This is a note to let you know that I've just added the patch titled
riscv: kexec: Avoid deadlock in kexec crash path
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
riscv-kexec-avoid-deadlock-in-kexec-crash-path.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit ae4566b0e3a5e7470b1ab3f71a9864feb8047a07
Author: Song Shuai <songshuaishuai@xxxxxxxxxxx>
Date: Wed Jun 26 10:33:16 2024 +0800
riscv: kexec: Avoid deadlock in kexec crash path
[ Upstream commit c562ba719df570c986caf0941fea2449150bcbc4 ]
If the kexec crash code is called in the interrupt context, the
machine_kexec_mask_interrupts() function will trigger a deadlock while
trying to acquire the irqdesc spinlock and then deactivate irqchip in
irq_set_irqchip_state() function.
Unlike arm64, riscv only requires irq_eoi handler to complete EOI and
keeping irq_set_irqchip_state() will only leave this possible deadlock
without any use. So we simply remove it.
Link: https://lore.kernel.org/linux-riscv/20231208111015.173237-1-songshuaishuai@xxxxxxxxxxx/
Fixes: b17d19a5314a ("riscv: kexec: Fixup irq controller broken in kexec crash path")
Signed-off-by: Song Shuai <songshuaishuai@xxxxxxxxxxx>
Reviewed-by: Ryo Takakura <takakura@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20240626023316.539971-1-songshuaishuai@xxxxxxxxxxx
Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/riscv/kernel/machine_kexec.c b/arch/riscv/kernel/machine_kexec.c
index 2d139b724bc84..ccb0c5d5c63c4 100644
--- a/arch/riscv/kernel/machine_kexec.c
+++ b/arch/riscv/kernel/machine_kexec.c
@@ -147,20 +147,12 @@ static void machine_kexec_mask_interrupts(void)
for_each_irq_desc(i, desc) {
struct irq_chip *chip;
- int ret;
chip = irq_desc_get_chip(desc);
if (!chip)
continue;
- /*
- * First try to remove the active state. If this
- * fails, try to EOI the interrupt.
- */
- ret = irq_set_irqchip_state(i, IRQCHIP_STATE_ACTIVE, false);
-
- if (ret && irqd_irq_inprogress(&desc->irq_data) &&
- chip->irq_eoi)
+ if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data))
chip->irq_eoi(&desc->irq_data);
if (chip->irq_mask)
