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[180.15.148.177]) by smtp.gmail.com with ESMTPSA id 41be03b00d2f7-ad51ea79a47sm2877843a12.76.2025.02.07.05.31.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 07 Feb 2025 05:31:33 -0800 (PST) From: FUJITA Tomonori To: linux-kernel@vger.kernel.org Cc: Alice Ryhl , Boqun Feng , rust-for-linux@vger.kernel.org, netdev@vger.kernel.org, andrew@lunn.ch, hkallweit1@gmail.com, tmgross@umich.edu, ojeda@kernel.org, alex.gaynor@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, benno.lossin@proton.me, a.hindborg@samsung.com, anna-maria@linutronix.de, frederic@kernel.org, tglx@linutronix.de, arnd@arndb.de, jstultz@google.com, sboyd@kernel.org, mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, tgunders@redhat.com, me@kloenk.dev Subject: [PATCH v10 1/8] sched/core: Add __might_sleep_precision() Date: Fri, 7 Feb 2025 22:26:16 +0900 Message-ID: <20250207132623.168854-2-fujita.tomonori@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250207132623.168854-1-fujita.tomonori@gmail.com> References: <20250207132623.168854-1-fujita.tomonori@gmail.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Add __might_sleep_precision(), Rust friendly version of __might_sleep(), which takes a pointer to a string with the length instead of a null-terminated string. Rust's core::panic::Location::file(), which gives the file name of a caller, doesn't provide a null-terminated string. __might_sleep_precision() uses a precision specifier in the printk format, which specifies the length of a string; a string doesn't need to be a null-terminated. Modify __might_sleep() to call __might_sleep_precision() but the impact should be negligible. strlen() isn't called in a normal case; it's called only when printing the error (sleeping function called from invalid context). Note that Location::file() providing a null-terminated string for better C interoperability is under discussion [1]. Link: https://github.com/rust-lang/libs-team/issues/466 [1] Reviewed-by: Alice Ryhl Co-developed-by: Boqun Feng Signed-off-by: Boqun Feng Signed-off-by: FUJITA Tomonori --- include/linux/kernel.h | 2 ++ kernel/sched/core.c | 55 ++++++++++++++++++++++++++---------------- 2 files changed, 36 insertions(+), 21 deletions(-) diff --git a/include/linux/kernel.h b/include/linux/kernel.h index be2e8c0a187e..086ee1dc447e 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -87,6 +87,7 @@ extern int dynamic_might_resched(void); #ifdef CONFIG_DEBUG_ATOMIC_SLEEP extern void __might_resched(const char *file, int line, unsigned int offsets); extern void __might_sleep(const char *file, int line); +extern void __might_sleep_precision(const char *file, int len, int line); extern void __cant_sleep(const char *file, int line, int preempt_offset); extern void __cant_migrate(const char *file, int line); @@ -145,6 +146,7 @@ extern void __cant_migrate(const char *file, int line); static inline void __might_resched(const char *file, int line, unsigned int offsets) { } static inline void __might_sleep(const char *file, int line) { } +static inline void __might_sleep_precision(const char *file, int len, int line) { } # define might_sleep() do { might_resched(); } while (0) # define cant_sleep() do { } while (0) # define cant_migrate() do { } while (0) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 165c90ba64ea..d308f2a8692e 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -8678,24 +8678,6 @@ void __init sched_init(void) #ifdef CONFIG_DEBUG_ATOMIC_SLEEP -void __might_sleep(const char *file, int line) -{ - unsigned int state = get_current_state(); - /* - * Blocking primitives will set (and therefore destroy) current->state, - * since we will exit with TASK_RUNNING make sure we enter with it, - * otherwise we will destroy state. - */ - WARN_ONCE(state != TASK_RUNNING && current->task_state_change, - "do not call blocking ops when !TASK_RUNNING; " - "state=%x set at [<%p>] %pS\n", state, - (void *)current->task_state_change, - (void *)current->task_state_change); - - __might_resched(file, line, 0); -} -EXPORT_SYMBOL(__might_sleep); - static void print_preempt_disable_ip(int preempt_offset, unsigned long ip) { if (!IS_ENABLED(CONFIG_DEBUG_PREEMPT)) @@ -8717,7 +8699,8 @@ static inline bool resched_offsets_ok(unsigned int offsets) return nested == offsets; } -void __might_resched(const char *file, int line, unsigned int offsets) +static void __might_resched_precision(const char *file, int len, int line, + unsigned int offsets) { /* Ratelimiting timestamp: */ static unsigned long prev_jiffy; @@ -8740,8 +8723,10 @@ void __might_resched(const char *file, int line, unsigned int offsets) /* Save this before calling printk(), since that will clobber it: */ preempt_disable_ip = get_preempt_disable_ip(current); - pr_err("BUG: sleeping function called from invalid context at %s:%d\n", - file, line); + if (len < 0) + len = strlen(file); + pr_err("BUG: sleeping function called from invalid context at %.*s:%d\n", + len, file, line); pr_err("in_atomic(): %d, irqs_disabled(): %d, non_block: %d, pid: %d, name: %s\n", in_atomic(), irqs_disabled(), current->non_block_count, current->pid, current->comm); @@ -8766,8 +8751,36 @@ void __might_resched(const char *file, int line, unsigned int offsets) dump_stack(); add_taint(TAINT_WARN, LOCKDEP_STILL_OK); } + +void __might_resched(const char *file, int line, unsigned int offsets) +{ + __might_resched_precision(file, -1, line, offsets); +} EXPORT_SYMBOL(__might_resched); +void __might_sleep_precision(const char *file, int len, int line) +{ + unsigned int state = get_current_state(); + /* + * Blocking primitives will set (and therefore destroy) current->state, + * since we will exit with TASK_RUNNING make sure we enter with it, + * otherwise we will destroy state. + */ + WARN_ONCE(state != TASK_RUNNING && current->task_state_change, + "do not call blocking ops when !TASK_RUNNING; " + "state=%x set at [<%p>] %pS\n", state, + (void *)current->task_state_change, + (void *)current->task_state_change); + + __might_resched_precision(file, len, line, 0); +} + +void __might_sleep(const char *file, int line) +{ + __might_sleep_precision(file, -1, line); +} +EXPORT_SYMBOL(__might_sleep); + void __cant_sleep(const char *file, int line, int preempt_offset) { static unsigned long prev_jiffy;