;
+ }
+#endif
+ force_sig_info_fault(SIGBUS, code, address, tsk);
}

static noinline void
@@ -856,8 +866,8 @@
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_POISON))
+ do_sigbus(regs, error_code, address, fault);
else
BUG();
}