FAILED: patch "[PATCH] riscv/atomic: Do proper sign extension also for unsigned in" failed to apply to 5.10-stable tree
Subsystems (2)
[email protected]
maintainerThe patch below does not apply to the 5.10-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 <[email protected]>.
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-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x 1898300abf3508bca152e65b36cce5bf93d7e63e
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2025030409-senior-devotion-4685@gregkh' --subject-prefix 'PATCH 5.10.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 <[email protected]>
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.
arch/riscv/include/asm/cmpxchg.h +1 -1
@@ -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, \