diff options
| author | Shrikanth Hegde <sshegde@linux.ibm.com> | 2026-06-03 18:40:54 +0530 |
|---|---|---|
| committer | Madhavan Srinivasan <maddy@linux.ibm.com> | 2026-06-08 15:58:03 +0530 |
| commit | 334f3f6d7a1660fd65597bad9960bfa33a716d35 (patch) | |
| tree | b8f605390fe3882a00b8496ecf2f80c862212f2b | |
| parent | 052f67a1ae6ffa6e43c82193bf2e6c0dfd2e6d8f (diff) | |
| download | linux-stable-334f3f6d7a1660fd65597bad9960bfa33a716d35.tar.gz linux-stable-334f3f6d7a1660fd65597bad9960bfa33a716d35.zip | |
powerpc/entry: Disable interrupts before irqentry_exit
Venkat reported a panic on powerpc-next tree where GENERIC_ENTRY has
been enabled.
kernel BUG at kernel/sched/core.c:7512!
NIP preempt_schedule_irq+0x44/0x118
LR dynamic_irqentry_exit_cond_resched+0x40/0x1a4
Call Trace:
dynamic_irqentry_exit_cond_resched+0x40/0x1a4
do_page_fault+0xc0/0x104
data_access_common_virt+0x210/0x220
This happens since __do_page_fault ends up enabling the interrupts and
it could take significant time such that need_resched could be set. This
leads to schedule call in irqentry_exit leading to the bug.
There are many such irq handlers which enables the interrupts.
Fix it by disabling the irq before calling irqentry_exit. The same
pattern exists today in interrupt_exit_kernel_prepare.
Fixes: bee25f97ad24 ("powerpc: Enable GENERIC_ENTRY feature")
Reported-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Closes: https://lore.kernel.org/all/7904105b-9dfa-4efd-a5ef-bc0276ed255d@linux.ibm.com/
Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Reviewed-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260603131054.216235-1-sshegde@linux.ibm.com
| -rw-r--r-- | arch/powerpc/include/asm/entry-common.h | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/powerpc/include/asm/entry-common.h b/arch/powerpc/include/asm/entry-common.h index de5601282755..fc636c42e89a 100644 --- a/arch/powerpc/include/asm/entry-common.h +++ b/arch/powerpc/include/asm/entry-common.h @@ -260,9 +260,10 @@ static inline void arch_interrupt_exit_prepare(struct pt_regs *regs) * AMR can only have been unlocked if we interrupted the kernel. */ kuap_assert_locked(); - - local_irq_disable(); } + + /* irqentry_exit expects to be called with interrupts disabled */ + local_irq_disable(); } static inline void arch_interrupt_async_enter_prepare(struct pt_regs *regs) |