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authorArd Biesheuvel <ard.biesheuvel@linaro.org>2016-03-22 14:28:17 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-03-22 15:36:02 -0700
commit29934b0fb8ff5afa61832ea56aec65befab30511 (patch)
treec394d51226af4191107cf0aa9be5ca64ca7d49d0 /arch
parentc352e8b6de9808ec5edc792d54f8785de6626d02 (diff)
x86/extable: use generic search and sort routines
Replace the arch specific versions of search_extable() and sort_extable() with calls to the generic ones, which now support relative exception tables as well. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/include/asm/uaccess.h5
-rw-r--r--arch/x86/mm/extable.c108
2 files changed, 2 insertions, 111 deletions
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index 88bff6dd23ad..a969ae607be8 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -105,9 +105,8 @@ static inline bool __chk_range_not_ok(unsigned long addr, unsigned long size, un
struct exception_table_entry {
int insn, fixup, handler;
};
-/* This is not the generic standard exception_table_entry format */
-#define ARCH_HAS_SORT_EXTABLE
-#define ARCH_HAS_SEARCH_EXTABLE
+
+#define ARCH_HAS_RELATIVE_EXTABLE
extern int fixup_exception(struct pt_regs *regs, int trapnr);
extern bool ex_has_fault_handler(unsigned long ip);
diff --git a/arch/x86/mm/extable.c b/arch/x86/mm/extable.c
index 9dd7e4b7fcde..82447b3fba38 100644
--- a/arch/x86/mm/extable.c
+++ b/arch/x86/mm/extable.c
@@ -1,17 +1,10 @@
#include <linux/module.h>
-#include <linux/spinlock.h>
-#include <linux/sort.h>
#include <asm/uaccess.h>
typedef bool (*ex_handler_t)(const struct exception_table_entry *,
struct pt_regs *, int);
static inline unsigned long
-ex_insn_addr(const struct exception_table_entry *x)
-{
- return (unsigned long)&x->insn + x->insn;
-}
-static inline unsigned long
ex_fixup_addr(const struct exception_table_entry *x)
{
return (unsigned long)&x->fixup + x->fixup;
@@ -110,104 +103,3 @@ int __init early_fixup_exception(unsigned long *ip)
*ip = new_ip;
return 1;
}
-
-/*
- * Search one exception table for an entry corresponding to the
- * given instruction address, and return the address of the entry,
- * or NULL if none is found.
- * We use a binary search, and thus we assume that the table is
- * already sorted.
- */
-const struct exception_table_entry *
-search_extable(const struct exception_table_entry *first,
- const struct exception_table_entry *last,
- unsigned long value)
-{
- while (first <= last) {
- const struct exception_table_entry *mid;
- unsigned long addr;
-
- mid = ((last - first) >> 1) + first;
- addr = ex_insn_addr(mid);
- if (addr < value)
- first = mid + 1;
- else if (addr > value)
- last = mid - 1;
- else
- return mid;
- }
- return NULL;
-}
-
-/*
- * 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;
-
- /*
- * This value will always end up fittin in an int, because on
- * both i386 and x86-64 the kernel symbol-reachable address
- * space is < 2 GiB.
- *
- * This compare is only valid after normalization.
- */
- return x->insn - y->insn;
-}
-
-void sort_extable(struct exception_table_entry *start,
- struct exception_table_entry *finish)
-{
- struct exception_table_entry *p;
- int i;
-
- /* Convert all entries to being relative to the start of the section */
- i = 0;
- for (p = start; p < finish; p++) {
- p->insn += i;
- i += 4;
- p->fixup += i;
- i += 4;
- p->handler += i;
- i += 4;
- }
-
- sort(start, finish - start, sizeof(struct exception_table_entry),
- cmp_ex, NULL);
-
- /* Denormalize all entries */
- i = 0;
- for (p = start; p < finish; p++) {
- p->insn -= i;
- i += 4;
- p->fixup -= i;
- i += 4;
- p->handler -= i;
- i += 4;
- }
-}
-
-#ifdef CONFIG_MODULES
-/*
- * If the exception table is sorted, any referring to the module init
- * will be at the beginning or the end.
- */
-void trim_init_extable(struct module *m)
-{
- /*trim the beginning*/
- while (m->num_exentries &&
- within_module_init(ex_insn_addr(&m->extable[0]), m)) {
- m->extable++;
- m->num_exentries--;
- }
- /*trim the end*/
- while (m->num_exentries &&
- within_module_init(ex_insn_addr(&m->extable[m->num_exentries-1]), m))
- m->num_exentries--;
-}
-#endif /* CONFIG_MODULES */

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