aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorIvan Kokshaysky <ink@jurassic.park.msu.ru>2009-04-30 15:08:47 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-05-02 15:36:10 -0700
commit08a42e86bce511b45ca3eee40f51674b02a777d1 (patch)
tree48a518301cf5a7bf9fecbdb554668a68cfb454c2
parentalpha: titan and marvel build fixes (diff)
downloadlinux-dev-08a42e86bce511b45ca3eee40f51674b02a777d1.tar.xz
linux-dev-08a42e86bce511b45ca3eee40f51674b02a777d1.zip
alpha: exception table sorting
Exception fixups for sections other than .text (like one in futex_init()) break the natural ordering of fixup entries, so sorting is required. Without that the result of the exception table search depends on phase of the moon. Signed-off-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Richard Henderson <rth@twiddle.net Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--arch/alpha/include/asm/uaccess.h2
-rw-r--r--arch/alpha/mm/extable.c40
2 files changed, 41 insertions, 1 deletions
diff --git a/arch/alpha/include/asm/uaccess.h b/arch/alpha/include/asm/uaccess.h
index 163f3053001c..b49ec2f8d6e3 100644
--- a/arch/alpha/include/asm/uaccess.h
+++ b/arch/alpha/include/asm/uaccess.h
@@ -507,5 +507,7 @@ struct exception_table_entry
(pc) + (_fixup)->fixup.bits.nextinsn; \
})
+#define ARCH_HAS_SORT_EXTABLE
+#define ARCH_HAS_SEARCH_EXTABLE
#endif /* __ALPHA_UACCESS_H */
diff --git a/arch/alpha/mm/extable.c b/arch/alpha/mm/extable.c
index dc7aeda15773..62dc379d301a 100644
--- a/arch/alpha/mm/extable.c
+++ b/arch/alpha/mm/extable.c
@@ -3,11 +3,49 @@
*/
#include <linux/module.h>
+#include <linux/sort.h>
#include <asm/uaccess.h>
+static inline unsigned long ex_to_addr(const struct exception_table_entry *x)
+{
+ return (unsigned long)&x->insn + x->insn;
+}
+
+static void swap_ex(void *a, void *b, int size)
+{
+ struct exception_table_entry *ex_a = a, *ex_b = b;
+ unsigned long addr_a = ex_to_addr(ex_a), addr_b = ex_to_addr(ex_b);
+ unsigned int t = ex_a->fixup.unit;
+
+ ex_a->fixup.unit = ex_b->fixup.unit;
+ ex_b->fixup.unit = t;
+ ex_a->insn = (int)(addr_b - (unsigned long)&ex_a->insn);
+ ex_b->insn = (int)(addr_a - (unsigned long)&ex_b->insn);
+}
+
+/*
+ * The exception table needs to be sorted so that the binary
+ * search that we use to find entries in it works properly.
+ * This is used both for the kernel exception table and for
+ * the exception tables of modules that get loaded.
+ */
+static int cmp_ex(const void *a, const void *b)
+{
+ const struct exception_table_entry *x = a, *y = b;
+
+ /* avoid overflow */
+ if (ex_to_addr(x) > ex_to_addr(y))
+ return 1;
+ if (ex_to_addr(x) < ex_to_addr(y))
+ return -1;
+ return 0;
+}
+
void sort_extable(struct exception_table_entry *start,
struct exception_table_entry *finish)
{
+ sort(start, finish - start, sizeof(struct exception_table_entry),
+ cmp_ex, swap_ex);
}
const struct exception_table_entry *
@@ -20,7 +58,7 @@ search_extable(const struct exception_table_entry *first,
unsigned long mid_value;
mid = (last - first) / 2 + first;
- mid_value = (unsigned long)&mid->insn + mid->insn;
+ mid_value = ex_to_addr(mid);
if (mid_value == value)
return mid;
else if (mid_value < value)