[PATCH v2] riscv: Establish entry state for kernel software-check exceptions

[Jisheng Zhang]

The kernel-mode software-check exception path calls die() without
performing the entry bookkeeping used by other kernel trap handlers.
die() invokes diagnostics and notifiers which need the corresponding
RCU and tracing state established.

Wrap the kernel fault handling with irqentry_nmi_enter() and
irqentry_nmi_exit(), following the existing kernel trap paths.

Fixes: 9d42fc28fc17 ("riscv/traps: Introduce software check exception and uprobe handling")
Signed-off-by: Jisheng Zhang <jszhang@xxxxxxxxxx>
Assisted-by: LLM
---
since v1:
 - add Fixes tag

 arch/riscv/kernel/traps.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c
index f8292adda099..f28e03f98af0 100644
--- a/arch/riscv/kernel/traps.c
+++ b/arch/riscv/kernel/traps.c
@@ -402,8 +402,11 @@ asmlinkage __visible __trap_section void do_trap_software_check(struct pt_regs *
 
 		irqentry_exit_to_user_mode(regs);
 	} else {
+		irqentry_state_t state = irqentry_nmi_enter(regs);
+
 		/* sw check exception coming from kernel is a bug in kernel */
 		die(regs, "Kernel BUG");
+		irqentry_nmi_exit(regs, state);
 	}
 }
 
-- 
2.55.0