HWPOISON: x86: Add VM_FAULT_HWPOISON handling to x86 page fault handler v2

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

Cc: x86@kernel.org

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

1 files changed, 15 insertions, 4 deletions

diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 775a020990a5..8ba562408200 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -167,6 +167,7 @@ force_sig_info_fault(int si_signo, int si_code, unsigned long address,
         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);
 }
@@ -790,10 +791,12 @@ out_of_memory(struct pt_regs *regs, unsigned long error_code,
 }
 
 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);
 
@@ -809,7 +812,15 @@ do_sigbus(struct pt_regs *regs, unsigned long error_code, unsigned long address)
         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
@@ -819,8 +830,8 @@ mm_fault_error(struct pt_regs *regs, unsigned long error_code,
         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();
         }