From 9d504f9aa5c1b76673018da9503e76b351a24b8c Mon Sep 17 00:00:00 2001 From: Jisheng Zhang Date: Thu, 18 Nov 2021 19:25:14 +0800 Subject: [PATCH] riscv: lib: uaccess: fold fixups into body uaccess functions such __asm_copy_to_user(), __arch_copy_from_user() and __clear_user() place their exception fixups in the `.fixup` section without any clear association with themselves. If we backtrace the fixup code, it will be symbolized as an offset from the nearest prior symbol. Similar as arm64 does, we must move fixups into the body of the functions themselves, after the usual fast-path returns. Signed-off-by: Jisheng Zhang Signed-off-by: Palmer Dabbelt --- arch/riscv/lib/uaccess.S | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/arch/riscv/lib/uaccess.S b/arch/riscv/lib/uaccess.S index 55f80f84e23f..047f517ac780 100644 --- a/arch/riscv/lib/uaccess.S +++ b/arch/riscv/lib/uaccess.S @@ -173,6 +173,13 @@ ENTRY(__asm_copy_from_user) csrc CSR_STATUS, t6 li a0, 0 ret + + /* Exception fixup code */ +10: + /* Disable access to user memory */ + csrs CSR_STATUS, t6 + mv a0, t5 + ret ENDPROC(__asm_copy_to_user) ENDPROC(__asm_copy_from_user) EXPORT_SYMBOL(__asm_copy_to_user) @@ -218,19 +225,12 @@ ENTRY(__clear_user) addi a0, a0, 1 bltu a0, a3, 5b j 3b -ENDPROC(__clear_user) -EXPORT_SYMBOL(__clear_user) - .section .fixup,"ax" - .balign 4 - /* Fixup code for __copy_user(10) and __clear_user(11) */ -10: - /* Disable access to user memory */ - csrs CSR_STATUS, t6 - mv a0, t5 - ret + /* Exception fixup code */ 11: + /* Disable access to user memory */ csrs CSR_STATUS, t6 mv a0, a1 ret - .previous +ENDPROC(__clear_user) +EXPORT_SYMBOL(__clear_user) -- 2.25.1