The patch titled
alpha: exception table sorting
has been added to the -mm tree. Its filename is
alpha-exception-table-sorting.patch
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------------------------------------------------------
Subject: alpha: exception table sorting
From: Ivan Kokshaysky <ink@xxxxxxxxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Richard Henderson <rth@xxxxxxxxxxx
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/alpha/include/asm/uaccess.h | 2 +
arch/alpha/mm/extable.c | 40 ++++++++++++++++++++++++++++-
2 files changed, 41 insertions(+), 1 deletion(-)
diff -puN arch/alpha/include/asm/uaccess.h~alpha-exception-table-sorting arch/alpha/include/asm/uaccess.h
--- a/arch/alpha/include/asm/uaccess.h~alpha-exception-table-sorting
+++ a/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 -puN arch/alpha/mm/extable.c~alpha-exception-table-sorting arch/alpha/mm/extable.c
--- a/arch/alpha/mm/extable.c~alpha-exception-table-sorting
+++ a/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_ta
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)
_
Patches currently in -mm which might be from ink@xxxxxxxxxxxxxxxxxxxx are
linux-next.patch
time-create-arch_gettimeoffset-infrastructure-for-use-in-the-generic-timekeeping-core.patch
alpha-titan-and-marvel-build-fixes.patch
alpha-exception-table-sorting.patch
alpha-futex-implementation.patch
alpha-binfmt_aout-fix.patch
kmap_types-make-most-arches-use-generic-header-file.patch
make-sure-nobodys-leaking-resources.patch
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