function_graph: remove unnecessary initialization in ftrace_graph_ret_addr()
PATCH 1/1 function_graph: remove unnecessary initialization in ftrace_graph_ret_addr()
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.
--- kernel/trace/fgraph.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)
kernel/trace/fgraph.c +2 -3
@@ -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 ;/*
Signature · 1 line
2.25.1.362.g51ebf55
Steven Rostedt
maintainerQuoted 4 lines · On Mon, 16 Sep 2024 15:56:43 +0200 Oleg Nesterov <[email protected]> wrote:
After the commit
29c1c24a2707("function_graph: Fix upftrace_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.
Quoted 11 lines
Signed-off-by Oleg Nesterov <[email protected]>--- kernel/trace/fgraph.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)kernel/trace/fgraph.c +0
-0
kernel/trace/fgraph.c ftrace_graph_get_ret_stack(struct task_struct *task, int idx) · line 894
Quoted 7 lines
kernel/trace/fgraph.c +1
-2@@ -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.
kernel/trace/fgraph.c unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx, · line 904
Quoted 9 lines
kernel/trace/fgraph.c +1
-1if (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
Quoted 3 lines
kernel/trace/fgraph.c +0
-0if (!ret_stack)break ;/*
PATCH v2 1/1 function_graph: remove unnecessary initialization in ftrace_graph_ret_addr()
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.
--- kernel/trace/fgraph.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
kernel/trace/fgraph.c +1 -1
@@ -892,7 +892,7 @@ unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx, {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;
Signature · 1 line
2.25.1.362.g51ebf55