tracing/kprobes: Support basic types on dynamic events (93ccae7a) · Commits · 戴 / test

Support basic types of integer (u8, u16, u32, u64, s8, s16, s32, s64) in kprobe tracer. With this patch, users can specify above basic types on each arguments after ':'. If omitted, the argument type is set as unsigned long (u32 or u64, arch-dependent). e.g. echo 'p account_system_time+0 hardirq_offset=%si:s32' > kprobe_events adds a probe recording hardirq_offset in signed-32bits value on the entry of account_system_time. Cc: Ingo Molnar <mingo@elte.hu> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <20100412171708.3790.18599.stgit@localhost6.localdomain6> Signed-off-by:

Masami Hiramatsu <mhiramat@redhat.com> Signed-off-by:

Arnaldo Carvalho de Melo <acme@redhat.com>

Documentation/trace/kprobetrace.txt

+3 −1

Original line number	Diff line number	Diff line
		@@ -41,6 +41,8 @@ Synopsis of kprobe_events
		$retval : Fetch return value.(*)
		+\|-offs(FETCHARG) : Fetch memory at FETCHARG +\|- offs address.(**)
		NAME=FETCHARG : Set NAME as the argument name of FETCHARG.
		FETCHARG:TYPE : Set TYPE as the type of FETCHARG. Currently, basic types
		(u8/u16/u32/u64/s8/s16/s32/s64) are supported.

		(*) only for return probe.
		(**) this is useful for fetching a field of data structures.

kernel/trace/trace.h

+2 −14

Original line number	Diff line number	Diff line
		@@ -102,29 +102,17 @@ struct syscall_trace_exit {
		long ret;
		};

		struct kprobe_trace_entry {
		struct kprobe_trace_entry_head {
		struct trace_entry ent;
		unsigned long ip;
		int nargs;
		unsigned long args[];
		};

		#define SIZEOF_KPROBE_TRACE_ENTRY(n) \
		(offsetof(struct kprobe_trace_entry, args) + \
		(sizeof(unsigned long) * (n)))

		struct kretprobe_trace_entry {
		struct kretprobe_trace_entry_head {
		struct trace_entry ent;
		unsigned long func;
		unsigned long ret_ip;
		int nargs;
		unsigned long args[];
		};

		#define SIZEOF_KRETPROBE_TRACE_ENTRY(n) \
		(offsetof(struct kretprobe_trace_entry, args) + \
		(sizeof(unsigned long) * (n)))

		/*
		* trace_flag_type is an enumeration that holds different
		* states when a trace occurs. These are:

kernel/trace/trace_kprobe.c

+329 −206

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