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From: David Woodhouse <dwmw@amazon.co.uk>
To: Andi Kleen <ak@linux.intel.com>
Cc: Paul Turner <pjt@google.com>, LKML <linux-kernel@vger.kernel.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Greg Kroah-Hartman <gregkh@linux-foundation.org>,
	Tim Chen <tim.c.chen@linux.intel.com>,
	Dave Hansen <dave.hansen@intel.com>,
	tglx@linutronix.de, Kees Cook <keescook@google.com>,
	Rik van Riel <riel@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Andy Lutomirski <luto@amacapital.net>,
	Jiri Kosina <jikos@kernel.org>,
	gnomes@lxorguk.ukuu.org.uk
Subject: [PATCH v5 05/12] x86/retpoline/ftrace: Convert ftrace assembler indirect jumps
Date: Sat,  6 Jan 2018 11:49:27 +0000	[thread overview]
Message-ID: <1515239374-23361-6-git-send-email-dwmw@amazon.co.uk> (raw)
In-Reply-To: <1515239374-23361-1-git-send-email-dwmw@amazon.co.uk>

Convert all indirect jumps in ftrace assembler code to use non-speculative
sequences when CONFIG_RETPOLINE is enabled.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
---
 arch/x86/kernel/ftrace_32.S | 6 ++++--
 arch/x86/kernel/ftrace_64.S | 8 ++++----
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/ftrace_32.S b/arch/x86/kernel/ftrace_32.S
index b6c6468..c3842c9 100644
--- a/arch/x86/kernel/ftrace_32.S
+++ b/arch/x86/kernel/ftrace_32.S
@@ -8,6 +8,7 @@
 #include <asm/segment.h>
 #include <asm/export.h>
 #include <asm/ftrace.h>
+#include <asm/nospec-branch.h>
 
 #ifdef CC_USING_FENTRY
 # define function_hook	__fentry__
@@ -197,7 +198,8 @@ ftrace_stub:
 	movl	0x4(%ebp), %edx
 	subl	$MCOUNT_INSN_SIZE, %eax
 
-	call	*ftrace_trace_function
+	movl	ftrace_trace_function, %ecx
+	NOSPEC_CALL %ecx
 
 	popl	%edx
 	popl	%ecx
@@ -241,5 +243,5 @@ return_to_handler:
 	movl	%eax, %ecx
 	popl	%edx
 	popl	%eax
-	jmp	*%ecx
+	NOSPEC_JMP %ecx
 #endif
diff --git a/arch/x86/kernel/ftrace_64.S b/arch/x86/kernel/ftrace_64.S
index c832291..0893068 100644
--- a/arch/x86/kernel/ftrace_64.S
+++ b/arch/x86/kernel/ftrace_64.S
@@ -7,7 +7,7 @@
 #include <asm/ptrace.h>
 #include <asm/ftrace.h>
 #include <asm/export.h>
-
+#include <asm/nospec-branch.h>
 
 	.code64
 	.section .entry.text, "ax"
@@ -286,8 +286,8 @@ trace:
 	 * ip and parent ip are used and the list function is called when
 	 * function tracing is enabled.
 	 */
-	call   *ftrace_trace_function
-
+	movq ftrace_trace_function, %r8
+	NOSPEC_CALL %r8
 	restore_mcount_regs
 
 	jmp fgraph_trace
@@ -329,5 +329,5 @@ GLOBAL(return_to_handler)
 	movq 8(%rsp), %rdx
 	movq (%rsp), %rax
 	addq $24, %rsp
-	jmp *%rdi
+	NOSPEC_JMP %rdi
 #endif
-- 
2.7.4

  parent reply	other threads:[~2018-01-06 11:52 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-01-06 11:49 [PATCH v5 00/12] Retpoline: Avoid speculative indirect calls in kernel David Woodhouse
2018-01-06 11:49 ` [PATCH v5 01/12] x86/spectre: Add X86_BUG_SPECTRE_V[12] David Woodhouse
2018-01-06 21:05   ` [tip:x86/pti] x86/cpufeatures: " tip-bot for David Woodhouse
2018-01-06 11:49 ` [PATCH v5 02/12] x86/retpoline: Add initial retpoline support David Woodhouse
2018-01-06 17:32   ` David Woodhouse
2018-01-06 18:05   ` [PATCH v5.1 " David Woodhouse
2018-01-06 18:35   ` [PATCH v5 " Eric Biggers
2018-01-06 19:17     ` David Woodhouse
2018-01-06 21:16   ` Andrew Cooper
2018-01-06 21:21     ` Woodhouse, David
2018-01-07  1:44       ` Tom Lendacky
2018-01-06 21:23     ` Thomas Gleixner
2018-01-06 21:34       ` Andrew Cooper
2018-01-06 21:49         ` Woodhouse, David
2018-01-06 11:49 ` [PATCH v5 03/12] x86/retpoline/crypto: Convert crypto assembler indirect jumps David Woodhouse
2018-01-06 11:49 ` [PATCH v5 04/12] x86/retpoline/entry: Convert entry " David Woodhouse
2018-01-06 11:49 ` David Woodhouse [this message]
2018-01-06 18:13   ` [PATCH v5 05/12] x86/retpoline/ftrace: Convert ftrace " Linus Torvalds
2018-01-06 19:53     ` Thomas Gleixner
2018-01-07  1:27       ` Linus Torvalds
2018-01-06 11:49 ` [PATCH v5 06/12] x86/retpoline/hyperv: Convert " David Woodhouse
2018-01-06 11:49 ` [PATCH v5 07/12] x86/retpoline/xen: Convert Xen hypercall " David Woodhouse
2018-01-06 11:49 ` [PATCH v5 08/12] x86/retpoline/checksum32: Convert assembler " David Woodhouse
2018-01-06 11:49 ` [PATCH v5 09/12] x86/retpoline/irq32: " David Woodhouse
2018-01-06 11:49 ` [PATCH v5 10/12] x86/retpoline: Add boot time option to disable retpoline David Woodhouse
2018-01-06 11:49 ` [PATCH v5 11/12] x86/retpoline: Exclude objtool with retpoline David Woodhouse
2018-01-06 11:49 ` [PATCH v5 12/12] retpoline/modpost: Quieten MODVERSION retpoline build David Woodhouse
2018-01-07  0:10 ` [RFC PATCH 13/12] Retpoline vs. CONFIG_TRIM_UNUSED_SYMBOLS David Woodhouse
2018-01-07  8:03   ` David Woodhouse
2018-01-07 15:09     ` Lu, Hongjiu
2018-01-07 17:32       ` David Woodhouse
2018-01-07 17:57         ` Lu, Hongjiu
2018-01-07 18:18           ` Thomas Gleixner
2018-01-07 18:32             ` Lu, Hongjiu
2018-01-07 20:57               ` David Woodhouse
2018-01-07 22:16               ` David Woodhouse

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