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| author | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2010-05-07 11:29:25 +1000 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2010-05-07 11:29:25 +1000 |
| commit | 1ed31d6db90d51010545921e59d369d2f92b7ac2 (patch) | |
| tree | 358a0b346bc8135cd5e53700eb44308b1a7c8c5b /mm/util.c | |
| parent | ceba1abcb00b0ef0b1efcd715285f6e05523edef (diff) | |
| parent | 722154e4cacf015161efe60009ae9be23d492296 (diff) | |
| download | kernel-crypto-1ed31d6db90d51010545921e59d369d2f92b7ac2.tar.gz kernel-crypto-1ed31d6db90d51010545921e59d369d2f92b7ac2.tar.xz kernel-crypto-1ed31d6db90d51010545921e59d369d2f92b7ac2.zip | |
Merge commit 'origin/master' into next
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 |