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alpha/extable: use generic search and sort routines

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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: Richard Henderson <rth@twiddle.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Ard Biesheuvel 2016-03-22 14:28:12 -07:00 committed by Linus Torvalds
parent a395d6a7e3
commit e77986b560
3 changed files with 9 additions and 95 deletions
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10
arch/alpha/include/asm/uaccess.h
View file

@ -483,7 +483,13 @@ struct exception_table_entry
(pc) + (_fixup)->fixup.bits.nextinsn; \
})
#define ARCH_HAS_SORT_EXTABLE
#define ARCH_HAS_SEARCH_EXTABLE
#define ARCH_HAS_RELATIVE_EXTABLE
#define swap_ex_entry_fixup(a, b, tmp, delta) \
do { \
(a)->fixup.unit = (b)->fixup.unit; \
(b)->fixup.unit = (tmp).fixup.unit; \
} while (0)
#endif /* __ALPHA_UACCESS_H */

2
arch/alpha/mm/Makefile
View file

@ -4,6 +4,6 @@
ccflags-y := -Werror
obj-y := init.o fault.o extable.o
obj-y := init.o fault.o
obj-$(CONFIG_DISCONTIGMEM) += numa.o

92
arch/alpha/mm/extable.c
View file

@ -1,92 +0,0 @@
/*
* linux/arch/alpha/mm/extable.c
*/
#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);
}
#ifdef CONFIG_MODULES
/*
* Any entry 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_to_addr(&m->extable[0]), m)) {
m->extable++;
m->num_exentries--;
}
/*trim the end*/
while (m->num_exentries &&
within_module_init(ex_to_addr(&m->extable[m->num_exentries-1]),
m))
m->num_exentries--;
}
#endif /* CONFIG_MODULES */
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 mid_value;
mid = (last - first) / 2 + first;
mid_value = ex_to_addr(mid);
if (mid_value == value)
return mid;
else if (mid_value < value)
first = mid+1;
else
last = mid-1;
}
return NULL;
}