This commit was manufactured by cvs2svn to create tag

[linux-2.6.git] / arch / ppc64 / mm / fault.c

diff --git a/arch/ppc64/mm/fault.c b/arch/ppc64/mm/fault.c
index b78e7f4..72eba98 100644 (file)
--- a/arch/ppc64/mm/fault.c
+++ b/arch/ppc64/mm/fault.c
@@ -93,15 +93,13 @@ int do_page_fault(struct pt_regs *regs, unsigned long address,
        unsigned long is_write = error_code & 0x02000000;
        unsigned long trap = TRAP(regs);
 
-       BUG_ON((trap == 0x380) || (trap == 0x480));
-
-       if (trap == 0x300) {
+       if (trap == 0x300 || trap == 0x380) {
                if (debugger_fault_handler(regs))
                        return 0;
        }
 
        /* On a kernel SLB miss we can only check for a valid exception entry */
-       if (!user_mode(regs) && (address >= TASK_SIZE))
+       if (!user_mode(regs) && (trap == 0x380 || address >= TASK_SIZE))
                return SIGSEGV;
 
        if (error_code & 0x00400000) {
@@ -121,28 +119,7 @@ int do_page_fault(struct pt_regs *regs, unsigned long address,
                die("Weird page fault", regs, SIGSEGV);
        }
 
-       /* When running in the kernel we expect faults to occur only to
-        * addresses in user space.  All other faults represent errors in the
-        * kernel and should generate an OOPS.  Unfortunatly, in the case of an
-        * erroneous fault occuring in a code path which already holds mmap_sem
-        * we will deadlock attempting to validate the fault against the
-        * address space.  Luckily the kernel only validly references user
-        * space from well defined areas of code, which are listed in the
-        * exceptions table.
-        *
-        * As the vast majority of faults will be valid we will only perform
-        * the source reference check when there is a possibilty of a deadlock.
-        * Attempt to lock the address space, if we cannot we then validate the
-        * source.  If this is invalid we can skip the address space check,
-        * thus avoiding the deadlock.
-        */
-       if (!down_read_trylock(&mm->mmap_sem)) {
-               if (!user_mode(regs) && !search_exception_tables(regs->nip))
-                       goto bad_area_nosemaphore;
-
-               down_read(&mm->mmap_sem);
-       }
-
+       down_read(&mm->mmap_sem);
        vma = find_vma(mm, address);
        if (!vma)
                goto bad_area;
@@ -232,13 +209,12 @@ good_area:
 bad_area:
        up_read(&mm->mmap_sem);
 
-bad_area_nosemaphore:
        /* User mode accesses cause a SIGSEGV */
        if (user_mode(regs)) {
                info.si_signo = SIGSEGV;
                info.si_errno = 0;
                info.si_code = code;
-               info.si_addr = (void __user *) address;
+               info.si_addr = (void *) address;
                force_sig_info(SIGSEGV, &info, current);
                return 0;
        }
@@ -267,7 +243,7 @@ do_sigbus:
                info.si_signo = SIGBUS;
                info.si_errno = 0;
                info.si_code = BUS_ADRERR;
-               info.si_addr = (void __user *)address;
+               info.si_addr = (void *)address;
                force_sig_info(SIGBUS, &info, current);
                return 0;
        }