ASR_BASE
Change-Id: Icf3719cc0afe3eeb3edc7fa80a2eb5199ca9dda1
diff --git a/marvell/linux/kernel/trace/trace_kprobe.c b/marvell/linux/kernel/trace/trace_kprobe.c
new file mode 100644
index 0000000..56d2275
--- /dev/null
+++ b/marvell/linux/kernel/trace/trace_kprobe.c
@@ -0,0 +1,1980 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Kprobes-based tracing events
+ *
+ * Created by Masami Hiramatsu <mhiramat@redhat.com>
+ *
+ */
+#define pr_fmt(fmt) "trace_kprobe: " fmt
+
+#include <linux/security.h>
+#include <linux/module.h>
+#include <linux/uaccess.h>
+#include <linux/rculist.h>
+#include <linux/error-injection.h>
+
+#include <asm/setup.h> /* for COMMAND_LINE_SIZE */
+
+#include "trace_dynevent.h"
+#include "trace_kprobe_selftest.h"
+#include "trace_probe.h"
+#include "trace_probe_tmpl.h"
+
+#define KPROBE_EVENT_SYSTEM "kprobes"
+#define KRETPROBE_MAXACTIVE_MAX 4096
+#define MAX_KPROBE_CMDLINE_SIZE 1024
+
+/* Kprobe early definition from command line */
+static char kprobe_boot_events_buf[COMMAND_LINE_SIZE] __initdata;
+static bool kprobe_boot_events_enabled __initdata;
+
+static int __init set_kprobe_boot_events(char *str)
+{
+ strlcpy(kprobe_boot_events_buf, str, COMMAND_LINE_SIZE);
+ return 0;
+}
+__setup("kprobe_event=", set_kprobe_boot_events);
+
+static int trace_kprobe_create(int argc, const char **argv);
+static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev);
+static int trace_kprobe_release(struct dyn_event *ev);
+static bool trace_kprobe_is_busy(struct dyn_event *ev);
+static bool trace_kprobe_match(const char *system, const char *event,
+ int argc, const char **argv, struct dyn_event *ev);
+
+static struct dyn_event_operations trace_kprobe_ops = {
+ .create = trace_kprobe_create,
+ .show = trace_kprobe_show,
+ .is_busy = trace_kprobe_is_busy,
+ .free = trace_kprobe_release,
+ .match = trace_kprobe_match,
+};
+
+/*
+ * Kprobe event core functions
+ */
+struct trace_kprobe {
+ struct dyn_event devent;
+ struct kretprobe rp; /* Use rp.kp for kprobe use */
+ unsigned long __percpu *nhit;
+ const char *symbol; /* symbol name */
+ struct trace_probe tp;
+};
+
+static bool is_trace_kprobe(struct dyn_event *ev)
+{
+ return ev->ops == &trace_kprobe_ops;
+}
+
+static struct trace_kprobe *to_trace_kprobe(struct dyn_event *ev)
+{
+ return container_of(ev, struct trace_kprobe, devent);
+}
+
+/**
+ * for_each_trace_kprobe - iterate over the trace_kprobe list
+ * @pos: the struct trace_kprobe * for each entry
+ * @dpos: the struct dyn_event * to use as a loop cursor
+ */
+#define for_each_trace_kprobe(pos, dpos) \
+ for_each_dyn_event(dpos) \
+ if (is_trace_kprobe(dpos) && (pos = to_trace_kprobe(dpos)))
+
+#define SIZEOF_TRACE_KPROBE(n) \
+ (offsetof(struct trace_kprobe, tp.args) + \
+ (sizeof(struct probe_arg) * (n)))
+
+static nokprobe_inline bool trace_kprobe_is_return(struct trace_kprobe *tk)
+{
+ return tk->rp.handler != NULL;
+}
+
+static nokprobe_inline const char *trace_kprobe_symbol(struct trace_kprobe *tk)
+{
+ return tk->symbol ? tk->symbol : "unknown";
+}
+
+static nokprobe_inline unsigned long trace_kprobe_offset(struct trace_kprobe *tk)
+{
+ return tk->rp.kp.offset;
+}
+
+static nokprobe_inline bool trace_kprobe_has_gone(struct trace_kprobe *tk)
+{
+ return !!(kprobe_gone(&tk->rp.kp));
+}
+
+static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk,
+ struct module *mod)
+{
+ int len = strlen(mod->name);
+ const char *name = trace_kprobe_symbol(tk);
+ return strncmp(mod->name, name, len) == 0 && name[len] == ':';
+}
+
+static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk)
+{
+ char *p;
+ bool ret;
+
+ if (!tk->symbol)
+ return false;
+ p = strchr(tk->symbol, ':');
+ if (!p)
+ return true;
+ *p = '\0';
+ mutex_lock(&module_mutex);
+ ret = !!find_module(tk->symbol);
+ mutex_unlock(&module_mutex);
+ *p = ':';
+
+ return ret;
+}
+
+static bool trace_kprobe_is_busy(struct dyn_event *ev)
+{
+ struct trace_kprobe *tk = to_trace_kprobe(ev);
+
+ return trace_probe_is_enabled(&tk->tp);
+}
+
+static bool trace_kprobe_match_command_head(struct trace_kprobe *tk,
+ int argc, const char **argv)
+{
+ char buf[MAX_ARGSTR_LEN + 1];
+
+ if (!argc)
+ return true;
+
+ if (!tk->symbol)
+ snprintf(buf, sizeof(buf), "0x%p", tk->rp.kp.addr);
+ else if (tk->rp.kp.offset)
+ snprintf(buf, sizeof(buf), "%s+%u",
+ trace_kprobe_symbol(tk), tk->rp.kp.offset);
+ else
+ snprintf(buf, sizeof(buf), "%s", trace_kprobe_symbol(tk));
+ if (strcmp(buf, argv[0]))
+ return false;
+ argc--; argv++;
+
+ return trace_probe_match_command_args(&tk->tp, argc, argv);
+}
+
+static bool trace_kprobe_match(const char *system, const char *event,
+ int argc, const char **argv, struct dyn_event *ev)
+{
+ struct trace_kprobe *tk = to_trace_kprobe(ev);
+
+ return strcmp(trace_probe_name(&tk->tp), event) == 0 &&
+ (!system || strcmp(trace_probe_group_name(&tk->tp), system) == 0) &&
+ trace_kprobe_match_command_head(tk, argc, argv);
+}
+
+static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk)
+{
+ unsigned long nhit = 0;
+ int cpu;
+
+ for_each_possible_cpu(cpu)
+ nhit += *per_cpu_ptr(tk->nhit, cpu);
+
+ return nhit;
+}
+
+static nokprobe_inline bool trace_kprobe_is_registered(struct trace_kprobe *tk)
+{
+ return !(list_empty(&tk->rp.kp.list) &&
+ hlist_unhashed(&tk->rp.kp.hlist));
+}
+
+/* Return 0 if it fails to find the symbol address */
+static nokprobe_inline
+unsigned long trace_kprobe_address(struct trace_kprobe *tk)
+{
+ unsigned long addr;
+
+ if (tk->symbol) {
+ addr = (unsigned long)
+ kallsyms_lookup_name(trace_kprobe_symbol(tk));
+ if (addr)
+ addr += tk->rp.kp.offset;
+ } else {
+ addr = (unsigned long)tk->rp.kp.addr;
+ }
+ return addr;
+}
+
+static nokprobe_inline struct trace_kprobe *
+trace_kprobe_primary_from_call(struct trace_event_call *call)
+{
+ struct trace_probe *tp;
+
+ tp = trace_probe_primary_from_call(call);
+ if (WARN_ON_ONCE(!tp))
+ return NULL;
+
+ return container_of(tp, struct trace_kprobe, tp);
+}
+
+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,
+ tk->rp.kp.addr ? NULL : tk->rp.kp.symbol_name,
+ tk->rp.kp.addr ? 0 : tk->rp.kp.offset) == 0) : false;
+}
+
+bool trace_kprobe_error_injectable(struct trace_event_call *call)
+{
+ struct trace_kprobe *tk = trace_kprobe_primary_from_call(call);
+
+ return tk ? within_error_injection_list(trace_kprobe_address(tk)) :
+ false;
+}
+
+static int register_kprobe_event(struct trace_kprobe *tk);
+static int unregister_kprobe_event(struct trace_kprobe *tk);
+
+static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs);
+static int kretprobe_dispatcher(struct kretprobe_instance *ri,
+ struct pt_regs *regs);
+
+static void free_trace_kprobe(struct trace_kprobe *tk)
+{
+ if (tk) {
+ trace_probe_cleanup(&tk->tp);
+ kfree(tk->symbol);
+ free_percpu(tk->nhit);
+ kfree(tk);
+ }
+}
+
+/*
+ * Allocate new trace_probe and initialize it (including kprobes).
+ */
+static struct trace_kprobe *alloc_trace_kprobe(const char *group,
+ const char *event,
+ void *addr,
+ const char *symbol,
+ unsigned long offs,
+ int maxactive,
+ int nargs, bool is_return)
+{
+ struct trace_kprobe *tk;
+ int ret = -ENOMEM;
+
+ tk = kzalloc(SIZEOF_TRACE_KPROBE(nargs), GFP_KERNEL);
+ if (!tk)
+ return ERR_PTR(ret);
+
+ tk->nhit = alloc_percpu(unsigned long);
+ if (!tk->nhit)
+ goto error;
+
+ if (symbol) {
+ tk->symbol = kstrdup(symbol, GFP_KERNEL);
+ if (!tk->symbol)
+ goto error;
+ tk->rp.kp.symbol_name = tk->symbol;
+ tk->rp.kp.offset = offs;
+ } else
+ tk->rp.kp.addr = addr;
+
+ if (is_return)
+ tk->rp.handler = kretprobe_dispatcher;
+ else
+ tk->rp.kp.pre_handler = kprobe_dispatcher;
+
+ tk->rp.maxactive = maxactive;
+ INIT_HLIST_NODE(&tk->rp.kp.hlist);
+ INIT_LIST_HEAD(&tk->rp.kp.list);
+
+ ret = trace_probe_init(&tk->tp, event, group, false);
+ if (ret < 0)
+ goto error;
+
+ dyn_event_init(&tk->devent, &trace_kprobe_ops);
+ return tk;
+error:
+ free_trace_kprobe(tk);
+ return ERR_PTR(ret);
+}
+
+static struct trace_kprobe *find_trace_kprobe(const char *event,
+ const char *group)
+{
+ struct dyn_event *pos;
+ struct trace_kprobe *tk;
+
+ for_each_trace_kprobe(tk, pos)
+ if (strcmp(trace_probe_name(&tk->tp), event) == 0 &&
+ strcmp(trace_probe_group_name(&tk->tp), group) == 0)
+ return tk;
+ return NULL;
+}
+
+static inline int __enable_trace_kprobe(struct trace_kprobe *tk)
+{
+ int ret = 0;
+
+ if (trace_kprobe_is_registered(tk) && !trace_kprobe_has_gone(tk)) {
+ if (trace_kprobe_is_return(tk))
+ ret = enable_kretprobe(&tk->rp);
+ else
+ ret = enable_kprobe(&tk->rp.kp);
+ }
+
+ return ret;
+}
+
+static void __disable_trace_kprobe(struct trace_probe *tp)
+{
+ struct trace_probe *pos;
+ struct trace_kprobe *tk;
+
+ list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
+ tk = container_of(pos, struct trace_kprobe, tp);
+ if (!trace_kprobe_is_registered(tk))
+ continue;
+ if (trace_kprobe_is_return(tk))
+ disable_kretprobe(&tk->rp);
+ else
+ disable_kprobe(&tk->rp.kp);
+ }
+}
+
+/*
+ * Enable trace_probe
+ * if the file is NULL, enable "perf" handler, or enable "trace" handler.
+ */
+static int enable_trace_kprobe(struct trace_event_call *call,
+ struct trace_event_file *file)
+{
+ struct trace_probe *pos, *tp;
+ struct trace_kprobe *tk;
+ bool enabled;
+ int ret = 0;
+
+ tp = trace_probe_primary_from_call(call);
+ if (WARN_ON_ONCE(!tp))
+ return -ENODEV;
+ enabled = trace_probe_is_enabled(tp);
+
+ /* This also changes "enabled" state */
+ if (file) {
+ ret = trace_probe_add_file(tp, file);
+ if (ret)
+ return ret;
+ } else
+ trace_probe_set_flag(tp, TP_FLAG_PROFILE);
+
+ if (enabled)
+ return 0;
+
+ list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
+ tk = container_of(pos, struct trace_kprobe, tp);
+ if (trace_kprobe_has_gone(tk))
+ continue;
+ ret = __enable_trace_kprobe(tk);
+ if (ret)
+ break;
+ enabled = true;
+ }
+
+ if (ret) {
+ /* Failed to enable one of them. Roll back all */
+ if (enabled)
+ __disable_trace_kprobe(tp);
+ if (file)
+ trace_probe_remove_file(tp, file);
+ else
+ trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
+ }
+
+ return ret;
+}
+
+/*
+ * Disable trace_probe
+ * if the file is NULL, disable "perf" handler, or disable "trace" handler.
+ */
+static int disable_trace_kprobe(struct trace_event_call *call,
+ struct trace_event_file *file)
+{
+ struct trace_probe *tp;
+
+ tp = trace_probe_primary_from_call(call);
+ if (WARN_ON_ONCE(!tp))
+ return -ENODEV;
+
+ if (file) {
+ if (!trace_probe_get_file_link(tp, file))
+ return -ENOENT;
+ if (!trace_probe_has_single_file(tp))
+ goto out;
+ trace_probe_clear_flag(tp, TP_FLAG_TRACE);
+ } else
+ trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
+
+ if (!trace_probe_is_enabled(tp))
+ __disable_trace_kprobe(tp);
+
+ out:
+ if (file)
+ /*
+ * Synchronization is done in below function. For perf event,
+ * file == NULL and perf_trace_event_unreg() calls
+ * tracepoint_synchronize_unregister() to ensure synchronize
+ * event. We don't need to care about it.
+ */
+ trace_probe_remove_file(tp, file);
+
+ return 1;
+}
+
+#if defined(CONFIG_DYNAMIC_FTRACE) && \
+ !defined(CONFIG_KPROBE_EVENTS_ON_NOTRACE)
+static bool __within_notrace_func(unsigned long addr)
+{
+ unsigned long offset, size;
+
+ if (!addr || !kallsyms_lookup_size_offset(addr, &size, &offset))
+ return false;
+
+ /* Get the entry address of the target function */
+ addr -= offset;
+
+ /*
+ * Since ftrace_location_range() does inclusive range check, we need
+ * to subtract 1 byte from the end address.
+ */
+ return !ftrace_location_range(addr, addr + size - 1);
+}
+
+static bool within_notrace_func(struct trace_kprobe *tk)
+{
+ unsigned long addr = trace_kprobe_address(tk);
+ char symname[KSYM_NAME_LEN], *p;
+
+ if (!__within_notrace_func(addr))
+ return false;
+
+ /* Check if the address is on a suffixed-symbol */
+ if (!lookup_symbol_name(addr, symname)) {
+ p = strchr(symname, '.');
+ if (!p)
+ return true;
+ *p = '\0';
+ addr = (unsigned long)kprobe_lookup_name(symname, 0);
+ if (addr)
+ return __within_notrace_func(addr);
+ }
+
+ return true;
+}
+#else
+#define within_notrace_func(tk) (false)
+#endif
+
+/* Internal register function - just handle k*probes and flags */
+static int __register_trace_kprobe(struct trace_kprobe *tk)
+{
+ int i, ret;
+
+ ret = security_locked_down(LOCKDOWN_KPROBES);
+ if (ret)
+ return ret;
+
+ if (trace_kprobe_is_registered(tk))
+ return -EINVAL;
+
+ if (within_notrace_func(tk)) {
+ pr_warn("Could not probe notrace function %s\n",
+ trace_kprobe_symbol(tk));
+ return -EINVAL;
+ }
+
+ for (i = 0; i < tk->tp.nr_args; i++) {
+ ret = traceprobe_update_arg(&tk->tp.args[i]);
+ if (ret)
+ return ret;
+ }
+
+ /* Set/clear disabled flag according to tp->flag */
+ if (trace_probe_is_enabled(&tk->tp))
+ tk->rp.kp.flags &= ~KPROBE_FLAG_DISABLED;
+ else
+ tk->rp.kp.flags |= KPROBE_FLAG_DISABLED;
+
+ if (trace_kprobe_is_return(tk))
+ ret = register_kretprobe(&tk->rp);
+ else
+ ret = register_kprobe(&tk->rp.kp);
+
+ return ret;
+}
+
+/* Internal unregister function - just handle k*probes and flags */
+static void __unregister_trace_kprobe(struct trace_kprobe *tk)
+{
+ if (trace_kprobe_is_registered(tk)) {
+ if (trace_kprobe_is_return(tk))
+ unregister_kretprobe(&tk->rp);
+ else
+ unregister_kprobe(&tk->rp.kp);
+ /* Cleanup kprobe for reuse and mark it unregistered */
+ INIT_HLIST_NODE(&tk->rp.kp.hlist);
+ INIT_LIST_HEAD(&tk->rp.kp.list);
+ if (tk->rp.kp.symbol_name)
+ tk->rp.kp.addr = NULL;
+ }
+}
+
+/* Unregister a trace_probe and probe_event */
+static int unregister_trace_kprobe(struct trace_kprobe *tk)
+{
+ /* If other probes are on the event, just unregister kprobe */
+ if (trace_probe_has_sibling(&tk->tp))
+ goto unreg;
+
+ /* Enabled event can not be unregistered */
+ if (trace_probe_is_enabled(&tk->tp))
+ return -EBUSY;
+
+ /* Will fail if probe is being used by ftrace or perf */
+ if (unregister_kprobe_event(tk))
+ return -EBUSY;
+
+unreg:
+ __unregister_trace_kprobe(tk);
+ dyn_event_remove(&tk->devent);
+ trace_probe_unlink(&tk->tp);
+
+ return 0;
+}
+
+static bool trace_kprobe_has_same_kprobe(struct trace_kprobe *orig,
+ struct trace_kprobe *comp)
+{
+ struct trace_probe_event *tpe = orig->tp.event;
+ struct trace_probe *pos;
+ int i;
+
+ list_for_each_entry(pos, &tpe->probes, list) {
+ orig = container_of(pos, struct trace_kprobe, tp);
+ if (strcmp(trace_kprobe_symbol(orig),
+ trace_kprobe_symbol(comp)) ||
+ trace_kprobe_offset(orig) != trace_kprobe_offset(comp))
+ continue;
+
+ /*
+ * trace_probe_compare_arg_type() ensured that nr_args and
+ * each argument name and type are same. Let's compare comm.
+ */
+ for (i = 0; i < orig->tp.nr_args; i++) {
+ if (strcmp(orig->tp.args[i].comm,
+ comp->tp.args[i].comm))
+ break;
+ }
+
+ if (i == orig->tp.nr_args)
+ return true;
+ }
+
+ return false;
+}
+
+static int append_trace_kprobe(struct trace_kprobe *tk, struct trace_kprobe *to)
+{
+ int ret;
+
+ ret = trace_probe_compare_arg_type(&tk->tp, &to->tp);
+ if (ret) {
+ /* Note that argument starts index = 2 */
+ trace_probe_log_set_index(ret + 1);
+ trace_probe_log_err(0, DIFF_ARG_TYPE);
+ return -EEXIST;
+ }
+ if (trace_kprobe_has_same_kprobe(to, tk)) {
+ trace_probe_log_set_index(0);
+ trace_probe_log_err(0, SAME_PROBE);
+ return -EEXIST;
+ }
+
+ /* Append to existing event */
+ ret = trace_probe_append(&tk->tp, &to->tp);
+ if (ret)
+ return ret;
+
+ /* Register k*probe */
+ ret = __register_trace_kprobe(tk);
+ if (ret == -ENOENT && !trace_kprobe_module_exist(tk)) {
+ pr_warn("This probe might be able to register after target module is loaded. Continue.\n");
+ ret = 0;
+ }
+
+ if (ret)
+ trace_probe_unlink(&tk->tp);
+ else
+ dyn_event_add(&tk->devent);
+
+ return ret;
+}
+
+/* Register a trace_probe and probe_event */
+static int register_trace_kprobe(struct trace_kprobe *tk)
+{
+ struct trace_kprobe *old_tk;
+ int ret;
+
+ mutex_lock(&event_mutex);
+
+ old_tk = find_trace_kprobe(trace_probe_name(&tk->tp),
+ trace_probe_group_name(&tk->tp));
+ if (old_tk) {
+ if (trace_kprobe_is_return(tk) != trace_kprobe_is_return(old_tk)) {
+ trace_probe_log_set_index(0);
+ trace_probe_log_err(0, DIFF_PROBE_TYPE);
+ ret = -EEXIST;
+ } else {
+ ret = append_trace_kprobe(tk, old_tk);
+ }
+ goto end;
+ }
+
+ /* Register new event */
+ ret = register_kprobe_event(tk);
+ if (ret) {
+ if (ret == -EEXIST) {
+ trace_probe_log_set_index(0);
+ trace_probe_log_err(0, EVENT_EXIST);
+ } else
+ pr_warn("Failed to register probe event(%d)\n", ret);
+ goto end;
+ }
+
+ /* Register k*probe */
+ ret = __register_trace_kprobe(tk);
+ if (ret == -ENOENT && !trace_kprobe_module_exist(tk)) {
+ pr_warn("This probe might be able to register after target module is loaded. Continue.\n");
+ ret = 0;
+ }
+
+ if (ret < 0)
+ unregister_kprobe_event(tk);
+ else
+ dyn_event_add(&tk->devent);
+
+end:
+ mutex_unlock(&event_mutex);
+ return ret;
+}
+
+/* Module notifier call back, checking event on the module */
+static int trace_kprobe_module_callback(struct notifier_block *nb,
+ unsigned long val, void *data)
+{
+ struct module *mod = data;
+ struct dyn_event *pos;
+ struct trace_kprobe *tk;
+ int ret;
+
+ if (val != MODULE_STATE_COMING)
+ return NOTIFY_DONE;
+
+ /* Update probes on coming module */
+ mutex_lock(&event_mutex);
+ for_each_trace_kprobe(tk, pos) {
+ if (trace_kprobe_within_module(tk, mod)) {
+ /* Don't need to check busy - this should have gone. */
+ __unregister_trace_kprobe(tk);
+ ret = __register_trace_kprobe(tk);
+ if (ret)
+ pr_warn("Failed to re-register probe %s on %s: %d\n",
+ trace_probe_name(&tk->tp),
+ mod->name, ret);
+ }
+ }
+ mutex_unlock(&event_mutex);
+
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block trace_kprobe_module_nb = {
+ .notifier_call = trace_kprobe_module_callback,
+ .priority = 2 /* Invoked after kprobe and jump_label module callback */
+};
+
+/* Convert certain expected symbols into '_' when generating event names */
+static inline void sanitize_event_name(char *name)
+{
+ while (*name++ != '\0')
+ if (*name == ':' || *name == '.')
+ *name = '_';
+}
+
+struct count_symbols_struct {
+ const char *func_name;
+ unsigned int count;
+};
+
+static int count_symbols(void *data, const char *name, struct module *unused0,
+ unsigned long unused1)
+{
+ struct count_symbols_struct *args = data;
+
+ if (strcmp(args->func_name, name))
+ return 0;
+
+ args->count++;
+
+ return 0;
+}
+
+static unsigned int number_of_same_symbols(char *func_name)
+{
+ struct count_symbols_struct args = {
+ .func_name = func_name,
+ .count = 0,
+ };
+
+ kallsyms_on_each_symbol(count_symbols, &args);
+
+ module_kallsyms_on_each_symbol(count_symbols, &args);
+
+ return args.count;
+}
+
+static int trace_kprobe_create(int argc, const char *argv[])
+{
+ /*
+ * Argument syntax:
+ * - Add kprobe:
+ * p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS]
+ * - Add kretprobe:
+ * r[MAXACTIVE][:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS]
+ * Fetch args:
+ * $retval : fetch return value
+ * $stack : fetch stack address
+ * $stackN : fetch Nth of stack (N:0-)
+ * $comm : fetch current task comm
+ * @ADDR : fetch memory at ADDR (ADDR should be in kernel)
+ * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol)
+ * %REG : fetch register REG
+ * Dereferencing memory fetch:
+ * +|-offs(ARG) : fetch memory at ARG +|- offs address.
+ * Alias name of args:
+ * NAME=FETCHARG : set NAME as alias of FETCHARG.
+ * Type of args:
+ * FETCHARG:TYPE : use TYPE instead of unsigned long.
+ */
+ struct trace_kprobe *tk = NULL;
+ int i, len, ret = 0;
+ bool is_return = false;
+ char *symbol = NULL, *tmp = NULL;
+ const char *event = NULL, *group = KPROBE_EVENT_SYSTEM;
+ int maxactive = 0;
+ long offset = 0;
+ void *addr = NULL;
+ char buf[MAX_EVENT_NAME_LEN];
+ unsigned int flags = TPARG_FL_KERNEL;
+
+ switch (argv[0][0]) {
+ case 'r':
+ is_return = true;
+ flags |= TPARG_FL_RETURN;
+ break;
+ case 'p':
+ break;
+ default:
+ return -ECANCELED;
+ }
+ if (argc < 2)
+ return -ECANCELED;
+
+ trace_probe_log_init("trace_kprobe", argc, argv);
+
+ event = strchr(&argv[0][1], ':');
+ if (event)
+ event++;
+
+ if (isdigit(argv[0][1])) {
+ if (!is_return) {
+ trace_probe_log_err(1, MAXACT_NO_KPROBE);
+ goto parse_error;
+ }
+ if (event)
+ len = event - &argv[0][1] - 1;
+ else
+ len = strlen(&argv[0][1]);
+ if (len > MAX_EVENT_NAME_LEN - 1) {
+ trace_probe_log_err(1, BAD_MAXACT);
+ goto parse_error;
+ }
+ memcpy(buf, &argv[0][1], len);
+ buf[len] = '\0';
+ ret = kstrtouint(buf, 0, &maxactive);
+ if (ret || !maxactive) {
+ trace_probe_log_err(1, BAD_MAXACT);
+ goto parse_error;
+ }
+ /* kretprobes instances are iterated over via a list. The
+ * maximum should stay reasonable.
+ */
+ if (maxactive > KRETPROBE_MAXACTIVE_MAX) {
+ trace_probe_log_err(1, MAXACT_TOO_BIG);
+ goto parse_error;
+ }
+ }
+
+ /* try to parse an address. if that fails, try to read the
+ * input as a symbol. */
+ if (kstrtoul(argv[1], 0, (unsigned long *)&addr)) {
+ trace_probe_log_set_index(1);
+ /* Check whether uprobe event specified */
+ if (strchr(argv[1], '/') && strchr(argv[1], ':')) {
+ ret = -ECANCELED;
+ goto error;
+ }
+ /* a symbol specified */
+ symbol = kstrdup(argv[1], GFP_KERNEL);
+ if (!symbol)
+ return -ENOMEM;
+ /* TODO: support .init module functions */
+ ret = traceprobe_split_symbol_offset(symbol, &offset);
+ if (ret || offset < 0 || offset > UINT_MAX) {
+ trace_probe_log_err(0, BAD_PROBE_ADDR);
+ goto parse_error;
+ }
+ ret = kprobe_on_func_entry(NULL, symbol, offset);
+ if (ret == 0)
+ 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;
+ }
+ }
+
+ if (symbol && !strchr(symbol, ':')) {
+ unsigned int count;
+
+ count = number_of_same_symbols(symbol);
+ if (count > 1) {
+ /*
+ * Users should use ADDR to remove the ambiguity of
+ * using KSYM only.
+ */
+ trace_probe_log_err(0, NON_UNIQ_SYMBOL);
+ ret = -EADDRNOTAVAIL;
+
+ goto error;
+ } else if (count == 0) {
+ /*
+ * We can return ENOENT earlier than when register the
+ * kprobe.
+ */
+ trace_probe_log_err(0, BAD_PROBE_ADDR);
+ ret = -ENOENT;
+
+ goto error;
+ }
+ }
+
+ trace_probe_log_set_index(0);
+ if (event) {
+ ret = traceprobe_parse_event_name(&event, &group, buf,
+ event - argv[0]);
+ if (ret)
+ goto parse_error;
+ } else {
+ /* Make a new event name */
+ if (symbol)
+ snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld",
+ is_return ? 'r' : 'p', symbol, offset);
+ else
+ snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p",
+ is_return ? 'r' : 'p', addr);
+ sanitize_event_name(buf);
+ event = buf;
+ }
+
+ /* setup a probe */
+ tk = alloc_trace_kprobe(group, event, addr, symbol, offset, maxactive,
+ argc - 2, is_return);
+ if (IS_ERR(tk)) {
+ ret = PTR_ERR(tk);
+ /* This must return -ENOMEM, else there is a bug */
+ WARN_ON_ONCE(ret != -ENOMEM);
+ goto out; /* We know tk is not allocated */
+ }
+ argc -= 2; argv += 2;
+
+ /* parse arguments */
+ for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
+ tmp = kstrdup(argv[i], GFP_KERNEL);
+ if (!tmp) {
+ ret = -ENOMEM;
+ goto error;
+ }
+
+ trace_probe_log_set_index(i + 2);
+ ret = traceprobe_parse_probe_arg(&tk->tp, i, tmp, flags);
+ kfree(tmp);
+ if (ret)
+ goto error; /* This can be -ENOMEM */
+ }
+
+ ret = traceprobe_set_print_fmt(&tk->tp, is_return);
+ if (ret < 0)
+ goto error;
+
+ ret = register_trace_kprobe(tk);
+ if (ret) {
+ trace_probe_log_set_index(1);
+ if (ret == -EILSEQ)
+ trace_probe_log_err(0, BAD_INSN_BNDRY);
+ else if (ret == -ENOENT)
+ trace_probe_log_err(0, BAD_PROBE_ADDR);
+ else if (ret != -ENOMEM && ret != -EEXIST)
+ trace_probe_log_err(0, FAIL_REG_PROBE);
+ goto error;
+ }
+
+out:
+ trace_probe_log_clear();
+ kfree(symbol);
+ return ret;
+
+parse_error:
+ ret = -EINVAL;
+error:
+ free_trace_kprobe(tk);
+ goto out;
+}
+
+static int create_or_delete_trace_kprobe(int argc, char **argv)
+{
+ int ret;
+
+ if (argv[0][0] == '-')
+ return dyn_event_release(argc, argv, &trace_kprobe_ops);
+
+ ret = trace_kprobe_create(argc, (const char **)argv);
+ return ret == -ECANCELED ? -EINVAL : ret;
+}
+
+static int trace_kprobe_release(struct dyn_event *ev)
+{
+ struct trace_kprobe *tk = to_trace_kprobe(ev);
+ int ret = unregister_trace_kprobe(tk);
+
+ if (!ret)
+ free_trace_kprobe(tk);
+ return ret;
+}
+
+static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev)
+{
+ struct trace_kprobe *tk = to_trace_kprobe(ev);
+ int i;
+
+ seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p');
+ if (trace_kprobe_is_return(tk) && tk->rp.maxactive)
+ seq_printf(m, "%d", tk->rp.maxactive);
+ seq_printf(m, ":%s/%s", trace_probe_group_name(&tk->tp),
+ trace_probe_name(&tk->tp));
+
+ if (!tk->symbol)
+ seq_printf(m, " 0x%p", tk->rp.kp.addr);
+ else if (tk->rp.kp.offset)
+ seq_printf(m, " %s+%u", trace_kprobe_symbol(tk),
+ tk->rp.kp.offset);
+ else
+ seq_printf(m, " %s", trace_kprobe_symbol(tk));
+
+ for (i = 0; i < tk->tp.nr_args; i++)
+ seq_printf(m, " %s=%s", tk->tp.args[i].name, tk->tp.args[i].comm);
+ seq_putc(m, '\n');
+
+ return 0;
+}
+
+static int probes_seq_show(struct seq_file *m, void *v)
+{
+ struct dyn_event *ev = v;
+
+ if (!is_trace_kprobe(ev))
+ return 0;
+
+ return trace_kprobe_show(m, ev);
+}
+
+static const struct seq_operations probes_seq_op = {
+ .start = dyn_event_seq_start,
+ .next = dyn_event_seq_next,
+ .stop = dyn_event_seq_stop,
+ .show = probes_seq_show
+};
+
+static int probes_open(struct inode *inode, struct file *file)
+{
+ int ret;
+
+ ret = security_locked_down(LOCKDOWN_TRACEFS);
+ if (ret)
+ return ret;
+
+ if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
+ ret = dyn_events_release_all(&trace_kprobe_ops);
+ if (ret < 0)
+ return ret;
+ }
+
+ return seq_open(file, &probes_seq_op);
+}
+
+static ssize_t probes_write(struct file *file, const char __user *buffer,
+ size_t count, loff_t *ppos)
+{
+ return trace_parse_run_command(file, buffer, count, ppos,
+ create_or_delete_trace_kprobe);
+}
+
+static const struct file_operations kprobe_events_ops = {
+ .owner = THIS_MODULE,
+ .open = probes_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+ .write = probes_write,
+};
+
+/* Probes profiling interfaces */
+static int probes_profile_seq_show(struct seq_file *m, void *v)
+{
+ struct dyn_event *ev = v;
+ struct trace_kprobe *tk;
+ unsigned long nmissed;
+
+ if (!is_trace_kprobe(ev))
+ return 0;
+
+ tk = to_trace_kprobe(ev);
+ nmissed = trace_kprobe_is_return(tk) ?
+ tk->rp.kp.nmissed + tk->rp.nmissed : tk->rp.kp.nmissed;
+ seq_printf(m, " %-44s %15lu %15lu\n",
+ trace_probe_name(&tk->tp),
+ trace_kprobe_nhit(tk),
+ nmissed);
+
+ return 0;
+}
+
+static const struct seq_operations profile_seq_op = {
+ .start = dyn_event_seq_start,
+ .next = dyn_event_seq_next,
+ .stop = dyn_event_seq_stop,
+ .show = probes_profile_seq_show
+};
+
+static int profile_open(struct inode *inode, struct file *file)
+{
+ int ret;
+
+ ret = security_locked_down(LOCKDOWN_TRACEFS);
+ if (ret)
+ return ret;
+
+ return seq_open(file, &profile_seq_op);
+}
+
+static const struct file_operations kprobe_profile_ops = {
+ .owner = THIS_MODULE,
+ .open = profile_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+/* Kprobe specific fetch functions */
+
+/* Return the length of string -- including null terminal byte */
+static nokprobe_inline int
+fetch_store_strlen(unsigned long addr)
+{
+ int ret, len = 0;
+ u8 c;
+
+ do {
+ ret = probe_kernel_read(&c, (u8 *)addr + len, 1);
+ len++;
+ } while (c && ret == 0 && len < MAX_STRING_SIZE);
+
+ return (ret < 0) ? ret : len;
+}
+
+/* Return the length of string -- including null terminal byte */
+static nokprobe_inline int
+fetch_store_strlen_user(unsigned long addr)
+{
+ const void __user *uaddr = (__force const void __user *)addr;
+
+ return strnlen_unsafe_user(uaddr, MAX_STRING_SIZE);
+}
+
+/*
+ * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max
+ * length and relative data location.
+ */
+static nokprobe_inline int
+fetch_store_string(unsigned long addr, void *dest, void *base)
+{
+ int maxlen = get_loc_len(*(u32 *)dest);
+ void *__dest;
+ long ret;
+
+ if (unlikely(!maxlen))
+ return -ENOMEM;
+
+ __dest = get_loc_data(dest, base);
+
+ /*
+ * Try to get string again, since the string can be changed while
+ * probing.
+ */
+ ret = strncpy_from_unsafe(__dest, (void *)addr, maxlen);
+ if (ret >= 0)
+ *(u32 *)dest = make_data_loc(ret, __dest - base);
+
+ return ret;
+}
+
+/*
+ * Fetch a null-terminated string from user. Caller MUST set *(u32 *)buf
+ * with max length and relative data location.
+ */
+static nokprobe_inline int
+fetch_store_string_user(unsigned long addr, void *dest, void *base)
+{
+ const void __user *uaddr = (__force const void __user *)addr;
+ int maxlen = get_loc_len(*(u32 *)dest);
+ void *__dest;
+ long ret;
+
+ if (unlikely(!maxlen))
+ return -ENOMEM;
+
+ __dest = get_loc_data(dest, base);
+
+ ret = strncpy_from_unsafe_user(__dest, uaddr, maxlen);
+ if (ret >= 0)
+ *(u32 *)dest = make_data_loc(ret, __dest - base);
+
+ return ret;
+}
+
+static nokprobe_inline int
+probe_mem_read(void *dest, void *src, size_t size)
+{
+ return probe_kernel_read(dest, src, size);
+}
+
+static nokprobe_inline int
+probe_mem_read_user(void *dest, void *src, size_t size)
+{
+ const void __user *uaddr = (__force const void __user *)src;
+
+ return probe_user_read(dest, uaddr, size);
+}
+
+/* Note that we don't verify it, since the code does not come from user space */
+static int
+process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
+ void *base)
+{
+ struct pt_regs *regs = rec;
+ unsigned long val;
+
+retry:
+ /* 1st stage: get value from context */
+ switch (code->op) {
+ case FETCH_OP_REG:
+ val = regs_get_register(regs, code->param);
+ break;
+ case FETCH_OP_STACK:
+ val = regs_get_kernel_stack_nth(regs, code->param);
+ break;
+ case FETCH_OP_STACKP:
+ val = kernel_stack_pointer(regs);
+ break;
+ case FETCH_OP_RETVAL:
+ val = regs_return_value(regs);
+ break;
+ case FETCH_OP_IMM:
+ val = code->immediate;
+ break;
+ case FETCH_OP_COMM:
+ val = (unsigned long)current->comm;
+ break;
+ case FETCH_OP_DATA:
+ val = (unsigned long)code->data;
+ break;
+#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
+ case FETCH_OP_ARG:
+ val = regs_get_kernel_argument(regs, code->param);
+ break;
+#endif
+ case FETCH_NOP_SYMBOL: /* Ignore a place holder */
+ code++;
+ goto retry;
+ default:
+ return -EILSEQ;
+ }
+ code++;
+
+ return process_fetch_insn_bottom(code, val, dest, base);
+}
+NOKPROBE_SYMBOL(process_fetch_insn)
+
+/* Kprobe handler */
+static nokprobe_inline void
+__kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
+ struct trace_event_file *trace_file)
+{
+ struct kprobe_trace_entry_head *entry;
+ struct ring_buffer_event *event;
+ struct ring_buffer *buffer;
+ int size, dsize, pc;
+ unsigned long irq_flags;
+ struct trace_event_call *call = trace_probe_event_call(&tk->tp);
+
+ WARN_ON(call != trace_file->event_call);
+
+ if (trace_trigger_soft_disabled(trace_file))
+ return;
+
+ local_save_flags(irq_flags);
+ pc = preempt_count();
+
+ dsize = __get_data_size(&tk->tp, regs);
+ size = sizeof(*entry) + tk->tp.size + dsize;
+
+ event = trace_event_buffer_lock_reserve(&buffer, trace_file,
+ call->event.type,
+ size, irq_flags, pc);
+ if (!event)
+ return;
+
+ entry = ring_buffer_event_data(event);
+ entry->ip = (unsigned long)tk->rp.kp.addr;
+ store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
+
+ event_trigger_unlock_commit_regs(trace_file, buffer, event,
+ entry, irq_flags, pc, regs);
+}
+
+static void
+kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs)
+{
+ struct event_file_link *link;
+
+ trace_probe_for_each_link_rcu(link, &tk->tp)
+ __kprobe_trace_func(tk, regs, link->file);
+}
+NOKPROBE_SYMBOL(kprobe_trace_func);
+
+/* Kretprobe handler */
+static nokprobe_inline void
+__kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
+ struct pt_regs *regs,
+ struct trace_event_file *trace_file)
+{
+ struct kretprobe_trace_entry_head *entry;
+ struct ring_buffer_event *event;
+ struct ring_buffer *buffer;
+ int size, pc, dsize;
+ unsigned long irq_flags;
+ struct trace_event_call *call = trace_probe_event_call(&tk->tp);
+
+ WARN_ON(call != trace_file->event_call);
+
+ if (trace_trigger_soft_disabled(trace_file))
+ return;
+
+ local_save_flags(irq_flags);
+ pc = preempt_count();
+
+ dsize = __get_data_size(&tk->tp, regs);
+ size = sizeof(*entry) + tk->tp.size + dsize;
+
+ event = trace_event_buffer_lock_reserve(&buffer, trace_file,
+ call->event.type,
+ size, irq_flags, pc);
+ if (!event)
+ return;
+
+ entry = ring_buffer_event_data(event);
+ entry->func = (unsigned long)tk->rp.kp.addr;
+ entry->ret_ip = (unsigned long)ri->ret_addr;
+ store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
+
+ event_trigger_unlock_commit_regs(trace_file, buffer, event,
+ entry, irq_flags, pc, regs);
+}
+
+static void
+kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
+ struct pt_regs *regs)
+{
+ struct event_file_link *link;
+
+ trace_probe_for_each_link_rcu(link, &tk->tp)
+ __kretprobe_trace_func(tk, ri, regs, link->file);
+}
+NOKPROBE_SYMBOL(kretprobe_trace_func);
+
+/* Event entry printers */
+static enum print_line_t
+print_kprobe_event(struct trace_iterator *iter, int flags,
+ struct trace_event *event)
+{
+ struct kprobe_trace_entry_head *field;
+ struct trace_seq *s = &iter->seq;
+ struct trace_probe *tp;
+
+ field = (struct kprobe_trace_entry_head *)iter->ent;
+ tp = trace_probe_primary_from_call(
+ container_of(event, struct trace_event_call, event));
+ if (WARN_ON_ONCE(!tp))
+ goto out;
+
+ trace_seq_printf(s, "%s: (", trace_probe_name(tp));
+
+ if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET))
+ goto out;
+
+ trace_seq_putc(s, ')');
+
+ if (print_probe_args(s, tp->args, tp->nr_args,
+ (u8 *)&field[1], field) < 0)
+ goto out;
+
+ trace_seq_putc(s, '\n');
+ out:
+ return trace_handle_return(s);
+}
+
+static enum print_line_t
+print_kretprobe_event(struct trace_iterator *iter, int flags,
+ struct trace_event *event)
+{
+ struct kretprobe_trace_entry_head *field;
+ struct trace_seq *s = &iter->seq;
+ struct trace_probe *tp;
+
+ field = (struct kretprobe_trace_entry_head *)iter->ent;
+ tp = trace_probe_primary_from_call(
+ container_of(event, struct trace_event_call, event));
+ if (WARN_ON_ONCE(!tp))
+ goto out;
+
+ trace_seq_printf(s, "%s: (", trace_probe_name(tp));
+
+ if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET))
+ goto out;
+
+ trace_seq_puts(s, " <- ");
+
+ if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET))
+ goto out;
+
+ trace_seq_putc(s, ')');
+
+ if (print_probe_args(s, tp->args, tp->nr_args,
+ (u8 *)&field[1], field) < 0)
+ goto out;
+
+ trace_seq_putc(s, '\n');
+
+ out:
+ return trace_handle_return(s);
+}
+
+
+static int kprobe_event_define_fields(struct trace_event_call *event_call)
+{
+ int ret;
+ struct kprobe_trace_entry_head field;
+ struct trace_probe *tp;
+
+ tp = trace_probe_primary_from_call(event_call);
+ if (WARN_ON_ONCE(!tp))
+ return -ENOENT;
+
+ DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);
+
+ return traceprobe_define_arg_fields(event_call, sizeof(field), tp);
+}
+
+static int kretprobe_event_define_fields(struct trace_event_call *event_call)
+{
+ int ret;
+ struct kretprobe_trace_entry_head field;
+ struct trace_probe *tp;
+
+ tp = trace_probe_primary_from_call(event_call);
+ if (WARN_ON_ONCE(!tp))
+ return -ENOENT;
+
+ DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0);
+ DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0);
+
+ return traceprobe_define_arg_fields(event_call, sizeof(field), tp);
+}
+
+#ifdef CONFIG_PERF_EVENTS
+
+/* Kprobe profile handler */
+static int
+kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)
+{
+ struct trace_event_call *call = trace_probe_event_call(&tk->tp);
+ struct kprobe_trace_entry_head *entry;
+ struct hlist_head *head;
+ int size, __size, dsize;
+ int rctx;
+
+ if (bpf_prog_array_valid(call)) {
+ unsigned long orig_ip = instruction_pointer(regs);
+ int ret;
+
+ ret = trace_call_bpf(call, regs);
+
+ /*
+ * We need to check and see if we modified the pc of the
+ * pt_regs, and if so return 1 so that we don't do the
+ * single stepping.
+ */
+ if (orig_ip != instruction_pointer(regs))
+ return 1;
+ if (!ret)
+ return 0;
+ }
+
+ head = this_cpu_ptr(call->perf_events);
+ if (hlist_empty(head))
+ return 0;
+
+ dsize = __get_data_size(&tk->tp, regs);
+ __size = sizeof(*entry) + tk->tp.size + dsize;
+ size = ALIGN(__size + sizeof(u32), sizeof(u64));
+ size -= sizeof(u32);
+
+ entry = perf_trace_buf_alloc(size, NULL, &rctx);
+ if (!entry)
+ return 0;
+
+ entry->ip = (unsigned long)tk->rp.kp.addr;
+ memset(&entry[1], 0, dsize);
+ store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
+ perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
+ head, NULL);
+ return 0;
+}
+NOKPROBE_SYMBOL(kprobe_perf_func);
+
+/* Kretprobe profile handler */
+static void
+kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
+ struct pt_regs *regs)
+{
+ struct trace_event_call *call = trace_probe_event_call(&tk->tp);
+ struct kretprobe_trace_entry_head *entry;
+ struct hlist_head *head;
+ int size, __size, dsize;
+ int rctx;
+
+ if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs))
+ return;
+
+ head = this_cpu_ptr(call->perf_events);
+ if (hlist_empty(head))
+ return;
+
+ dsize = __get_data_size(&tk->tp, regs);
+ __size = sizeof(*entry) + tk->tp.size + dsize;
+ size = ALIGN(__size + sizeof(u32), sizeof(u64));
+ size -= sizeof(u32);
+
+ entry = perf_trace_buf_alloc(size, NULL, &rctx);
+ if (!entry)
+ return;
+
+ entry->func = (unsigned long)tk->rp.kp.addr;
+ entry->ret_ip = (unsigned long)ri->ret_addr;
+ store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
+ perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
+ head, NULL);
+}
+NOKPROBE_SYMBOL(kretprobe_perf_func);
+
+int bpf_get_kprobe_info(const struct perf_event *event, u32 *fd_type,
+ const char **symbol, u64 *probe_offset,
+ u64 *probe_addr, bool perf_type_tracepoint)
+{
+ const char *pevent = trace_event_name(event->tp_event);
+ const char *group = event->tp_event->class->system;
+ struct trace_kprobe *tk;
+
+ if (perf_type_tracepoint)
+ tk = find_trace_kprobe(pevent, group);
+ else
+ tk = trace_kprobe_primary_from_call(event->tp_event);
+ if (!tk)
+ return -EINVAL;
+
+ *fd_type = trace_kprobe_is_return(tk) ? BPF_FD_TYPE_KRETPROBE
+ : BPF_FD_TYPE_KPROBE;
+ if (tk->symbol) {
+ *symbol = tk->symbol;
+ *probe_offset = tk->rp.kp.offset;
+ *probe_addr = 0;
+ } else {
+ *symbol = NULL;
+ *probe_offset = 0;
+ *probe_addr = (unsigned long)tk->rp.kp.addr;
+ }
+ return 0;
+}
+#endif /* CONFIG_PERF_EVENTS */
+
+/*
+ * called by perf_trace_init() or __ftrace_set_clr_event() under event_mutex.
+ *
+ * kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe
+ * lockless, but we can't race with this __init function.
+ */
+static int kprobe_register(struct trace_event_call *event,
+ enum trace_reg type, void *data)
+{
+ struct trace_event_file *file = data;
+
+ switch (type) {
+ case TRACE_REG_REGISTER:
+ return enable_trace_kprobe(event, file);
+ case TRACE_REG_UNREGISTER:
+ return disable_trace_kprobe(event, file);
+
+#ifdef CONFIG_PERF_EVENTS
+ case TRACE_REG_PERF_REGISTER:
+ return enable_trace_kprobe(event, NULL);
+ case TRACE_REG_PERF_UNREGISTER:
+ return disable_trace_kprobe(event, NULL);
+ case TRACE_REG_PERF_OPEN:
+ case TRACE_REG_PERF_CLOSE:
+ case TRACE_REG_PERF_ADD:
+ case TRACE_REG_PERF_DEL:
+ return 0;
+#endif
+ }
+ return 0;
+}
+
+static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
+{
+ struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp);
+ int ret = 0;
+
+ raw_cpu_inc(*tk->nhit);
+
+ if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE))
+ kprobe_trace_func(tk, regs);
+#ifdef CONFIG_PERF_EVENTS
+ if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE))
+ ret = kprobe_perf_func(tk, regs);
+#endif
+ return ret;
+}
+NOKPROBE_SYMBOL(kprobe_dispatcher);
+
+static int
+kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
+{
+ struct trace_kprobe *tk = container_of(ri->rp, struct trace_kprobe, rp);
+
+ raw_cpu_inc(*tk->nhit);
+
+ if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE))
+ kretprobe_trace_func(tk, ri, regs);
+#ifdef CONFIG_PERF_EVENTS
+ if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE))
+ kretprobe_perf_func(tk, ri, regs);
+#endif
+ return 0; /* We don't tweek kernel, so just return 0 */
+}
+NOKPROBE_SYMBOL(kretprobe_dispatcher);
+
+static struct trace_event_functions kretprobe_funcs = {
+ .trace = print_kretprobe_event
+};
+
+static struct trace_event_functions kprobe_funcs = {
+ .trace = print_kprobe_event
+};
+
+static inline void init_trace_event_call(struct trace_kprobe *tk)
+{
+ struct trace_event_call *call = trace_probe_event_call(&tk->tp);
+
+ if (trace_kprobe_is_return(tk)) {
+ call->event.funcs = &kretprobe_funcs;
+ call->class->define_fields = kretprobe_event_define_fields;
+ } else {
+ call->event.funcs = &kprobe_funcs;
+ call->class->define_fields = kprobe_event_define_fields;
+ }
+
+ call->flags = TRACE_EVENT_FL_KPROBE;
+ call->class->reg = kprobe_register;
+}
+
+static int register_kprobe_event(struct trace_kprobe *tk)
+{
+ init_trace_event_call(tk);
+
+ return trace_probe_register_event_call(&tk->tp);
+}
+
+static int unregister_kprobe_event(struct trace_kprobe *tk)
+{
+ return trace_probe_unregister_event_call(&tk->tp);
+}
+
+#ifdef CONFIG_PERF_EVENTS
+
+/* create a trace_kprobe, but don't add it to global lists */
+struct trace_event_call *
+create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
+ bool is_return)
+{
+ struct trace_kprobe *tk;
+ int ret;
+ char *event;
+
+ if (func && !strchr(func, ':')) {
+ unsigned int count;
+
+ count = number_of_same_symbols(func);
+ if (count > 1)
+ /*
+ * Users should use addr to remove the ambiguity of
+ * using func only.
+ */
+ return ERR_PTR(-EADDRNOTAVAIL);
+ else if (count == 0)
+ /*
+ * We can return ENOENT earlier than when register the
+ * kprobe.
+ */
+ return ERR_PTR(-ENOENT);
+ }
+
+ /*
+ * local trace_kprobes are not added to dyn_event, so they are never
+ * searched in find_trace_kprobe(). Therefore, there is no concern of
+ * duplicated name here.
+ */
+ event = func ? func : "DUMMY_EVENT";
+
+ tk = alloc_trace_kprobe(KPROBE_EVENT_SYSTEM, event, (void *)addr, func,
+ offs, 0 /* maxactive */, 0 /* nargs */,
+ is_return);
+
+ if (IS_ERR(tk)) {
+ pr_info("Failed to allocate trace_probe.(%d)\n",
+ (int)PTR_ERR(tk));
+ return ERR_CAST(tk);
+ }
+
+ init_trace_event_call(tk);
+
+ if (traceprobe_set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) {
+ ret = -ENOMEM;
+ goto error;
+ }
+
+ ret = __register_trace_kprobe(tk);
+ if (ret < 0)
+ goto error;
+
+ return trace_probe_event_call(&tk->tp);
+error:
+ free_trace_kprobe(tk);
+ return ERR_PTR(ret);
+}
+
+void destroy_local_trace_kprobe(struct trace_event_call *event_call)
+{
+ struct trace_kprobe *tk;
+
+ tk = trace_kprobe_primary_from_call(event_call);
+ if (unlikely(!tk))
+ return;
+
+ if (trace_probe_is_enabled(&tk->tp)) {
+ WARN_ON(1);
+ return;
+ }
+
+ __unregister_trace_kprobe(tk);
+
+ free_trace_kprobe(tk);
+}
+#endif /* CONFIG_PERF_EVENTS */
+
+static __init void enable_boot_kprobe_events(void)
+{
+ struct trace_array *tr = top_trace_array();
+ struct trace_event_file *file;
+ struct trace_kprobe *tk;
+ struct dyn_event *pos;
+
+ mutex_lock(&event_mutex);
+ for_each_trace_kprobe(tk, pos) {
+ list_for_each_entry(file, &tr->events, list)
+ if (file->event_call == trace_probe_event_call(&tk->tp))
+ trace_event_enable_disable(file, 1, 0);
+ }
+ mutex_unlock(&event_mutex);
+}
+
+static __init void setup_boot_kprobe_events(void)
+{
+ char *p, *cmd = kprobe_boot_events_buf;
+ int ret;
+
+ strreplace(kprobe_boot_events_buf, ',', ' ');
+
+ while (cmd && *cmd != '\0') {
+ p = strchr(cmd, ';');
+ if (p)
+ *p++ = '\0';
+
+ ret = trace_run_command(cmd, create_or_delete_trace_kprobe);
+ if (ret)
+ pr_warn("Failed to add event(%d): %s\n", ret, cmd);
+ else
+ kprobe_boot_events_enabled = true;
+
+ cmd = p;
+ }
+
+ enable_boot_kprobe_events();
+}
+
+/* Make a tracefs interface for controlling probe points */
+static __init int init_kprobe_trace(void)
+{
+ struct dentry *d_tracer;
+ struct dentry *entry;
+ int ret;
+
+ ret = dyn_event_register(&trace_kprobe_ops);
+ if (ret)
+ return ret;
+
+ if (register_module_notifier(&trace_kprobe_module_nb))
+ return -EINVAL;
+
+ d_tracer = tracing_init_dentry();
+ if (IS_ERR(d_tracer))
+ return 0;
+
+ entry = tracefs_create_file("kprobe_events", 0644, d_tracer,
+ NULL, &kprobe_events_ops);
+
+ /* Event list interface */
+ if (!entry)
+ pr_warn("Could not create tracefs 'kprobe_events' entry\n");
+
+ /* Profile interface */
+ entry = tracefs_create_file("kprobe_profile", 0444, d_tracer,
+ NULL, &kprobe_profile_ops);
+
+ if (!entry)
+ pr_warn("Could not create tracefs 'kprobe_profile' entry\n");
+
+ setup_boot_kprobe_events();
+
+ return 0;
+}
+fs_initcall(init_kprobe_trace);
+
+
+#ifdef CONFIG_FTRACE_STARTUP_TEST
+static __init struct trace_event_file *
+find_trace_probe_file(struct trace_kprobe *tk, struct trace_array *tr)
+{
+ struct trace_event_file *file;
+
+ list_for_each_entry(file, &tr->events, list)
+ if (file->event_call == trace_probe_event_call(&tk->tp))
+ return file;
+
+ return NULL;
+}
+
+/*
+ * Nobody but us can call enable_trace_kprobe/disable_trace_kprobe at this
+ * stage, we can do this lockless.
+ */
+static __init int kprobe_trace_self_tests_init(void)
+{
+ int ret, warn = 0;
+ int (*target)(int, int, int, int, int, int);
+ struct trace_kprobe *tk;
+ struct trace_event_file *file;
+
+ if (tracing_is_disabled())
+ return -ENODEV;
+
+ if (kprobe_boot_events_enabled) {
+ pr_info("Skipping kprobe tests due to kprobe_event on cmdline\n");
+ return 0;
+ }
+
+ target = kprobe_trace_selftest_target;
+
+ pr_info("Testing kprobe tracing: ");
+
+ ret = trace_run_command("p:testprobe kprobe_trace_selftest_target $stack $stack0 +0($stack)",
+ create_or_delete_trace_kprobe);
+ if (WARN_ON_ONCE(ret)) {
+ pr_warn("error on probing function entry.\n");
+ warn++;
+ } else {
+ /* Enable trace point */
+ tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM);
+ if (WARN_ON_ONCE(tk == NULL)) {
+ pr_warn("error on getting new probe.\n");
+ warn++;
+ } else {
+ file = find_trace_probe_file(tk, top_trace_array());
+ if (WARN_ON_ONCE(file == NULL)) {
+ pr_warn("error on getting probe file.\n");
+ warn++;
+ } else
+ enable_trace_kprobe(
+ trace_probe_event_call(&tk->tp), file);
+ }
+ }
+
+ ret = trace_run_command("r:testprobe2 kprobe_trace_selftest_target $retval",
+ create_or_delete_trace_kprobe);
+ if (WARN_ON_ONCE(ret)) {
+ pr_warn("error on probing function return.\n");
+ warn++;
+ } else {
+ /* Enable trace point */
+ tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM);
+ if (WARN_ON_ONCE(tk == NULL)) {
+ pr_warn("error on getting 2nd new probe.\n");
+ warn++;
+ } else {
+ file = find_trace_probe_file(tk, top_trace_array());
+ if (WARN_ON_ONCE(file == NULL)) {
+ pr_warn("error on getting probe file.\n");
+ warn++;
+ } else
+ enable_trace_kprobe(
+ trace_probe_event_call(&tk->tp), file);
+ }
+ }
+
+ if (warn)
+ goto end;
+
+ ret = target(1, 2, 3, 4, 5, 6);
+
+ /*
+ * Not expecting an error here, the check is only to prevent the
+ * optimizer from removing the call to target() as otherwise there
+ * are no side-effects and the call is never performed.
+ */
+ if (ret != 21)
+ warn++;
+
+ /* Disable trace points before removing it */
+ tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM);
+ if (WARN_ON_ONCE(tk == NULL)) {
+ pr_warn("error on getting test probe.\n");
+ warn++;
+ } else {
+ if (trace_kprobe_nhit(tk) != 1) {
+ pr_warn("incorrect number of testprobe hits\n");
+ warn++;
+ }
+
+ file = find_trace_probe_file(tk, top_trace_array());
+ if (WARN_ON_ONCE(file == NULL)) {
+ pr_warn("error on getting probe file.\n");
+ warn++;
+ } else
+ disable_trace_kprobe(
+ trace_probe_event_call(&tk->tp), file);
+ }
+
+ tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM);
+ if (WARN_ON_ONCE(tk == NULL)) {
+ pr_warn("error on getting 2nd test probe.\n");
+ warn++;
+ } else {
+ if (trace_kprobe_nhit(tk) != 1) {
+ pr_warn("incorrect number of testprobe2 hits\n");
+ warn++;
+ }
+
+ file = find_trace_probe_file(tk, top_trace_array());
+ if (WARN_ON_ONCE(file == NULL)) {
+ pr_warn("error on getting probe file.\n");
+ warn++;
+ } else
+ disable_trace_kprobe(
+ trace_probe_event_call(&tk->tp), file);
+ }
+
+ ret = trace_run_command("-:testprobe", create_or_delete_trace_kprobe);
+ if (WARN_ON_ONCE(ret)) {
+ pr_warn("error on deleting a probe.\n");
+ warn++;
+ }
+
+ ret = trace_run_command("-:testprobe2", create_or_delete_trace_kprobe);
+ if (WARN_ON_ONCE(ret)) {
+ pr_warn("error on deleting a probe.\n");
+ warn++;
+ }
+
+end:
+ ret = dyn_events_release_all(&trace_kprobe_ops);
+ if (WARN_ON_ONCE(ret)) {
+ pr_warn("error on cleaning up probes.\n");
+ warn++;
+ }
+ /*
+ * Wait for the optimizer work to finish. Otherwise it might fiddle
+ * with probes in already freed __init text.
+ */
+ wait_for_kprobe_optimizer();
+ if (warn)
+ pr_cont("NG: Some tests are failed. Please check them.\n");
+ else
+ pr_cont("OK\n");
+ return 0;
+}
+
+late_initcall(kprobe_trace_self_tests_init);
+
+#endif