diff options
| author | Rusty Russell <rusty@rustcorp.com.au> | 2009-03-17 14:50:34 +1030 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-03-18 09:40:35 +0100 |
| commit | 30e1e6d1af2b67558bccf322af2b3e0676b209ae (patch) | |
| tree | dae658631d0bb038c373cc2ba34ecf43f31ebd25 /arch/x86/kernel | |
| parent | 082edb7bf443eb8eda15b482d16ad9dd8137ad24 (diff) | |
cpumask: fix CONFIG_CPUMASK_OFFSTACK=y cpu hotunplug crash
Impact: Fix cpu offline when CONFIG_MAXSMP=y
Changeset bc9b83dd1f66402b870301c3c7117b9c1484abb4 "cpumask: convert
c1e_mask in arch/x86/kernel/process.c to cpumask_var_t" contained a
bug: c1e_mask is manipulated even if C1E isn't detected (and hence
not allocated).
This is simply fixed by checking for NULL (which gcc optimizes out
anyway of CONFIG_CPUMASK_OFFSTACK=n, since it knows ce1_mask can never
be NULL).
In addition, fix a leak where select_idle_routine re-allocates
(and re-clears) c1e_mask on every cpu init.
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Mike Travis <travis@sgi.com>
LKML-Reference: <200903171450.34549.rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel')
| -rw-r--r-- | arch/x86/kernel/cpu/common.c | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/process.c | 14 |
2 files changed, 12 insertions, 3 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 82f6cc045ad..d7dd3c294e2 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -812,6 +812,7 @@ static void vgetcpu_set_mode(void) void __init identify_boot_cpu(void) { identify_cpu(&boot_cpu_data); + init_c1e_mask(); #ifdef CONFIG_X86_32 sysenter_setup(); enable_sep_cpu(); diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 6638294cec8..78533a519d8 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -479,7 +479,8 @@ static int c1e_detected; void c1e_remove_cpu(int cpu) { - cpumask_clear_cpu(cpu, c1e_mask); + if (c1e_mask != NULL) + cpumask_clear_cpu(cpu, c1e_mask); } /* @@ -556,13 +557,20 @@ void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c) pm_idle = mwait_idle; } else if (check_c1e_idle(c)) { printk(KERN_INFO "using C1E aware idle routine\n"); - alloc_cpumask_var(&c1e_mask, GFP_KERNEL); - cpumask_clear(c1e_mask); pm_idle = c1e_idle; } else pm_idle = default_idle; } +void __init init_c1e_mask(void) +{ + /* If we're using c1e_idle, we need to allocate c1e_mask. */ + if (pm_idle == c1e_idle) { + alloc_cpumask_var(&c1e_mask, GFP_KERNEL); + cpumask_clear(c1e_mask); + } +} + static int __init idle_setup(char *str) { if (!str) |