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* [PATCH] x86/asm/entry/64: fold test_in_nmi macro into its only user
@ 2015-04-01 14:50 Denys Vlasenko
  2015-04-01 14:50 ` [PATCH] x86/asm/head/64: Use __BOOT_TSS instead of literal 0x20 Denys Vlasenko
                   ` (2 more replies)
  0 siblings, 3 replies; 7+ messages in thread
From: Denys Vlasenko @ 2015-04-01 14:50 UTC (permalink / raw)
  To: Ingo Molnar
  Cc: Denys Vlasenko, Linus Torvalds, Steven Rostedt, Borislav Petkov,
	H. Peter Anvin, Andy Lutomirski, Oleg Nesterov,
	Frederic Weisbecker, Alexei Starovoitov, Will Drewry, Kees Cook,
	x86, linux-kernel

No code changes.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Acked-by: Borislav Petkov <bp@suse.de>
CC: Linus Torvalds <torvalds@linux-foundation.org>
CC: Steven Rostedt <rostedt@goodmis.org>
CC: Ingo Molnar <mingo@kernel.org>
CC: Borislav Petkov <bp@alien8.de>
CC: "H. Peter Anvin" <hpa@zytor.com>
CC: Andy Lutomirski <luto@amacapital.net>
CC: Oleg Nesterov <oleg@redhat.com>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: Alexei Starovoitov <ast@plumgrid.com>
CC: Will Drewry <wad@chromium.org>
CC: Kees Cook <keescook@chromium.org>
CC: x86@kernel.org
CC: linux-kernel@vger.kernel.org
---

Changes since v1: added comments as requested by Steven Rostedt

 arch/x86/kernel/entry_64.S | 28 +++++++++++++---------------
 1 file changed, 13 insertions(+), 15 deletions(-)

diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index e498542..175393d 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -1355,19 +1355,7 @@ ENTRY(error_exit)
 	CFI_ENDPROC
 END(error_exit)
 
-/*
- * Test if a given stack is an NMI stack or not.
- */
-	.macro test_in_nmi reg stack nmi_ret normal_ret
-	cmpq %\reg, \stack
-	ja \normal_ret
-	subq $EXCEPTION_STKSZ, %\reg
-	cmpq %\reg, \stack
-	jb \normal_ret
-	jmp \nmi_ret
-	.endm
-
-	/* runs on exception stack */
+/* Runs on exception stack */
 ENTRY(nmi)
 	INTR_FRAME
 	PARAVIRT_ADJUST_EXCEPTION_FRAME
@@ -1428,8 +1416,18 @@ ENTRY(nmi)
 	 * We check the variable because the first NMI could be in a
 	 * breakpoint routine using a breakpoint stack.
 	 */
-	lea 6*8(%rsp), %rdx
-	test_in_nmi rdx, 4*8(%rsp), nested_nmi, first_nmi
+	lea	6*8(%rsp), %rdx
+	/* Compare the NMI stack (rdx) with the stack we came from (4*8(%rsp)) */
+	cmpq	%rdx, 4*8(%rsp)
+	/* If the stack pointer is above the NMI stack, this is a normal NMI */
+	ja	first_nmi
+	subq	$EXCEPTION_STKSZ, %rdx
+	cmpq	%rdx, 4*8(%rsp)
+	/* If it is below the NMI stack, it is a normal NMI */
+	jb	first_nmi
+	/* Ah, it is within the NMI stack, treat it as nested */
+	jmp	nested_nmi
+
 	CFI_REMEMBER_STATE
 
 nested_nmi:
-- 
1.8.1.4


^ permalink raw reply	[flat|nested] 7+ messages in thread

* [PATCH] x86/asm/head/64: Use __BOOT_TSS instead of literal 0x20
  2015-04-01 14:50 [PATCH] x86/asm/entry/64: fold test_in_nmi macro into its only user Denys Vlasenko
@ 2015-04-01 14:50 ` Denys Vlasenko
  2015-04-01 16:46   ` Borislav Petkov
                     ` (2 more replies)
  2015-04-01 15:45 ` [PATCH] x86/asm/entry/64: fold test_in_nmi macro into its only user Steven Rostedt
  2015-04-02 12:33 ` [tip:x86/asm] x86/asm/entry/64: Fold the 'test_in_nmi' " tip-bot for Denys Vlasenko
  2 siblings, 3 replies; 7+ messages in thread
From: Denys Vlasenko @ 2015-04-01 14:50 UTC (permalink / raw)
  To: Ingo Molnar
  Cc: Denys Vlasenko, Linus Torvalds, Steven Rostedt, Borislav Petkov,
	H. Peter Anvin, Andy Lutomirski, Oleg Nesterov,
	Frederic Weisbecker, Alexei Starovoitov, Will Drewry, Kees Cook,
	x86, linux-kernel

No code changes.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
CC: Linus Torvalds <torvalds@linux-foundation.org>
CC: Steven Rostedt <rostedt@goodmis.org>
CC: Ingo Molnar <mingo@kernel.org>
CC: Borislav Petkov <bp@alien8.de>
CC: "H. Peter Anvin" <hpa@zytor.com>
CC: Andy Lutomirski <luto@amacapital.net>
CC: Oleg Nesterov <oleg@redhat.com>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: Alexei Starovoitov <ast@plumgrid.com>
CC: Will Drewry <wad@chromium.org>
CC: Kees Cook <keescook@chromium.org>
CC: x86@kernel.org
CC: linux-kernel@vger.kernel.org
---
 arch/x86/boot/compressed/head_64.S | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index 90c1521..b0c0d16 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -165,7 +165,7 @@ ENTRY(startup_32)
 	/* After gdt is loaded */
 	xorl	%eax, %eax
 	lldt	%ax
-	movl    $0x20, %eax
+	movl    $__BOOT_TSS, %eax
 	ltr	%ax
 
 	/*
-- 
1.8.1.4


^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH] x86/asm/entry/64: fold test_in_nmi macro into its only user
  2015-04-01 14:50 [PATCH] x86/asm/entry/64: fold test_in_nmi macro into its only user Denys Vlasenko
  2015-04-01 14:50 ` [PATCH] x86/asm/head/64: Use __BOOT_TSS instead of literal 0x20 Denys Vlasenko
@ 2015-04-01 15:45 ` Steven Rostedt
  2015-04-02 12:33 ` [tip:x86/asm] x86/asm/entry/64: Fold the 'test_in_nmi' " tip-bot for Denys Vlasenko
  2 siblings, 0 replies; 7+ messages in thread
From: Steven Rostedt @ 2015-04-01 15:45 UTC (permalink / raw)
  To: Denys Vlasenko
  Cc: Ingo Molnar, Linus Torvalds, Borislav Petkov, H. Peter Anvin,
	Andy Lutomirski, Oleg Nesterov, Frederic Weisbecker,
	Alexei Starovoitov, Will Drewry, Kees Cook, x86, linux-kernel

On Wed,  1 Apr 2015 16:50:57 +0200
Denys Vlasenko <dvlasenk@redhat.com> wrote:

> -	/* runs on exception stack */
> +/* Runs on exception stack */
>  ENTRY(nmi)
>  	INTR_FRAME
>  	PARAVIRT_ADJUST_EXCEPTION_FRAME
> @@ -1428,8 +1416,18 @@ ENTRY(nmi)
>  	 * We check the variable because the first NMI could be in a
>  	 * breakpoint routine using a breakpoint stack.
>  	 */
> -	lea 6*8(%rsp), %rdx
> -	test_in_nmi rdx, 4*8(%rsp), nested_nmi, first_nmi
> +	lea	6*8(%rsp), %rdx
> +	/* Compare the NMI stack (rdx) with the stack we came from (4*8(%rsp)) */
> +	cmpq	%rdx, 4*8(%rsp)
> +	/* If the stack pointer is above the NMI stack, this is a normal NMI */
> +	ja	first_nmi
> +	subq	$EXCEPTION_STKSZ, %rdx
> +	cmpq	%rdx, 4*8(%rsp)
> +	/* If it is below the NMI stack, it is a normal NMI */
> +	jb	first_nmi
> +	/* Ah, it is within the NMI stack, treat it as nested */
> +	jmp	nested_nmi

I guess we can get rid of the jmp nested_nmi, as it just jumps to the
next instruction. Although, I would keep the comment.

-- Steve

> +
>  	CFI_REMEMBER_STATE
>  
>  nested_nmi:


^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH] x86/asm/head/64: Use __BOOT_TSS instead of literal 0x20
  2015-04-01 14:50 ` [PATCH] x86/asm/head/64: Use __BOOT_TSS instead of literal 0x20 Denys Vlasenko
@ 2015-04-01 16:46   ` Borislav Petkov
  2015-04-01 17:01   ` Steven Rostedt
  2015-04-02 12:33   ` [tip:x86/asm] x86/asm/boot/64: Use __BOOT_TSS instead of literal $0x20 tip-bot for Denys Vlasenko
  2 siblings, 0 replies; 7+ messages in thread
From: Borislav Petkov @ 2015-04-01 16:46 UTC (permalink / raw)
  To: Denys Vlasenko
  Cc: Ingo Molnar, Linus Torvalds, Steven Rostedt, H. Peter Anvin,
	Andy Lutomirski, Oleg Nesterov, Frederic Weisbecker,
	Alexei Starovoitov, Will Drewry, Kees Cook, x86, linux-kernel

On Wed, Apr 01, 2015 at 04:50:58PM +0200, Denys Vlasenko wrote:
> No code changes.
> 
> Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
> CC: Linus Torvalds <torvalds@linux-foundation.org>
> CC: Steven Rostedt <rostedt@goodmis.org>
> CC: Ingo Molnar <mingo@kernel.org>
> CC: Borislav Petkov <bp@alien8.de>
> CC: "H. Peter Anvin" <hpa@zytor.com>
> CC: Andy Lutomirski <luto@amacapital.net>
> CC: Oleg Nesterov <oleg@redhat.com>
> CC: Frederic Weisbecker <fweisbec@gmail.com>
> CC: Alexei Starovoitov <ast@plumgrid.com>
> CC: Will Drewry <wad@chromium.org>
> CC: Kees Cook <keescook@chromium.org>
> CC: x86@kernel.org
> CC: linux-kernel@vger.kernel.org
> ---
>  arch/x86/boot/compressed/head_64.S | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
> index 90c1521..b0c0d16 100644
> --- a/arch/x86/boot/compressed/head_64.S
> +++ b/arch/x86/boot/compressed/head_64.S
> @@ -165,7 +165,7 @@ ENTRY(startup_32)
>  	/* After gdt is loaded */
>  	xorl	%eax, %eax
>  	lldt	%ax
> -	movl    $0x20, %eax
> +	movl    $__BOOT_TSS, %eax
>  	ltr	%ax

Acked-by: Borislav Petkov <bp@suse.de>

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
--

^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH] x86/asm/head/64: Use __BOOT_TSS instead of literal 0x20
  2015-04-01 14:50 ` [PATCH] x86/asm/head/64: Use __BOOT_TSS instead of literal 0x20 Denys Vlasenko
  2015-04-01 16:46   ` Borislav Petkov
@ 2015-04-01 17:01   ` Steven Rostedt
  2015-04-02 12:33   ` [tip:x86/asm] x86/asm/boot/64: Use __BOOT_TSS instead of literal $0x20 tip-bot for Denys Vlasenko
  2 siblings, 0 replies; 7+ messages in thread
From: Steven Rostedt @ 2015-04-01 17:01 UTC (permalink / raw)
  To: Denys Vlasenko
  Cc: Ingo Molnar, Linus Torvalds, Borislav Petkov, H. Peter Anvin,
	Andy Lutomirski, Oleg Nesterov, Frederic Weisbecker,
	Alexei Starovoitov, Will Drewry, Kees Cook, x86, linux-kernel

On Wed,  1 Apr 2015 16:50:58 +0200
Denys Vlasenko <dvlasenk@redhat.com> wrote:

> No code changes.
> 


> diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
> index 90c1521..b0c0d16 100644
> --- a/arch/x86/boot/compressed/head_64.S
> +++ b/arch/x86/boot/compressed/head_64.S
> @@ -165,7 +165,7 @@ ENTRY(startup_32)
>  	/* After gdt is loaded */
>  	xorl	%eax, %eax
>  	lldt	%ax
> -	movl    $0x20, %eax
> +	movl    $__BOOT_TSS, %eax

        __BOOT_TSS = (GDT_ENTRY_BOOT_TSS * 8)
GDT_ENTRY_BOOT_TSS = (GDT_ENTRY_BOOT_CS + 2)
 GDT_ENTRY_BOOT_CS = 2

(2 + 2) * 8 = 4 * 8 = 32 = 0x20

Reviewed-by: Steven Rostedt <rostedt@goodmis.org>

-- Steve

>  	ltr	%ax
>  
>  	/*


^ permalink raw reply	[flat|nested] 7+ messages in thread

* [tip:x86/asm] x86/asm/entry/64: Fold the 'test_in_nmi' macro into its only user
  2015-04-01 14:50 [PATCH] x86/asm/entry/64: fold test_in_nmi macro into its only user Denys Vlasenko
  2015-04-01 14:50 ` [PATCH] x86/asm/head/64: Use __BOOT_TSS instead of literal 0x20 Denys Vlasenko
  2015-04-01 15:45 ` [PATCH] x86/asm/entry/64: fold test_in_nmi macro into its only user Steven Rostedt
@ 2015-04-02 12:33 ` tip-bot for Denys Vlasenko
  2 siblings, 0 replies; 7+ messages in thread
From: tip-bot for Denys Vlasenko @ 2015-04-02 12:33 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: bp, rostedt, dvlasenk, keescook, fweisbec, ast, wad, luto, mingo,
	bp, linux-kernel, hpa, oleg, torvalds, tglx

Commit-ID:  0784b36448a2a85b95b6eb21a69b9045c896c065
Gitweb:     http://git.kernel.org/tip/0784b36448a2a85b95b6eb21a69b9045c896c065
Author:     Denys Vlasenko <dvlasenk@redhat.com>
AuthorDate: Wed, 1 Apr 2015 16:50:57 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 2 Apr 2015 12:00:10 +0200

x86/asm/entry/64: Fold the 'test_in_nmi' macro into its only user

No code changes.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Acked-by: Borislav Petkov <bp@suse.de>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1427899858-7165-1-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/kernel/entry_64.S | 28 +++++++++++++---------------
 1 file changed, 13 insertions(+), 15 deletions(-)

diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 03c52e2..386375d 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -1355,19 +1355,7 @@ ENTRY(error_exit)
 	CFI_ENDPROC
 END(error_exit)
 
-/*
- * Test if a given stack is an NMI stack or not.
- */
-	.macro test_in_nmi reg stack nmi_ret normal_ret
-	cmpq %\reg, \stack
-	ja \normal_ret
-	subq $EXCEPTION_STKSZ, %\reg
-	cmpq %\reg, \stack
-	jb \normal_ret
-	jmp \nmi_ret
-	.endm
-
-	/* runs on exception stack */
+/* Runs on exception stack */
 ENTRY(nmi)
 	INTR_FRAME
 	PARAVIRT_ADJUST_EXCEPTION_FRAME
@@ -1428,8 +1416,18 @@ ENTRY(nmi)
 	 * We check the variable because the first NMI could be in a
 	 * breakpoint routine using a breakpoint stack.
 	 */
-	lea 6*8(%rsp), %rdx
-	test_in_nmi rdx, 4*8(%rsp), nested_nmi, first_nmi
+	lea	6*8(%rsp), %rdx
+	/* Compare the NMI stack (rdx) with the stack we came from (4*8(%rsp)) */
+	cmpq	%rdx, 4*8(%rsp)
+	/* If the stack pointer is above the NMI stack, this is a normal NMI */
+	ja	first_nmi
+	subq	$EXCEPTION_STKSZ, %rdx
+	cmpq	%rdx, 4*8(%rsp)
+	/* If it is below the NMI stack, it is a normal NMI */
+	jb	first_nmi
+	/* Ah, it is within the NMI stack, treat it as nested */
+	jmp	nested_nmi
+
 	CFI_REMEMBER_STATE
 
 nested_nmi:

^ permalink raw reply	[flat|nested] 7+ messages in thread

* [tip:x86/asm] x86/asm/boot/64: Use __BOOT_TSS instead of literal $0x20
  2015-04-01 14:50 ` [PATCH] x86/asm/head/64: Use __BOOT_TSS instead of literal 0x20 Denys Vlasenko
  2015-04-01 16:46   ` Borislav Petkov
  2015-04-01 17:01   ` Steven Rostedt
@ 2015-04-02 12:33   ` tip-bot for Denys Vlasenko
  2 siblings, 0 replies; 7+ messages in thread
From: tip-bot for Denys Vlasenko @ 2015-04-02 12:33 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: bp, luto, tglx, bp, wad, mingo, hpa, torvalds, fweisbec, rostedt,
	keescook, linux-kernel, oleg, ast, dvlasenk

Commit-ID:  40e4f2d177f748a83e7639554ea7d11568a9fa1f
Gitweb:     http://git.kernel.org/tip/40e4f2d177f748a83e7639554ea7d11568a9fa1f
Author:     Denys Vlasenko <dvlasenk@redhat.com>
AuthorDate: Wed, 1 Apr 2015 16:50:58 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 2 Apr 2015 12:00:20 +0200

x86/asm/boot/64: Use __BOOT_TSS instead of literal $0x20

__BOOT_TSS = (GDT_ENTRY_BOOT_TSS * 8)
GDT_ENTRY_BOOT_TSS = (GDT_ENTRY_BOOT_CS + 2)
GDT_ENTRY_BOOT_CS = 2

(2 + 2) * 8 = 4 * 8 = 32 = 0x20

No code changes.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Borislav Petkov <bp@suse.de>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1427899858-7165-2-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/boot/compressed/head_64.S | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index 90c1521..b0c0d16 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -165,7 +165,7 @@ ENTRY(startup_32)
 	/* After gdt is loaded */
 	xorl	%eax, %eax
 	lldt	%ax
-	movl    $0x20, %eax
+	movl    $__BOOT_TSS, %eax
 	ltr	%ax
 
 	/*

^ permalink raw reply	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2015-04-02 12:33 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
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2015-04-01 14:50 [PATCH] x86/asm/entry/64: fold test_in_nmi macro into its only user Denys Vlasenko
2015-04-01 14:50 ` [PATCH] x86/asm/head/64: Use __BOOT_TSS instead of literal 0x20 Denys Vlasenko
2015-04-01 16:46   ` Borislav Petkov
2015-04-01 17:01   ` Steven Rostedt
2015-04-02 12:33   ` [tip:x86/asm] x86/asm/boot/64: Use __BOOT_TSS instead of literal $0x20 tip-bot for Denys Vlasenko
2015-04-01 15:45 ` [PATCH] x86/asm/entry/64: fold test_in_nmi macro into its only user Steven Rostedt
2015-04-02 12:33 ` [tip:x86/asm] x86/asm/entry/64: Fold the 'test_in_nmi' " tip-bot for Denys Vlasenko

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