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).

[[email protected]: fix alpha build]
[[email protected]: fix s390 build]
[[email protected]: fix sparc build]
[[email protected]: fix sparc64 build]
[[email protected]: fix ia64 build]
Signed-off-by: Nick Piggin <[email protected]>
Cc: Richard Henderson <[email protected]>
Cc: Ivan Kokshaysky <[email protected]>
Cc: Russell King <[email protected]>
Cc: Ian Molton <[email protected]>
Cc: Bryan Wu <[email protected]>
Cc: Mikael Starvik <[email protected]>
Cc: David Howells <[email protected]>
Cc: Yoshinori Sato <[email protected]>
Cc: "Luck, Tony" <[email protected]>
Cc: Hirokazu Takata <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Cc: Roman Zippel <[email protected]>
Cc: Greg Ungerer <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: Paul Mundt <[email protected]>
Cc: Kazumoto Kojima <[email protected]>
Cc: Richard Curnow <[email protected]>
Cc: William Lee Irwin III <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Jeff Dike <[email protected]>
Cc: Paolo 'Blaisorblade' Giarrusso <[email protected]>
Cc: Miles Bader <[email protected]>
Cc: Chris Zankel <[email protected]>
Acked-by: Kyle McMartin <[email protected]>
Acked-by: Haavard Skinnemoen <[email protected]>
Acked-by: Ralf Baechle <[email protected]>
Acked-by: Andi Kleen <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
[ Still apparently needs some ARM and PPC loving - Linus ]
Signed-off-by: Linus Torvalds <[email protected]>

1 files changed, 15 insertions, 14 deletions

diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c
index abab90c3803f..3850d53f79fd 100644
--- a/arch/um/kernel/trap.c
+++ b/arch/um/kernel/trap.c
@@ -76,23 +76,24 @@ good_area:
 		goto out;
 
 	do {
+		int 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:
-			err = -EACCES;
-			goto out;
-		case VM_FAULT_OOM:
-			err = -ENOMEM;
-			goto out_of_memory;
-		default:
+		fault = handle_mm_fault(mm, vma, address, is_write);
+		if (unlikely(fault & VM_FAULT_ERROR)) {
+			if (fault & VM_FAULT_OOM) {
+				err = -ENOMEM;
+				goto out_of_memory;
+			} else if (fault & VM_FAULT_SIGBUS) {
+				err = -EACCES;
+				goto out;
+			}
 			BUG();
 		}
+		if (fault & VM_FAULT_MAJOR)
+			current->maj_flt++;
+		else
+			current->min_flt++;
+
 		pgd = pgd_offset(mm, address);
 		pud = pud_offset(pgd, address);
 		pmd = pmd_offset(pud, address);