Messages in this thread | | | Date | Sun, 8 Mar 2009 17:24:44 +0100 | From | Ingo Molnar <> | Subject | Re: [RFC][PATCH 1/2] tracing/ftrace: syscall tracing infrastructure |
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* Frederic Weisbecker <fweisbec@gmail.com> wrote:
> +static const struct syscall_trace_entry syscall_trace_entries[] = { > + /* For open, the first argument is a string, hence the given mask */ > + [SYSCALL_TRACE_OPEN] = SYS_TRACE_ENTRY(open, 3, 0x1), > + [SYSCALL_TRACE_CLOSE] = SYS_TRACE_ENTRY(close, 1, 0), > + [SYSCALL_TRACE_READ] = SYS_TRACE_ENTRY(read, 3, 0), > + [SYSCALL_TRACE_WRITE] = SYS_TRACE_ENTRY(read, 3, 0), > +};
s/read/write in the last entry i guess.
But i think the whole concept of duplicating the syscall table is the wrong way around.
Note that we dont have to build this information at all - in 2.6.29-rc1 all syscalls got wrapper macros:
SYSCALL_DEFINE1(nice, int, increment) SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param) SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len, unsigned long __user *, user_mask_ptr)
We also have the syscall table itself.
So what we can do: by changing the SYSCALL_DEFINEX() macros we can emit the following information into a table:
(syscall_fn_address, syscall_name_string, #of arguments, array of argument names and type sizeof()s)
then during bootup we can match up the sys_call_table[] to the secondary table we built, so that we can order the secondary table based on syscall NR. 99% of the syscalls will match up just fine.
Ingo
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