FAILED: patch "[PATCH] riscv: Avoid enabling interrupts in die()" failed to apply to 5.15-stable tree

FAILED: patch "[PATCH] riscv: Avoid enabling interrupts in die()" failed to apply to 5.15-stable tree

[gregkh]

The patch below does not apply to the 5.15-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-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 130aee3fd9981297ff9354e5d5609cd59aafbbea
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '1678204667104220@kroah.com' --subject-prefix 'PATCH 5.15.y' HEAD^..

Possible dependencies:

130aee3fd998 ("riscv: Avoid enabling interrupts in die()")
f2913d006fcd ("RISC-V: Avoid dereferening NULL regs in die()")
3f1901110a89 ("RISC-V: Add fast call path of crash_kexec()")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 130aee3fd9981297ff9354e5d5609cd59aafbbea Mon Sep 17 00:00:00 2001
From: Mattias Nissler <mnissler@rivosinc.com>
Date: Wed, 15 Feb 2023 14:48:28 +0000
Subject: [PATCH] riscv: Avoid enabling interrupts in die()
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

While working on something else, I noticed that the kernel would start
accepting interrupts again after crashing in an interrupt handler. Since
the kernel is already in inconsistent state, enabling interrupts is
dangerous and opens up risk of kernel state deteriorating further.
Interrupts do get enabled via what looks like an unintended side effect of
spin_unlock_irq, so switch to the more cautious
spin_lock_irqsave/spin_unlock_irqrestore instead.

Fixes: 76d2a0493a17 ("RISC-V: Init and Halt Code")
Signed-off-by: Mattias Nissler <mnissler@rivosinc.com>
Reviewed-by: Björn Töpel <bjorn@kernel.org>
Link: https://lore.kernel.org/r/20230215144828.3370316-1-mnissler@rivosinc.com
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c
index 549bde5c970a..70c98ce23be2 100644
--- a/arch/riscv/kernel/traps.c
+++ b/arch/riscv/kernel/traps.c
@@ -34,10 +34,11 @@ void die(struct pt_regs *regs, const char *str)
 	static int die_counter;
 	int ret;
 	long cause;
+	unsigned long flags;
 
 	oops_enter();
 
-	spin_lock_irq(&die_lock);
+	spin_lock_irqsave(&die_lock, flags);
 	console_verbose();
 	bust_spinlocks(1);
 
@@ -54,7 +55,7 @@ void die(struct pt_regs *regs, const char *str)
 
 	bust_spinlocks(0);
 	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
-	spin_unlock_irq(&die_lock);
+	spin_unlock_irqrestore(&die_lock, flags);
 	oops_exit();
 
 	if (in_interrupt())