[PATCH] riscv: keep interrupts disabled for BREAKPOINT exception

From: Jisheng Zhang
Date: Mon Mar 29 2021 - 14:22:12 EST


From: Jisheng Zhang <jszhang@xxxxxxxxxx>

Current riscv's kprobe handlers are run with both preemption and
interrupt enabled, this violates kprobe requirements. Fix this issue
by keeping interrupts disabled for BREAKPOINT exception.

Fixes: c22b0bcb1dd0 ("riscv: Add kprobes supported")
Signed-off-by: Jisheng Zhang <jszhang@xxxxxxxxxx>
---
arch/riscv/kernel/entry.S | 2 ++
1 file changed, 2 insertions(+)

diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S
index 744f3209c48d..4114b65698ec 100644
--- a/arch/riscv/kernel/entry.S
+++ b/arch/riscv/kernel/entry.S
@@ -130,6 +130,8 @@ skip_context_tracking:
*/
andi t0, s1, SR_PIE
beqz t0, 1f
+ li t0, EXC_BREAKPOINT
+ beq s4, t0, 1f
#ifdef CONFIG_TRACE_IRQFLAGS
call trace_hardirqs_on
#endif
--
2.31.0