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From: Peter Zijlstra <peterz@infradead.org>
To: seanjc@google.com, pbonzini@redhat.com, jpoimboe@redhat.com,
	tglx@linutronix.de
Cc: linux-kernel@vger.kernel.org, x86@kernel.org,
	kvm@vger.kernel.org, jthoughton@google.com,
	"Peter Zijlstra (Intel)" <peterz@infradead.org>
Subject: [PATCH v2 09/12] x86/nospec: JMP_NOSPEC
Date: Mon, 11 Nov 2024 12:59:44 +0100	[thread overview]
Message-ID: <20241111125219.033699387@infradead.org> (raw)
In-Reply-To: 20241111115935.796797988@infradead.org


Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 arch/x86/include/asm/nospec-branch.h |   32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -403,6 +403,17 @@ static inline void call_depth_return_thu
 	"call *%[thunk_target]\n",				\
 	X86_FEATURE_RETPOLINE_LFENCE)
 
+# define JMP_NOSPEC						\
+	ALTERNATIVE_2(						\
+	ANNOTATE_RETPOLINE_SAFE					\
+	"jmp *%[thunk_target]\n",				\
+	"jmp __x86_indirect_thunk_%V[thunk_target]\n",		\
+	X86_FEATURE_RETPOLINE,					\
+	"lfence;\n"						\
+	ANNOTATE_RETPOLINE_SAFE					\
+	"jmp *%[thunk_target]\n",				\
+	X86_FEATURE_RETPOLINE_LFENCE)
+
 # define THUNK_TARGET(addr) [thunk_target] "r" (addr)
 
 #else /* CONFIG_X86_32 */
@@ -433,10 +444,31 @@ static inline void call_depth_return_thu
 	"call *%[thunk_target]\n",				\
 	X86_FEATURE_RETPOLINE_LFENCE)
 
+# define JMP_NOSPEC						\
+	ALTERNATIVE_2(						\
+	ANNOTATE_RETPOLINE_SAFE					\
+	"jmp *%[thunk_target]\n",				\
+	"       jmp    901f;\n"					\
+	"       .align 16\n"					\
+	"901:	call   903f;\n"					\
+	"902:	pause;\n"					\
+	"       lfence;\n"					\
+	"       jmp    902b;\n"					\
+	"       .align 16\n"					\
+	"903:	lea    4(%%esp), %%esp;\n"			\
+	"       pushl  %[thunk_target];\n"			\
+	"       ret;\n",					\
+	X86_FEATURE_RETPOLINE,					\
+	"lfence;\n"						\
+	ANNOTATE_RETPOLINE_SAFE					\
+	"jmp *%[thunk_target]\n",				\
+	X86_FEATURE_RETPOLINE_LFENCE)
+
 # define THUNK_TARGET(addr) [thunk_target] "rm" (addr)
 #endif
 #else /* No retpoline for C / inline asm */
 # define CALL_NOSPEC "call *%[thunk_target]\n"
+# define JMP_NOSPEC "jmp *%[thunk_target]\n"
 # define THUNK_TARGET(addr) [thunk_target] "rm" (addr)
 #endif
 



  parent reply	other threads:[~2024-11-11 12:54 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-11-11 11:59 [PATCH v2 00/12] x86/kvm/emulate: Avoid RET for FASTOPs Peter Zijlstra
2024-11-11 11:59 ` [PATCH v2 01/12] objtool: Generic annotation infrastructure Peter Zijlstra
2024-11-15 18:38   ` Josh Poimboeuf
2024-11-16  9:33     ` Peter Zijlstra
2024-11-20  0:31       ` Josh Poimboeuf
2024-11-20  1:04         ` Josh Poimboeuf
2024-11-20  8:52           ` Peter Zijlstra
2024-11-20 16:03             ` Josh Poimboeuf
2024-11-20 16:03               ` Josh Poimboeuf
2024-11-21 11:46                 ` Peter Zijlstra
2024-11-11 11:59 ` [PATCH v2 02/12] objtool: Convert ANNOTATE_NOENDBR to ANNOTATE Peter Zijlstra
2024-11-11 11:59 ` [PATCH v2 03/12] objtool: Convert ANNOTATE_RETPOLINE_SAFE " Peter Zijlstra
2024-11-15 18:39   ` Josh Poimboeuf
2024-11-16  9:34     ` Peter Zijlstra
2024-11-11 11:59 ` [PATCH v2 04/12] objtool: Convert instrumentation_{begin,end}() " Peter Zijlstra
2024-11-15 18:40   ` Josh Poimboeuf
2024-11-16  9:36     ` Peter Zijlstra
2024-11-16  9:51       ` Peter Zijlstra
2024-11-16 10:06     ` Peter Zijlstra
2024-11-11 11:59 ` [PATCH v2 05/12] objtool: Convert VALIDATE_UNRET_BEGIN " Peter Zijlstra
2024-11-11 11:59 ` [PATCH v2 06/12] objtool: Convert ANNOTATE_IGNORE_ALTERNATIVE " Peter Zijlstra
2024-11-11 11:59 ` [PATCH v2 07/12] objtool: Convert ANNOTATE_INTRA_FUNCTION_CALLS " Peter Zijlstra
2024-11-15 18:40   ` Josh Poimboeuf
2024-11-16  9:37     ` Peter Zijlstra
2024-11-11 11:59 ` [PATCH v2 08/12] objtool: Collapse annotate sequences Peter Zijlstra
2024-11-11 11:59 ` Peter Zijlstra [this message]
2024-11-11 11:59 ` [PATCH v2 10/12] x86,nospec: Simplify {JMP,CALL}_NOSPEC (part 2) Peter Zijlstra
2024-11-15 18:40   ` Josh Poimboeuf
2024-11-16  9:39     ` Peter Zijlstra
2024-11-11 11:59 ` [PATCH v2 11/12] x86/kvm/emulate: Implement test_cc() in C Peter Zijlstra
2024-11-11 17:13   ` Sean Christopherson
2024-11-11 11:59 ` [PATCH v2 12/12] x86/kvm/emulate: Avoid RET for fastops Peter Zijlstra
2024-11-11 16:27   ` Peter Zijlstra
2024-11-11 17:26   ` Sean Christopherson
2024-11-11 18:28     ` Peter Zijlstra
2024-11-15 18:41   ` Josh Poimboeuf
2024-11-16  9:39     ` Peter Zijlstra
2024-11-11 17:27 ` [PATCH v2 00/12] x86/kvm/emulate: Avoid RET for FASTOPs Sean Christopherson

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