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Miller" , Dietmar Eggemann , Dmitry Vyukov , "H. Peter Anvin" , Ian Rogers , Ingo Molnar , James Clark , Jinchao Wang , Jinjie Ruan , Jiri Olsa , Jonathan Corbet , Juri Lelli , Justin Stitt , kasan-dev@googlegroups.com, Kees Cook , "Liam R. Howlett" , "Liang Kan" , Linus Walleij , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-perf-users@vger.kernel.org, linux-trace-kernel@vger.kernel.org, llvm@lists.linux.dev, Lorenzo Stoakes , Mark Rutland , Masahiro Yamada , Mathieu Desnoyers , Mel Gorman , Michal Hocko , Miguel Ojeda , Nam Cao , Namhyung Kim , Nathan Chancellor , Naveen N Rao , Nick Desaulniers , Rong Xu , Sami Tolvanen , Steven Rostedt , Suren Baghdasaryan , Thomas Gleixner , =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= , Valentin Schneider , Vincent Guittot , Vincenzo Frascino , Vlastimil Babka , Will Deacon , workflows@vger.kernel.org, x86@kernel.org Subject: [PATCH v8 19/27] arm64/hwbp/ksw: integrate KStackWatch handler support Date: Tue, 11 Nov 2025 00:36:14 +0800 Message-ID: <20251110163634.3686676-20-wangjinchao600@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20251110163634.3686676-1-wangjinchao600@gmail.com> References: <20251110163634.3686676-1-wangjinchao600@gmail.com> Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Add support for identifying KStackWatch watchpoints in the ARM64 hardware breakpoint handler. When a watchpoint belongs to KStackWatch, the handler bypasses single-step re-arming to allow proper recovery. Introduce is_ksw_watch_handler() to detect KStackWatch-managed breakpoints and use it in watchpoint_report() under CONFIG_KSTACKWATCH. Signed-off-by: Jinchao Wang --- arch/arm64/kernel/hw_breakpoint.c | 7 +++++++ include/linux/kstackwatch.h | 2 ++ mm/kstackwatch/watch.c | 8 ++++++++ 3 files changed, 17 insertions(+) diff --git a/arch/arm64/kernel/hw_breakpoint.c b/arch/arm64/kernel/hw_breakpoint.c index bd7d23d7893d..7abcd988c5c2 100644 --- a/arch/arm64/kernel/hw_breakpoint.c +++ b/arch/arm64/kernel/hw_breakpoint.c @@ -14,6 +14,9 @@ #include #include #include +#ifdef CONFIG_KSTACKWATCH +#include +#endif #include #include #include @@ -738,6 +741,10 @@ static int watchpoint_report(struct perf_event *wp, unsigned long addr, struct pt_regs *regs) { int step = is_default_overflow_handler(wp); +#ifdef CONFIG_KSTACKWATCH + if (is_ksw_watch_handler(wp)) + step = 1; +#endif struct arch_hw_breakpoint *info = counter_arch_bp(wp); info->trigger = addr; diff --git a/include/linux/kstackwatch.h b/include/linux/kstackwatch.h index afedd9823de9..ce3882acc5dc 100644 --- a/include/linux/kstackwatch.h +++ b/include/linux/kstackwatch.h @@ -53,6 +53,8 @@ struct ksw_watchpoint { struct llist_node node; // for atomic watch_on and off struct list_head list; // for cpu online and offline }; + +bool is_ksw_watch_handler(struct perf_event *event); int ksw_watch_init(void); void ksw_watch_exit(void); int ksw_watch_get(struct ksw_watchpoint **out_wp); diff --git a/mm/kstackwatch/watch.c b/mm/kstackwatch/watch.c index 99184f63d7e3..c2aa912bf4c4 100644 --- a/mm/kstackwatch/watch.c +++ b/mm/kstackwatch/watch.c @@ -64,6 +64,14 @@ static void ksw_watch_handler(struct perf_event *bp, panic("Stack corruption detected"); } +bool is_ksw_watch_handler(struct perf_event *event) +{ + perf_overflow_handler_t overflow_handler = event->overflow_handler; + + if (unlikely(overflow_handler == ksw_watch_handler)) + return true; + return false; +} static void ksw_watch_on_local_cpu(void *info) { struct ksw_watchpoint *wp = info; -- 2.43.0