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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 | 48a5431777fa6cd7b369073a2cb1f1b4b0f76911 (patch) | |
| tree | 6404243ed431d510c1f9a4c1b94173b2b05fbaaf | |
| parent | d37e8522233419d629d611c836794cb320d97388 (diff) | |
| download | master-187ad058-48a5431777fa6cd7b369073a2cb1f1b4b0f76911.tar.gz master-187ad058-48a5431777fa6cd7b369073a2cb1f1b4b0f76911.tar.bz2 master-187ad058-48a5431777fa6cd7b369073a2cb1f1b4b0f76911.zip | |
kernel: add MIPS kernel fix for an uninitialized CPU map
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@48956 3c298f89-4303-0410-b956-a3cf2f4a3e73
| -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) |