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authorIngo Molnar <mingo@elte.hu>2011-07-21 09:32:40 +0200
committerIngo Molnar <mingo@elte.hu>2011-07-21 09:32:40 +0200
commit40bcea7bbe8fe452a2d272e2ffd3dea281eec9ff (patch)
treeaedb6d02e53e3cf84cc32fd81db84032cee205e1 /kernel/trace
parent492f73a303b488ffd67097b2351d54aa6e6c7c73 (diff)
parent14a8fd7ceea6915c613746203d6e9a2bf273f16c (diff)
Merge branch 'tip/perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/core
Diffstat (limited to 'kernel/trace')
-rw-r--r--kernel/trace/ftrace.c95
-rw-r--r--kernel/trace/trace.c92
-rw-r--r--kernel/trace/trace.h50
-rw-r--r--kernel/trace/trace_entries.h3
-rw-r--r--kernel/trace/trace_functions_graph.c2
-rw-r--r--kernel/trace/trace_kprobe.c318
-rw-r--r--kernel/trace/trace_output.c11
7 files changed, 419 insertions, 152 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index a0e246e2cee..c3e4575e782 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -88,6 +88,7 @@ static struct ftrace_ops ftrace_list_end __read_mostly = {
static struct ftrace_ops *ftrace_global_list __read_mostly = &ftrace_list_end;
static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end;
ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
+static ftrace_func_t __ftrace_trace_function_delay __read_mostly = ftrace_stub;
ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub;
ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub;
static struct ftrace_ops global_ops;
@@ -146,9 +147,11 @@ void clear_ftrace_function(void)
{
ftrace_trace_function = ftrace_stub;
__ftrace_trace_function = ftrace_stub;
+ __ftrace_trace_function_delay = ftrace_stub;
ftrace_pid_function = ftrace_stub;
}
+#undef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
#ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
/*
* For those archs that do not test ftrace_trace_stop in their
@@ -208,7 +211,12 @@ static void update_ftrace_function(void)
#ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
ftrace_trace_function = func;
#else
+#ifdef CONFIG_DYNAMIC_FTRACE
+ /* do not update till all functions have been modified */
+ __ftrace_trace_function_delay = func;
+#else
__ftrace_trace_function = func;
+#endif
ftrace_trace_function = ftrace_test_stop_func;
#endif
}
@@ -1170,8 +1178,14 @@ alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
return NULL;
}
+static void
+ftrace_hash_rec_disable(struct ftrace_ops *ops, int filter_hash);
+static void
+ftrace_hash_rec_enable(struct ftrace_ops *ops, int filter_hash);
+
static int
-ftrace_hash_move(struct ftrace_hash **dst, struct ftrace_hash *src)
+ftrace_hash_move(struct ftrace_ops *ops, int enable,
+ struct ftrace_hash **dst, struct ftrace_hash *src)
{
struct ftrace_func_entry *entry;
struct hlist_node *tp, *tn;
@@ -1181,9 +1195,16 @@ ftrace_hash_move(struct ftrace_hash **dst, struct ftrace_hash *src)
unsigned long key;
int size = src->count;
int bits = 0;
+ int ret;
int i;
/*
+ * Remove the current set, update the hash and add
+ * them back.
+ */
+ ftrace_hash_rec_disable(ops, enable);
+
+ /*
* If the new source is empty, just free dst and assign it
* the empty_hash.
*/
@@ -1203,9 +1224,10 @@ ftrace_hash_move(struct ftrace_hash **dst, struct ftrace_hash *src)
if (bits > FTRACE_HASH_MAX_BITS)
bits = FTRACE_HASH_MAX_BITS;
+ ret = -ENOMEM;
new_hash = alloc_ftrace_hash(bits);
if (!new_hash)
- return -ENOMEM;
+ goto out;
size = 1 << src->size_bits;
for (i = 0; i < size; i++) {
@@ -1224,7 +1246,16 @@ ftrace_hash_move(struct ftrace_hash **dst, struct ftrace_hash *src)
rcu_assign_pointer(*dst, new_hash);
free_ftrace_hash_rcu(old_hash);
- return 0;
+ ret = 0;
+ out:
+ /*
+ * Enable regardless of ret:
+ * On success, we enable the new hash.
+ * On failure, we re-enable the original hash.
+ */
+ ftrace_hash_rec_enable(ops, enable);
+
+ return ret;
}
/*
@@ -1584,6 +1615,12 @@ static int __ftrace_modify_code(void *data)
{
int *command = data;
+ /*
+ * Do not call function tracer while we update the code.
+ * We are in stop machine, no worrying about races.
+ */
+ function_trace_stop++;
+
if (*command & FTRACE_ENABLE_CALLS)
ftrace_replace_code(1);
else if (*command & FTRACE_DISABLE_CALLS)
@@ -1597,6 +1634,18 @@ static int __ftrace_modify_code(void *data)
else if (*command & FTRACE_STOP_FUNC_RET)
ftrace_disable_ftrace_graph_caller();
+#ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
+ /*
+ * For archs that call ftrace_test_stop_func(), we must
+ * wait till after we update all the function callers
+ * before we update the callback. This keeps different
+ * ops that record different functions from corrupting
+ * each other.
+ */
+ __ftrace_trace_function = __ftrace_trace_function_delay;
+#endif
+ function_trace_stop--;
+
return 0;
}
@@ -2865,7 +2914,11 @@ ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
ftrace_match_records(hash, buf, len);
mutex_lock(&ftrace_lock);
- ret = ftrace_hash_move(orig_hash, hash);
+ ret = ftrace_hash_move(ops, enable, orig_hash, hash);
+ if (!ret && ops->flags & FTRACE_OPS_FL_ENABLED
+ && ftrace_enabled)
+ ftrace_run_update_code(FTRACE_ENABLE_CALLS);
+
mutex_unlock(&ftrace_lock);
mutex_unlock(&ftrace_regex_lock);
@@ -3048,18 +3101,12 @@ ftrace_regex_release(struct inode *inode, struct file *file)
orig_hash = &iter->ops->notrace_hash;
mutex_lock(&ftrace_lock);
- /*
- * Remove the current set, update the hash and add
- * them back.
- */
- ftrace_hash_rec_disable(iter->ops, filter_hash);
- ret = ftrace_hash_move(orig_hash, iter->hash);
- if (!ret) {
- ftrace_hash_rec_enable(iter->ops, filter_hash);
- if (iter->ops->flags & FTRACE_OPS_FL_ENABLED
- && ftrace_enabled)
- ftrace_run_update_code(FTRACE_ENABLE_CALLS);
- }
+ ret = ftrace_hash_move(iter->ops, filter_hash,
+ orig_hash, iter->hash);
+ if (!ret && (iter->ops->flags & FTRACE_OPS_FL_ENABLED)
+ && ftrace_enabled)
+ ftrace_run_update_code(FTRACE_ENABLE_CALLS);
+
mutex_unlock(&ftrace_lock);
}
free_ftrace_hash(iter->hash);
@@ -3338,7 +3385,7 @@ static int ftrace_process_locs(struct module *mod,
{
unsigned long *p;
unsigned long addr;
- unsigned long flags;
+ unsigned long flags = 0; /* Shut up gcc */
mutex_lock(&ftrace_lock);
p = start;
@@ -3356,12 +3403,18 @@ static int ftrace_process_locs(struct module *mod,
}
/*
- * Disable interrupts to prevent interrupts from executing
- * code that is being modified.
+ * We only need to disable interrupts on start up
+ * because we are modifying code that an interrupt
+ * may execute, and the modification is not atomic.
+ * But for modules, nothing runs the code we modify
+ * until we are finished with it, and there's no
+ * reason to cause large interrupt latencies while we do it.
*/
- local_irq_save(flags);
+ if (!mod)
+ local_irq_save(flags);
ftrace_update_code(mod);
- local_irq_restore(flags);
+ if (!mod)
+ local_irq_restore(flags);
mutex_unlock(&ftrace_lock);
return 0;
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index d9c16123f6e..e5df02c69b1 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1248,6 +1248,15 @@ ftrace(struct trace_array *tr, struct trace_array_cpu *data,
}
#ifdef CONFIG_STACKTRACE
+
+#define FTRACE_STACK_MAX_ENTRIES (PAGE_SIZE / sizeof(unsigned long))
+struct ftrace_stack {
+ unsigned long calls[FTRACE_STACK_MAX_ENTRIES];
+};
+
+static DEFINE_PER_CPU(struct ftrace_stack, ftrace_stack);
+static DEFINE_PER_CPU(int, ftrace_stack_reserve);
+
static void __ftrace_trace_stack(struct ring_buffer *buffer,
unsigned long flags,
int skip, int pc, struct pt_regs *regs)
@@ -1256,25 +1265,77 @@ static void __ftrace_trace_stack(struct ring_buffer *buffer,
struct ring_buffer_event *event;
struct stack_entry *entry;
struct stack_trace trace;
+ int use_stack;
+ int size = FTRACE_STACK_ENTRIES;
+
+ trace.nr_entries = 0;
+ trace.skip = skip;
+
+ /*
+ * Since events can happen in NMIs there's no safe way to
+ * use the per cpu ftrace_stacks. We reserve it and if an interrupt
+ * or NMI comes in, it will just have to use the default
+ * FTRACE_STACK_SIZE.
+ */
+ preempt_disable_notrace();
+
+ use_stack = ++__get_cpu_var(ftrace_stack_reserve);
+ /*
+ * We don't need any atomic variables, just a barrier.
+ * If an interrupt comes in, we don't care, because it would
+ * have exited and put the counter back to what we want.
+ * We just need a barrier to keep gcc from moving things
+ * around.
+ */
+ barrier();
+ if (use_stack == 1) {
+ trace.entries = &__get_cpu_var(ftrace_stack).calls[0];
+ trace.max_entries = FTRACE_STACK_MAX_ENTRIES;
+
+ if (regs)
+ save_stack_trace_regs(regs, &trace);
+ else
+ save_stack_trace(&trace);
+
+ if (trace.nr_entries > size)
+ size = trace.nr_entries;
+ } else
+ /* From now on, use_stack is a boolean */
+ use_stack = 0;
+
+ size *= sizeof(unsigned long);
event = trace_buffer_lock_reserve(buffer, TRACE_STACK,
- sizeof(*entry), flags, pc);
+ sizeof(*entry) + size, flags, pc);
if (!event)
- return;
- entry = ring_buffer_event_data(event);
- memset(&entry->caller, 0, sizeof(entry->caller));
+ goto out;
+ entry = ring_buffer_event_data(event);
- trace.nr_entries = 0;
- trace.max_entries = FTRACE_STACK_ENTRIES;
- trace.skip = skip;
- trace.entries = entry->caller;
+ memset(&entry->caller, 0, size);
+
+ if (use_stack)
+ memcpy(&entry->caller, trace.entries,
+ trace.nr_entries * sizeof(unsigned long));
+ else {
+ trace.max_entries = FTRACE_STACK_ENTRIES;
+ trace.entries = entry->caller;
+ if (regs)
+ save_stack_trace_regs(regs, &trace);
+ else
+ save_stack_trace(&trace);
+ }
+
+ entry->size = trace.nr_entries;
- if (regs)
- save_stack_trace_regs(regs, &trace);
- else
- save_stack_trace(&trace);
if (!filter_check_discard(call, entry, buffer, event))
ring_buffer_unlock_commit(buffer, event);
+
+ out:
+ /* Again, don't let gcc optimize things here */
+ barrier();
+ __get_cpu_var(ftrace_stack_reserve)--;
+ preempt_enable_notrace();
+
}
void ftrace_trace_stack_regs(struct ring_buffer *buffer, unsigned long flags,
@@ -1562,7 +1623,12 @@ peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts,
ftrace_enable_cpu();
- return event ? ring_buffer_event_data(event) : NULL;
+ if (event) {
+ iter->ent_size = ring_buffer_event_length(event);
+ return ring_buffer_event_data(event);
+ }
+ iter->ent_size = 0;
+ return NULL;
}
static struct trace_entry *
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 30a94c26dcb..3f381d0b20a 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -278,6 +278,29 @@ struct tracer {
};
+/* Only current can touch trace_recursion */
+#define trace_recursion_inc() do { (current)->trace_recursion++; } while (0)
+#define trace_recursion_dec() do { (current)->trace_recursion--; } while (0)
+
+/* Ring buffer has the 10 LSB bits to count */
+#define trace_recursion_buffer() ((current)->trace_recursion & 0x3ff)
+
+/* for function tracing recursion */
+#define TRACE_INTERNAL_BIT (1<<11)
+#define TRACE_GLOBAL_BIT (1<<12)
+/*
+ * Abuse of the trace_recursion.
+ * As we need a way to maintain state if we are tracing the function
+ * graph in irq because we want to trace a particular function that
+ * was called in irq context but we have irq tracing off. Since this
+ * can only be modified by current, we can reuse trace_recursion.
+ */
+#define TRACE_IRQ_BIT (1<<13)
+
+#define trace_recursion_set(bit) do { (current)->trace_recursion |= (bit); } while (0)
+#define trace_recursion_clear(bit) do { (current)->trace_recursion &= ~(bit); } while (0)
+#define trace_recursion_test(bit) ((current)->trace_recursion & (bit))
+
#define TRACE_PIPE_ALL_CPU -1
int tracer_init(struct tracer *t, struct trace_array *tr);
@@ -516,8 +539,18 @@ static inline int ftrace_graph_addr(unsigned long addr)
return 1;
for (i = 0; i < ftrace_graph_count; i++) {
- if (addr == ftrace_graph_funcs[i])
+ if (addr == ftrace_graph_funcs[i]) {
+ /*
+ * If no irqs are to be traced, but a set_graph_function
+ * is set, and called by an interrupt handler, we still
+ * want to trace it.
+ */
+ if (in_irq())
+ trace_recursion_set(TRACE_IRQ_BIT);
+ else
+ trace_recursion_clear(TRACE_IRQ_BIT);
return 1;
+ }
}
return 0;
@@ -795,19 +828,4 @@ extern const char *__stop___trace_bprintk_fmt[];
FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
#include "trace_entries.h"
-/* Only current can touch trace_recursion */
-#define trace_recursion_inc() do { (current)->trace_recursion++; } while (0)
-#define trace_recursion_dec() do { (current)->trace_recursion--; } while (0)
-
-/* Ring buffer has the 10 LSB bits to count */
-#define trace_recursion_buffer() ((current)->trace_recursion & 0x3ff)
-
-/* for function tracing recursion */
-#define TRACE_INTERNAL_BIT (1<<11)
-#define TRACE_GLOBAL_BIT (1<<12)
-
-#define trace_recursion_set(bit) do { (current)->trace_recursion |= (bit); } while (0)
-#define trace_recursion_clear(bit) do { (current)->trace_recursion &= ~(bit); } while (0)
-#define trace_recursion_test(bit) ((current)->trace_recursion & (bit))
-
#endif /* _LINUX_KERNEL_TRACE_H */
diff --git a/kernel/trace/trace_entries.h b/kernel/trace/trace_entries.h
index e32744c84d9..93365907f21 100644
--- a/kernel/trace/trace_entries.h
+++ b/kernel/trace/trace_entries.h
@@ -161,7 +161,8 @@ FTRACE_ENTRY(kernel_stack, stack_entry,
TRACE_STACK,
F_STRUCT(
- __array( unsigned long, caller, FTRACE_STACK_ENTRIES )
+ __field( int, size )
+ __dynamic_array(unsigned long, caller )
),
F_printk("\t=> (%08lx)\n\t=> (%08lx)\n\t=> (%08lx)\n\t=> (%08lx)\n"
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index e8d6bb55d71..a7d2a4c653d 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -227,7 +227,7 @@ int __trace_graph_entry(struct trace_array *tr,
static inline int ftrace_graph_ignore_irqs(void)
{
- if (!ftrace_graph_skip_irqs)
+ if (!ftrace_graph_skip_irqs || trace_recursion_test(TRACE_IRQ_BIT))
return 0;
return in_irq();
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 7db7b68c6c3..5fb3697bf0e 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -343,6 +343,14 @@ DEFINE_BASIC_FETCH_FUNCS(deref)
DEFINE_FETCH_deref(string)
DEFINE_FETCH_deref(string_size)
+static __kprobes void update_deref_fetch_param(struct deref_fetch_param *data)
+{
+ if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
+ update_deref_fetch_param(data->orig.data);
+ else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
+ update_symbol_cache(data->orig.data);
+}
+
static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data)
{
if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
@@ -377,6 +385,19 @@ DEFINE_BASIC_FETCH_FUNCS(bitfield)
#define fetch_bitfield_string_size NULL
static __kprobes void
+update_bitfield_fetch_param(struct bitfield_fetch_param *data)
+{
+ /*
+ * Don't check the bitfield itself, because this must be the
+ * last fetch function.
+ */
+ if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
+ update_deref_fetch_param(data->orig.data);
+ else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
+ update_symbol_cache(data->orig.data);
+}
+
+static __kprobes void
free_bitfield_fetch_param(struct bitfield_fetch_param *data)
{
/*
@@ -389,6 +410,7 @@ free_bitfield_fetch_param(struct bitfield_fetch_param *data)
free_symbol_cache(data->orig.data);
kfree(data);
}
+
/* Default (unsigned long) fetch type */
#define __DEFAULT_FETCH_TYPE(t) u##t
#define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t)
@@ -536,6 +558,7 @@ struct probe_arg {
/* Flags for trace_probe */
#define TP_FLAG_TRACE 1
#define TP_FLAG_PROFILE 2
+#define TP_FLAG_REGISTERED 4
struct trace_probe {
struct list_head list;
@@ -555,16 +578,49 @@ struct trace_probe {
(sizeof(struct probe_arg) * (n)))
-static __kprobes int probe_is_return(struct trace_probe *tp)
+static __kprobes int trace_probe_is_return(struct trace_probe *tp)
{
return tp->rp.handler != NULL;
}
-static __kprobes const char *probe_symbol(struct trace_probe *tp)
+static __kprobes const char *trace_probe_symbol(struct trace_probe *tp)
{
return tp->symbol ? tp->symbol : "unknown";
}
+static __kprobes unsigned long trace_probe_offset(struct trace_probe *tp)
+{
+ return tp->rp.kp.offset;
+}
+
+static __kprobes bool trace_probe_is_enabled(struct trace_probe *tp)
+{
+ return !!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE));
+}
+
+static __kprobes bool trace_probe_is_registered(struct trace_probe *tp)
+{
+ return !!(tp->flags & TP_FLAG_REGISTERED);
+}
+
+static __kprobes bool trace_probe_has_gone(struct trace_probe *tp)
+{
+ return !!(kprobe_gone(&tp->rp.kp));
+}
+
+static __kprobes bool trace_probe_within_module(struct trace_probe *tp,
+ struct module *mod)
+{
+ int len = strlen(mod->name);
+ const char *name = trace_probe_symbol(tp);
+ return strncmp(mod->name, name, len) == 0 && name[len] == ':';
+}
+
+static __kprobes bool trace_probe_is_on_module(struct trace_probe *tp)
+{
+ return !!strchr(trace_probe_symbol(tp), ':');
+}
+
static int register_probe_event(struct trace_probe *tp);
static void unregister_probe_event(struct trace_probe *tp);
@@ -646,6 +702,16 @@ error:
return ERR_PTR(ret);
}
+static void update_probe_arg(struct probe_arg *arg)
+{
+ if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
+ update_bitfield_fetch_param(arg->fetch.data);
+ else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
+ update_deref_fetch_param(arg->fetch.data);
+ else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
+ update_symbol_cache(arg->fetch.data);
+}
+
static void free_probe_arg(struct probe_arg *arg)
{
if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
@@ -671,7 +737,7 @@ static void free_trace_probe(struct trace_probe *tp)
kfree(tp);
}
-static struct trace_probe *find_probe_event(const char *event,
+static struct trace_probe *find_trace_probe(const char *event,
const char *group)
{
struct trace_probe *tp;
@@ -683,13 +749,96 @@ static struct trace_probe *find_probe_event(const char *event,
return NULL;
}
+/* Enable trace_probe - @flag must be TP_FLAG_TRACE or TP_FLAG_PROFILE */
+static int enable_trace_probe(struct trace_probe *tp, int flag)
+{
+ int ret = 0;
+
+ tp->flags |= flag;
+ if (trace_probe_is_enabled(tp) && trace_probe_is_registered(tp) &&
+ !trace_probe_has_gone(tp)) {
+ if (trace_probe_is_return(tp))
+ ret = enable_kretprobe(&tp->rp);
+ else
+ ret = enable_kprobe(&tp->rp.kp);
+ }
+
+ return ret;
+}
+
+/* Disable trace_probe - @flag must be TP_FLAG_TRACE or TP_FLAG_PROFILE */
+static void disable_trace_probe(struct trace_probe *tp, int flag)
+{
+ tp->flags &= ~flag;
+ if (!trace_probe_is_enabled(tp) && trace_probe_is_registered(tp)) {
+ if (trace_probe_is_return(tp))
+ disable_kretprobe(&tp->rp);
+ else
+ disable_kprobe(&tp->rp.kp);
+ }
+}
+
+/* Internal register function - just handle k*probes and flags */
+static int __register_trace_probe(struct trace_probe *tp)
+{
+ int i, ret;
+
+ if (trace_probe_is_registered(tp))
+ return -EINVAL;
+
+ for (i = 0; i < tp->nr_args; i++)
+ update_probe_arg(&tp->args[i]);
+
+ /* Set/clear disabled flag according to tp->flag */
+ if (trace_probe_is_enabled(tp))
+ tp->rp.kp.flags &= ~KPROBE_FLAG_DISABLED;
+ else
+ tp->rp.kp.flags |= KPROBE_FLAG_DISABLED;
+
+ if (trace_probe_is_return(tp))
+ ret = register_kretprobe(&tp->rp);
+ else
+ ret = register_kprobe(&tp->rp.kp);
+
+ if (ret == 0)
+ tp->flags |= TP_FLAG_REGISTERED;
+ else {
+ pr_warning("Could not insert probe at %s+%lu: %d\n",
+ trace_probe_symbol(tp), trace_probe_offset(tp), ret);
+ if (ret == -ENOENT && trace_probe_is_on_module(tp)) {
+ pr_warning("This probe might be able to register after"
+ "target module is loaded. Continue.\n");
+ ret = 0;
+ } else if (ret == -EILSEQ) {
+ pr_warning("Probing address(0x%p) is not an "
+ "instruction boundary.\n",
+ tp->rp.kp.addr);
+ ret = -EINVAL;
+ }
+ }
+
+ return ret;
+}
+
+/* Internal unregister function - just handle k*probes and flags */
+static void __unregister_trace_probe(struct trace_probe *tp)
+{
+ if (trace_probe_is_registered(tp)) {
+ if (trace_probe_is_return(tp))
+ unregister_kretprobe(&tp->rp);
+ else
+ unregister_kprobe(&tp->rp.kp);
+ tp->flags &= ~TP_FLAG_REGISTERED;
+ /* Cleanup kprobe for reuse */
+ if (tp->rp.kp.symbol_name)
+ tp->rp.kp.addr = NULL;
+ }
+}
+
/* Unregister a trace_probe and probe_event: call with locking probe_lock */
static void unregister_trace_probe(struct trace_probe *tp)
{
- if (probe_is_return(tp))
- unregister_kretprobe(&tp->rp);
- else
- unregister_kprobe(&tp->rp.kp);
+ __unregister_trace_probe(tp);
list_del(&tp->list);
unregister_probe_event(tp);
}
@@ -702,41 +851,65 @@ static int register_trace_probe(struct trace_probe *tp)
mutex_lock(&probe_lock);
- /* register as an event */
- old_tp = find_probe_event(tp->call.name, tp->call.class->system);
+ /* Delete old (same name) event if exist */
+ old_tp = find_trace_probe(tp->call.name, tp->call.class->system);
if (old_tp) {
- /* delete old event */
unregister_trace_probe(old_tp);
free_trace_probe(old_tp);
}
+
+ /* Register new event */
ret = register_probe_event(tp);
if (ret) {
pr_warning("Failed to register probe event(%d)\n", ret);
goto end;
}
- tp->rp.kp.flags |= KPROBE_FLAG_DISABLED;
- if (probe_is_return(tp))
- ret = register_kretprobe(&tp->rp);
- else
- ret = register_kprobe(&tp->rp.kp);
-
- if (ret) {
- pr_warning("Could not insert probe(%d)\n", ret);
- if (ret == -EILSEQ) {
- pr_warning("Probing address(0x%p) is not an "
- "instruction boundary.\n",
- tp->rp.kp.addr);
- ret = -EINVAL;
- }
+ /* Register k*probe */
+ ret = __register_trace_probe(tp);
+ if (ret < 0)
unregister_probe_event(tp);
- } else
+ else
list_add_tail(&tp->list, &probe_list);
+
end:
mutex_unlock(&probe_lock);
return ret;
}
+/* Module notifier call back, checking event on the module */
+static int trace_probe_module_callback(struct notifier_block *nb,
+ unsigned long val, void *data)
+{
+ struct module *mod = data;
+ struct trace_probe *tp;
+ int ret;
+
+ if (val != MODULE_STATE_COMING)
+ return NOTIFY_DONE;
+
+ /* Update probes on coming module */
+ mutex_lock(&probe_lock);
+ list_for_each_entry(tp, &probe_list, list) {
+ if (trace_probe_within_module(tp, mod)) {
+ __unregister_trace_probe(tp);
+ ret = __register_trace_probe(tp);
+ if (ret)
+ pr_warning("Failed to re-register probe %s on"
+ "%s: %d\n",
+ tp->call.name, mod->name, ret);
+ }
+ }
+ mutex_unlock(&probe_lock);
+
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block trace_probe_module_nb = {
+ .notifier_call = trace_probe_module_callback,
+ .priority = 1 /* Invoked after kprobe module callback */
+};
+
/* Split symbol and offset. */
static int split_symbol_offset(char *symbol, unsigned long *offset)
{
@@ -962,8 +1135,8 @@ static int create_trace_probe(int argc, char **argv)
{
/*
* Argument syntax:
- * - Add kprobe: p[:[GRP/]EVENT] KSYM[+OFFS]|KADDR [FETCHARGS]
- * - Add kretprobe: r[:[GRP/]EVENT] KSYM[+0] [FETCHARGS]
+ * - Add kprobe: p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS]
+ * - Add kretprobe: r[:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS]
* Fetch args:
* $retval : fetch return value
* $stack : fetch stack address
@@ -1025,7 +1198,7 @@ static int create_trace_probe(int argc, char **argv)
return -EINVAL;
}
mutex_lock(&probe_lock);
- tp = find_probe_event(event, group);
+ tp = find_trace_probe(event, group);
if (!tp) {
mutex_unlock(&probe_lock);
pr_info("Event %s/%s doesn't exist.\n", group, event);
@@ -1144,7 +1317,7 @@ error:
return ret;
}
-static void cleanup_all_probes(void)
+static void release_all_trace_probes(void)
{
struct trace_probe *tp;
@@ -1158,7 +1331,6 @@ static void cleanup_all_probes(void)
mutex_unlock(&probe_lock);
}
-
/* Probes listing interfaces */
static void *probes_seq_start(struct seq_file *m, loff_t *pos)
{
@@ -1181,15 +1353,16 @@ static int probes_seq_show(struct seq_file *m, void *v)
struct trace_probe *tp = v;
int i;
- seq_printf(m, "%c", probe_is_return(tp) ? 'r' : 'p');
+ seq_printf(m, "%c", trace_probe_is_return(tp) ? 'r' : 'p');
seq_printf(m, ":%s/%s", tp->call.class->system, tp->call.name);
if (!tp->symbol)
seq_printf(m, " 0x%p", tp->rp.kp.addr);
else if (tp->rp.kp.offset)
- seq_printf(m, " %s+%u", probe_symbol(tp), tp->rp.kp.offset);
+ seq_printf(m, " %s+%u", trace_probe_symbol(tp),
+ tp->rp.kp.offset);
else
- seq_printf(m, " %s", probe_symbol(tp));
+ seq_printf(m, " %s", trace_probe_symbol(tp));
for (i = 0; i < tp->nr_args; i++)
seq_printf(m, " %s=%s", tp->args[i].name, tp->args[i].comm);
@@ -1209,7 +1382,7 @@ static int probes_open(struct inode *inode, struct file *file)
{
if ((file->f_mode & FMODE_WRITE) &&
(file->f_flags & O_TRUNC))
- cleanup_all_probes();
+ release_all_trace_probes();
return seq_open(file, &probes_seq_op);
}
@@ -1513,30 +1686,6 @@ partial:
return TRACE_TYPE_PARTIAL_LINE;
}
-static int probe_event_enable(struct ftrace_event_call *call)
-{
- struct trace_probe *tp = (struct trace_probe *)call->data;
-
- tp->flags |= TP_FLAG_TRACE;
- if (probe_is_return(tp))
- return enable_kretprobe(&tp->rp);
- else
- return enable_kprobe(&tp->rp.kp);
-}
-
-static void probe_event_disable(struct ftrace_event_call *call)
-{
- struct trace_probe *tp = (struct trace_probe *)call->data;
-
- tp->flags &= ~TP_FLAG_TRACE;
- if (!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE))) {
- if (probe_is_return(tp))
- disable_kretprobe(&tp->rp);
- else
- disable_kprobe(&tp->rp.kp);
- }
-}
-
#undef DEFINE_FIELD
#define DEFINE_FIELD(type, item, name, is_signed) \
do { \
@@ -1598,7 +1747,7 @@ static int __set_print_fmt(struct trace_probe *tp, char *buf, int len)
const char *fmt, *arg;
- if (!probe_is_return(tp)) {
+ if (!trace_probe_is_return(tp)) {
fmt = "(%lx)";
arg = "REC->" FIELD_STRING_IP;
} else {
@@ -1715,49 +1864,25 @@ static __kprobes void kretprobe_perf_func(struct kretprobe_instance *ri,
head = this_cpu_ptr(call->perf_events);
perf_trace_buf_submit(entry, size, rctx, entry->ret_ip, 1, regs, head);
}
-
-static int probe_perf_enable(struct ftrace_event_call *call)
-{
- struct trace_probe *tp = (struct trace_probe *)call->data;
-
- tp->flags |= TP_FLAG_PROFILE;
-
- if (probe_is_return(tp))
- return enable_kretprobe(&tp->rp);
- else
- return enable_kprobe(&tp->rp.kp);
-}
-
-static void probe_perf_disable(struct ftrace_event_call *call)
-{
- struct trace_probe *tp = (struct trace_probe *)call->data;
-
- tp->flags &= ~TP_FLAG_PROFILE;
-
- if (!(tp->flags & TP_FLAG_TRACE)) {
- if (probe_is_return(tp))
- disable_kretprobe(&tp->rp);
- else
- disable_kprobe(&tp->rp.kp);
- }
-}
#endif /* CONFIG_PERF_EVENTS */
static __kprobes
int kprobe_register(struct ftrace_event_call *event, enum trace_reg type)
{
+ struct trace_probe *tp = (struct trace_probe *)event->data;
+
switch (type) {
case TRACE_REG_REGISTER:
- return probe_event_enable(event);
+ return enable_trace_probe(tp, TP_FLAG_TRACE);
case TRACE_REG_UNREGISTER:
- probe_event_disable(event);
+ disable_trace_probe(tp, TP_FLAG_TRACE);
return 0;
#ifdef CONFIG_PERF_EVENTS
case TRACE_REG_PERF_REGISTER:
- return probe_perf_enable(event);
+ return enable_trace_probe(tp, TP_FLAG_PROFILE);
case TRACE_REG_PERF_UNREGISTER:
- probe_perf_disable(event);
+ disable_trace_probe(tp, TP_FLAG_PROFILE);
return 0;
#endif
}
@@ -1807,7 +1932,7 @@ static int register_probe_event(struct trace_probe *tp)
/* Initialize ftrace_event_call */
INIT_LIST_HEAD(&call->class->fields);
- if (probe_is_return(tp)) {
+ if (trace_probe_is_return(tp)) {
call->event.funcs = &kretprobe_funcs;
call->class->define_fields = kretprobe_event_define_fields;
} else {
@@ -1846,6 +1971,9 @@ static __init int init_kprobe_trace(void)
struct dentry *d_tracer;
struct dentry *entry;
+ if (register_module_notifier(&trace_probe_module_nb))
+ return -EINVAL;
+
d_tracer = tracing_init_dentry();
if (!d_tracer)
return 0;
@@ -1899,12 +2027,12 @@ static __init int kprobe_trace_self_tests_init(void)
warn++;
} else {
/* Enable trace point */
- tp = find_probe_event("testprobe", KPROBE_EVENT_SYSTEM);
+ tp = find_trace_probe("testprobe", KPROBE_EVENT_SYSTEM);
if (WARN_ON_ONCE(tp == NULL)) {
pr_warning("error on getting new probe.\n");
warn++;
} else
- probe_event_enable(&tp->call);
+ enable_trace_probe(tp, TP_FLAG_TRACE);
}
ret = command_trace_probe("r:testprobe2 kprobe_trace_selftest_target "
@@ -1914,12 +2042,12 @@ static __init int kprobe_trace_self_tests_init(void)
warn++;
} else {
/* Enable trace point */
- tp = find_probe_event("testprobe2", KPROBE_EVENT_SYSTEM);
+ tp = find_trace_probe("testprobe2", KPROBE_EVENT_SYSTEM);
if (WARN_ON_ONCE(tp == NULL)) {
pr_warning("error on getting new probe.\n");
warn++;
} else
- probe_event_enable(&tp->call);
+ enable_trace_probe(tp, TP_FLAG_TRACE);
}
if (warn)
@@ -1940,7 +2068,7 @@ static __init int kprobe_trace_self_tests_init(void)
}
end:
- cleanup_all_probes();
+ release_all_trace_probes();
if (warn)
pr_cont("NG: Some tests are failed. Please check them.\n");
else
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index e37de492a9e..51999309a6c 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -1107,19 +1107,20 @@ static enum print_line_t trace_stack_print(struct trace_iterator *iter,
{
struct stack_entry *field;
struct trace_seq *s = &iter->seq;
- int i;
+ unsigned long *p;
+ unsigned long *end;
trace_assign_type(field, iter->ent);
+ end = (unsigned long *)((long)iter->ent + iter->ent_size);
if (!trace_seq_puts(s, "<stack trace>\n"))
goto partial;
- for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
- if (!field->caller[i] || (field->caller[i] == ULONG_MAX))
- break;
+
+ for (p = field->caller; p && *p != ULONG_MAX && p < end; p++) {
if (!trace_seq_puts(s, " => "))
goto partial;
- if (!seq_print_ip_sym(s, field->caller[i], flags))
+ if (!seq_print_ip_sym(s, *p, flags))
goto partial;
if (!trace_seq_puts(s, "\n"))
goto partial;