Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.kernel > #1493694 > unrolled thread
| Started by | Andy Lutomirski <luto@kernel.org> |
|---|---|
| First post | 2016-09-29 21:50 +0200 |
| Last post | 2016-09-30 12:50 +0200 |
| Articles | 3 — 3 participants |
Back to article view | Back to linux.kernel
This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by
below is the oldest one visible, not the original post.
[PATCH v2 1/2] x86/boot: Fix another __read_cr4() case on 486 Andy Lutomirski <luto@kernel.org> - 2016-09-29 21:50 +0200
Re: [PATCH v2 1/2] x86/boot: Fix another __read_cr4() case on 486 Borislav Petkov <bp@alien8.de> - 2016-09-30 00:40 +0200
[tip:x86/urgent] x86/boot: Fix another __read_cr4() case on 486 tip-bot for Andy Lutomirski <tipbot@zytor.com> - 2016-09-30 12:50 +0200
| From | Andy Lutomirski <luto@kernel.org> |
|---|---|
| Date | 2016-09-29 21:50 +0200 |
| Subject | [PATCH v2 1/2] x86/boot: Fix another __read_cr4() case on 486 |
| Message-ID | <smPvb-8lN-3@gated-at.bofh.it> |
The condition for reading CR4 was wrong: there are some CPUs with
CPUID but not CR4. Rather than trying to make the condition exact,
using __read_cr4_safe().
Reported-by: david@saggiorato.net
Fixes: 18bc7bd523e0 ("x86/boot: Synchronize trampoline_cr4_features and mmu_cr4_features directly")
Signed-off-by: Andy Lutomirski <luto@kernel.org>
---
arch/x86/kernel/setup.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 0fa60f5f5a16..98c9cd6f3b5d 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1137,9 +1137,7 @@ void __init setup_arch(char **cmdline_p)
* auditing all the early-boot CR4 manipulation would be needed to
* rule it out.
*/
- if (boot_cpu_data.cpuid_level >= 0)
- /* A CPU has %cr4 if and only if it has CPUID. */
- mmu_cr4_features = __read_cr4();
+ mmu_cr4_features = __read_cr4_safe();
memblock_set_current_limit(get_max_mapped());
--
2.7.4
[toc] | [next] | [standalone]
| From | Borislav Petkov <bp@alien8.de> |
|---|---|
| Date | 2016-09-30 00:40 +0200 |
| Message-ID | <smS9H-1Ph-9@gated-at.bofh.it> |
| In reply to | #1493694 |
On Thu, Sep 29, 2016 at 12:48:11PM -0700, Andy Lutomirski wrote:
> The condition for reading CR4 was wrong: there are some CPUs with
> CPUID but not CR4. Rather than trying to make the condition exact,
> using __read_cr4_safe().
Please s/using/use/ while applying.
> Reported-by: david@saggiorato.net
> Fixes: 18bc7bd523e0 ("x86/boot: Synchronize trampoline_cr4_features and mmu_cr4_features directly")
> Signed-off-by: Andy Lutomirski <luto@kernel.org>
> ---
> arch/x86/kernel/setup.c | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
> index 0fa60f5f5a16..98c9cd6f3b5d 100644
> --- a/arch/x86/kernel/setup.c
> +++ b/arch/x86/kernel/setup.c
> @@ -1137,9 +1137,7 @@ void __init setup_arch(char **cmdline_p)
> * auditing all the early-boot CR4 manipulation would be needed to
> * rule it out.
> */
> - if (boot_cpu_data.cpuid_level >= 0)
> - /* A CPU has %cr4 if and only if it has CPUID. */
> - mmu_cr4_features = __read_cr4();
> + mmu_cr4_features = __read_cr4_safe();
>
> memblock_set_current_limit(get_max_mapped());
>
> --
Reviewed-by: Borislav Petkov <bp@suse.de>
--
Regards/Gruss,
Boris.
ECO tip #101: Trim your mails when you reply.
--
[toc] | [prev] | [next] | [standalone]
| From | tip-bot for Andy Lutomirski <tipbot@zytor.com> |
|---|---|
| Date | 2016-09-30 12:50 +0200 |
| Subject | [tip:x86/urgent] x86/boot: Fix another __read_cr4() case on 486 |
| Message-ID | <sn3ya-FI-13@gated-at.bofh.it> |
| In reply to | #1493694 |
Commit-ID: 192d1dccbfc5b901b66527df9df80304693cf06e
Gitweb: http://git.kernel.org/tip/192d1dccbfc5b901b66527df9df80304693cf06e
Author: Andy Lutomirski <luto@kernel.org>
AuthorDate: Thu, 29 Sep 2016 12:48:11 -0700
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Fri, 30 Sep 2016 12:37:40 +0200
x86/boot: Fix another __read_cr4() case on 486
The condition for reading CR4 was wrong: there are some CPUs with
CPUID but not CR4. Rather than trying to make the condition exact,
use __read_cr4_safe().
Fixes: 18bc7bd523e0 ("x86/boot: Synchronize trampoline_cr4_features and mmu_cr4_features directly")
Reported-by: david@saggiorato.net
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Reviewed-by: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Link: http://lkml.kernel.org/r/8c453a61c4f44ab6ff43c29780ba04835234d2e5.1475178369.git.luto@kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
arch/x86/kernel/setup.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 0fa60f5..98c9cd6 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1137,9 +1137,7 @@ void __init setup_arch(char **cmdline_p)
* auditing all the early-boot CR4 manipulation would be needed to
* rule it out.
*/
- if (boot_cpu_data.cpuid_level >= 0)
- /* A CPU has %cr4 if and only if it has CPUID. */
- mmu_cr4_features = __read_cr4();
+ mmu_cr4_features = __read_cr4_safe();
memblock_set_current_limit(get_max_mapped());
[toc] | [prev] | [standalone]
Back to top | Article view | linux.kernel
csiph-web