vm: add VM_FAULT_SIGSEGV handling support

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / mips / mm / fault.c

diff --git a/arch/mips/mm/fault.c b/arch/mips/mm/fault.c
index 0fead53d1c26b261affa89d00c1fa06844f9e602..c40a8d1c43baaf5267c2f01e325c7108540b7f07 100644 (file)
--- a/arch/mips/mm/fault.c
+++ b/arch/mips/mm/fault.c
@@ -41,8 +41,7 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs, unsigned long writ
        const int field = sizeof(unsigned long) * 2;
        siginfo_t info;
        int fault;
-       unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE |
-                                                (write ? FAULT_FLAG_WRITE : 0);
+       unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
 
 #if 0
        printk("Cpu%d[%s:%d:%0*lx:%ld:%0*lx]\n", raw_smp_processor_id(),
@@ -92,6 +91,8 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs, unsigned long writ
        if (in_atomic() || !mm)
                goto bad_area_nosemaphore;
 
+       if (user_mode(regs))
+               flags |= FAULT_FLAG_USER;
 retry:
        down_read(&mm->mmap_sem);
        vma = find_vma(mm, address);
@@ -113,6 +114,7 @@ good_area:
        if (write) {
                if (!(vma->vm_flags & VM_WRITE))
                        goto bad_area;
+               flags |= FAULT_FLAG_WRITE;
        } else {
                if (cpu_has_rixi) {
                        if (address == regs->cp0_epc && !(vma->vm_flags & VM_EXEC)) {
@@ -155,6 +157,8 @@ good_area:
        if (unlikely(fault & VM_FAULT_ERROR)) {
                if (fault & VM_FAULT_OOM)
                        goto out_of_memory;
+               else if (fault & VM_FAULT_SIGSEGV)
+                       goto bad_area;
                else if (fault & VM_FAULT_SIGBUS)
                        goto do_sigbus;
                BUG();
@@ -240,6 +244,8 @@ out_of_memory:
         * (which will retry the fault, or kill us if we got oom-killed).
         */
        up_read(&mm->mmap_sem);
+       if (!user_mode(regs))
+               goto no_context;
        pagefault_out_of_memory();
        return;