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author | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2018-11-19 20:54:08 -0500 |
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committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2018-12-08 20:54:07 -0500 |
commit | b0e21a61d3196762b61f43ae994ffd255f646774 (patch) | |
tree | c8d44c604668ecde57890429bc2b6f4fd81cc04f | |
parent | 76b42b63ed0d004961097d3a3cd979129d4afd26 (diff) | |
download | linux-b0e21a61d3196762b61f43ae994ffd255f646774.tar.gz linux-b0e21a61d3196762b61f43ae994ffd255f646774.tar.bz2 linux-b0e21a61d3196762b61f43ae994ffd255f646774.zip |
function_graph: Have profiler use new helper ftrace_graph_get_ret_stack()
The ret_stack processing is going to change, and that is going
to break anything that is accessing the ret_stack directly. One user is the
function graph profiler. By using the ftrace_graph_get_ret_stack() helper
function, the profiler can access the ret_stack entry without relying on the
implementation details of the stack itself.
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
-rw-r--r-- | include/linux/ftrace.h | 3 | ||||
-rw-r--r-- | kernel/trace/fgraph.c | 11 | ||||
-rw-r--r-- | kernel/trace/ftrace.c | 21 |
3 files changed, 25 insertions, 10 deletions
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 21c80491ccde..98e141c71ad0 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -785,6 +785,9 @@ extern int function_graph_enter(unsigned long ret, unsigned long func, unsigned long frame_pointer, unsigned long *retp); +struct ftrace_ret_stack * +ftrace_graph_get_ret_stack(struct task_struct *task, int idx); + unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx, unsigned long ret, unsigned long *retp); diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c index 90fcefcaff2a..a3704ec8b599 100644 --- a/kernel/trace/fgraph.c +++ b/kernel/trace/fgraph.c @@ -232,6 +232,17 @@ unsigned long ftrace_return_to_handler(unsigned long frame_pointer) return ret; } +struct ftrace_ret_stack * +ftrace_graph_get_ret_stack(struct task_struct *task, int idx) +{ + idx = current->curr_ret_stack - idx; + + if (idx >= 0 && idx <= task->curr_ret_stack) + return ¤t->ret_stack[idx]; + + return NULL; +} + /** * ftrace_graph_ret_addr - convert a potentially modified stack return address * to its original value diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index d06fe588e650..8ef9fc226037 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -792,7 +792,7 @@ void ftrace_graph_graph_time_control(bool enable) static int profile_graph_entry(struct ftrace_graph_ent *trace) { - int index = current->curr_ret_stack; + struct ftrace_ret_stack *ret_stack; function_profile_call(trace->func, 0, NULL, NULL); @@ -800,14 +800,16 @@ static int profile_graph_entry(struct ftrace_graph_ent *trace) if (!current->ret_stack) return 0; - if (index >= 0 && index < FTRACE_RETFUNC_DEPTH) - current->ret_stack[index].subtime = 0; + ret_stack = ftrace_graph_get_ret_stack(current, 0); + if (ret_stack) + ret_stack->subtime = 0; return 1; } static void profile_graph_return(struct ftrace_graph_ret *trace) { + struct ftrace_ret_stack *ret_stack; struct ftrace_profile_stat *stat; unsigned long long calltime; struct ftrace_profile *rec; @@ -825,16 +827,15 @@ static void profile_graph_return(struct ftrace_graph_ret *trace) calltime = trace->rettime - trace->calltime; if (!fgraph_graph_time) { - int index; - - index = current->curr_ret_stack; /* Append this call time to the parent time to subtract */ - if (index) - current->ret_stack[index - 1].subtime += calltime; + ret_stack = ftrace_graph_get_ret_stack(current, 1); + if (ret_stack) + ret_stack->subtime += calltime; - if (current->ret_stack[index].subtime < calltime) - calltime -= current->ret_stack[index].subtime; + ret_stack = ftrace_graph_get_ret_stack(current, 0); + if (ret_stack && ret_stack->subtime < calltime) + calltime -= ret_stack->subtime; else calltime = 0; } |