[PATCH v8 18/22] riscv: mm: Add page fault trace points

Nam Cao
2025-05-12T10:51:22Z

Add page fault trace points, which are useful to implement RV monitor that
watches page faults.

Signed-off-by: Nam Cao <namcao@linutronix.de>
Acked-by: Alexandre Ghiti <alexghiti@rivosinc.com>
---
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: linux-riscv@lists.infradead.org
---
arch/riscv/mm/fault.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c
index 0194324a0c50..04ed6f8acae4 100644
--- a/arch/riscv/mm/fault.c
+++ b/arch/riscv/mm/fault.c
@@ -20,6 +20,9 @@
#include <asm/ptrace.h>
#include <asm/tlbflush.h>

+#define CREATE_TRACE_POINTS
+#include <trace/events/exceptions.h>
+
#include "../kernel/head.h"

static void show_pte(unsigned long addr)
@@ -291,6 +294,11 @@ void handle_page_fault(struct pt_regs *regs)
if (kprobe_page_fault(regs, cause))
return;

+ if (user_mode(regs))
+ trace_page_fault_user(addr, regs, cause);
+ else
+ trace_page_fault_kernel(addr, regs, cause);
+
/*
* Fault-in kernel-space virtual memory on-demand.
* The 'reference' page table is init_mm.pgd.
--
2.39.5