mirror of
https://github.com/torvalds/linux.git
synced 2024-11-16 00:52:01 +00:00
556637cdab
After the loop in walk_pte_range() pte might point to the first address after the pmd it walks. The pte_unmap() is then applied to something bad. Spotted by Roel Kluin and Andreas Schwab. Signed-off-by: Johannes Weiner <hannes@saeurebad.de> Cc: Roel Kluin <12o3l@tiscali.nl> Cc: Andreas Schwab <schwab@suse.de> Acked-by: Matt Mackall <mpm@selenic.com> Acked-by: Mikael Pettersson <mikpe@it.uu.se> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
136 lines
3.4 KiB
C
136 lines
3.4 KiB
C
#include <linux/mm.h>
|
|
#include <linux/highmem.h>
|
|
#include <linux/sched.h>
|
|
|
|
static int walk_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
|
|
const struct mm_walk *walk, void *private)
|
|
{
|
|
pte_t *pte;
|
|
int err = 0;
|
|
|
|
pte = pte_offset_map(pmd, addr);
|
|
for (;;) {
|
|
err = walk->pte_entry(pte, addr, addr + PAGE_SIZE, private);
|
|
if (err)
|
|
break;
|
|
addr += PAGE_SIZE;
|
|
if (addr == end)
|
|
break;
|
|
pte++;
|
|
}
|
|
|
|
pte_unmap(pte);
|
|
return err;
|
|
}
|
|
|
|
static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
|
|
const struct mm_walk *walk, void *private)
|
|
{
|
|
pmd_t *pmd;
|
|
unsigned long next;
|
|
int err = 0;
|
|
|
|
pmd = pmd_offset(pud, addr);
|
|
do {
|
|
next = pmd_addr_end(addr, end);
|
|
if (pmd_none_or_clear_bad(pmd)) {
|
|
if (walk->pte_hole)
|
|
err = walk->pte_hole(addr, next, private);
|
|
if (err)
|
|
break;
|
|
continue;
|
|
}
|
|
if (walk->pmd_entry)
|
|
err = walk->pmd_entry(pmd, addr, next, private);
|
|
if (!err && walk->pte_entry)
|
|
err = walk_pte_range(pmd, addr, next, walk, private);
|
|
if (err)
|
|
break;
|
|
} while (pmd++, addr = next, addr != end);
|
|
|
|
return err;
|
|
}
|
|
|
|
static int walk_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end,
|
|
const struct mm_walk *walk, void *private)
|
|
{
|
|
pud_t *pud;
|
|
unsigned long next;
|
|
int err = 0;
|
|
|
|
pud = pud_offset(pgd, addr);
|
|
do {
|
|
next = pud_addr_end(addr, end);
|
|
if (pud_none_or_clear_bad(pud)) {
|
|
if (walk->pte_hole)
|
|
err = walk->pte_hole(addr, next, private);
|
|
if (err)
|
|
break;
|
|
continue;
|
|
}
|
|
if (walk->pud_entry)
|
|
err = walk->pud_entry(pud, addr, next, private);
|
|
if (!err && (walk->pmd_entry || walk->pte_entry))
|
|
err = walk_pmd_range(pud, addr, next, walk, private);
|
|
if (err)
|
|
break;
|
|
} while (pud++, addr = next, addr != end);
|
|
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* walk_page_range - walk a memory map's page tables with a callback
|
|
* @mm: memory map to walk
|
|
* @addr: starting address
|
|
* @end: ending address
|
|
* @walk: set of callbacks to invoke for each level of the tree
|
|
* @private: private data passed to the callback function
|
|
*
|
|
* Recursively walk the page table for the memory area in a VMA,
|
|
* calling supplied callbacks. Callbacks are called in-order (first
|
|
* PGD, first PUD, first PMD, first PTE, second PTE... second PMD,
|
|
* etc.). If lower-level callbacks are omitted, walking depth is reduced.
|
|
*
|
|
* Each callback receives an entry pointer, the start and end of the
|
|
* associated range, and a caller-supplied private data pointer.
|
|
*
|
|
* No locks are taken, but the bottom level iterator will map PTE
|
|
* directories from highmem if necessary.
|
|
*
|
|
* If any callback returns a non-zero value, the walk is aborted and
|
|
* the return value is propagated back to the caller. Otherwise 0 is returned.
|
|
*/
|
|
int walk_page_range(const struct mm_struct *mm,
|
|
unsigned long addr, unsigned long end,
|
|
const struct mm_walk *walk, void *private)
|
|
{
|
|
pgd_t *pgd;
|
|
unsigned long next;
|
|
int err = 0;
|
|
|
|
if (addr >= end)
|
|
return err;
|
|
|
|
pgd = pgd_offset(mm, addr);
|
|
do {
|
|
next = pgd_addr_end(addr, end);
|
|
if (pgd_none_or_clear_bad(pgd)) {
|
|
if (walk->pte_hole)
|
|
err = walk->pte_hole(addr, next, private);
|
|
if (err)
|
|
break;
|
|
continue;
|
|
}
|
|
if (walk->pgd_entry)
|
|
err = walk->pgd_entry(pgd, addr, next, private);
|
|
if (!err &&
|
|
(walk->pud_entry || walk->pmd_entry || walk->pte_entry))
|
|
err = walk_pud_range(pgd, addr, next, walk, private);
|
|
if (err)
|
|
break;
|
|
} while (pgd++, addr = next, addr != end);
|
|
|
|
return err;
|
|
}
|