Otherwise arch_task_struct_size == 0 and we die. While we're at it,
set X86_FEATURE_ALWAYS, too.
Cc: stable@xxxxxxxxxxxxxxx
Cc: Dave Hansen <dave@xxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Fixes: aaeb5c01c5b ("x86/fpu, sched: Introduce CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT and use it on x86")
Reported-by: david@xxxxxxxxxxxxxx
Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
---
Totally untested except by the 0-day bot, since I don't have an
affected machine and QEMU can't emulate anything without CPUID.
arch/x86/kernel/cpu/common.c | 23 +++++++++++------------
1 file changed, 11 insertions(+), 12 deletions(-)
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 809eda03c527..bcc9ccc220c9 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -804,21 +804,20 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c)
identify_cpu_without_cpuid(c);
/* cyrix could have cpuid enabled via c_identify()*/
- if (!have_cpuid_p())
- return;
+ if (have_cpuid_p()) {
+ cpu_detect(c);
+ get_cpu_vendor(c);
+ get_cpu_cap(c);
- cpu_detect(c);
- get_cpu_vendor(c);
- get_cpu_cap(c);
-
- if (this_cpu->c_early_init)
- this_cpu->c_early_init(c);
+ if (this_cpu->c_early_init)
+ this_cpu->c_early_init(c);
- c->cpu_index = 0;
- filter_cpuid_features(c, false);
+ c->cpu_index = 0;
+ filter_cpuid_features(c, false);
- if (this_cpu->c_bsp_init)
- this_cpu->c_bsp_init(c);
+ if (this_cpu->c_bsp_init)
+ this_cpu->c_bsp_init(c);
+ }
setup_force_cpu_cap(X86_FEATURE_ALWAYS);
fpu__init_system(c);
--
2.7.4
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html