[RFC PATCH v2 12/31] function_graph: Have the instances use their own ftrace_ops for filtering
From: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Date: 2023-11-08 14:27:07
Also in:
bpf, lkml
Subsystem:
function hooks (ftrace), the rest, tracing · Maintainers:
Steven Rostedt, Masami Hiramatsu, Linus Torvalds
From: Steven Rostedt (VMware) <rostedt@goodmis.org>
Allow for instances to have their own ftrace_ops part of the fgraph_ops
that makes the funtion_graph tracer filter on the set_ftrace_filter file
of the instance and not the top instance.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
---
Changes in v2:
- Use ftrace_graph_func and FTRACE_OPS_GRAPH_STUB instead of
ftrace_stub and FTRACE_OPS_FL_STUB for new ftrace based fgraph.
---
include/linux/ftrace.h | 1 +
kernel/trace/fgraph.c | 60 +++++++++++++++++++++-------------
kernel/trace/ftrace.c | 6 ++-
kernel/trace/trace.h | 16 +++++----
kernel/trace/trace_functions.c | 2 +
kernel/trace/trace_functions_graph.c | 8 +++--
6 files changed, 58 insertions(+), 35 deletions(-)
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 84e06ad1b121..d30eb8a97a50 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h@@ -1069,6 +1069,7 @@ extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace, struct fgraph struct fgraph_ops { trace_func_graph_ent_t entryfunc; trace_func_graph_ret_t retfunc; + struct ftrace_ops ops; /* for the hash lists */ void *private; };
diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c
index 16bbb9fa3e03..97cf320d20a8 100644
--- a/kernel/trace/fgraph.c
+++ b/kernel/trace/fgraph.c@@ -17,14 +17,6 @@ #include "ftrace_internal.h" #include "trace.h" -#ifdef CONFIG_DYNAMIC_FTRACE -#define ASSIGN_OPS_HASH(opsname, val) \ - .func_hash = val, \ - .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock), -#else -#define ASSIGN_OPS_HASH(opsname, val) -#endif - #define FGRAPH_RET_SIZE sizeof(struct ftrace_ret_stack) #define FGRAPH_RET_INDEX (FGRAPH_RET_SIZE / sizeof(long))
@@ -337,9 +329,6 @@ int function_graph_enter(unsigned long ret, unsigned long func, return -EBUSY; #endif - if (!ftrace_ops_test(&global_ops, func, NULL)) - return -EBUSY; - trace.func = func; trace.depth = ++current->curr_ret_depth;
@@ -360,7 +349,8 @@ int function_graph_enter(unsigned long ret, unsigned long func, atomic_inc(¤t->trace_overrun); break; } - if (fgraph_array[i]->entryfunc(&trace, fgraph_array[i])) { + if (ftrace_ops_test(&gops->ops, func, NULL) && + gops->entryfunc(&trace, gops)) { offset = current->curr_ret_stack; /* Check the top level stored word */ type = get_fgraph_type(current, offset - 1);
@@ -655,17 +645,25 @@ unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx, } #endif /* HAVE_FUNCTION_GRAPH_RET_ADDR_PTR */ -static struct ftrace_ops graph_ops = { - .func = ftrace_graph_func, - .flags = FTRACE_OPS_FL_INITIALIZED | - FTRACE_OPS_FL_PID | - FTRACE_OPS_GRAPH_STUB, +void fgraph_init_ops(struct ftrace_ops *dst_ops, + struct ftrace_ops *src_ops) +{ + dst_ops->func = ftrace_graph_func; + dst_ops->flags = FTRACE_OPS_FL_PID | FTRACE_OPS_GRAPH_STUB; + #ifdef FTRACE_GRAPH_TRAMP_ADDR - .trampoline = FTRACE_GRAPH_TRAMP_ADDR, + dst_ops->trampoline = FTRACE_GRAPH_TRAMP_ADDR; /* trampoline_size is only needed for dynamically allocated tramps */ #endif - ASSIGN_OPS_HASH(graph_ops, &global_ops.local_hash) -}; + +#ifdef CONFIG_DYNAMIC_FTRACE + if (src_ops) { + dst_ops->func_hash = &src_ops->local_hash; + mutex_init(&dst_ops->local_hash.regex_lock); + dst_ops->flags |= FTRACE_OPS_FL_INITIALIZED; + } +#endif +} void ftrace_graph_sleep_time_control(bool enable) {
@@ -870,11 +868,20 @@ static int start_graph_tracing(void) int register_ftrace_graph(struct fgraph_ops *gops) { + int command = 0; int ret = 0; int i; mutex_lock(&ftrace_lock); + if (!gops->ops.func) { + gops->ops.flags |= FTRACE_OPS_GRAPH_STUB; + gops->ops.func = ftrace_graph_func; +#ifdef FTRACE_GRAPH_TRAMP_ADDR + gops->ops.trampoline = FTRACE_GRAPH_TRAMP_ADDR; +#endif + } + if (!fgraph_array[0]) { /* The array must always have real data on it */ for (i = 0; i < FGRAPH_ARRAY_SIZE; i++)
@@ -910,9 +917,10 @@ int register_ftrace_graph(struct fgraph_ops *gops) */ ftrace_graph_return = return_run; ftrace_graph_entry = entry_run; - - ret = ftrace_startup(&graph_ops, FTRACE_START_FUNC_RET); + command = FTRACE_START_FUNC_RET; } + + ret = ftrace_startup(&gops->ops, command); out: mutex_unlock(&ftrace_lock); return ret;
@@ -920,6 +928,7 @@ int register_ftrace_graph(struct fgraph_ops *gops) void unregister_ftrace_graph(struct fgraph_ops *gops) { + int command = 0; int i; mutex_lock(&ftrace_lock);
@@ -942,10 +951,15 @@ void unregister_ftrace_graph(struct fgraph_ops *gops) } ftrace_graph_active--; + + if (!ftrace_graph_active) + command = FTRACE_STOP_FUNC_RET; + + ftrace_shutdown(&gops->ops, command); + if (!ftrace_graph_active) { ftrace_graph_return = ftrace_stub_graph; ftrace_graph_entry = ftrace_graph_entry_stub; - ftrace_shutdown(&graph_ops, FTRACE_STOP_FUNC_RET); unregister_pm_notifier(&ftrace_suspend_notifier); unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); }
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 83fbfb7b48f8..c4cc2a9d0047 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c@@ -3050,6 +3050,8 @@ int ftrace_startup(struct ftrace_ops *ops, int command) if (unlikely(ftrace_disabled)) return -ENODEV; + ftrace_ops_init(ops); + ret = __register_ftrace_function(ops); if (ret) return ret;
@@ -7319,7 +7321,7 @@ __init void ftrace_init_global_array_ops(struct trace_array *tr) tr->ops = &global_ops; tr->ops->private = tr; ftrace_init_trace_array(tr); - init_array_fgraph_ops(tr); + init_array_fgraph_ops(tr, tr->ops); } void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func)
@@ -8051,7 +8053,7 @@ static int register_ftrace_function_nolock(struct ftrace_ops *ops) */ int register_ftrace_function(struct ftrace_ops *ops) { - int ret; + int ret = -1; lock_direct_mutex(); ret = prepare_direct_functions_for_ipmodify(ops);
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index febb9c6d01c7..f77322e3b177 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h@@ -885,8 +885,8 @@ extern int __trace_graph_entry(struct trace_array *tr, extern void __trace_graph_return(struct trace_array *tr, struct ftrace_graph_ret *trace, unsigned int trace_ctx); -extern void init_array_fgraph_ops(struct trace_array *tr); -extern int allocate_fgraph_ops(struct trace_array *tr); +extern void init_array_fgraph_ops(struct trace_array *tr, struct ftrace_ops *ops); +extern int allocate_fgraph_ops(struct trace_array *tr, struct ftrace_ops *ops); extern void free_fgraph_ops(struct trace_array *tr); #ifdef CONFIG_DYNAMIC_FTRACE
@@ -969,6 +969,7 @@ static inline int ftrace_graph_notrace_addr(unsigned long addr) preempt_enable_notrace(); return ret; } + #else static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace) {
@@ -994,18 +995,19 @@ static inline bool ftrace_graph_ignore_func(struct ftrace_graph_ent *trace) (fgraph_max_depth && trace->depth >= fgraph_max_depth); } +void fgraph_init_ops(struct ftrace_ops *dst_ops, + struct ftrace_ops *src_ops); + #else /* CONFIG_FUNCTION_GRAPH_TRACER */ static inline enum print_line_t print_graph_function_flags(struct trace_iterator *iter, u32 flags) { return TRACE_TYPE_UNHANDLED; } -static inline void init_array_fgraph_ops(struct trace_array *tr) { } -static inline int allocate_fgraph_ops(struct trace_array *tr) -{ - return 0; -} static inline void free_fgraph_ops(struct trace_array *tr) { } +/* ftrace_ops may not be defined */ +#define init_array_fgraph_ops(tr, ops) do { } while (0) +#define allocate_fgraph_ops(tr, ops) ({ 0; }) #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ extern struct list_head ftrace_pids;
diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index 8e8da0d0ee52..13bf2415245d 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c@@ -91,7 +91,7 @@ int ftrace_create_function_files(struct trace_array *tr, if (!tr->ops) return -EINVAL; - ret = allocate_fgraph_ops(tr); + ret = allocate_fgraph_ops(tr, tr->ops); if (ret) { kfree(tr->ops); return ret;
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 9ccc904a7703..7f30652f0e97 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c@@ -288,7 +288,7 @@ static struct fgraph_ops funcgraph_ops = { .retfunc = &trace_graph_return, }; -int allocate_fgraph_ops(struct trace_array *tr) +int allocate_fgraph_ops(struct trace_array *tr, struct ftrace_ops *ops) { struct fgraph_ops *gops;
@@ -301,6 +301,9 @@ int allocate_fgraph_ops(struct trace_array *tr) tr->gops = gops; gops->private = tr; + + fgraph_init_ops(&gops->ops, ops); + return 0; }
@@ -309,10 +312,11 @@ void free_fgraph_ops(struct trace_array *tr) kfree(tr->gops); } -__init void init_array_fgraph_ops(struct trace_array *tr) +__init void init_array_fgraph_ops(struct trace_array *tr, struct ftrace_ops *ops) { tr->gops = &funcgraph_ops; funcgraph_ops.private = tr; + fgraph_init_ops(&tr->gops->ops, ops); } static int graph_trace_init(struct trace_array *tr)