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ia64/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: Tony Luck <tony.luck@intel.com>
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 14:28:20 -07:00 committed by Linus Torvalds
parent 29934b0fb8
commit 8fe9752ef1
2 changed files with 4 additions and 101 deletions
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8
arch/ia64/include/asm/uaccess.h
View File

@ -341,13 +341,11 @@ extern unsigned long __strnlen_user (const char __user *, long);
__su_ret; \
})
/* Generic code can't deal with the location-relative format that we use for compactness. */
#define ARCH_HAS_SORT_EXTABLE
#define ARCH_HAS_SEARCH_EXTABLE
#define ARCH_HAS_RELATIVE_EXTABLE
struct exception_table_entry {
int addr; /* location-relative address of insn this fixup is for */
int cont; /* location-relative continuation addr.; if bit 2 is set, r9 is set to 0 */
int insn; /* location-relative address of insn this fixup is for */
int fixup; /* location-relative continuation addr.; if bit 2 is set, r9 is set to 0 */
};
extern void ia64_handle_exception (struct pt_regs *regs, const struct exception_table_entry *e);

97
arch/ia64/mm/extable.c
View File

@ -5,107 +5,12 @@
* David Mosberger-Tang <davidm@hpl.hp.com>
*/
#include <linux/sort.h>
#include <asm/uaccess.h>
#include <linux/module.h>
static int cmp_ex(const void *a, const void *b)
{
const struct exception_table_entry *l = a, *r = b;
u64 lip = (u64) &l->addr + l->addr;
u64 rip = (u64) &r->addr + r->addr;
/* avoid overflow */
if (lip > rip)
return 1;
if (lip < rip)
return -1;
return 0;
}
static void swap_ex(void *a, void *b, int size)
{
struct exception_table_entry *l = a, *r = b, tmp;
u64 delta = (u64) r - (u64) l;
tmp = *l;
l->addr = r->addr + delta;
l->cont = r->cont + delta;
r->addr = tmp.addr - delta;
r->cont = tmp.cont - delta;
}
/*
* Sort the exception table. It's usually already sorted, but there
* may be unordered entries due to multiple text sections (such as the
* .init text section). Note that the exception-table-entries contain
* location-relative addresses, which requires a bit of care during
* sorting to avoid overflows in the offset members (e.g., it would
* not be safe to make a temporary copy of an exception-table entry on
* the stack, because the stack may be more than 2GB away from the
* exception-table).
*/
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);
}
static inline unsigned long ex_to_addr(const struct exception_table_entry *x)
{
return (unsigned long)&x->addr + x->addr;
}
#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 ip)
{
const struct exception_table_entry *mid;
unsigned long mid_ip;
long diff;
while (first <= last) {
mid = &first[(last - first)/2];
mid_ip = (u64) &mid->addr + mid->addr;
diff = mid_ip - ip;
if (diff == 0)
return mid;
else if (diff < 0)
first = mid + 1;
else
last = mid - 1;
}
return NULL;
}
void
ia64_handle_exception (struct pt_regs *regs, const struct exception_table_entry *e)
{
long fix = (u64) &e->cont + e->cont;
long fix = (u64) &e->fixup + e->fixup;
regs->r8 = -EFAULT;
if (fix & 4)