31 lines
1.2 KiB
Diff
31 lines
1.2 KiB
Diff
From: James Hogan <james.hogan@imgtec.com>
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Date: Fri, 4 Mar 2016 10:10:51 +0000
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Subject: [PATCH] MIPS: smp.c: Fix uninitialised temp_foreign_map
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When calculate_cpu_foreign_map() recalculates the cpu_foreign_map
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cpumask it uses the local variable temp_foreign_map without initialising
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it to zero. Since the calculation only ever sets bits in this cpumask
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any existing bits at that memory location will remain set and find their
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way into cpu_foreign_map too. This could potentially lead to cache
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operations suboptimally doing smp calls to multiple VPEs in the same
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core, even though the VPEs share primary caches.
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Therefore initialise temp_foreign_map using cpumask_clear() before use.
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Fixes: cccf34e9411c ("MIPS: c-r4k: Fix cache flushing for MT cores")
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Signed-off-by: James Hogan <james.hogan@imgtec.com>
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Cc: Ralf Baechle <ralf@linux-mips.org>
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Cc: Paul Burton <paul.burton@imgtec.com>
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Cc: linux-mips@linux-mips.org
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---
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--- a/arch/mips/kernel/smp.c
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+++ b/arch/mips/kernel/smp.c
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@@ -121,6 +121,7 @@ static inline void calculate_cpu_foreign
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cpumask_t temp_foreign_map;
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/* Re-calculate the mask */
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+ cpumask_clear(&temp_foreign_map);
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for_each_online_cpu(i) {
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core_present = 0;
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for_each_cpu(k, &temp_foreign_map)
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