vm: add VM_FAULT_SIGSEGV handling support

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

diff --git a/arch/arc/mm/fault.c b/arch/arc/mm/fault.c
index af55aab803d26899f717b9a50e1562e7e033c2f0..4b70fc309c1732dd6ab4ebf74b2b45f84cbe54d9 100644 (file)
--- a/arch/arc/mm/fault.c
+++ b/arch/arc/mm/fault.c
@@ -12,12 +12,11 @@
 #include <linux/sched.h>
 #include <linux/errno.h>
 #include <linux/ptrace.h>
-#include <linux/version.h>
 #include <linux/uaccess.h>
 #include <linux/kdebug.h>
 #include <asm/pgalloc.h>
 
-static int handle_vmalloc_fault(struct mm_struct *mm, unsigned long address)
+static int handle_vmalloc_fault(unsigned long address)
 {
        /*
         * Synchronize this task's top level page-table
@@ -27,7 +26,7 @@ static int handle_vmalloc_fault(struct mm_struct *mm, unsigned long address)
        pud_t *pud, *pud_k;
        pmd_t *pmd, *pmd_k;
 
-       pgd = pgd_offset_fast(mm, address);
+       pgd = pgd_offset_fast(current->active_mm, address);
        pgd_k = pgd_offset_k(address);
 
        if (!pgd_present(*pgd_k))
@@ -60,8 +59,7 @@ void do_page_fault(struct pt_regs *regs, int write, unsigned long address,
        struct mm_struct *mm = tsk->mm;
        siginfo_t info;
        int fault, ret;
-       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;
 
        /*
         * We fault-in kernel-space virtual memory on-demand. The
@@ -73,7 +71,7 @@ void do_page_fault(struct pt_regs *regs, int write, unsigned long address,
         * nothing more.
         */
        if (address >= VMALLOC_START && address <= VMALLOC_END) {
-               ret = handle_vmalloc_fault(mm, address);
+               ret = handle_vmalloc_fault(address);
                if (unlikely(ret))
                        goto bad_area_nosemaphore;
                else
@@ -89,6 +87,8 @@ void do_page_fault(struct pt_regs *regs, int write, unsigned long address,
        if (in_atomic() || !mm)
                goto no_context;
 
+       if (user_mode(regs))
+               flags |= FAULT_FLAG_USER;
 retry:
        down_read(&mm->mmap_sem);
        vma = find_vma(mm, address);
@@ -116,12 +116,12 @@ good_area:
        if (write) {
                if (!(vma->vm_flags & VM_WRITE))
                        goto bad_area;
+               flags |= FAULT_FLAG_WRITE;
        } else {
                if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
                        goto bad_area;
        }
 
-survive:
        /*
         * If for any reason at all we couldn't handle the fault,
         * make sure we exit gracefully rather than endlessly redo
@@ -160,6 +160,8 @@ survive:
        /* TBD: switch to pagefault_out_of_memory() */
        if (fault & VM_FAULT_OOM)
                goto out_of_memory;
+       else if (fault & VM_FAULT_SIGSEV)
+               goto bad_area;
        else if (fault & VM_FAULT_SIGBUS)
                goto do_sigbus;
 
@@ -201,14 +203,12 @@ no_context:
        die("Oops", regs, address, cause_code);
 
 out_of_memory:
-       if (is_global_init(tsk)) {
-               yield();
-               goto survive;
-       }
        up_read(&mm->mmap_sem);
 
-       if (user_mode(regs))
-               do_group_exit(SIGKILL); /* This will never return */
+       if (user_mode(regs)) {
+               pagefault_out_of_memory();
+               return;
+       }
 
        goto no_context;