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From: Peter Zijlstra <peterz@infradead.org>
To: x86@kernel.org
Cc: linux-kernel@vger.kernel.org, peterz@infradead.org,
	jpoimboe@redhat.com, mark.rutland@arm.com, dvyukov@google.com,
	seanjc@google.com, pbonzini@redhat.com, mbenes@suse.cz
Subject: [PATCH 09/22] x86,futex: Remove .fixup usage
Date: Fri, 05 Nov 2021 18:10:32 +0100	[thread overview]
Message-ID: <20211105171820.987853861@infradead.org> (raw)
In-Reply-To: <20211105171023.989862879@infradead.org>

Use the new EX_TYPE_IMM_REG to store -EFAULT into the designated 'ret'
register, this removes the need for anonymous .fixup code.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 arch/x86/include/asm/extable_fixup_types.h |    2 ++
 arch/x86/include/asm/futex.h               |   28 ++++++++--------------------
 2 files changed, 10 insertions(+), 20 deletions(-)

--- a/arch/x86/include/asm/extable_fixup_types.h
+++ b/arch/x86/include/asm/extable_fixup_types.h
@@ -32,6 +32,8 @@
 #define	EX_TYPE_DEFAULT_MCE_SAFE	14
 #define	EX_TYPE_FAULT_MCE_SAFE		15
 #define	EX_TYPE_POP_ZERO		16
+
 #define	EX_TYPE_IMM_REG			17 /* reg := (long)imm */
+#define	EX_TYPE_EFAULT_REG		(EX_TYPE_IMM_REG | EX_DATA_IMM(-EFAULT))
 
 #endif
--- a/arch/x86/include/asm/futex.h
+++ b/arch/x86/include/asm/futex.h
@@ -17,13 +17,9 @@ do {								\
 	int oldval = 0, ret;					\
 	asm volatile("1:\t" insn "\n"				\
 		     "2:\n"					\
-		     "\t.section .fixup,\"ax\"\n"		\
-		     "3:\tmov\t%3, %1\n"			\
-		     "\tjmp\t2b\n"				\
-		     "\t.previous\n"				\
-		     _ASM_EXTABLE_UA(1b, 3b)			\
+		     _ASM_EXTABLE_TYPE_REG(1b, 2b, EX_TYPE_EFAULT_REG, %1) \
 		     : "=r" (oldval), "=r" (ret), "+m" (*uaddr)	\
-		     : "i" (-EFAULT), "0" (oparg), "1" (0));	\
+		     : "0" (oparg), "1" (0));	\
 	if (ret)						\
 		goto label;					\
 	*oval = oldval;						\
@@ -39,15 +35,11 @@ do {								\
 		     "3:\t" LOCK_PREFIX "cmpxchgl %3, %2\n"	\
 		     "\tjnz\t2b\n"				\
 		     "4:\n"					\
-		     "\t.section .fixup,\"ax\"\n"		\
-		     "5:\tmov\t%5, %1\n"			\
-		     "\tjmp\t4b\n"				\
-		     "\t.previous\n"				\
-		     _ASM_EXTABLE_UA(1b, 5b)			\
-		     _ASM_EXTABLE_UA(3b, 5b)			\
+		     _ASM_EXTABLE_TYPE_REG(1b, 4b, EX_TYPE_EFAULT_REG, %1) \
+		     _ASM_EXTABLE_TYPE_REG(3b, 4b, EX_TYPE_EFAULT_REG, %1) \
 		     : "=&a" (oldval), "=&r" (ret),		\
 		       "+m" (*uaddr), "=&r" (tem)		\
-		     : "r" (oparg), "i" (-EFAULT), "1" (0));	\
+		     : "r" (oparg), "1" (0));			\
 	if (ret)						\
 		goto label;					\
 	*oval = oldval;						\
@@ -95,15 +87,11 @@ static inline int futex_atomic_cmpxchg_i
 	if (!user_access_begin(uaddr, sizeof(u32)))
 		return -EFAULT;
 	asm volatile("\n"
-		"1:\t" LOCK_PREFIX "cmpxchgl %4, %2\n"
+		"1:\t" LOCK_PREFIX "cmpxchgl %3, %2\n"
 		"2:\n"
-		"\t.section .fixup, \"ax\"\n"
-		"3:\tmov     %3, %0\n"
-		"\tjmp     2b\n"
-		"\t.previous\n"
-		_ASM_EXTABLE_UA(1b, 3b)
+		_ASM_EXTABLE_TYPE_REG(1b, 2b, EX_TYPE_EFAULT_REG, %0) \
 		: "+r" (ret), "=a" (oldval), "+m" (*uaddr)
-		: "i" (-EFAULT), "r" (newval), "1" (oldval)
+		: "r" (newval), "1" (oldval)
 		: "memory"
 	);
 	user_access_end();



  parent reply	other threads:[~2021-11-05 17:24 UTC|newest]

Thread overview: 54+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-11-05 17:10 [PATCH 00/22] x86: Remove anonymous out-of-line fixups Peter Zijlstra
2021-11-05 17:10 ` [PATCH 01/22] bitfield.h: Fix "type of reg too small for mask" test Peter Zijlstra
2021-11-05 17:10 ` [PATCH 02/22] x86,mmx_32: Remove .fixup usage Peter Zijlstra
2021-11-05 17:10 ` [PATCH 03/22] x86,copy_user_64: " Peter Zijlstra
2021-11-05 17:10 ` [PATCH 04/22] x86,copy_mc_64: " Peter Zijlstra
2021-11-05 17:10 ` [PATCH 05/22] x86,entry_64: " Peter Zijlstra
2021-11-05 17:10 ` [PATCH 06/22] x86,entry_32: " Peter Zijlstra
2021-11-05 17:10 ` [PATCH 07/22] x86,extable: Extend extable functionality Peter Zijlstra
2021-11-05 17:10 ` [PATCH 08/22] x86,msr: Remove .fixup usage Peter Zijlstra
2021-11-05 17:10 ` Peter Zijlstra [this message]
2021-11-05 17:10 ` [PATCH 10/22] x86,uaccess: " Peter Zijlstra
2021-11-05 17:10 ` [PATCH 11/22] x86,xen: " Peter Zijlstra
2021-11-05 17:10 ` [PATCH 12/22] x86,fpu: " Peter Zijlstra
2021-11-05 17:10 ` [PATCH 13/22] x86,segment: " Peter Zijlstra
2021-11-05 17:10 ` [PATCH 14/22] x86,vmx: " Peter Zijlstra
2021-11-05 17:10 ` [PATCH 15/22] x86,checksum_32: " Peter Zijlstra
2021-11-05 17:10 ` [PATCH 16/22] x86,sgx: " Peter Zijlstra
2021-11-05 17:10 ` [PATCH 17/22] x86,kvm: " Peter Zijlstra
2021-11-05 17:10 ` [PATCH 18/22] x86,usercopy_32: Simplify __copy_user_intel_nocache() Peter Zijlstra
2021-11-05 17:10 ` [PATCH 19/22] x86,usercopy: Remove .fixup usage Peter Zijlstra
2021-11-05 17:10 ` [PATCH 20/22] x86,word-at-a-time: " Peter Zijlstra
2021-11-05 18:01   ` Josh Poimboeuf
2021-11-05 18:07     ` Peter Zijlstra
2021-11-08 16:47   ` Josh Poimboeuf
2021-11-08 18:29     ` Peter Zijlstra
2021-11-08 18:53       ` Nick Desaulniers
2021-11-09  8:23         ` Peter Zijlstra
2021-11-09 19:22           ` Nick Desaulniers
2021-11-09 20:59             ` Bill Wendling
2021-11-09 21:21               ` Peter Zijlstra
2021-11-09 21:25                 ` Nick Desaulniers
2021-11-09 22:11                   ` Peter Zijlstra
2021-11-09 22:15                     ` Nick Desaulniers
2021-11-09 21:07             ` Peter Zijlstra
2021-11-10 10:18               ` Peter Zijlstra
2021-11-10 10:46               ` David Laight
2021-11-10 11:09                 ` Peter Zijlstra
2021-11-10 12:20                   ` David Laight
2021-11-12  1:50                     ` Josh Poimboeuf
2021-11-12  9:33                       ` Peter Zijlstra
2021-11-13  5:35                         ` Josh Poimboeuf
2021-11-15 12:36                           ` Miroslav Benes
2021-11-15 13:01                             ` Joe Lawrence
2021-11-15 23:40                               ` Josh Poimboeuf
2021-11-16  7:25                                 ` Miroslav Benes
2021-11-15 12:59                           ` Miroslav Benes
2021-11-16 21:27                             ` Josh Poimboeuf
2021-11-18  7:15                               ` Miroslav Benes
2021-11-22 17:46                       ` Petr Mladek
2021-11-24 17:42                         ` Josh Poimboeuf
2021-11-25  8:18                           ` Petr Mladek
2021-11-10 12:14               ` Segher Boessenkool
2021-11-05 17:10 ` [PATCH 21/22] x86: Remove .fixup section Peter Zijlstra
2021-11-05 17:10 ` [PATCH 22/22] objtool: Remove .fixup handling Peter Zijlstra

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