From 1ba28e02a18cbdbea123836f6c98efb09cbf59ec Mon Sep 17 00:00:00 2001 From: Lai Jiangshan Date: Fri, 6 Mar 2009 17:21:48 +0100 Subject: tracing: add trace_bprintk() Impact: add a generic printk() for tracing, like trace_printk() trace_bprintk() uses the infrastructure to record events on ring_buffer. [ fweisbec@gmail.com: ported to latest -tip, made it work if !CONFIG_MODULES, never free the format strings from modules because we can't keep track of them and conditionnaly create the ftrace format strings section (reported by Steven Rostedt) ] Signed-off-by: Lai Jiangshan Signed-off-by: Frederic Weisbecker Acked-by: Steven Rostedt LKML-Reference: <1236356510-8381-4-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar --- include/asm-generic/vmlinux.lds.h | 9 +++++++++ include/linux/ftrace.h | 21 +++++++++++++++++++++ include/linux/module.h | 5 +++++ 3 files changed, 35 insertions(+) (limited to 'include') diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 0add6b28c36..48ade3168b1 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -69,6 +69,14 @@ #define FTRACE_EVENTS() #endif +#ifdef CONFIG_TRACING +#define TRACE_PRINTKS() VMLINUX_SYMBOL(__start___trace_bprintk_fmt) = .; \ + *(__trace_printk_fmt) /* Trace_printk fmt' pointer */ \ + VMLINUX_SYMBOL(__stop___trace_bprintk_fmt) = .; +#else +#define TRACE_PRINTKS() +#endif + /* .data section */ #define DATA_DATA \ *(.data) \ @@ -100,6 +108,7 @@ *(__vermagic) /* Kernel version magic */ \ *(__markers_strings) /* Markers: strings */ \ *(__tracepoints_strings)/* Tracepoints: strings */ \ + TRACE_PRINTKS() \ } \ \ .rodata1 : AT(ADDR(.rodata1) - LOAD_OFFSET) { \ diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 1c9cdca0258..1cc8ca453a9 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -225,6 +225,27 @@ extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr); #ifdef CONFIG_TRACE_BPRINTK extern int trace_vbprintk(unsigned long ip, const char *fmt, va_list args); +extern int __trace_bprintk(unsigned long ip, const char *fmt, ...) + __attribute__ ((format (printf, 2, 3))); + +static inline void ____trace_bprintk_check_format(const char *fmt, ...) + __attribute__ ((format (printf, 1, 2))); +static inline void ____trace_bprintk_check_format(const char *fmt, ...) {} +#define __trace_bprintk_check_format(fmt, args...) \ +do { \ + if (0) \ + ____trace_bprintk_check_format(fmt, ##args); \ +} while (0) + +#define trace_bprintk(fmt, args...) \ +do { \ + static char *__attribute__((section("__trace_bprintk_fmt"))) \ + trace_bprintk_fmt = fmt; \ + __trace_bprintk_check_format(fmt, ##args); \ + __trace_bprintk(_THIS_IP_, trace_bprintk_fmt, ##args); \ +} while (0) +#else +#define trace_bprintk trace_printk #endif /* May be defined in arch */ diff --git a/include/linux/module.h b/include/linux/module.h index 145a75528cc..8cbec972d8e 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -329,6 +329,11 @@ struct module unsigned int num_tracepoints; #endif +#ifdef CONFIG_TRACE_BPRINTK + const char **trace_bprintk_fmt_start; + unsigned int num_trace_bprintk_fmt; +#endif + #ifdef CONFIG_MODULE_UNLOAD /* What modules depend on me? */ struct list_head modules_which_use_me; -- cgit