diff options
| author | Huacai Chen <chenhc@lemote.com> | 2013-03-17 12:50:14 +0100 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2013-05-08 01:19:06 +0200 |
| commit | 224786779d04bbcd5f61eaafc86bf8fee350388a (patch) | |
| tree | 3db7c2ce9fdda70337de38ab344177b199153efb /arch | |
| parent | MIPS: Build uasm-generated code only once to avoid CPU Hotplug problem (diff) | |
| download | linux-224786779d04bbcd5f61eaafc86bf8fee350388a.tar.xz linux-224786779d04bbcd5f61eaafc86bf8fee350388a.zip | |
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 <chenhc@lemote.com>
Acked-by: David Daney <david.daney@cavium.com>
Patchwork: http://patchwork.linux-mips.org/patch/4995/
Acked-by: John Crispin <blogic@openwrt.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/mips/include/asm/mmu_context.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/mips/include/asm/mmu_context.h b/arch/mips/include/asm/mmu_context.h index e81d719efcd1..49d220ccc145 100644 --- a/arch/mips/include/asm/mmu_context.h +++ b/arch/mips/include/asm/mmu_context.h @@ -133,7 +133,7 @@ init_new_context(struct task_struct *tsk, struct mm_struct *mm) { int i; - for_each_online_cpu(i) + for_each_possible_cpu(i) cpu_context(i, mm) = 0; return 0; |