Linus,
Tracing fixes:
- Initialize tracing-graph-pause at task creation, not start of
function tracing. Causes the pause counter to be corrupted.
- Set "pause-on-trace" for latency tracers as that option breaks
their output (regression).
- Fix the wrong error return for setting kretprobes on future
modules (before they are loaded).
- Fix re-registering the same kretprobe.
- Add missing value check for added RCU variable reload.
Please pull the latest trace-v5.11-rc5 tree, which can be found at:
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git
trace-v5.11-rc5
Tag SHA1: 829bb4de5bb3102d8e2bf2031c05641b2101e437
Head SHA1: c8b186a8d54d7e12d28e9f9686cb00ff18fc2ab2
Alexey Kardashevskiy (1):
tracepoint: Fix race between tracing and removing tracepoint
Masami Hiramatsu (1):
tracing/kprobe: Fix to support kretprobe events on unloaded modules
Steven Rostedt (VMware) (1):
fgraph: Initialize tracing_graph_pause at task creation
Viktor Rosendahl (1):
tracing: Use pause-on-trace with the latency tracers
Wang ShaoBo (1):
kretprobe: Avoid re-registration of the same kretprobe earlier
----
include/linux/kprobes.h | 2 +-
include/linux/tracepoint.h | 12 +++++++-----
init/init_task.c | 3 ++-
kernel/kprobes.c | 36 ++++++++++++++++++++++++++++--------
kernel/trace/fgraph.c | 2 --
kernel/trace/trace_irqsoff.c | 4 ++++
kernel/trace/trace_kprobe.c | 10 ++++++----
7 files changed, 48 insertions(+), 21 deletions(-)
---------------------------
diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h
index b3a36b0cfc81..1883a4a9f16a 100644
--- a/include/linux/kprobes.h
+++ b/include/linux/kprobes.h
@@ -266,7 +266,7 @@ extern void kprobes_inc_nmissed_count(struct kprobe *p);
extern bool arch_within_kprobe_blacklist(unsigned long addr);
extern int arch_populate_kprobe_blacklist(void);
extern bool arch_kprobe_on_func_entry(unsigned long offset);
-extern bool kprobe_on_func_entry(kprobe_opcode_t *addr, const char *sym,
unsigned long offset);
+extern int kprobe_on_func_entry(kprobe_opcode_t *addr, const char *sym,
unsigned long offset);
extern bool within_kprobe_blacklist(unsigned long addr);
extern int kprobe_add_ksym_blacklist(unsigned long entry);
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index 0f21617f1a66..966ed8980327 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -307,11 +307,13 @@ static inline struct tracepoint
*tracepoint_ptr_deref(tracepoint_ptr_t *p)
\
it_func_ptr = \
rcu_dereference_raw((&__tracepoint_##_name)->funcs); \
- do { \
- it_func = (it_func_ptr)->func; \
- __data = (it_func_ptr)->data; \
- ((void(*)(void *, proto))(it_func))(__data, args); \
- } while ((++it_func_ptr)->func); \
+ if (it_func_ptr) { \
+ do { \
+ it_func = (it_func_ptr)->func; \
+ __data = (it_func_ptr)->data; \
+ ((void(*)(void *, proto))(it_func))(__data,
args); \
+ } while ((++it_func_ptr)->func); \
+ } \
return 0; \
} \
DEFINE_STATIC_CALL(tp_func_##_name, __traceiter_##_name);
diff --git a/init/init_task.c b/init/init_task.c
index 8a992d73e6fb..3711cdaafed2 100644
--- a/init/init_task.c
+++ b/init/init_task.c
@@ -198,7 +198,8 @@ struct task_struct init_task
.lockdep_recursion = 0,
#endif
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
- .ret_stack = NULL,
+ .ret_stack = NULL,
+ .tracing_graph_pause = ATOMIC_INIT(0),
#endif
#if defined(CONFIG_TRACING) && defined(CONFIG_PREEMPTION)
.trace_recursion = 0,
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index f7fb5d135930..d5a3eb74a657 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1954,28 +1954,48 @@ bool __weak arch_kprobe_on_func_entry(unsigned long
offset)
return !offset;
}
-bool kprobe_on_func_entry(kprobe_opcode_t *addr, const char *sym, unsigned
long offset)
+/**
+ * kprobe_on_func_entry() -- check whether given address is function entry
+ * @addr: Target address
+ * @sym: Target symbol name
+ * @offset: The offset from the symbol or the address
+ *
+ * This checks whether the given @addr+@offset or @sym+@offset is on the
+ * function entry address or not.
+ * This returns 0 if it is the function entry, or -EINVAL if it is not.
+ * And also it returns -ENOENT if it fails the symbol or address lookup.
+ * Caller must pass @addr or @sym (either one must be NULL), or this
+ * returns -EINVAL.
+ */
+int kprobe_on_func_entry(kprobe_opcode_t *addr, const char *sym, unsigned long
offset)
{
kprobe_opcode_t *kp_addr = _kprobe_addr(addr, sym, offset);
if (IS_ERR(kp_addr))
- return false;
+ return PTR_ERR(kp_addr);
- if (!kallsyms_lookup_size_offset((unsigned long)kp_addr, NULL, &offset)
||
-
!arch_kprobe_on_func_entry(offset))
- return false;
+ if (!kallsyms_lookup_size_offset((unsigned long)kp_addr, NULL, &offset))
+ return -ENOENT;
- return true;
+ if (!arch_kprobe_on_func_entry(offset))
+ return -EINVAL;
+
+ return 0;
}
int register_kretprobe(struct kretprobe *rp)
{
- int ret = 0;
+ int ret;
struct kretprobe_instance *inst;
int i;
void *addr;
- if (!kprobe_on_func_entry(rp->kp.addr, rp->kp.symbol_name,
rp->kp.offset))
+ ret = kprobe_on_func_entry(rp->kp.addr, rp->kp.symbol_name,
rp->kp.offset);
+ if (ret)
+ return ret;
+
+ /* If only rp->kp.addr is specified, check reregistering kprobes */
+ if (rp->kp.addr && check_kprobe_rereg(&rp->kp))
return -EINVAL;
if (kretprobe_blacklist_size) {
diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c
index 73edb9e4f354..29a6ebeebc9e 100644
--- a/kernel/trace/fgraph.c
+++ b/kernel/trace/fgraph.c
@@ -394,7 +394,6 @@ static int alloc_retstack_tasklist(struct ftrace_ret_stack
**ret_stack_list)
}
if (t->ret_stack == NULL) {
- atomic_set(&t->tracing_graph_pause, 0);
atomic_set(&t->trace_overrun, 0);
t->curr_ret_stack = -1;
t->curr_ret_depth = -1;
@@ -489,7 +488,6 @@ static DEFINE_PER_CPU(struct ftrace_ret_stack *,
idle_ret_stack);
static void
graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack)
{
- atomic_set(&t->tracing_graph_pause, 0);
atomic_set(&t->trace_overrun, 0);
t->ftrace_timestamp = 0;
/* make curr_ret_stack visible before we add the ret_stack */
diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
index d06aab4dcbb8..6756379b661f 100644
--- a/kernel/trace/trace_irqsoff.c
+++ b/kernel/trace/trace_irqsoff.c
@@ -562,6 +562,8 @@ static int __irqsoff_tracer_init(struct trace_array *tr)
/* non overwrite screws up the latency tracers */
set_tracer_flag(tr, TRACE_ITER_OVERWRITE, 1);
set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, 1);
+ /* without pause, we will produce garbage if another latency occurs */
+ set_tracer_flag(tr, TRACE_ITER_PAUSE_ON_TRACE, 1);
tr->max_latency = 0;
irqsoff_trace = tr;
@@ -583,11 +585,13 @@ static void __irqsoff_tracer_reset(struct trace_array *tr)
{
int lat_flag = save_flags & TRACE_ITER_LATENCY_FMT;
int overwrite_flag = save_flags & TRACE_ITER_OVERWRITE;
+ int pause_flag = save_flags & TRACE_ITER_PAUSE_ON_TRACE;
stop_irqsoff_tracer(tr, is_graph(tr));
set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, lat_flag);
set_tracer_flag(tr, TRACE_ITER_OVERWRITE, overwrite_flag);
+ set_tracer_flag(tr, TRACE_ITER_PAUSE_ON_TRACE, pause_flag);
ftrace_reset_array_ops(tr);
irqsoff_busy = false;
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index e6fba1798771..56c7fbff7bd7 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -221,9 +221,9 @@ bool trace_kprobe_on_func_entry(struct trace_event_call
*call)
{
struct trace_kprobe *tk = trace_kprobe_primary_from_call(call);
- return tk ? kprobe_on_func_entry(tk->rp.kp.addr,
+ return tk ? (kprobe_on_func_entry(tk->rp.kp.addr,
tk->rp.kp.addr ? NULL : tk->rp.kp.symbol_name,
- tk->rp.kp.addr ? 0 : tk->rp.kp.offset) : false;
+ tk->rp.kp.addr ? 0 : tk->rp.kp.offset) == 0) : false;
}
bool trace_kprobe_error_injectable(struct trace_event_call *call)
@@ -828,9 +828,11 @@ static int trace_kprobe_create(int argc, const char
*argv[])
}
if (is_return)
flags |= TPARG_FL_RETURN;
- if (kprobe_on_func_entry(NULL, symbol, offset))
+ ret = kprobe_on_func_entry(NULL, symbol, offset);
+ if (ret == 0)
flags |= TPARG_FL_FENTRY;
- if (offset && is_return && !(flags & TPARG_FL_FENTRY)) {
+ /* Defer the ENOENT case until register kprobe */
+ if (ret == -EINVAL && is_return) {
trace_probe_log_err(0, BAD_RETPROBE);
goto parse_error;
}
