anierin/msm-5.15
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

riscv: lib: uaccess: fold fixups into body

Browse Source 
[ Upstream commit 9d504f9aa5c1b76673018da9503e76b351a24b8c ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Jisheng Zhang
2021-11-18 19:25:14 +08:00
committed by Greg Kroah-Hartman
parent 9de35edff0
commit 093cb743dc
1 changed files with 11 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

22
arch/riscv/lib/uaccess.S
View File

@@ -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)