The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 1898300abf3508bca152e65b36cce5bf93d7e63e # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025030410-humbling-occupy-f10c@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 1898300abf3508bca152e65b36cce5bf93d7e63e Mon Sep 17 00:00:00 2001 From: Andreas Schwab schwab@suse.de Date: Thu, 30 Jan 2025 10:25:38 +0100 Subject: [PATCH] riscv/atomic: Do proper sign extension also for unsigned in arch_cmpxchg
Sign extend also an unsigned compare value to match what lr.w is doing. Otherwise try_cmpxchg may spuriously return true when used on a u32 value that has the sign bit set, as it happens often in inode_set_ctime_current.
Do this in three conversion steps. The first conversion to long is needed to avoid a -Wpointer-to-int-cast warning when arch_cmpxchg is used with a pointer type. Then convert to int and back to long to always sign extend the 32-bit value to 64-bit.
Fixes: 6c58f25e6938 ("riscv/atomic: Fix sign extension for RV64I") Signed-off-by: Andreas Schwab schwab@suse.de Reviewed-by: Alexandre Ghiti alexghiti@rivosinc.com Reviewed-by: Andrew Jones ajones@ventanamicro.com Tested-by: Xi Ruoyao xry111@xry111.site Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/mvmed0k4prh.fsf@suse.de Signed-off-by: Palmer Dabbelt palmer@rivosinc.com
diff --git a/arch/riscv/include/asm/cmpxchg.h b/arch/riscv/include/asm/cmpxchg.h index 4cadc56220fe..427c41dde643 100644 --- a/arch/riscv/include/asm/cmpxchg.h +++ b/arch/riscv/include/asm/cmpxchg.h @@ -231,7 +231,7 @@ __arch_cmpxchg(".w", ".w" sc_sfx, ".w" cas_sfx, \ sc_prepend, sc_append, \ cas_prepend, cas_append, \ - __ret, __ptr, (long), __old, __new); \ + __ret, __ptr, (long)(int)(long), __old, __new); \ break; \ case 8: \ __arch_cmpxchg(".d", ".d" sc_sfx, ".d" cas_sfx, \