[PATCH v5 16/23] mm/ksw: add self-debug helpers
From: Jinchao Wang <hidden>
Date: 2025-09-24 12:00:15
Also in:
linux-doc, linux-mm, linux-perf-users, lkml, llvm, workflows
Subsystem:
memory management, the rest · Maintainers:
Andrew Morton, Linus Torvalds
Provide two debug helpers: - ksw_watch_show(): print the current watch target address and length. - ksw_watch_fire(): intentionally trigger the watchpoint immediately by writing to the watched address, useful for testing HWBP behavior. Signed-off-by: Jinchao Wang <redacted> --- mm/kstackwatch/kstackwatch.h | 2 ++ mm/kstackwatch/watch.c | 34 ++++++++++++++++++++++++++++++++++ 2 files changed, 36 insertions(+)
diff --git a/mm/kstackwatch/kstackwatch.h b/mm/kstackwatch/kstackwatch.h
index 4045890e5652..528001534047 100644
--- a/mm/kstackwatch/kstackwatch.h
+++ b/mm/kstackwatch/kstackwatch.h@@ -52,5 +52,7 @@ void ksw_watch_exit(void); int ksw_watch_get(struct ksw_watchpoint **out_wp); int ksw_watch_on(struct ksw_watchpoint *wp, ulong watch_addr, u16 watch_len); int ksw_watch_off(struct ksw_watchpoint *wp); +void ksw_watch_show(void); +void ksw_watch_fire(void); #endif /* _KSTACKWATCH_H */
diff --git a/mm/kstackwatch/watch.c b/mm/kstackwatch/watch.c
index f32b1e46168c..9837d6873d92 100644
--- a/mm/kstackwatch/watch.c
+++ b/mm/kstackwatch/watch.c@@ -269,3 +269,37 @@ void ksw_watch_exit(void) { ksw_watch_free(); } + +/* self debug function */ +void ksw_watch_show(void) +{ + struct ksw_watchpoint *wp = current->ksw_ctx.wp; + + if (!wp) { + pr_info("nothing to show\n"); + return; + } + + pr_info("watch target bp_addr: 0x%llx len:%llu\n", wp->attr.bp_addr, + wp->attr.bp_len); +} +EXPORT_SYMBOL_GPL(ksw_watch_show); + +/* self debug function */ +void ksw_watch_fire(void) +{ + struct ksw_watchpoint *wp; + char *ptr; + + wp = current->ksw_ctx.wp; + + if (!wp) { + pr_info("nothing to fire\n"); + return; + } + + ptr = (char *)wp->attr.bp_addr; + pr_warn("watch triggered immediately\n"); + *ptr = 0x42; // This should trigger immediately for any bp_len +} +EXPORT_SYMBOL_GPL(ksw_watch_fire);
--
2.43.0