Messages in this thread | | | Date | Fri, 12 Jun 2009 17:24:34 -0400 | From | Jason Baron <> | Subject | [PATCH 0/7] add syscall tracepoints |
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hi,
The following is an implementation of Frederic's syscall tracer on top of tracepoints. It adds the ability to toggle the entry/exit of each syscall via the standard events/syscalls/syscall_blah/enable interface. The implementation is done by adding 2 tracepoints. One on entry and one for exit.
This implementation required a few 'core' api changes. I've added 'DECLARE_TRACE_REG()' macro which takes a register and and an unregister function as arguments. This allowed me to toggle the ftrace tif flag when the first tracepoint callback is added and the last is removed. Current callers of 'DECLARE_TRACE()' are not impacted.
Another change was to call arch_init_ftrace_syscalls via an 'arch_initall'. In this implmentation I needed to access the syscalls_metadata structure at runtime in order to determine which syscalls were 'traceable'. Although the implementation uses SYSCALL_DEFINE() to set up the the trace events, for some reason at runtime there is no syscalls_metadata, associated with some of the SYSCALL_DEFINE() calls. I'm not quite sure why that is. However, by calling arch_init_ftrace_syscalls() at boot I can make sure the lists are in sync.
thanks,
-Jason
arch/x86/include/asm/ftrace.h | 4 +- arch/x86/kernel/ftrace.c | 24 +++++- arch/x86/kernel/ptrace.c | 6 +- include/linux/syscalls.h | 63 +++++++++++++++ include/linux/tracepoint.h | 27 ++++++- include/trace/syscall.h | 37 +++++++--- kernel/trace/trace_events.c | 29 +++++--- kernel/trace/trace_syscalls.c | 172 +++++++++++++++++++---------------------- kernel/tracepoint.c | 38 +++++++++ 9 files changed, 278 insertions(+), 122 deletions(-)
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