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authorJames Hogan <james.hogan@imgtec.com>2016-03-04 10:10:51 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-03-16 08:43:01 -0700
commita2cee580a541ab6f3ed75fe35b11d8074c2b58a1 (patch)
tree129ee11cc7fe13a7bd3942b3958579021dcf0b67
parent588bad2ef32cae7abad24d5ca2f4611a7a7fb2a2 (diff)
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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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--arch/mips/kernel/smp.c1
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)