From: Huacai Chen Date: Sun, 17 Mar 2013 11:50:14 +0000 (+0000) Subject: MIPS: Init new mmu_context for each possible CPU to avoid memory corruption X-Git-Tag: v3.10-rc1~15^2~2^2~33 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=224786779d04bbcd5f61eaafc86bf8fee350388a;p=pandora-kernel.git MIPS: Init new mmu_context for each possible CPU to avoid memory corruption Currently, init_new_context() only for each online CPU, this may cause memory corruption when CPU hotplug and fork() happens at the same time. To avoid this, we make init_new_context() cover each possible CPU. Scenario: 1, CPU#1 is being offline; 2, On CPU#0, do_fork() call dup_mm() and copy a mm_struct to the child; 3, On CPU#0, dup_mm() call init_new_context(), since CPU#1 is offline and init_new_context() only covers the online CPUs, child has the same asid as its parent on CPU#1 (however, child's asid should be 0); 4, CPU#1 is being online; 5, Now, if both parent and child run on CPU#1, memory corruption (e.g. segfault, bus error, etc.) will occur. Signed-off-by: Huacai Chen Acked-by: David Daney Patchwork: http://patchwork.linux-mips.org/patch/4995/ Acked-by: John Crispin --- Reading git-diff-tree failed