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authorJisheng Zhang <jszhang@kernel.org>2021-11-18 14:25:14 +0300
committerPalmer Dabbelt <palmer@rivosinc.com>2022-01-06 04:52:39 +0300
commit9d504f9aa5c1b76673018da9503e76b351a24b8c (patch)
tree103562bddbad3b5421870983ac69cc20fbcacea7
parent4c2e7ce8b9864fa1c5f9fc5ea19af11205730cd6 (diff)
downloadlinux-9d504f9aa5c1b76673018da9503e76b351a24b8c.tar.xz
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 <jszhang@kernel.org> Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
-rw-r--r--arch/riscv/lib/uaccess.S22
1 files 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)