All of lore.kernel.org
 help / color / mirror / Atom feed
From: tip-bot for Denys Vlasenko <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: bp@suse.de, rostedt@goodmis.org, dvlasenk@redhat.com,
	keescook@chromium.org, fweisbec@gmail.com, ast@plumgrid.com,
	wad@chromium.org, luto@amacapital.net, mingo@kernel.org,
	bp@alien8.de, linux-kernel@vger.kernel.org, hpa@zytor.com,
	oleg@redhat.com, torvalds@linux-foundation.org,
	tglx@linutronix.de
Subject: [tip:x86/asm] x86/asm/entry/64: Fold the 'test_in_nmi' macro into its only user
Date: Thu, 2 Apr 2015 05:33:02 -0700	[thread overview]
Message-ID: <tip-0784b36448a2a85b95b6eb21a69b9045c896c065@git.kernel.org> (raw)
In-Reply-To: <1427899858-7165-1-git-send-email-dvlasenk@redhat.com>

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:

      parent reply	other threads:[~2015-04-02 12:33 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
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-bot for Denys Vlasenko [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=tip-0784b36448a2a85b95b6eb21a69b9045c896c065@git.kernel.org \
    --to=tipbot@zytor.com \
    --cc=ast@plumgrid.com \
    --cc=bp@alien8.de \
    --cc=bp@suse.de \
    --cc=dvlasenk@redhat.com \
    --cc=fweisbec@gmail.com \
    --cc=hpa@zytor.com \
    --cc=keescook@chromium.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-tip-commits@vger.kernel.org \
    --cc=luto@amacapital.net \
    --cc=mingo@kernel.org \
    --cc=oleg@redhat.com \
    --cc=rostedt@goodmis.org \
    --cc=tglx@linutronix.de \
    --cc=torvalds@linux-foundation.org \
    --cc=wad@chromium.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.