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| author | Mark Brown <broonie@opensource.wolfsonmicro.com> | 2010-05-31 14:07:15 +0400 |
|---|---|---|
| committer | Mark Brown <broonie@opensource.wolfsonmicro.com> | 2010-05-31 14:07:15 +0400 |
| commit | e37c83c06c2690157a989df40dc99a6b61c9ea15 (patch) | |
| tree | 024dfb8b2c9abeec9ca7cb0c0136c276d9aacc91 /mm/util.c | |
| parent | ce1f7d30766f6549db6fa0b9e595e0d26a5b7d9a (diff) | |
| parent | 67a3e12b05e055c0415c556a315a3d3eb637e29e (diff) | |
| download | linux-e37c83c06c2690157a989df40dc99a6b61c9ea15.tar.xz | |
Merge commit 'v2.6.35-rc1' into for-2.6.36
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 834db7be240f..f5712e8964be 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 |