From f3f096cfedf8113380c56fc855275cc75cd8cf55 Mon Sep 17 00:00:00 2001 From: Srikar Dronamraju Date: Wed, 11 Apr 2012 16:00:43 +0530 Subject: tracing: Provide trace events interface for uprobes Implements trace_event support for uprobes. In its current form it can be used to put probes at a specified offset in a file and dump the required registers when the code flow reaches the probed address. The following example shows how to dump the instruction pointer and %ax a register at the probed text address. Here we are trying to probe zfree in /bin/zsh: # cd /sys/kernel/debug/tracing/ # cat /proc/`pgrep zsh`/maps | grep /bin/zsh | grep r-xp 00400000-0048a000 r-xp 00000000 08:03 130904 /bin/zsh # objdump -T /bin/zsh | grep -w zfree 0000000000446420 g DF .text 0000000000000012 Base zfree # echo 'p /bin/zsh:0x46420 %ip %ax' > uprobe_events # cat uprobe_events p:uprobes/p_zsh_0x46420 /bin/zsh:0x0000000000046420 # echo 1 > events/uprobes/enable # sleep 20 # echo 0 > events/uprobes/enable # cat trace # tracer: nop # # TASK-PID CPU# TIMESTAMP FUNCTION # | | | | | zsh-24842 [006] 258544.995456: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 zsh-24842 [007] 258545.000270: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 zsh-24842 [002] 258545.043929: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 zsh-24842 [004] 258547.046129: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 Signed-off-by: Srikar Dronamraju Acked-by: Steven Rostedt Acked-by: Masami Hiramatsu Cc: Linus Torvalds Cc: Ananth N Mavinakayanahalli Cc: Jim Keniston Cc: Linux-mm Cc: Oleg Nesterov Cc: Andi Kleen Cc: Christoph Hellwig Cc: Arnaldo Carvalho de Melo Cc: Anton Arapov Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20120411103043.GB29437@linux.vnet.ibm.com Signed-off-by: Ingo Molnar --- kernel/trace/trace.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'kernel/trace/trace.h') diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 95059f091a24..1bcdbec95a11 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -103,6 +103,11 @@ struct kretprobe_trace_entry_head { unsigned long ret_ip; }; +struct uprobe_trace_entry_head { + struct trace_entry ent; + unsigned long ip; +}; + /* * trace_flag_type is an enumeration that holds different * states when a trace occurs. These are: -- cgit v1.2.3