File-copy from v4.4.100
This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Please refer to that tree for all history prior to this point.
Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
new file mode 100644
index 0000000..d2f6d0b
--- /dev/null
+++ b/kernel/trace/trace_uprobe.c
@@ -0,0 +1,1356 @@
+/*
+ * uprobes-based tracing events
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Copyright (C) IBM Corporation, 2010-2012
+ * Author: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
+ */
+
+#include <linux/module.h>
+#include <linux/uaccess.h>
+#include <linux/uprobes.h>
+#include <linux/namei.h>
+#include <linux/string.h>
+
+#include "trace_probe.h"
+
+#define UPROBE_EVENT_SYSTEM "uprobes"
+
+struct uprobe_trace_entry_head {
+ struct trace_entry ent;
+ unsigned long vaddr[];
+};
+
+#define SIZEOF_TRACE_ENTRY(is_return) \
+ (sizeof(struct uprobe_trace_entry_head) + \
+ sizeof(unsigned long) * (is_return ? 2 : 1))
+
+#define DATAOF_TRACE_ENTRY(entry, is_return) \
+ ((void*)(entry) + SIZEOF_TRACE_ENTRY(is_return))
+
+struct trace_uprobe_filter {
+ rwlock_t rwlock;
+ int nr_systemwide;
+ struct list_head perf_events;
+};
+
+/*
+ * uprobe event core functions
+ */
+struct trace_uprobe {
+ struct list_head list;
+ struct trace_uprobe_filter filter;
+ struct uprobe_consumer consumer;
+ struct inode *inode;
+ char *filename;
+ unsigned long offset;
+ unsigned long nhit;
+ struct trace_probe tp;
+};
+
+#define SIZEOF_TRACE_UPROBE(n) \
+ (offsetof(struct trace_uprobe, tp.args) + \
+ (sizeof(struct probe_arg) * (n)))
+
+static int register_uprobe_event(struct trace_uprobe *tu);
+static int unregister_uprobe_event(struct trace_uprobe *tu);
+
+static DEFINE_MUTEX(uprobe_lock);
+static LIST_HEAD(uprobe_list);
+
+struct uprobe_dispatch_data {
+ struct trace_uprobe *tu;
+ unsigned long bp_addr;
+};
+
+static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs);
+static int uretprobe_dispatcher(struct uprobe_consumer *con,
+ unsigned long func, struct pt_regs *regs);
+
+#ifdef CONFIG_STACK_GROWSUP
+static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
+{
+ return addr - (n * sizeof(long));
+}
+#else
+static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
+{
+ return addr + (n * sizeof(long));
+}
+#endif
+
+static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n)
+{
+ unsigned long ret;
+ unsigned long addr = user_stack_pointer(regs);
+
+ addr = adjust_stack_addr(addr, n);
+
+ if (copy_from_user(&ret, (void __force __user *) addr, sizeof(ret)))
+ return 0;
+
+ return ret;
+}
+
+/*
+ * Uprobes-specific fetch functions
+ */
+#define DEFINE_FETCH_stack(type) \
+static void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs, \
+ void *offset, void *dest) \
+{ \
+ *(type *)dest = (type)get_user_stack_nth(regs, \
+ ((unsigned long)offset)); \
+}
+DEFINE_BASIC_FETCH_FUNCS(stack)
+/* No string on the stack entry */
+#define fetch_stack_string NULL
+#define fetch_stack_string_size NULL
+
+#define DEFINE_FETCH_memory(type) \
+static void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs, \
+ void *addr, void *dest) \
+{ \
+ type retval; \
+ void __user *vaddr = (void __force __user *) addr; \
+ \
+ if (copy_from_user(&retval, vaddr, sizeof(type))) \
+ *(type *)dest = 0; \
+ else \
+ *(type *) dest = retval; \
+}
+DEFINE_BASIC_FETCH_FUNCS(memory)
+/*
+ * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
+ * length and relative data location.
+ */
+static void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs,
+ void *addr, void *dest)
+{
+ long ret;
+ u32 rloc = *(u32 *)dest;
+ int maxlen = get_rloc_len(rloc);
+ u8 *dst = get_rloc_data(dest);
+ void __user *src = (void __force __user *) addr;
+
+ if (!maxlen)
+ return;
+
+ ret = strncpy_from_user(dst, src, maxlen);
+
+ if (ret < 0) { /* Failed to fetch string */
+ ((u8 *)get_rloc_data(dest))[0] = '\0';
+ *(u32 *)dest = make_data_rloc(0, get_rloc_offs(rloc));
+ } else {
+ *(u32 *)dest = make_data_rloc(ret, get_rloc_offs(rloc));
+ }
+}
+
+static void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs,
+ void *addr, void *dest)
+{
+ int len;
+ void __user *vaddr = (void __force __user *) addr;
+
+ len = strnlen_user(vaddr, MAX_STRING_SIZE);
+
+ if (len == 0 || len > MAX_STRING_SIZE) /* Failed to check length */
+ *(u32 *)dest = 0;
+ else
+ *(u32 *)dest = len;
+}
+
+static unsigned long translate_user_vaddr(void *file_offset)
+{
+ unsigned long base_addr;
+ struct uprobe_dispatch_data *udd;
+
+ udd = (void *) current->utask->vaddr;
+
+ base_addr = udd->bp_addr - udd->tu->offset;
+ return base_addr + (unsigned long)file_offset;
+}
+
+#define DEFINE_FETCH_file_offset(type) \
+static void FETCH_FUNC_NAME(file_offset, type)(struct pt_regs *regs, \
+ void *offset, void *dest)\
+{ \
+ void *vaddr = (void *)translate_user_vaddr(offset); \
+ \
+ FETCH_FUNC_NAME(memory, type)(regs, vaddr, dest); \
+}
+DEFINE_BASIC_FETCH_FUNCS(file_offset)
+DEFINE_FETCH_file_offset(string)
+DEFINE_FETCH_file_offset(string_size)
+
+/* Fetch type information table */
+static const struct fetch_type uprobes_fetch_type_table[] = {
+ /* Special types */
+ [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string,
+ sizeof(u32), 1, "__data_loc char[]"),
+ [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32,
+ string_size, sizeof(u32), 0, "u32"),
+ /* Basic types */
+ ASSIGN_FETCH_TYPE(u8, u8, 0),
+ ASSIGN_FETCH_TYPE(u16, u16, 0),
+ ASSIGN_FETCH_TYPE(u32, u32, 0),
+ ASSIGN_FETCH_TYPE(u64, u64, 0),
+ ASSIGN_FETCH_TYPE(s8, u8, 1),
+ ASSIGN_FETCH_TYPE(s16, u16, 1),
+ ASSIGN_FETCH_TYPE(s32, u32, 1),
+ ASSIGN_FETCH_TYPE(s64, u64, 1),
+
+ ASSIGN_FETCH_TYPE_END
+};
+
+static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter)
+{
+ rwlock_init(&filter->rwlock);
+ filter->nr_systemwide = 0;
+ INIT_LIST_HEAD(&filter->perf_events);
+}
+
+static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter)
+{
+ return !filter->nr_systemwide && list_empty(&filter->perf_events);
+}
+
+static inline bool is_ret_probe(struct trace_uprobe *tu)
+{
+ return tu->consumer.ret_handler != NULL;
+}
+
+/*
+ * Allocate new trace_uprobe and initialize it (including uprobes).
+ */
+static struct trace_uprobe *
+alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret)
+{
+ struct trace_uprobe *tu;
+
+ if (!event || !is_good_name(event))
+ return ERR_PTR(-EINVAL);
+
+ if (!group || !is_good_name(group))
+ return ERR_PTR(-EINVAL);
+
+ tu = kzalloc(SIZEOF_TRACE_UPROBE(nargs), GFP_KERNEL);
+ if (!tu)
+ return ERR_PTR(-ENOMEM);
+
+ tu->tp.call.class = &tu->tp.class;
+ tu->tp.call.name = kstrdup(event, GFP_KERNEL);
+ if (!tu->tp.call.name)
+ goto error;
+
+ tu->tp.class.system = kstrdup(group, GFP_KERNEL);
+ if (!tu->tp.class.system)
+ goto error;
+
+ INIT_LIST_HEAD(&tu->list);
+ INIT_LIST_HEAD(&tu->tp.files);
+ tu->consumer.handler = uprobe_dispatcher;
+ if (is_ret)
+ tu->consumer.ret_handler = uretprobe_dispatcher;
+ init_trace_uprobe_filter(&tu->filter);
+ return tu;
+
+error:
+ kfree(tu->tp.call.name);
+ kfree(tu);
+
+ return ERR_PTR(-ENOMEM);
+}
+
+static void free_trace_uprobe(struct trace_uprobe *tu)
+{
+ int i;
+
+ for (i = 0; i < tu->tp.nr_args; i++)
+ traceprobe_free_probe_arg(&tu->tp.args[i]);
+
+ iput(tu->inode);
+ kfree(tu->tp.call.class->system);
+ kfree(tu->tp.call.name);
+ kfree(tu->filename);
+ kfree(tu);
+}
+
+static struct trace_uprobe *find_probe_event(const char *event, const char *group)
+{
+ struct trace_uprobe *tu;
+
+ list_for_each_entry(tu, &uprobe_list, list)
+ if (strcmp(trace_event_name(&tu->tp.call), event) == 0 &&
+ strcmp(tu->tp.call.class->system, group) == 0)
+ return tu;
+
+ return NULL;
+}
+
+/* Unregister a trace_uprobe and probe_event: call with locking uprobe_lock */
+static int unregister_trace_uprobe(struct trace_uprobe *tu)
+{
+ int ret;
+
+ ret = unregister_uprobe_event(tu);
+ if (ret)
+ return ret;
+
+ list_del(&tu->list);
+ free_trace_uprobe(tu);
+ return 0;
+}
+
+/* Register a trace_uprobe and probe_event */
+static int register_trace_uprobe(struct trace_uprobe *tu)
+{
+ struct trace_uprobe *old_tu;
+ int ret;
+
+ mutex_lock(&uprobe_lock);
+
+ /* register as an event */
+ old_tu = find_probe_event(trace_event_name(&tu->tp.call),
+ tu->tp.call.class->system);
+ if (old_tu) {
+ /* delete old event */
+ ret = unregister_trace_uprobe(old_tu);
+ if (ret)
+ goto end;
+ }
+
+ ret = register_uprobe_event(tu);
+ if (ret) {
+ pr_warning("Failed to register probe event(%d)\n", ret);
+ goto end;
+ }
+
+ list_add_tail(&tu->list, &uprobe_list);
+
+end:
+ mutex_unlock(&uprobe_lock);
+
+ return ret;
+}
+
+/*
+ * Argument syntax:
+ * - Add uprobe: p|r[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS]
+ *
+ * - Remove uprobe: -:[GRP/]EVENT
+ */
+static int create_trace_uprobe(int argc, char **argv)
+{
+ struct trace_uprobe *tu;
+ struct inode *inode;
+ char *arg, *event, *group, *filename;
+ char buf[MAX_EVENT_NAME_LEN];
+ struct path path;
+ unsigned long offset;
+ bool is_delete, is_return;
+ int i, ret;
+
+ inode = NULL;
+ ret = 0;
+ is_delete = false;
+ is_return = false;
+ event = NULL;
+ group = NULL;
+
+ /* argc must be >= 1 */
+ if (argv[0][0] == '-')
+ is_delete = true;
+ else if (argv[0][0] == 'r')
+ is_return = true;
+ else if (argv[0][0] != 'p') {
+ pr_info("Probe definition must be started with 'p', 'r' or '-'.\n");
+ return -EINVAL;
+ }
+
+ if (argv[0][1] == ':') {
+ event = &argv[0][2];
+ arg = strchr(event, '/');
+
+ if (arg) {
+ group = event;
+ event = arg + 1;
+ event[-1] = '\0';
+
+ if (strlen(group) == 0) {
+ pr_info("Group name is not specified\n");
+ return -EINVAL;
+ }
+ }
+ if (strlen(event) == 0) {
+ pr_info("Event name is not specified\n");
+ return -EINVAL;
+ }
+ }
+ if (!group)
+ group = UPROBE_EVENT_SYSTEM;
+
+ if (is_delete) {
+ int ret;
+
+ if (!event) {
+ pr_info("Delete command needs an event name.\n");
+ return -EINVAL;
+ }
+ mutex_lock(&uprobe_lock);
+ tu = find_probe_event(event, group);
+
+ if (!tu) {
+ mutex_unlock(&uprobe_lock);
+ pr_info("Event %s/%s doesn't exist.\n", group, event);
+ return -ENOENT;
+ }
+ /* delete an event */
+ ret = unregister_trace_uprobe(tu);
+ mutex_unlock(&uprobe_lock);
+ return ret;
+ }
+
+ if (argc < 2) {
+ pr_info("Probe point is not specified.\n");
+ return -EINVAL;
+ }
+ if (isdigit(argv[1][0])) {
+ pr_info("probe point must be have a filename.\n");
+ return -EINVAL;
+ }
+ arg = strchr(argv[1], ':');
+ if (!arg) {
+ ret = -EINVAL;
+ goto fail_address_parse;
+ }
+
+ *arg++ = '\0';
+ filename = argv[1];
+ ret = kern_path(filename, LOOKUP_FOLLOW, &path);
+ if (ret)
+ goto fail_address_parse;
+
+ inode = igrab(d_inode(path.dentry));
+ path_put(&path);
+
+ if (!inode || !S_ISREG(inode->i_mode)) {
+ ret = -EINVAL;
+ goto fail_address_parse;
+ }
+
+ ret = kstrtoul(arg, 0, &offset);
+ if (ret)
+ goto fail_address_parse;
+
+ argc -= 2;
+ argv += 2;
+
+ /* setup a probe */
+ if (!event) {
+ char *tail;
+ char *ptr;
+
+ tail = kstrdup(kbasename(filename), GFP_KERNEL);
+ if (!tail) {
+ ret = -ENOMEM;
+ goto fail_address_parse;
+ }
+
+ ptr = strpbrk(tail, ".-_");
+ if (ptr)
+ *ptr = '\0';
+
+ snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset);
+ event = buf;
+ kfree(tail);
+ }
+
+ tu = alloc_trace_uprobe(group, event, argc, is_return);
+ if (IS_ERR(tu)) {
+ pr_info("Failed to allocate trace_uprobe.(%d)\n", (int)PTR_ERR(tu));
+ ret = PTR_ERR(tu);
+ goto fail_address_parse;
+ }
+ tu->offset = offset;
+ tu->inode = inode;
+ tu->filename = kstrdup(filename, GFP_KERNEL);
+
+ if (!tu->filename) {
+ pr_info("Failed to allocate filename.\n");
+ ret = -ENOMEM;
+ goto error;
+ }
+
+ /* parse arguments */
+ ret = 0;
+ for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
+ struct probe_arg *parg = &tu->tp.args[i];
+
+ /* Increment count for freeing args in error case */
+ tu->tp.nr_args++;
+
+ /* Parse argument name */
+ arg = strchr(argv[i], '=');
+ if (arg) {
+ *arg++ = '\0';
+ parg->name = kstrdup(argv[i], GFP_KERNEL);
+ } else {
+ arg = argv[i];
+ /* If argument name is omitted, set "argN" */
+ snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1);
+ parg->name = kstrdup(buf, GFP_KERNEL);
+ }
+
+ if (!parg->name) {
+ pr_info("Failed to allocate argument[%d] name.\n", i);
+ ret = -ENOMEM;
+ goto error;
+ }
+
+ if (!is_good_name(parg->name)) {
+ pr_info("Invalid argument[%d] name: %s\n", i, parg->name);
+ ret = -EINVAL;
+ goto error;
+ }
+
+ if (traceprobe_conflict_field_name(parg->name, tu->tp.args, i)) {
+ pr_info("Argument[%d] name '%s' conflicts with "
+ "another field.\n", i, argv[i]);
+ ret = -EINVAL;
+ goto error;
+ }
+
+ /* Parse fetch argument */
+ ret = traceprobe_parse_probe_arg(arg, &tu->tp.size, parg,
+ is_return, false,
+ uprobes_fetch_type_table);
+ if (ret) {
+ pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
+ goto error;
+ }
+ }
+
+ ret = register_trace_uprobe(tu);
+ if (ret)
+ goto error;
+ return 0;
+
+error:
+ free_trace_uprobe(tu);
+ return ret;
+
+fail_address_parse:
+ iput(inode);
+
+ pr_info("Failed to parse address or file.\n");
+
+ return ret;
+}
+
+static int cleanup_all_probes(void)
+{
+ struct trace_uprobe *tu;
+ int ret = 0;
+
+ mutex_lock(&uprobe_lock);
+ while (!list_empty(&uprobe_list)) {
+ tu = list_entry(uprobe_list.next, struct trace_uprobe, list);
+ ret = unregister_trace_uprobe(tu);
+ if (ret)
+ break;
+ }
+ mutex_unlock(&uprobe_lock);
+ return ret;
+}
+
+/* Probes listing interfaces */
+static void *probes_seq_start(struct seq_file *m, loff_t *pos)
+{
+ mutex_lock(&uprobe_lock);
+ return seq_list_start(&uprobe_list, *pos);
+}
+
+static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ return seq_list_next(v, &uprobe_list, pos);
+}
+
+static void probes_seq_stop(struct seq_file *m, void *v)
+{
+ mutex_unlock(&uprobe_lock);
+}
+
+static int probes_seq_show(struct seq_file *m, void *v)
+{
+ struct trace_uprobe *tu = v;
+ char c = is_ret_probe(tu) ? 'r' : 'p';
+ int i;
+
+ seq_printf(m, "%c:%s/%s", c, tu->tp.call.class->system,
+ trace_event_name(&tu->tp.call));
+ seq_printf(m, " %s:", tu->filename);
+
+ /* Don't print "0x (null)" when offset is 0 */
+ if (tu->offset) {
+ seq_printf(m, "0x%p", (void *)tu->offset);
+ } else {
+ switch (sizeof(void *)) {
+ case 4:
+ seq_printf(m, "0x00000000");
+ break;
+ case 8:
+ default:
+ seq_printf(m, "0x0000000000000000");
+ break;
+ }
+ }
+
+ for (i = 0; i < tu->tp.nr_args; i++)
+ seq_printf(m, " %s=%s", tu->tp.args[i].name, tu->tp.args[i].comm);
+
+ seq_putc(m, '\n');
+ return 0;
+}
+
+static const struct seq_operations probes_seq_op = {
+ .start = probes_seq_start,
+ .next = probes_seq_next,
+ .stop = probes_seq_stop,
+ .show = probes_seq_show
+};
+
+static int probes_open(struct inode *inode, struct file *file)
+{
+ int ret;
+
+ if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
+ ret = cleanup_all_probes();
+ if (ret)
+ 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 traceprobe_probes_write(file, buffer, count, ppos, create_trace_uprobe);
+}
+
+static const struct file_operations uprobe_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 trace_uprobe *tu = v;
+
+ seq_printf(m, " %s %-44s %15lu\n", tu->filename,
+ trace_event_name(&tu->tp.call), tu->nhit);
+ return 0;
+}
+
+static const struct seq_operations profile_seq_op = {
+ .start = probes_seq_start,
+ .next = probes_seq_next,
+ .stop = probes_seq_stop,
+ .show = probes_profile_seq_show
+};
+
+static int profile_open(struct inode *inode, struct file *file)
+{
+ return seq_open(file, &profile_seq_op);
+}
+
+static const struct file_operations uprobe_profile_ops = {
+ .owner = THIS_MODULE,
+ .open = profile_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+struct uprobe_cpu_buffer {
+ struct mutex mutex;
+ void *buf;
+};
+static struct uprobe_cpu_buffer __percpu *uprobe_cpu_buffer;
+static int uprobe_buffer_refcnt;
+
+static int uprobe_buffer_init(void)
+{
+ int cpu, err_cpu;
+
+ uprobe_cpu_buffer = alloc_percpu(struct uprobe_cpu_buffer);
+ if (uprobe_cpu_buffer == NULL)
+ return -ENOMEM;
+
+ for_each_possible_cpu(cpu) {
+ struct page *p = alloc_pages_node(cpu_to_node(cpu),
+ GFP_KERNEL, 0);
+ if (p == NULL) {
+ err_cpu = cpu;
+ goto err;
+ }
+ per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf = page_address(p);
+ mutex_init(&per_cpu_ptr(uprobe_cpu_buffer, cpu)->mutex);
+ }
+
+ return 0;
+
+err:
+ for_each_possible_cpu(cpu) {
+ if (cpu == err_cpu)
+ break;
+ free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf);
+ }
+
+ free_percpu(uprobe_cpu_buffer);
+ return -ENOMEM;
+}
+
+static int uprobe_buffer_enable(void)
+{
+ int ret = 0;
+
+ BUG_ON(!mutex_is_locked(&event_mutex));
+
+ if (uprobe_buffer_refcnt++ == 0) {
+ ret = uprobe_buffer_init();
+ if (ret < 0)
+ uprobe_buffer_refcnt--;
+ }
+
+ return ret;
+}
+
+static void uprobe_buffer_disable(void)
+{
+ int cpu;
+
+ BUG_ON(!mutex_is_locked(&event_mutex));
+
+ if (--uprobe_buffer_refcnt == 0) {
+ for_each_possible_cpu(cpu)
+ free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer,
+ cpu)->buf);
+
+ free_percpu(uprobe_cpu_buffer);
+ uprobe_cpu_buffer = NULL;
+ }
+}
+
+static struct uprobe_cpu_buffer *uprobe_buffer_get(void)
+{
+ struct uprobe_cpu_buffer *ucb;
+ int cpu;
+
+ cpu = raw_smp_processor_id();
+ ucb = per_cpu_ptr(uprobe_cpu_buffer, cpu);
+
+ /*
+ * Use per-cpu buffers for fastest access, but we might migrate
+ * so the mutex makes sure we have sole access to it.
+ */
+ mutex_lock(&ucb->mutex);
+
+ return ucb;
+}
+
+static void uprobe_buffer_put(struct uprobe_cpu_buffer *ucb)
+{
+ mutex_unlock(&ucb->mutex);
+}
+
+static void __uprobe_trace_func(struct trace_uprobe *tu,
+ unsigned long func, struct pt_regs *regs,
+ struct uprobe_cpu_buffer *ucb, int dsize,
+ struct trace_event_file *trace_file)
+{
+ struct uprobe_trace_entry_head *entry;
+ struct ring_buffer_event *event;
+ struct ring_buffer *buffer;
+ void *data;
+ int size, esize;
+ struct trace_event_call *call = &tu->tp.call;
+
+ WARN_ON(call != trace_file->event_call);
+
+ if (WARN_ON_ONCE(tu->tp.size + dsize > PAGE_SIZE))
+ return;
+
+ if (trace_trigger_soft_disabled(trace_file))
+ return;
+
+ esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
+ size = esize + tu->tp.size + dsize;
+ event = trace_event_buffer_lock_reserve(&buffer, trace_file,
+ call->event.type, size, 0, 0);
+ if (!event)
+ return;
+
+ entry = ring_buffer_event_data(event);
+ if (is_ret_probe(tu)) {
+ entry->vaddr[0] = func;
+ entry->vaddr[1] = instruction_pointer(regs);
+ data = DATAOF_TRACE_ENTRY(entry, true);
+ } else {
+ entry->vaddr[0] = instruction_pointer(regs);
+ data = DATAOF_TRACE_ENTRY(entry, false);
+ }
+
+ memcpy(data, ucb->buf, tu->tp.size + dsize);
+
+ event_trigger_unlock_commit(trace_file, buffer, event, entry, 0, 0);
+}
+
+/* uprobe handler */
+static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs,
+ struct uprobe_cpu_buffer *ucb, int dsize)
+{
+ struct event_file_link *link;
+
+ if (is_ret_probe(tu))
+ return 0;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(link, &tu->tp.files, list)
+ __uprobe_trace_func(tu, 0, regs, ucb, dsize, link->file);
+ rcu_read_unlock();
+
+ return 0;
+}
+
+static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func,
+ struct pt_regs *regs,
+ struct uprobe_cpu_buffer *ucb, int dsize)
+{
+ struct event_file_link *link;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(link, &tu->tp.files, list)
+ __uprobe_trace_func(tu, func, regs, ucb, dsize, link->file);
+ rcu_read_unlock();
+}
+
+/* Event entry printers */
+static enum print_line_t
+print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event)
+{
+ struct uprobe_trace_entry_head *entry;
+ struct trace_seq *s = &iter->seq;
+ struct trace_uprobe *tu;
+ u8 *data;
+ int i;
+
+ entry = (struct uprobe_trace_entry_head *)iter->ent;
+ tu = container_of(event, struct trace_uprobe, tp.call.event);
+
+ if (is_ret_probe(tu)) {
+ trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)",
+ trace_event_name(&tu->tp.call),
+ entry->vaddr[1], entry->vaddr[0]);
+ data = DATAOF_TRACE_ENTRY(entry, true);
+ } else {
+ trace_seq_printf(s, "%s: (0x%lx)",
+ trace_event_name(&tu->tp.call),
+ entry->vaddr[0]);
+ data = DATAOF_TRACE_ENTRY(entry, false);
+ }
+
+ for (i = 0; i < tu->tp.nr_args; i++) {
+ struct probe_arg *parg = &tu->tp.args[i];
+
+ if (!parg->type->print(s, parg->name, data + parg->offset, entry))
+ goto out;
+ }
+
+ trace_seq_putc(s, '\n');
+
+ out:
+ return trace_handle_return(s);
+}
+
+typedef bool (*filter_func_t)(struct uprobe_consumer *self,
+ enum uprobe_filter_ctx ctx,
+ struct mm_struct *mm);
+
+static int
+probe_event_enable(struct trace_uprobe *tu, struct trace_event_file *file,
+ filter_func_t filter)
+{
+ bool enabled = trace_probe_is_enabled(&tu->tp);
+ struct event_file_link *link = NULL;
+ int ret;
+
+ if (file) {
+ if (tu->tp.flags & TP_FLAG_PROFILE)
+ return -EINTR;
+
+ link = kmalloc(sizeof(*link), GFP_KERNEL);
+ if (!link)
+ return -ENOMEM;
+
+ link->file = file;
+ list_add_tail_rcu(&link->list, &tu->tp.files);
+
+ tu->tp.flags |= TP_FLAG_TRACE;
+ } else {
+ if (tu->tp.flags & TP_FLAG_TRACE)
+ return -EINTR;
+
+ tu->tp.flags |= TP_FLAG_PROFILE;
+ }
+
+ WARN_ON(!uprobe_filter_is_empty(&tu->filter));
+
+ if (enabled)
+ return 0;
+
+ ret = uprobe_buffer_enable();
+ if (ret)
+ goto err_flags;
+
+ tu->consumer.filter = filter;
+ ret = uprobe_register(tu->inode, tu->offset, &tu->consumer);
+ if (ret)
+ goto err_buffer;
+
+ return 0;
+
+ err_buffer:
+ uprobe_buffer_disable();
+
+ err_flags:
+ if (file) {
+ list_del(&link->list);
+ kfree(link);
+ tu->tp.flags &= ~TP_FLAG_TRACE;
+ } else {
+ tu->tp.flags &= ~TP_FLAG_PROFILE;
+ }
+ return ret;
+}
+
+static void
+probe_event_disable(struct trace_uprobe *tu, struct trace_event_file *file)
+{
+ if (!trace_probe_is_enabled(&tu->tp))
+ return;
+
+ if (file) {
+ struct event_file_link *link;
+
+ link = find_event_file_link(&tu->tp, file);
+ if (!link)
+ return;
+
+ list_del_rcu(&link->list);
+ /* synchronize with u{,ret}probe_trace_func */
+ synchronize_sched();
+ kfree(link);
+
+ if (!list_empty(&tu->tp.files))
+ return;
+ }
+
+ WARN_ON(!uprobe_filter_is_empty(&tu->filter));
+
+ uprobe_unregister(tu->inode, tu->offset, &tu->consumer);
+ tu->tp.flags &= file ? ~TP_FLAG_TRACE : ~TP_FLAG_PROFILE;
+
+ uprobe_buffer_disable();
+}
+
+static int uprobe_event_define_fields(struct trace_event_call *event_call)
+{
+ int ret, i, size;
+ struct uprobe_trace_entry_head field;
+ struct trace_uprobe *tu = event_call->data;
+
+ if (is_ret_probe(tu)) {
+ DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0);
+ DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0);
+ size = SIZEOF_TRACE_ENTRY(true);
+ } else {
+ DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0);
+ size = SIZEOF_TRACE_ENTRY(false);
+ }
+ /* Set argument names as fields */
+ for (i = 0; i < tu->tp.nr_args; i++) {
+ struct probe_arg *parg = &tu->tp.args[i];
+
+ ret = trace_define_field(event_call, parg->type->fmttype,
+ parg->name, size + parg->offset,
+ parg->type->size, parg->type->is_signed,
+ FILTER_OTHER);
+
+ if (ret)
+ return ret;
+ }
+ return 0;
+}
+
+#ifdef CONFIG_PERF_EVENTS
+static bool
+__uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm)
+{
+ struct perf_event *event;
+
+ if (filter->nr_systemwide)
+ return true;
+
+ list_for_each_entry(event, &filter->perf_events, hw.tp_list) {
+ if (event->hw.target->mm == mm)
+ return true;
+ }
+
+ return false;
+}
+
+static inline bool
+uprobe_filter_event(struct trace_uprobe *tu, struct perf_event *event)
+{
+ return __uprobe_perf_filter(&tu->filter, event->hw.target->mm);
+}
+
+static int uprobe_perf_close(struct trace_uprobe *tu, struct perf_event *event)
+{
+ bool done;
+
+ write_lock(&tu->filter.rwlock);
+ if (event->hw.target) {
+ list_del(&event->hw.tp_list);
+ done = tu->filter.nr_systemwide ||
+ (event->hw.target->flags & PF_EXITING) ||
+ uprobe_filter_event(tu, event);
+ } else {
+ tu->filter.nr_systemwide--;
+ done = tu->filter.nr_systemwide;
+ }
+ write_unlock(&tu->filter.rwlock);
+
+ if (!done)
+ return uprobe_apply(tu->inode, tu->offset, &tu->consumer, false);
+
+ return 0;
+}
+
+static int uprobe_perf_open(struct trace_uprobe *tu, struct perf_event *event)
+{
+ bool done;
+ int err;
+
+ write_lock(&tu->filter.rwlock);
+ if (event->hw.target) {
+ /*
+ * event->parent != NULL means copy_process(), we can avoid
+ * uprobe_apply(). current->mm must be probed and we can rely
+ * on dup_mmap() which preserves the already installed bp's.
+ *
+ * attr.enable_on_exec means that exec/mmap will install the
+ * breakpoints we need.
+ */
+ done = tu->filter.nr_systemwide ||
+ event->parent || event->attr.enable_on_exec ||
+ uprobe_filter_event(tu, event);
+ list_add(&event->hw.tp_list, &tu->filter.perf_events);
+ } else {
+ done = tu->filter.nr_systemwide;
+ tu->filter.nr_systemwide++;
+ }
+ write_unlock(&tu->filter.rwlock);
+
+ err = 0;
+ if (!done) {
+ err = uprobe_apply(tu->inode, tu->offset, &tu->consumer, true);
+ if (err)
+ uprobe_perf_close(tu, event);
+ }
+ return err;
+}
+
+static bool uprobe_perf_filter(struct uprobe_consumer *uc,
+ enum uprobe_filter_ctx ctx, struct mm_struct *mm)
+{
+ struct trace_uprobe *tu;
+ int ret;
+
+ tu = container_of(uc, struct trace_uprobe, consumer);
+ read_lock(&tu->filter.rwlock);
+ ret = __uprobe_perf_filter(&tu->filter, mm);
+ read_unlock(&tu->filter.rwlock);
+
+ return ret;
+}
+
+static void __uprobe_perf_func(struct trace_uprobe *tu,
+ unsigned long func, struct pt_regs *regs,
+ struct uprobe_cpu_buffer *ucb, int dsize)
+{
+ struct trace_event_call *call = &tu->tp.call;
+ struct uprobe_trace_entry_head *entry;
+ struct bpf_prog *prog = call->prog;
+ struct hlist_head *head;
+ void *data;
+ int size, esize;
+ int rctx;
+
+ if (prog && !trace_call_bpf(prog, regs))
+ return;
+
+ esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
+
+ size = esize + tu->tp.size + dsize;
+ size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32);
+ if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough"))
+ return;
+
+ preempt_disable();
+ head = this_cpu_ptr(call->perf_events);
+ if (hlist_empty(head))
+ goto out;
+
+ entry = perf_trace_buf_prepare(size, call->event.type, NULL, &rctx);
+ if (!entry)
+ goto out;
+
+ if (is_ret_probe(tu)) {
+ entry->vaddr[0] = func;
+ entry->vaddr[1] = instruction_pointer(regs);
+ data = DATAOF_TRACE_ENTRY(entry, true);
+ } else {
+ entry->vaddr[0] = instruction_pointer(regs);
+ data = DATAOF_TRACE_ENTRY(entry, false);
+ }
+
+ memcpy(data, ucb->buf, tu->tp.size + dsize);
+
+ if (size - esize > tu->tp.size + dsize) {
+ int len = tu->tp.size + dsize;
+
+ memset(data + len, 0, size - esize - len);
+ }
+
+ perf_trace_buf_submit(entry, size, rctx, 0, 1, regs, head, NULL);
+ out:
+ preempt_enable();
+}
+
+/* uprobe profile handler */
+static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs,
+ struct uprobe_cpu_buffer *ucb, int dsize)
+{
+ if (!uprobe_perf_filter(&tu->consumer, 0, current->mm))
+ return UPROBE_HANDLER_REMOVE;
+
+ if (!is_ret_probe(tu))
+ __uprobe_perf_func(tu, 0, regs, ucb, dsize);
+ return 0;
+}
+
+static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func,
+ struct pt_regs *regs,
+ struct uprobe_cpu_buffer *ucb, int dsize)
+{
+ __uprobe_perf_func(tu, func, regs, ucb, dsize);
+}
+#endif /* CONFIG_PERF_EVENTS */
+
+static int
+trace_uprobe_register(struct trace_event_call *event, enum trace_reg type,
+ void *data)
+{
+ struct trace_uprobe *tu = event->data;
+ struct trace_event_file *file = data;
+
+ switch (type) {
+ case TRACE_REG_REGISTER:
+ return probe_event_enable(tu, file, NULL);
+
+ case TRACE_REG_UNREGISTER:
+ probe_event_disable(tu, file);
+ return 0;
+
+#ifdef CONFIG_PERF_EVENTS
+ case TRACE_REG_PERF_REGISTER:
+ return probe_event_enable(tu, NULL, uprobe_perf_filter);
+
+ case TRACE_REG_PERF_UNREGISTER:
+ probe_event_disable(tu, NULL);
+ return 0;
+
+ case TRACE_REG_PERF_OPEN:
+ return uprobe_perf_open(tu, data);
+
+ case TRACE_REG_PERF_CLOSE:
+ return uprobe_perf_close(tu, data);
+
+#endif
+ default:
+ return 0;
+ }
+ return 0;
+}
+
+static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
+{
+ struct trace_uprobe *tu;
+ struct uprobe_dispatch_data udd;
+ struct uprobe_cpu_buffer *ucb;
+ int dsize, esize;
+ int ret = 0;
+
+
+ tu = container_of(con, struct trace_uprobe, consumer);
+ tu->nhit++;
+
+ udd.tu = tu;
+ udd.bp_addr = instruction_pointer(regs);
+
+ current->utask->vaddr = (unsigned long) &udd;
+
+ if (WARN_ON_ONCE(!uprobe_cpu_buffer))
+ return 0;
+
+ dsize = __get_data_size(&tu->tp, regs);
+ esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
+
+ ucb = uprobe_buffer_get();
+ store_trace_args(esize, &tu->tp, regs, ucb->buf, dsize);
+
+ if (tu->tp.flags & TP_FLAG_TRACE)
+ ret |= uprobe_trace_func(tu, regs, ucb, dsize);
+
+#ifdef CONFIG_PERF_EVENTS
+ if (tu->tp.flags & TP_FLAG_PROFILE)
+ ret |= uprobe_perf_func(tu, regs, ucb, dsize);
+#endif
+ uprobe_buffer_put(ucb);
+ return ret;
+}
+
+static int uretprobe_dispatcher(struct uprobe_consumer *con,
+ unsigned long func, struct pt_regs *regs)
+{
+ struct trace_uprobe *tu;
+ struct uprobe_dispatch_data udd;
+ struct uprobe_cpu_buffer *ucb;
+ int dsize, esize;
+
+ tu = container_of(con, struct trace_uprobe, consumer);
+
+ udd.tu = tu;
+ udd.bp_addr = func;
+
+ current->utask->vaddr = (unsigned long) &udd;
+
+ if (WARN_ON_ONCE(!uprobe_cpu_buffer))
+ return 0;
+
+ dsize = __get_data_size(&tu->tp, regs);
+ esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
+
+ ucb = uprobe_buffer_get();
+ store_trace_args(esize, &tu->tp, regs, ucb->buf, dsize);
+
+ if (tu->tp.flags & TP_FLAG_TRACE)
+ uretprobe_trace_func(tu, func, regs, ucb, dsize);
+
+#ifdef CONFIG_PERF_EVENTS
+ if (tu->tp.flags & TP_FLAG_PROFILE)
+ uretprobe_perf_func(tu, func, regs, ucb, dsize);
+#endif
+ uprobe_buffer_put(ucb);
+ return 0;
+}
+
+static struct trace_event_functions uprobe_funcs = {
+ .trace = print_uprobe_event
+};
+
+static int register_uprobe_event(struct trace_uprobe *tu)
+{
+ struct trace_event_call *call = &tu->tp.call;
+ int ret;
+
+ /* Initialize trace_event_call */
+ INIT_LIST_HEAD(&call->class->fields);
+ call->event.funcs = &uprobe_funcs;
+ call->class->define_fields = uprobe_event_define_fields;
+
+ if (set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0)
+ return -ENOMEM;
+
+ ret = register_trace_event(&call->event);
+ if (!ret) {
+ kfree(call->print_fmt);
+ return -ENODEV;
+ }
+
+ call->flags = TRACE_EVENT_FL_UPROBE;
+ call->class->reg = trace_uprobe_register;
+ call->data = tu;
+ ret = trace_add_event_call(call);
+
+ if (ret) {
+ pr_info("Failed to register uprobe event: %s\n",
+ trace_event_name(call));
+ kfree(call->print_fmt);
+ unregister_trace_event(&call->event);
+ }
+
+ return ret;
+}
+
+static int unregister_uprobe_event(struct trace_uprobe *tu)
+{
+ int ret;
+
+ /* tu->event is unregistered in trace_remove_event_call() */
+ ret = trace_remove_event_call(&tu->tp.call);
+ if (ret)
+ return ret;
+ kfree(tu->tp.call.print_fmt);
+ tu->tp.call.print_fmt = NULL;
+ return 0;
+}
+
+/* Make a trace interface for controling probe points */
+static __init int init_uprobe_trace(void)
+{
+ struct dentry *d_tracer;
+
+ d_tracer = tracing_init_dentry();
+ if (IS_ERR(d_tracer))
+ return 0;
+
+ trace_create_file("uprobe_events", 0644, d_tracer,
+ NULL, &uprobe_events_ops);
+ /* Profile interface */
+ trace_create_file("uprobe_profile", 0444, d_tracer,
+ NULL, &uprobe_profile_ops);
+ return 0;
+}
+
+fs_initcall(init_uprobe_trace);