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Diffstat (limited to 'kernel/trace/trace_kprobe.c')
-rw-r--r--kernel/trace/trace_kprobe.c324
1 files changed, 227 insertions, 97 deletions
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 27d13b36b8b..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);
}
@@ -1397,7 +1570,8 @@ static __kprobes void kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs)
store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);
if (!filter_current_check_discard(buffer, call, entry, event))
- trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc);
+ trace_nowake_buffer_unlock_commit_regs(buffer, event,
+ irq_flags, pc, regs);
}
/* Kretprobe handler */
@@ -1429,7 +1603,8 @@ static __kprobes void kretprobe_trace_func(struct kretprobe_instance *ri,
store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);
if (!filter_current_check_discard(buffer, call, entry, event))
- trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc);
+ trace_nowake_buffer_unlock_commit_regs(buffer, event,
+ irq_flags, pc, regs);
}
/* Event entry printers */
@@ -1511,30 +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 { \
@@ -1596,7 +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 {
@@ -1713,49 +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
}
@@ -1805,7 +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 {
@@ -1844,6 +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;
@@ -1897,12 +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 "
@@ -1912,12 +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)
@@ -1938,7 +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