From: Peter Zijlstra peterz@infradead.org
[ Upstream commit 4c132d1d844a53fc4e4b5c34e36ef10d6124b783 ]
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 Reviewed-by: Josh Poimboeuf jpoimboe@redhat.com Link: https://lore.kernel.org/r/20211110101325.426016322@infradead.org Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/include/asm/extable_fixup_types.h | 2 ++ arch/x86/include/asm/futex.h | 28 +++++++--------------- 2 files changed, 10 insertions(+), 20 deletions(-)
diff --git a/arch/x86/include/asm/extable_fixup_types.h b/arch/x86/include/asm/extable_fixup_types.h index 9d597fe1017d..7469038de100 100644 --- a/arch/x86/include/asm/extable_fixup_types.h +++ b/arch/x86/include/asm/extable_fixup_types.h @@ -42,6 +42,8 @@ #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 diff --git a/arch/x86/include/asm/futex.h b/arch/x86/include/asm/futex.h index f9c00110a69a..99d345b686fa 100644 --- 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_inatomic(u32 *uval, u32 __user *uaddr, 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();