From d2cc859cc8885e98907cffd47b990491c5321a80 Mon Sep 17 00:00:00 2001 From: "Dr. David Alan Gilbert" Date: Tue, 7 May 2024 00:33:05 +0100 Subject: [PATCH] ftrace: Remove unused global 'ftrace_direct_func_count' Commit 8788ca164eb4b ("ftrace: Remove the legacy _ftrace_direct API") stopped setting the 'ftrace_direct_func_count' variable, but left it around. Clean it up. Link: https://lore.kernel.org/linux-trace-kernel/20240506233305.215735-1-linux@treblig.org Signed-off-by: Dr. David Alan Gilbert Signed-off-by: Steven Rostedt (Google) --- include/linux/ftrace.h | 2 -- kernel/trace/fgraph.c | 11 ----------- kernel/trace/ftrace.c | 1 - 3 files changed, 14 deletions(-) diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index b01cca36147f..e3a83ebd1b33 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -413,7 +413,6 @@ struct ftrace_func_entry { }; #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS -extern int ftrace_direct_func_count; unsigned long ftrace_find_rec_direct(unsigned long ip); int register_ftrace_direct(struct ftrace_ops *ops, unsigned long addr); int unregister_ftrace_direct(struct ftrace_ops *ops, unsigned long addr, @@ -425,7 +424,6 @@ void ftrace_stub_direct_tramp(void); #else struct ftrace_ops; -# define ftrace_direct_func_count 0 static inline unsigned long ftrace_find_rec_direct(unsigned long ip) { return 0; diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c index c83c005e654e..a130b2d898f7 100644 --- a/kernel/trace/fgraph.c +++ b/kernel/trace/fgraph.c @@ -125,17 +125,6 @@ int function_graph_enter(unsigned long ret, unsigned long func, { struct ftrace_graph_ent trace; -#ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS - /* - * Skip graph tracing if the return location is served by direct trampoline, - * since call sequence and return addresses are unpredictable anyway. - * Ex: BPF trampoline may call original function and may skip frame - * depending on type of BPF programs attached. - */ - if (ftrace_direct_func_count && - ftrace_find_rec_direct(ret - MCOUNT_INSN_SIZE)) - return -EBUSY; -#endif trace.func = func; trace.depth = ++current->curr_ret_depth; diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 4613bf67ef2c..5a01d72f66db 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -2538,7 +2538,6 @@ ftrace_find_unique_ops(struct dyn_ftrace *rec) /* Protected by rcu_tasks for reading, and direct_mutex for writing */ static struct ftrace_hash __rcu *direct_functions = EMPTY_HASH; static DEFINE_MUTEX(direct_mutex); -int ftrace_direct_func_count; /* * Search the direct_functions hash to see if the given instruction pointer