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authorRobert Richter <robert.richter@amd.com>2010-04-23 14:30:22 +0200
committerRobert Richter <robert.richter@amd.com>2010-04-23 14:30:22 +0200
commita36bf32e9e8a86f291f746b7f8292e042ee04a46 (patch)
treec5c999baa4c214218e3adea9b336cbd9f23950ad /mm/util.c
parentbc078e4eab65f11bbaeed380593ab8151b30d703 (diff)
parent01bf0b64579ead8a82e7cfc32ae44bc667e7ad0f (diff)
Merge commit 'v2.6.34-rc5' into oprofile/core
Diffstat (limited to 'mm/util.c')
-rw-r--r--mm/util.c21
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