4af4206be2
syscall_regfunc() and syscall_unregfunc() should set/clear
TIF_SYSCALL_TRACEPOINT system-wide, but do_each_thread() can race
with copy_process() and miss the new child which was not added to
the process/thread lists yet.
Change copy_process() to update the child's TIF_SYSCALL_TRACEPOINT
under tasklist.
Link: http://lkml.kernel.org/p/20140413185854.GB20668@redhat.com
Cc: stable@vger.kernel.org # 2.6.33
Fixes: a871bd33a6 "tracing: Add syscall tracepoints"
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
50 lines
1.3 KiB
C
50 lines
1.3 KiB
C
#ifndef _TRACE_SYSCALL_H
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#define _TRACE_SYSCALL_H
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#include <linux/tracepoint.h>
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#include <linux/unistd.h>
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#include <linux/ftrace_event.h>
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#include <linux/thread_info.h>
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#include <asm/ptrace.h>
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/*
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* A syscall entry in the ftrace syscalls array.
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*
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* @name: name of the syscall
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* @syscall_nr: number of the syscall
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* @nb_args: number of parameters it takes
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* @types: list of types as strings
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* @args: list of args as strings (args[i] matches types[i])
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* @enter_fields: list of fields for syscall_enter trace event
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* @enter_event: associated syscall_enter trace event
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* @exit_event: associated syscall_exit trace event
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*/
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struct syscall_metadata {
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const char *name;
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int syscall_nr;
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int nb_args;
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const char **types;
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const char **args;
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struct list_head enter_fields;
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struct ftrace_event_call *enter_event;
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struct ftrace_event_call *exit_event;
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};
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#if defined(CONFIG_TRACEPOINTS) && defined(CONFIG_HAVE_SYSCALL_TRACEPOINTS)
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static inline void syscall_tracepoint_update(struct task_struct *p)
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{
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if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
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set_tsk_thread_flag(p, TIF_SYSCALL_TRACEPOINT);
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else
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clear_tsk_thread_flag(p, TIF_SYSCALL_TRACEPOINT);
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}
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#else
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static inline void syscall_tracepoint_update(struct task_struct *p)
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{
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}
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#endif
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#endif /* _TRACE_SYSCALL_H */
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