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authorCatalin Marinas <catalin.marinas@arm.com>2010-02-08 11:16:24 +0000
committerPekka Enberg <penberg@cs.helsinki.fi>2010-02-17 21:39:08 +0200
commit81fc03909a80bead8f553287a2b749a1d29dca64 (patch)
tree6c62a780be628ea551bf1e5854260ce94608c521 /arch/x86/mm/kmemcheck
parent724e6d3fe8003c3f60bf404bf22e4e331327c596 (diff)
kmemcheck: Test the full object in kmemcheck_is_obj_initialized()
This is a fix for bug #14845 (bugzilla.kernel.org). The update_checksum() function in mm/kmemleak.c calls kmemcheck_is_obj_initialised() before scanning an object. When KMEMCHECK_PARTIAL_OK is enabled, this function returns true. However, the crc32_le() reads smaller intervals (32-bit) for which kmemleak_is_obj_initialised() may be false leading to a kmemcheck warning. Note that kmemcheck_is_obj_initialized() is currently only used by kmemleak before scanning a memory location. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Christian Casteyde <casteyde.christian@free.fr> Cc: Vegard Nossum <vegardno@ifi.uio.no> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Diffstat (limited to 'arch/x86/mm/kmemcheck')
-rw-r--r--arch/x86/mm/kmemcheck/kmemcheck.c2
-rw-r--r--arch/x86/mm/kmemcheck/shadow.c16
-rw-r--r--arch/x86/mm/kmemcheck/shadow.h2
3 files changed, 17 insertions, 3 deletions
diff --git a/arch/x86/mm/kmemcheck/kmemcheck.c b/arch/x86/mm/kmemcheck/kmemcheck.c
index 8cc18334414..b3b531a4f8e 100644
--- a/arch/x86/mm/kmemcheck/kmemcheck.c
+++ b/arch/x86/mm/kmemcheck/kmemcheck.c
@@ -337,7 +337,7 @@ bool kmemcheck_is_obj_initialized(unsigned long addr, size_t size)
if (!shadow)
return true;
- status = kmemcheck_shadow_test(shadow, size);
+ status = kmemcheck_shadow_test_all(shadow, size);
return status == KMEMCHECK_SHADOW_INITIALIZED;
}
diff --git a/arch/x86/mm/kmemcheck/shadow.c b/arch/x86/mm/kmemcheck/shadow.c
index 3f66b82076a..aec124214d9 100644
--- a/arch/x86/mm/kmemcheck/shadow.c
+++ b/arch/x86/mm/kmemcheck/shadow.c
@@ -125,12 +125,12 @@ void kmemcheck_mark_initialized_pages(struct page *p, unsigned int n)
enum kmemcheck_shadow kmemcheck_shadow_test(void *shadow, unsigned int size)
{
+#ifdef CONFIG_KMEMCHECK_PARTIAL_OK
uint8_t *x;
unsigned int i;
x = shadow;
-#ifdef CONFIG_KMEMCHECK_PARTIAL_OK
/*
* Make sure _some_ bytes are initialized. Gcc frequently generates
* code to access neighboring bytes.
@@ -139,13 +139,25 @@ enum kmemcheck_shadow kmemcheck_shadow_test(void *shadow, unsigned int size)
if (x[i] == KMEMCHECK_SHADOW_INITIALIZED)
return x[i];
}
+
+ return x[0];
#else
+ return kmemcheck_shadow_test_all(shadow, size);
+#endif
+}
+
+enum kmemcheck_shadow kmemcheck_shadow_test_all(void *shadow, unsigned int size)
+{
+ uint8_t *x;
+ unsigned int i;
+
+ x = shadow;
+
/* All bytes must be initialized. */
for (i = 0; i < size; ++i) {
if (x[i] != KMEMCHECK_SHADOW_INITIALIZED)
return x[i];
}
-#endif
return x[0];
}
diff --git a/arch/x86/mm/kmemcheck/shadow.h b/arch/x86/mm/kmemcheck/shadow.h
index af46d9ab9d8..ff0b2f70fbc 100644
--- a/arch/x86/mm/kmemcheck/shadow.h
+++ b/arch/x86/mm/kmemcheck/shadow.h
@@ -11,6 +11,8 @@ enum kmemcheck_shadow {
void *kmemcheck_shadow_lookup(unsigned long address);
enum kmemcheck_shadow kmemcheck_shadow_test(void *shadow, unsigned int size);
+enum kmemcheck_shadow kmemcheck_shadow_test_all(void *shadow,
+ unsigned int size);
void kmemcheck_shadow_set(void *shadow, unsigned int size);
#endif