diff options
| author | David Woodhouse <David.Woodhouse@intel.com> | 2010-05-10 14:32:46 +0100 |
|---|---|---|
| committer | David Woodhouse <David.Woodhouse@intel.com> | 2010-05-10 14:32:46 +0100 |
| commit | 0ae28a35bcb7984838acbf28bfba9c030f8b74f0 (patch) | |
| tree | 4f449d929b5df9e126e839f388ff0fd2b52028a0 /mm/util.c | |
| parent | 6f1f3d0ab5c3eeea9f04486481c25e9afdfa26c5 (diff) | |
| parent | b57f95a38233a2e73b679bea4a5453a1cc2a1cc9 (diff) | |
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
Conflicts:
drivers/mtd/mtdcore.c
Pull in the bdi fixes and ARM platform changes that other outstanding
patches depend on.
Diffstat (limited to 'mm/util.c')
| -rw-r--r-- | mm/util.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/mm/util.c b/mm/util.c index 834db7be240..f5712e8964b 100644 --- a/mm/util.c +++ b/mm/util.c @@ -186,6 +186,27 @@ void kzfree(const void *p) } EXPORT_SYMBOL(kzfree); +int kern_ptr_validate(const void *ptr, unsigned long size) +{ + unsigned long addr = (unsigned long)ptr; + unsigned long min_addr = PAGE_OFFSET; + unsigned long align_mask = sizeof(void *) - 1; + + if (unlikely(addr < min_addr)) + goto out; + if (unlikely(addr > (unsigned long)high_memory - size)) + goto out; + if (unlikely(addr & align_mask)) + goto out; + if (unlikely(!kern_addr_valid(addr))) + goto out; + if (unlikely(!kern_addr_valid(addr + size - 1))) + goto out; + return 1; +out: + return 0; +} + /* * strndup_user - duplicate an existing string from user space * @s: The string to duplicate |