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authorLinus Torvalds <torvalds@linux-foundation.org>2019-12-11 12:22:38 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2019-12-11 12:22:38 -0800
commit6674fdb25a9effc620c95d4c231a6ccc97b2f9b1 (patch)
tree66ad50239c3a6cc179d2857fa0a7b1bafaf5a652 /kernel
parentd1c6a2aa02af09238ad09493eb3c8685ccc3fe12 (diff)
parentff205766dbbee024a4a716638868d98ffb17748a (diff)
Merge tag 'trace-v5.5-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt: - Remove code I accidentally applied when doing a minor fix up to a patch, and then using "git commit -a --amend", which pulled in some other changes I was playing with. - Remove an used variable in trace_events_inject code - Fix function graph tracer when it traces a ftrace direct function. It will now ignore tracing a function that has a ftrace direct tramploine attached. This is needed for eBPF to use the ftrace direct code. * tag 'trace-v5.5-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ftrace: Fix function_graph tracer interaction with BPF trampoline tracing: remove set but not used variable 'buffer' module: Remove accidental change of module_enable_x()
Diffstat (limited to 'kernel')
-rw-r--r--kernel/module.c6
-rw-r--r--kernel/trace/fgraph.c9
-rw-r--r--kernel/trace/ftrace.c19
-rw-r--r--kernel/trace/trace_events_inject.c2
4 files changed, 17 insertions, 19 deletions
diff --git a/kernel/module.c b/kernel/module.c
index 3a486f826224..b56f3224b161 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -3730,6 +3730,7 @@ static int complete_formation(struct module *mod, struct load_info *info)
module_enable_ro(mod, false);
module_enable_nx(mod);
+ module_enable_x(mod);
/* Mark state as coming so strong_try_module_get() ignores us,
* but kallsyms etc. can see us. */
@@ -3752,11 +3753,6 @@ static int prepare_coming_module(struct module *mod)
if (err)
return err;
- /* Make module executable after ftrace is enabled */
- mutex_lock(&module_mutex);
- module_enable_x(mod);
- mutex_unlock(&module_mutex);
-
blocking_notifier_call_chain(&module_notify_list,
MODULE_STATE_COMING, mod);
return 0;
diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c
index 67e0c462b059..a2659735db73 100644
--- a/kernel/trace/fgraph.c
+++ b/kernel/trace/fgraph.c
@@ -101,6 +101,15 @@ int function_graph_enter(unsigned long ret, unsigned long func,
{
struct ftrace_graph_ent trace;
+ /*
+ * Skip graph tracing if the return location is served by direct trampoline,
+ * since call sequence and return addresses is unpredicatable anymore.
+ * 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;
trace.func = func;
trace.depth = ++current->curr_ret_depth;
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 74439ab5c2b6..ac99a3500076 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -2364,7 +2364,7 @@ int ftrace_direct_func_count;
* Search the direct_functions hash to see if the given instruction pointer
* has a direct caller attached to it.
*/
-static unsigned long find_rec_direct(unsigned long ip)
+unsigned long ftrace_find_rec_direct(unsigned long ip)
{
struct ftrace_func_entry *entry;
@@ -2380,7 +2380,7 @@ static void call_direct_funcs(unsigned long ip, unsigned long pip,
{
unsigned long addr;
- addr = find_rec_direct(ip);
+ addr = ftrace_find_rec_direct(ip);
if (!addr)
return;
@@ -2393,11 +2393,6 @@ struct ftrace_ops direct_ops = {
| FTRACE_OPS_FL_DIRECT | FTRACE_OPS_FL_SAVE_REGS
| FTRACE_OPS_FL_PERMANENT,
};
-#else
-static inline unsigned long find_rec_direct(unsigned long ip)
-{
- return 0;
-}
#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
/**
@@ -2417,7 +2412,7 @@ unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec)
if ((rec->flags & FTRACE_FL_DIRECT) &&
(ftrace_rec_count(rec) == 1)) {
- addr = find_rec_direct(rec->ip);
+ addr = ftrace_find_rec_direct(rec->ip);
if (addr)
return addr;
WARN_ON_ONCE(1);
@@ -2458,7 +2453,7 @@ unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec)
/* Direct calls take precedence over trampolines */
if (rec->flags & FTRACE_FL_DIRECT_EN) {
- addr = find_rec_direct(rec->ip);
+ addr = ftrace_find_rec_direct(rec->ip);
if (addr)
return addr;
WARN_ON_ONCE(1);
@@ -3604,7 +3599,7 @@ static int t_show(struct seq_file *m, void *v)
if (rec->flags & FTRACE_FL_DIRECT) {
unsigned long direct;
- direct = find_rec_direct(rec->ip);
+ direct = ftrace_find_rec_direct(rec->ip);
if (direct)
seq_printf(m, "\n\tdirect-->%pS", (void *)direct);
}
@@ -5008,7 +5003,7 @@ int register_ftrace_direct(unsigned long ip, unsigned long addr)
mutex_lock(&direct_mutex);
/* See if there's a direct function at @ip already */
- if (find_rec_direct(ip))
+ if (ftrace_find_rec_direct(ip))
goto out_unlock;
ret = -ENODEV;
@@ -5027,7 +5022,7 @@ int register_ftrace_direct(unsigned long ip, unsigned long addr)
if (ip != rec->ip) {
ip = rec->ip;
/* Need to check this ip for a direct. */
- if (find_rec_direct(ip))
+ if (ftrace_find_rec_direct(ip))
goto out_unlock;
}
diff --git a/kernel/trace/trace_events_inject.c b/kernel/trace/trace_events_inject.c
index d43710718ee5..d45079ee62f8 100644
--- a/kernel/trace/trace_events_inject.c
+++ b/kernel/trace/trace_events_inject.c
@@ -17,12 +17,10 @@ static int
trace_inject_entry(struct trace_event_file *file, void *rec, int len)
{
struct trace_event_buffer fbuffer;
- struct ring_buffer *buffer;
int written = 0;
void *entry;
rcu_read_lock_sched();
- buffer = file->tr->trace_buffer.buffer;
entry = trace_event_buffer_reserve(&fbuffer, file, len);
if (entry) {
memcpy(entry, rec, len);

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