[PATCH] poison invalid cpus
From: Olaf Hering <hidden>
Date: 2006-02-10 14:00:16
from Anton Blanchard [off-list ref] Novell bug145459 Ensure that per cpu access to !possible cpus causes a fault instead of silent corruption. Signed-off-by: Olaf Hering <redacted> arch/powerpc/kernel/setup_64.c | 8 ++++++++ 1 files changed, 8 insertions(+) Index: linux-2.6.16-rc1-git3/arch/powerpc/kernel/setup_64.c ===================================================================
--- linux-2.6.16-rc1-git3.orig/arch/powerpc/kernel/setup_64.c
+++ linux-2.6.16-rc1-git3/arch/powerpc/kernel/setup_64.c@@ -670,6 +670,14 @@ void __init setup_per_cpu_areas(void) size = PERCPU_ENOUGH_ROOM; #endif + /* + * Poison invalid cpus, with lots of high bits set this should + * always fault + */ + for (i = 0; i < NR_CPUS; i++) { + paca[i].data_offset = 0xeeeeeeeeeeeeeeeeULL; + } + for_each_cpu(i) { ptr = alloc_bootmem_node(NODE_DATA(cpu_to_node(i)), size); if (!ptr)
--
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