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| author | Felix Fietkau <nbd@openwrt.org> | 2016-03-07 21:00:46 +0000 |
|---|---|---|
| committer | Felix Fietkau <nbd@openwrt.org> | 2016-03-07 21:00:46 +0000 |
| commit | b9f52b6b869b52d52893ed2604f49689bda9a378 (patch) | |
| tree | c81bfde2e12db9a75432bf469fce269a8216b6aa | |
| parent | 46c7d0d1ab610701b91ac9ba465e63f51e80ee06 (diff) | |
| download | master-31e0f0ae-b9f52b6b869b52d52893ed2604f49689bda9a378.tar.gz master-31e0f0ae-b9f52b6b869b52d52893ed2604f49689bda9a378.tar.bz2 master-31e0f0ae-b9f52b6b869b52d52893ed2604f49689bda9a378.zip | |
kernel: add MIPS kernel fix for an uninitialized CPU map
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
SVN-Revision: 48956
| -rw-r--r-- | target/linux/generic/patches-4.4/103-MIPS-smp.c-Fix-uninitialised-temp_foreign_map.patch | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/target/linux/generic/patches-4.4/103-MIPS-smp.c-Fix-uninitialised-temp_foreign_map.patch b/target/linux/generic/patches-4.4/103-MIPS-smp.c-Fix-uninitialised-temp_foreign_map.patch new file mode 100644 index 0000000000..6fe9d96ccc --- /dev/null +++ b/target/linux/generic/patches-4.4/103-MIPS-smp.c-Fix-uninitialised-temp_foreign_map.patch @@ -0,0 +1,31 @@ +From: James Hogan <james.hogan@imgtec.com> +Date: Fri, 4 Mar 2016 10:10:51 +0000 +Subject: [PATCH] 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: Ralf Baechle <ralf@linux-mips.org> +Cc: Paul Burton <paul.burton@imgtec.com> +Cc: linux-mips@linux-mips.org +--- + +--- a/arch/mips/kernel/smp.c ++++ b/arch/mips/kernel/smp.c +@@ -121,6 +121,7 @@ static inline void calculate_cpu_foreign + 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) |