EDAC: Fix calculation of returned address and next offset in edac_align_ptr()

Do alignment logic properly and use the "ptr" local variable for
calculating the remainder of the alignment.

This became an issue because struct edac_mc_layer has a size that is not
zero modulo eight, and the next offset that was prepared for the private
data was unaligned, causing an alignment exception.

The patch in Fixes: which broke this actually wanted to "what we
actually care about is the alignment of the actual pointer that's about
to be returned." But it didn't check that alignment.

Use the correct variable "ptr" for that.

  [ bp: Massage commit message. ]

Fixes: 8447c4d15e35 ("edac: Do alignment logic properly in edac_align_ptr()")
Signed-off-by: Eliav Farber <farbere@amazon.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20220113100622.12783-2-farbere@amazon.com

diff --git a/drivers/edac/edac_mc.c b/drivers/edac/edac_mc.c
index 9d9aabdec96b78e3f758daa816ef679078166fb7..f5677d81bd2d5675fe5f4dc261c73d893bb911b3 100644 (file)
--- a/drivers/edac/edac_mc.c
+++ b/drivers/edac/edac_mc.c
@@ -215,7 +215,7 @@ void *edac_align_ptr(void **p, unsigned int size, int n_elems)
        else
                return (char *)ptr;
 
-       r = (unsigned long)p % align;
+       r = (unsigned long)ptr % align;
 
        if (r == 0)
                return (char *)ptr;