Comments
Patch
@@ -170,8 +170,11 @@ static int __amd64_set_scrub_rate(struct pci_dev *ctl, u32 new_bw, u32 min_rate)
* memory controller and apply to register. Search for the first
* bandwidth entry that is greater or equal than the setting requested
* and program that. If at last entry, turn off DRAM scrubbing.
+ *
+ * If no suitable bandwidth is found, turn off DRAM scrubbing entirely
+ * by falling back to the last element in scrubrates[].
*/
- for (i = 0; i < ARRAY_SIZE(scrubrates); i++) {
+ for (i = 0; i < ARRAY_SIZE(scrubrates) - 1; i++) {
/*
* skip scrub rates which aren't recommended
* (see F10 BKDG, F3x58)
@@ -181,12 +184,6 @@ static int __amd64_set_scrub_rate(struct pci_dev *ctl, u32 new_bw, u32 min_rate)
if (scrubrates[i].bandwidth <= new_bw)
break;
-
- /*
- * if no suitable bandwidth found, turn off DRAM scrubbing
- * entirely by falling back to the last element in the
- * scrubrates array.
- */
}
scrubval = scrubrates[i].scrubval;
This is a note to let you know that I have just added a patch titled amd64_edac:__amd64_set_scrub_rate(): avoid overindexing to the linux-3.5.y-queue branch of the 3.5.yuz extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.5.yuz tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Herton ------ From c41e0bb334eb41b90440f0b2fa88622a331303d7 Mon Sep 17 00:00:00 2001 From: Andrew Morton <akpm@linux-foundation.org> Date: Tue, 23 Oct 2012 14:09:39 -0700 Subject: [PATCH] amd64_edac:__amd64_set_scrub_rate(): avoid overindexing scrubrates[] commit 168bfeef7bba3f9784f7540b053e4ac72b769ce9 upstream. If none of the elements in scrubrates[] matches, this loop will cause __amd64_set_scrub_rate() to incorrectly use the n+1th element. As the function is designed to use the final scrubrates[] element in the case of no match, we can fix this bug by simply terminating the array search at the n-1th element. Boris: this code is fragile anyway, see here why: http://marc.info/?l=linux-kernel&m=135102834131236&w=2 It will be rewritten more robustly soonish. Reported-by: Denis Kirjanov <kirjanov@gmail.com> Cc: Doug Thompson <dougthompson@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Borislav Petkov <borislav.petkov@amd.com> Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> --- drivers/edac/amd64_edac.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) -- 1.7.9.5