| Message ID | 1458084399-21938-1-git-send-email-kamal@canonical.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c index a31896c..df62553 100644 --- a/arch/mips/kernel/smp.c +++ b/arch/mips/kernel/smp.c @@ -120,6 +120,7 @@ static inline void calculate_cpu_foreign_map(void) cpumask_t temp_foreign_map; /* Re-calculate the mask */ + cpumask_clear(&temp_foreign_map); for_each_online_cpu(i) { core_present = 0; for_each_cpu(k, &temp_foreign_map)
This is a note to let you know that I have just added a patch titled MIPS: smp.c: Fix uninitialised temp_foreign_map to the linux-4.2.y-queue branch of the 4.2.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-4.2.y-queue This patch is scheduled to be released in version 4.2.8-ckt6. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 4.2.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ---8<------------------------------------------------------------ From 244c83b790a98f3bda9779cb2ad43f50141d8584 Mon Sep 17 00:00:00 2001 From: James Hogan <james.hogan@imgtec.com> Date: Fri, 4 Mar 2016 10:10:51 +0000 Subject: MIPS: smp.c: Fix uninitialised temp_foreign_map commit d825c06bfe8b885b797f917ad47365d0e9c21fbb upstream. When calculate_cpu_foreign_map() recalculates the cpu_foreign_map cpumask it uses the local variable temp_foreign_map without initialising it to zero. Since the calculation only ever sets bits in this cpumask any existing bits at that memory location will remain set and find their way into cpu_foreign_map too. This could potentially lead to cache operations suboptimally doing smp calls to multiple VPEs in the same core, even though the VPEs share primary caches. Therefore initialise temp_foreign_map using cpumask_clear() before use. Fixes: cccf34e9411c ("MIPS: c-r4k: Fix cache flushing for MT cores") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/12759/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- arch/mips/kernel/smp.c | 1 + 1 file changed, 1 insertion(+) -- 2.7.0