diff options
| author | Dan Williams <dan.j.williams@intel.com> | 2010-05-17 16:30:58 -0700 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2010-05-17 16:30:58 -0700 |
| commit | 0b28330e39bbe0ffee4c56b09fc415fcec595ea3 (patch) | |
| tree | fcf504879883763557e696eff81427b1ab78f76b /mm/util.c | |
| parent | 058276303dbc4ed089c1f7dad0871810b1f5ddf1 (diff) | |
| parent | caa20d974c86af496b419eef70010e63b7fab7ac (diff) | |
Merge branch 'ioat' into dmaengine
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 |