shinys000114/linux
1
0
Fork 0
mirror of https://github.com/hardkernel/linux.git synced 2026-06-05 02:21:52 +09:00
Code Issues Packages Projects Releases Wiki Activity

riscv/futex: sign extend compare value in atomic cmpxchg

Browse Source 
commit 599c44cd21f4967774e0acf58f734009be4aea9a upstream.

Make sure the compare value in the lr/sc loop is sign extended to match
what lr.w does.  Fortunately, due to the compiler keeping the register
contents sign extended anyway the lack of the explicit extension didn't
result in wrong code so far, but this cannot be relied upon.

Fixes: b90edb3301 ("RISC-V: Add futex support.")
Signed-off-by: Andreas Schwab <schwab@suse.de>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Björn Töpel <bjorn@rivosinc.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/mvmfrkv2vhz.fsf@suse.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Andreas Schwab
2025-02-03 11:06:00 +01:00
committed by Greg Kroah-Hartman
parent 84586322e0
commit ee3ab05cf7
1 changed files with 1 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
arch/riscv/include/asm/futex.h
View File

@@ -93,7 +93,7 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
_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)
: [ov] "Jr" ((long)(int)oldval), [nv] "Jr" (newval)
: "memory");
__disable_user_access();