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| author | David S. Miller <davem@davemloft.net> | 2010-04-11 02:44:30 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-04-11 02:44:30 -0700 |
| commit | 4a1032faac94ebbf647460ae3e06fc21146eb280 (patch) | |
| tree | 7f31b97beb0406faa1523e619289ad0ab07c9787 /mm/util.c | |
| parent | ae4e8d63b5619d4d95f1d2bfa2b836caa6e62d06 (diff) | |
| parent | 0eddb519b9127c73d53db4bf3ec1d45b13f844d1 (diff) | |
Merge branch 'master' of /home/davem/src/GIT/linux-2.6/
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 |