[PATCH v4 14/21] mm/ksw: add self-debug helpers
From: Jinchao Wang <hidden>
Date: 2025-09-12 10:13:07
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 | 18 ++++++++++++++++++ 2 files changed, 20 insertions(+)
diff --git a/mm/kstackwatch/kstackwatch.h b/mm/kstackwatch/kstackwatch.h
index 5ea2db76cdfb..9a4900df8ff8 100644
--- a/mm/kstackwatch/kstackwatch.h
+++ b/mm/kstackwatch/kstackwatch.h@@ -47,5 +47,7 @@ int ksw_watch_init(void); void ksw_watch_exit(void); int ksw_watch_on(ulong watch_addr, u16 watch_len); int ksw_watch_off(ulong watch_addr, u16 watch_len); +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 795e779792da..2e9294595bf3 100644
--- a/mm/kstackwatch/watch.c
+++ b/mm/kstackwatch/watch.c@@ -161,3 +161,21 @@ void ksw_watch_exit(void) unregister_wide_hw_breakpoint(watch_events); watch_events = NULL; } + +/* self debug function */ +void ksw_watch_show(void) +{ + pr_info("watch target bp_addr: 0x%llx len:%llu\n", watch_attr.bp_addr, + watch_attr.bp_len); +} +EXPORT_SYMBOL_GPL(ksw_watch_show); + +/* self debug function */ +void ksw_watch_fire(void) +{ + char *ptr = (char *)watch_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);
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2.43.0