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authorJames Hogan <james.hogan@imgtec.com>2016-03-04 10:10:51 +0000
committerRalf Baechle <ralf@linux-mips.org>2016-03-13 10:59:19 +0100
commitd825c06bfe8b885b797f917ad47365d0e9c21fbb (patch)
parent7a50e4688dabb8005df39b2b992d76629b8af8aa (diff)
MIPS: smp.c: Fix uninitialised temp_foreign_map
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>
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c
index bd4385a8e6e8..2b521e07b860 100644
--- a/arch/mips/kernel/smp.c
+++ b/arch/mips/kernel/smp.c
@@ -121,6 +121,7 @@ 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)