* [RFC PATCH] x86/boot: Initialize FPU and X86_FEATURE_ALWAYS even if we don't have CPUID
@ 2016-09-28 23:06 Andy Lutomirski
2016-09-30 8:32 ` David Saggiorato
2016-09-30 12:06 ` [tip:x86/urgent] " tip-bot for Andy Lutomirski
0 siblings, 2 replies; 4+ messages in thread
From: Andy Lutomirski @ 2016-09-28 23:06 UTC (permalink / raw)
To: x86
Cc: david, Borislav Petkov, Brian Gerst, linux-kernel,
Andy Lutomirski, stable, Dave Hansen, Ingo Molnar
Otherwise arch_task_struct_size == 0 and we die. While we're at it,
set X86_FEATURE_ALWAYS, too.
Cc: stable@vger.kernel.org
Cc: Dave Hansen <dave@sr71.net>
Cc: Ingo Molnar <mingo@kernel.org>
Fixes: aaeb5c01c5b ("x86/fpu, sched: Introduce CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT and use it on x86")
Reported-by: david@saggiorato.net
Signed-off-by: Andy Lutomirski <luto@kernel.org>
---
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
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [RFC PATCH] x86/boot: Initialize FPU and X86_FEATURE_ALWAYS even if we don't have CPUID
2016-09-28 23:06 [RFC PATCH] x86/boot: Initialize FPU and X86_FEATURE_ALWAYS even if we don't have CPUID Andy Lutomirski
@ 2016-09-30 8:32 ` David Saggiorato
2016-09-30 12:06 ` [tip:x86/urgent] " tip-bot for Andy Lutomirski
1 sibling, 0 replies; 4+ messages in thread
From: David Saggiorato @ 2016-09-30 8:32 UTC (permalink / raw)
To: Andy Lutomirski, x86
Cc: Borislav Petkov, Brian Gerst, linux-kernel, stable, Dave Hansen,
Ingo Molnar
[-- Attachment #1: Type: text/plain, Size: 1891 bytes --]
Tested-by: David Saggiorato <david@saggiorato.net>Le mercredi 28 septembre 2016 à 16:06 -0700, Andy Lutomirski a écrit :
> Otherwise arch_task_struct_size == 0 and we die. While we're at it,
> set X86_FEATURE_ALWAYS, too.
>
> Cc: stable@vger.kernel.org
> Cc: Dave Hansen <dave@sr71.net>
> Cc: Ingo Molnar <mingo@kernel.org>
> Fixes: aaeb5c01c5b ("x86/fpu, sched: Introduce
> CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT and use it on x86")
> Reported-by: david@saggiorato.net
> Signed-off-by: Andy Lutomirski <luto@kernel.org>
> ---
>
> 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);
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^ permalink raw reply [flat|nested] 4+ messages in thread
* [tip:x86/urgent] x86/boot: Initialize FPU and X86_FEATURE_ALWAYS even if we don't have CPUID
2016-09-28 23:06 [RFC PATCH] x86/boot: Initialize FPU and X86_FEATURE_ALWAYS even if we don't have CPUID Andy Lutomirski
2016-09-30 8:32 ` David Saggiorato
@ 2016-09-30 12:06 ` tip-bot for Andy Lutomirski
2016-09-30 15:15 ` Borislav Petkov
1 sibling, 1 reply; 4+ messages in thread
From: tip-bot for Andy Lutomirski @ 2016-09-30 12:06 UTC (permalink / raw)
To: linux-tip-commits
Cc: david, brgerst, peterz, dave, dvlasenk, mingo, bp, jpoimboe, hpa,
luto, tglx, linux-kernel, torvalds
Commit-ID: 05fb3c199bb09f5b85de56cc3ede194ac95c5e1f
Gitweb: http://git.kernel.org/tip/05fb3c199bb09f5b85de56cc3ede194ac95c5e1f
Author: Andy Lutomirski <luto@kernel.org>
AuthorDate: Wed, 28 Sep 2016 16:06:33 -0700
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Fri, 30 Sep 2016 13:53:04 +0200
x86/boot: Initialize FPU and X86_FEATURE_ALWAYS even if we don't have CPUID
Otherwise arch_task_struct_size == 0 and we die. While we're at it,
set X86_FEATURE_ALWAYS, too.
Reported-by: David Saggiorato <david@saggiorato.net>
Tested-by: David Saggiorato <david@saggiorato.net>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Fixes: aaeb5c01c5b ("x86/fpu, sched: Introduce CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT and use it on x86")
Link: http://lkml.kernel.org/r/8de723afbf0811071185039f9088733188b606c9.1475103911.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
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 809eda0..bcc9ccc 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);
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [tip:x86/urgent] x86/boot: Initialize FPU and X86_FEATURE_ALWAYS even if we don't have CPUID
2016-09-30 12:06 ` [tip:x86/urgent] " tip-bot for Andy Lutomirski
@ 2016-09-30 15:15 ` Borislav Petkov
0 siblings, 0 replies; 4+ messages in thread
From: Borislav Petkov @ 2016-09-30 15:15 UTC (permalink / raw)
To: Andy Lutomirski
Cc: linux-tip-commits, david, brgerst, peterz, dave, dvlasenk, mingo,
jpoimboe, hpa, luto, tglx, linux-kernel, torvalds
On Fri, Sep 30, 2016 at 05:06:46AM -0700, tip-bot for Andy Lutomirski wrote:
> Commit-ID: 05fb3c199bb09f5b85de56cc3ede194ac95c5e1f
> Gitweb: http://git.kernel.org/tip/05fb3c199bb09f5b85de56cc3ede194ac95c5e1f
> Author: Andy Lutomirski <luto@kernel.org>
> AuthorDate: Wed, 28 Sep 2016 16:06:33 -0700
> Committer: Ingo Molnar <mingo@kernel.org>
> CommitDate: Fri, 30 Sep 2016 13:53:04 +0200
>
> x86/boot: Initialize FPU and X86_FEATURE_ALWAYS even if we don't have CPUID
>
> Otherwise arch_task_struct_size == 0 and we die. While we're at it,
> set X86_FEATURE_ALWAYS, too.
...
> diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
> index 809eda0..bcc9ccc 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()) {
Let's make it even simpler:
---
From: Borislav Petkov <bp@suse.de>
Date: Fri, 30 Sep 2016 17:08:10 +0200
Subject: [PATCH] x86/boot: Streamline CPUID check conditional
We have now:
if (!have_cpuid_p())
...
if (have_cpuid_p())
...
Turn it into a good, ole if-else conditional which is much more
readable.
No functionality change.
Signed-off-by: Borislav Petkov <bp@suse.de>
---
arch/x86/kernel/cpu/common.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 9bd910a7dd0a..0a6fa6174ed8 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -800,9 +800,6 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c)
memset(&c->x86_capability, 0, sizeof c->x86_capability);
c->extended_cpuid_level = 0;
- if (!have_cpuid_p())
- identify_cpu_without_cpuid(c);
-
/* cyrix could have cpuid enabled via c_identify()*/
if (have_cpuid_p()) {
cpu_detect(c);
@@ -817,6 +814,8 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c)
if (this_cpu->c_bsp_init)
this_cpu->c_bsp_init(c);
+ } else {
+ identify_cpu_without_cpuid(c);
}
setup_force_cpu_cap(X86_FEATURE_ALWAYS);
--
2.8.4
--
Regards/Gruss,
Boris.
ECO tip #101: Trim your mails when you reply.
--
^ permalink raw reply related [flat|nested] 4+ messages in thread
end of thread, other threads:[~2016-09-30 15:15 UTC | newest]
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2016-09-28 23:06 [RFC PATCH] x86/boot: Initialize FPU and X86_FEATURE_ALWAYS even if we don't have CPUID Andy Lutomirski
2016-09-30 8:32 ` David Saggiorato
2016-09-30 12:06 ` [tip:x86/urgent] " tip-bot for Andy Lutomirski
2016-09-30 15:15 ` Borislav Petkov
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