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mm/usercopy: Switch to using lm_alias

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The usercopy checking code currently calls __va(__pa(...)) to check for
aliases on symbols. Switch to using lm_alias instead.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
This commit is contained in:
Laura Abbott 2017-01-10 13:35:45 -08:00 committed by Will Deacon
parent 5c6a84a3f4
commit 46f6236aa1
1 changed files with 2 additions and 2 deletions
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4
mm/usercopy.c
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@ -108,13 +108,13 @@ static inline const char *check_kernel_text_object(const void *ptr,
* __pa() is not just the reverse of __va(). This can be detected
* and checked:
*/
textlow_linear = (unsigned long)__va(__pa(textlow));
textlow_linear = (unsigned long)lm_alias(textlow);
/* No different mapping: we're done. */
if (textlow_linear == textlow)
return NULL;
/* Check the secondary mapping... */
texthigh_linear = (unsigned long)__va(__pa(texthigh));
texthigh_linear = (unsigned long)lm_alias(texthigh);
if (overlaps(ptr, n, textlow_linear, texthigh_linear))
return "<linear kernel text>";