| Message ID | 20240916135643.GA23958@redhat.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | function_graph: remove unnecessary initialization in ftrace_graph_ret_addr() | expand |
On Mon, 16 Sep 2024 15:56:43 +0200 Oleg Nesterov <oleg@redhat.com> wrote: > After the commit 29c1c24a2707 ("function_graph: Fix up ftrace_graph_ret_addr()") > ftrace_graph_ret_addr() doesn't need to initialize "int i" at the start. > > While at it, move the declaration of "ret_stack" into the main loop. Should not make two changes like this, because it risks the entire patch being denied. > > Signed-off-by: Oleg Nesterov <oleg@redhat.com> > --- > kernel/trace/fgraph.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c > index d7d4fb403f6f..d45a8bc97997 100644 > --- a/kernel/trace/fgraph.c > +++ b/kernel/trace/fgraph.c > @@ -890,9 +890,8 @@ 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) > { > - struct ftrace_ret_stack *ret_stack; > unsigned long return_handler = (unsigned long)dereference_kernel_function_descriptor(return_to_handler); > - int i = task->curr_ret_stack; > + int i; I'm fine with removing the unneeded init of i. > > if (ret != return_handler) > return ret; > @@ -902,7 +901,7 @@ unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx, > > i = *idx ? : task->curr_ret_stack; > while (i > 0) { > - ret_stack = get_ret_stack(task, i, &i); > + struct ftrace_ret_stack *ret_stack = get_ret_stack(task, i, &i); This is just a preference. Sometimes I like the declaration up on top, sometimes in the block it used. But this case, I wont it at top. Please make a v2 with just the change to i. -- Steve > if (!ret_stack) > break; > /*
diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c index d7d4fb403f6f..d45a8bc97997 100644 --- a/kernel/trace/fgraph.c +++ b/kernel/trace/fgraph.c @@ -890,9 +890,8 @@ 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) { - struct ftrace_ret_stack *ret_stack; unsigned long return_handler = (unsigned long)dereference_kernel_function_descriptor(return_to_handler); - int i = task->curr_ret_stack; + int i; if (ret != return_handler) return ret; @@ -902,7 +901,7 @@ unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx, i = *idx ? : task->curr_ret_stack; while (i > 0) { - ret_stack = get_ret_stack(task, i, &i); + struct ftrace_ret_stack *ret_stack = get_ret_stack(task, i, &i); if (!ret_stack) break; /*
After the commit 29c1c24a2707 ("function_graph: Fix up ftrace_graph_ret_addr()") ftrace_graph_ret_addr() doesn't need to initialize "int i" at the start. While at it, move the declaration of "ret_stack" into the main loop. Signed-off-by: Oleg Nesterov <oleg@redhat.com> --- kernel/trace/fgraph.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)