mm: fault feedback #2

This patch completes Linus's wish that the fault return codes be made into
bit flags, which I agree makes everything nicer.  This requires requires
all handle_mm_fault callers to be modified (possibly the modifications
should go further and do things like fault accounting in handle_mm_fault --
however that would be for another patch).

[akpm@linux-foundation.org: fix alpha build]
[akpm@linux-foundation.org: fix s390 build]
[akpm@linux-foundation.org: fix sparc build]
[akpm@linux-foundation.org: fix sparc64 build]
[akpm@linux-foundation.org: fix ia64 build]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ian Molton <spyro@f2s.com>
Cc: Bryan Wu <bryan.wu@analog.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Greg Ungerer <gerg@uclinux.org>
Cc: Matthew Wilcox <willy@debian.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp>
Cc: Richard Curnow <rc@rc0.org.uk>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Miles Bader <uclinux-v850@lsi.nec.co.jp>
Cc: Chris Zankel <chris@zankel.net>
Acked-by: Kyle McMartin <kyle@mcmartin.ca>
Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[ Still apparently needs some ARM and PPC loving - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 24 insertions, 30 deletions

diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index 0ece51310bfe..3767211b3d0f 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -145,7 +145,7 @@ int __kprobes do_page_fault(struct pt_regs *regs, unsigned long address,
         struct mm_struct *mm = current->mm;
         siginfo_t info;
         int code = SEGV_MAPERR;
-        int is_write = 0;
+        int is_write = 0, ret;
         int trap = TRAP(regs);
         int is_exec = trap == 0x400;
 
@@ -330,22 +330,18 @@ good_area:
          * the fault.
          */
  survive:
-        switch (handle_mm_fault(mm, vma, address, is_write)) {
-
-        case VM_FAULT_MINOR:
-                current->min_flt++;
-                break;
-        case VM_FAULT_MAJOR:
-                current->maj_flt++;
-                break;
-        case VM_FAULT_SIGBUS:
-                goto do_sigbus;
-        case VM_FAULT_OOM:
-                goto out_of_memory;
-        default:
+        ret = handle_mm_fault(mm, vma, address, is_write);
+        if (unlikely(ret & VM_FAULT_ERROR)) {
+                if (ret & VM_FAULT_OOM)
+                        goto out_of_memory;
+                else if (ret & VM_FAULT_SIGBUS)
+                        goto do_sigbus;
                 BUG();
         }
-
+        if (ret & VM_FAULT_MAJOR)
+                current->maj_flt++;
+        else
+                current->min_flt++;
         up_read(&mm->mmap_sem);
         return 0;
 
diff --git a/arch/powerpc/platforms/cell/spufs/fault.c b/arch/powerpc/platforms/cell/spufs/fault.c
index e064d0c0d80e..07f88de0544d 100644
--- a/arch/powerpc/platforms/cell/spufs/fault.c
+++ b/arch/powerpc/platforms/cell/spufs/fault.c
@@ -74,23 +74,21 @@ good_area:
                         goto bad_area;
         }
         ret = 0;
-        *flt = handle_mm_fault(mm, vma, ea, is_write);
-        switch (*flt) {
-        case VM_FAULT_MINOR:
-                current->min_flt++;
-                break;
-        case VM_FAULT_MAJOR:
-                current->maj_flt++;
-                break;
-        case VM_FAULT_SIGBUS:
-                ret = -EFAULT;
-                goto bad_area;
-        case VM_FAULT_OOM:
-                ret = -ENOMEM;
-                goto bad_area;
-        default:
+        fault = handle_mm_fault(mm, vma, ea, is_write);
+        if (unlikely(fault & VM_FAULT_ERROR)) {
+                if (fault & VM_FAULT_OOM) {
+                        ret = -ENOMEM;
+                        goto bad_area;
+                } else if (fault & VM_FAULT_SIGBUS) {
+                        ret = -EFAULT;
+                        goto bad_area;
+                }
                 BUG();
         }
+        if (fault & VM_FAULT_MAJOR)
+                current->maj_flt++;
+        else
+                current->min_flt++;
         up_read(&mm->mmap_sem);
         return ret;