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| author | Jisheng Zhang <jszhang@kernel.org> | 2021-11-18 12:26:51 +0100 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@rivosinc.com> | 2022-01-06 02:53:29 +0100 |
| commit | 20802d8d477d5771368fdac8d476285adc713af0 (patch) | |
| tree | 6a89702c494a0eb3c28f0755db26de4576f0a35d /arch/riscv/include/asm/futex.h | |
| parent | riscv: add gpr-num.h (diff) | |
| download | linux-20802d8d477d5771368fdac8d476285adc713af0.tar.xz linux-20802d8d477d5771368fdac8d476285adc713af0.zip | |
riscv: extable: add a dedicated uaccess handler
Inspired by commit 2e77a62cb3a6 ("arm64: extable: add a dedicated
uaccess handler"), do similar to riscv to add a dedicated uaccess
exception handler to update registers in exception context and
subsequently return back into the function which faulted, so we remove
the need for fixups specialized to each faulting instruction.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'arch/riscv/include/asm/futex.h')
| -rw-r--r-- | arch/riscv/include/asm/futex.h | 23 |
1 files changed, 6 insertions, 17 deletions
diff --git a/arch/riscv/include/asm/futex.h b/arch/riscv/include/asm/futex.h index 2e15e8e89502..fc8130f995c1 100644 --- a/arch/riscv/include/asm/futex.h +++ b/arch/riscv/include/asm/futex.h @@ -21,20 +21,14 @@ #define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \ { \ - uintptr_t tmp; \ __enable_user_access(); \ __asm__ __volatile__ ( \ "1: " insn " \n" \ "2: \n" \ - " .section .fixup,\"ax\" \n" \ - " .balign 4 \n" \ - "3: li %[r],%[e] \n" \ - " jump 2b,%[t] \n" \ - " .previous \n" \ - _ASM_EXTABLE(1b, 3b) \ + _ASM_EXTABLE_UACCESS_ERR(1b, 2b, %[r]) \ : [r] "+r" (ret), [ov] "=&r" (oldval), \ - [u] "+m" (*uaddr), [t] "=&r" (tmp) \ - : [op] "Jr" (oparg), [e] "i" (-EFAULT) \ + [u] "+m" (*uaddr) \ + : [op] "Jr" (oparg) \ : "memory"); \ __disable_user_access(); \ } @@ -96,15 +90,10 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, "2: sc.w.aqrl %[t],%z[nv],%[u] \n" " bnez %[t],1b \n" "3: \n" - " .section .fixup,\"ax\" \n" - " .balign 4 \n" - "4: li %[r],%[e] \n" - " jump 3b,%[t] \n" - " .previous \n" - _ASM_EXTABLE(1b, 4b) \ - _ASM_EXTABLE(2b, 4b) \ + _ASM_EXTABLE_UACCESS_ERR(1b, 3b, %[r]) \ + _ASM_EXTABLE_UACCESS_ERR(2b, 3b, %[r]) \ : [r] "+r" (ret), [v] "=&r" (val), [u] "+m" (*uaddr), [t] "=&r" (tmp) - : [ov] "Jr" (oldval), [nv] "Jr" (newval), [e] "i" (-EFAULT) + : [ov] "Jr" (oldval), [nv] "Jr" (newval) : "memory"); __disable_user_access(); |