parisc: Add HWPOISON page fault handler code

Commit 24587380f61d ("parisc: Add MADV_HWPOISON and MADV_SOFT_OFFLINE") added
the necessary constants to handle hardware-poisoning. Those were needed to
support the page deallocation feature from firmware.

But I completely missed to add the relevant fault handler code. This now
showed up when I ran the madvise07 testcase from the Linux Test Project,
which failed with a kernel BUG at arch/parisc/mm/fault.c:320.

With this patch the parisc kernel now behaves like other platforms and
gives the same kernel syslog warnings when poisoning pages.

Signed-off-by: Helge Deller <deller@gmx.de>

diff --git a/arch/parisc/mm/fault.c b/arch/parisc/mm/fault.c
index 5b101f6a5607dc1ef9e229b6f2421a78d35355ce..e247edbca68ecd2f56500e467776c9d2fa1f1c11 100644 (file)
--- a/arch/parisc/mm/fault.c
+++ b/arch/parisc/mm/fault.c
@@ -17,6 +17,7 @@
 #include <linux/interrupt.h>
 #include <linux/extable.h>
 #include <linux/uaccess.h>
+#include <linux/hugetlb.h>
 
 #include <asm/traps.h>
 
@@ -261,7 +262,7 @@ void do_page_fault(struct pt_regs *regs, unsigned long code,
        struct task_struct *tsk;
        struct mm_struct *mm;
        unsigned long acc_type;
-       int fault;
+       int fault = 0;
        unsigned int flags;
 
        if (faulthandler_disabled())
@@ -315,7 +316,8 @@ good_area:
                        goto out_of_memory;
                else if (fault & VM_FAULT_SIGSEGV)
                        goto bad_area;
-               else if (fault & VM_FAULT_SIGBUS)
+               else if (fault & (VM_FAULT_SIGBUS|VM_FAULT_HWPOISON|
+                                 VM_FAULT_HWPOISON_LARGE))
                        goto bad_area;
                BUG();
        }
@@ -352,8 +354,7 @@ bad_area:
 
        if (user_mode(regs)) {
                struct siginfo si;
-
-               show_signal_msg(regs, code, address, tsk, vma);
+               unsigned int lsb = 0;
 
                switch (code) {
                case 15:        /* Data TLB miss fault/Data page fault */
@@ -386,6 +387,30 @@ bad_area:
                        si.si_code = (code == 26) ? SEGV_ACCERR : SEGV_MAPERR;
                        break;
                }
+
+#ifdef CONFIG_MEMORY_FAILURE
+               if (fault & (VM_FAULT_HWPOISON|VM_FAULT_HWPOISON_LARGE)) {
+                       printk(KERN_ERR
+       "MCE: Killing %s:%d due to hardware memory corruption fault at %08lx\n",
+                       tsk->comm, tsk->pid, address);
+                       si.si_signo = SIGBUS;
+                       si.si_code = BUS_MCEERR_AR;
+               }
+#endif
+
+               /*
+                * Either small page or large page may be poisoned.
+                * In other words, VM_FAULT_HWPOISON_LARGE and
+                * VM_FAULT_HWPOISON are mutually exclusive.
+                */
+               if (fault & VM_FAULT_HWPOISON_LARGE)
+                       lsb = hstate_index_to_shift(VM_FAULT_GET_HINDEX(fault));
+               else if (fault & VM_FAULT_HWPOISON)
+                       lsb = PAGE_SHIFT;
+               else
+                       show_signal_msg(regs, code, address, tsk, vma);
+               si.si_addr_lsb = lsb;
+
                si.si_errno = 0;
                si.si_addr = (void __user *) address;
                force_sig_info(si.si_signo, &si, current);