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: [RFC][PATCH 09/22] x86,futex: Remove .fixup usage
Date: Thu, 04 Nov 2021 17:47:38 +0100 [thread overview]
Message-ID: <20211104165525.045702474@infradead.org> (raw)
In-Reply-To: 20211104164729.226550532@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_SEG 16
+
#define EX_TYPE_IMM_REG 17 /* reg := (long)imm */
+#define EX_TYPE_EFAULT_REG (EX_TYPE_IMM_REG | EX_TYPE_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();
next prev parent reply other threads:[~2021-11-04 16:56 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-04 16:47 [RFC][PATCH 00/22] x86: Remove anonymous out-of-line fixups Peter Zijlstra
2021-11-04 16:47 ` [RFC][PATCH 01/22] bitfield.h: Fix "type of reg too small for mask" test Peter Zijlstra
2021-11-04 16:47 ` [RFC][PATCH 02/22] x86,mmx_32: Remove .fixup usage Peter Zijlstra
2021-11-04 18:00 ` Borislav Petkov
2021-11-05 11:20 ` David Laight
2021-11-04 20:22 ` Josh Poimboeuf
2021-11-05 8:05 ` Peter Zijlstra
2021-11-04 16:47 ` [RFC][PATCH 03/22] x86,copy_user_64: " Peter Zijlstra
2021-11-04 16:47 ` [RFC][PATCH 04/22] x86,copy_mc_64: " Peter Zijlstra
2021-11-04 16:47 ` [RFC][PATCH 05/22] x86,entry_64: " Peter Zijlstra
2021-11-04 16:47 ` [RFC][PATCH 06/22] x86,entry_32: " Peter Zijlstra
2021-11-04 20:39 ` Josh Poimboeuf
2021-11-05 7:43 ` Peter Zijlstra
2021-11-04 16:47 ` [RFC][PATCH 07/22] x86,extable: Extend extable functionality Peter Zijlstra
2021-11-04 21:49 ` Josh Poimboeuf
2021-11-05 7:54 ` Peter Zijlstra
2021-11-05 10:16 ` Mark Rutland
2021-11-05 17:32 ` Sean Christopherson
2021-11-05 18:45 ` Peter Zijlstra
2021-11-05 19:17 ` Sean Christopherson
2021-11-05 19:32 ` Peter Zijlstra
2021-11-05 19:47 ` Sean Christopherson
2021-11-05 20:15 ` Peter Zijlstra
2021-11-05 20:26 ` Peter Zijlstra
2021-11-05 22:30 ` Sean Christopherson
2021-11-04 16:47 ` [RFC][PATCH 08/22] x86,msr: Remove .fixup usage Peter Zijlstra
2021-11-04 16:47 ` Peter Zijlstra [this message]
2021-11-04 16:47 ` [RFC][PATCH 10/22] x86,uaccess: " Peter Zijlstra
2021-11-04 22:28 ` Josh Poimboeuf
2021-11-04 16:47 ` [RFC][PATCH 11/22] x86,xen: " Peter Zijlstra
2021-11-04 22:31 ` Josh Poimboeuf
2021-11-05 7:56 ` Peter Zijlstra
2021-11-04 16:47 ` [RFC][PATCH 12/22] x86,fpu: " Peter Zijlstra
2021-11-04 16:47 ` [RFC][PATCH 13/22] x86,segment: " Peter Zijlstra
2021-11-04 16:47 ` [RFC][PATCH 14/22] x86,ftrace: " Peter Zijlstra
2021-11-04 22:35 ` Josh Poimboeuf
2021-11-05 7:57 ` Peter Zijlstra
2021-11-04 16:47 ` [RFC][PATCH 15/22] x86,vmx: " Peter Zijlstra
2021-11-04 18:50 ` Paolo Bonzini
2021-11-05 18:17 ` Sean Christopherson
2021-11-05 18:52 ` Peter Zijlstra
2021-11-05 20:58 ` Peter Zijlstra
2021-11-05 22:29 ` Sean Christopherson
2021-11-06 7:05 ` Paolo Bonzini
2021-11-06 8:36 ` Peter Zijlstra
2021-11-07 19:13 ` Paolo Bonzini
2021-11-06 8:28 ` Peter Zijlstra
2021-11-04 16:47 ` [RFC][PATCH 16/22] x86,checksum_32: " Peter Zijlstra
2021-11-04 16:47 ` [RFC][PATCH 17/22] x86,sgx: " Peter Zijlstra
2021-11-04 16:47 ` [RFC][PATCH 18/22] x86,kvm: " Peter Zijlstra
2021-11-04 18:50 ` Paolo Bonzini
2021-11-05 7:58 ` Peter Zijlstra
2021-11-04 16:47 ` [RFC][PATCH 19/22] x86,usercopy_32: Simplify Peter Zijlstra
2021-11-04 16:47 ` [RFC][PATCH 20/22] x86,usercopy: Remove .fixup usage Peter Zijlstra
2021-11-04 16:47 ` [RFC][PATCH 21/22] x86,word-at-a-time: " Peter Zijlstra
2021-11-04 23:33 ` Josh Poimboeuf
2021-11-05 8:04 ` Peter Zijlstra
2021-11-04 16:47 ` [RFC][PATCH 22/22] x86: Remove .fixup section Peter Zijlstra
2021-11-04 23:00 ` Josh Poimboeuf
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