#define pr_fmt(fmt) "trace_uprobe: " fmt
#include <linux/bpf-cgroup.h>
#include <linux/cleanup.h>
#include <linux/ctype.h>
#include <linux/filter.h>
#include <linux/module.h>
#include <linux/namei.h>
#include <linux/percpu.h>
#include <linux/rculist.h>
#include <linux/security.h>
#include <linux/string.h>
#include <linux/uaccess.h>
#include <linux/uprobes.h>
#include "trace.h"
#include "trace_dynevent.h"
#include "trace_probe.h"
#include "trace_probe_tmpl.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))
static int trace_uprobe_create(const char *raw_command);
static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev);
static int trace_uprobe_release(struct dyn_event *ev);
static bool trace_uprobe_is_busy(struct dyn_event *ev);
static bool trace_uprobe_match(const char *system, const char *event,
int argc, const char **argv, struct dyn_event *ev);
static struct dyn_event_operations trace_uprobe_ops = {
.create = trace_uprobe_create,
.show = trace_uprobe_show,
.is_busy = trace_uprobe_is_busy,
.free = trace_uprobe_release,
.match = trace_uprobe_match,
};
struct trace_uprobe {
struct dyn_event devent;
struct uprobe_consumer consumer;
struct path path;
char *filename;
struct uprobe *uprobe;
unsigned long offset;
unsigned long ref_ctr_offset;
unsigned long __percpu *nhits;
struct trace_probe tp;
};
static bool is_trace_uprobe(struct dyn_event *ev)
{
return ev->ops == &trace_uprobe_ops;
}
static struct trace_uprobe *to_trace_uprobe(struct dyn_event *ev)
{
return container_of(ev, struct trace_uprobe, devent);
}
#define for_each_trace_uprobe(pos, dpos) \
for_each_dyn_event(dpos) \
if (is_trace_uprobe(dpos) && (pos = to_trace_uprobe(dpos)))
static int register_uprobe_event(struct trace_uprobe *tu);
static int unregister_uprobe_event(struct trace_uprobe *tu);
static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs,
__u64 *data);
static int uretprobe_dispatcher(struct uprobe_consumer *con,
unsigned long func, struct pt_regs *regs,
__u64 *data);
#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;
}
static nokprobe_inline int
probe_mem_read(void *dest, void *src, size_t size)
{
void __user *vaddr = (void __force __user *)src;
return copy_from_user(dest, vaddr, size) ? -EFAULT : 0;
}
static nokprobe_inline int
probe_mem_read_user(void *dest, void *src, size_t size)
{
return probe_mem_read(dest, src, size);
}
static nokprobe_inline int
fetch_store_string(unsigned long addr, void *dest, void *base)
{
long ret;
u32 loc = *(u32 *)dest;
int maxlen = get_loc_len(loc);
u8 *dst = get_loc_data(dest, base);
void __user *src = (void __force __user *) addr;
if (unlikely(!maxlen))
return -ENOMEM;
if (addr == FETCH_TOKEN_COMM)
ret = strscpy(dst, current->comm, maxlen);
else
ret = strncpy_from_user(dst, src, maxlen);
if (ret >= 0) {
if (ret == maxlen)
dst[ret - 1] = '\0';
else
ret++;
*(u32 *)dest = make_data_loc(ret, (void *)dst - base);
} else
*(u32 *)dest = make_data_loc(0, (void *)dst - base);
return ret;
}
static nokprobe_inline int
fetch_store_string_user(unsigned long addr, void *dest, void *base)
{
return fetch_store_string(addr, dest, base);
}
static nokprobe_inline int
fetch_store_strlen(unsigned long addr)
{
int len;
void __user *vaddr = (void __force __user *) addr;
if (addr == FETCH_TOKEN_COMM)
len = strlen(current->comm) + 1;
else
len = strnlen_user(vaddr, MAX_STRING_SIZE);
return (len > MAX_STRING_SIZE) ? 0 : len;
}
static nokprobe_inline int
fetch_store_strlen_user(unsigned long addr)
{
return fetch_store_strlen(addr);
}
static unsigned long translate_user_vaddr(unsigned long 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 + file_offset;
}
static int
process_fetch_insn(struct fetch_insn *code, void *rec, void *edata,
void *dest, void *base)
{
struct pt_regs *regs = rec;
unsigned long val;
int ret;
switch (code->op) {
case FETCH_OP_REG:
val = regs_get_register(regs, code->param);
break;
case FETCH_OP_STACK:
val = get_user_stack_nth(regs, code->param);
break;
case FETCH_OP_STACKP:
val = user_stack_pointer(regs);
break;
case FETCH_OP_RETVAL:
val = regs_return_value(regs);
break;
case FETCH_OP_COMM:
val = FETCH_TOKEN_COMM;
break;
case FETCH_OP_FOFFS:
val = translate_user_vaddr(code->immediate);
break;
default:
ret = process_common_fetch_insn(code, &val);
if (ret < 0)
return ret;
}
code++;
return process_fetch_insn_bottom(code, val, dest, base);
}
NOKPROBE_SYMBOL(process_fetch_insn)
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;
}
static bool trace_uprobe_is_busy(struct dyn_event *ev)
{
struct trace_uprobe *tu = to_trace_uprobe(ev);
return trace_probe_is_enabled(&tu->tp);
}
static bool trace_uprobe_match_command_head(struct trace_uprobe *tu,
int argc, const char **argv)
{
char buf[MAX_ARGSTR_LEN + 1];
int len;
if (!argc)
return true;
len = strlen(tu->filename);
if (strncmp(tu->filename, argv[0], len) || argv[0][len] != ':')
return false;
if (tu->ref_ctr_offset == 0)
snprintf(buf, sizeof(buf), "0x%0*lx",
(int)(sizeof(void *) * 2), tu->offset);
else
snprintf(buf, sizeof(buf), "0x%0*lx(0x%lx)",
(int)(sizeof(void *) * 2), tu->offset,
tu->ref_ctr_offset);
if (strcmp(buf, &argv[0][len + 1]))
return false;
argc--; argv++;
return trace_probe_match_command_args(&tu->tp, argc, argv);
}
static bool trace_uprobe_match(const char *system, const char *event,
int argc, const char **argv, struct dyn_event *ev)
{
struct trace_uprobe *tu = to_trace_uprobe(ev);
return (event[0] == '\0' ||
strcmp(trace_probe_name(&tu->tp), event) == 0) &&
(!system || strcmp(trace_probe_group_name(&tu->tp), system) == 0) &&
trace_uprobe_match_command_head(tu, argc, argv);
}
static nokprobe_inline struct trace_uprobe *
trace_uprobe_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_uprobe, tp);
}
static struct trace_uprobe *
alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret)
{
struct trace_uprobe *tu;
int ret;
tu = kzalloc_flex(*tu, tp.args, nargs);
if (!tu)
return ERR_PTR(-ENOMEM);
tu->nhits = alloc_percpu(unsigned long);
if (!tu->nhits) {
ret = -ENOMEM;
goto error;
}
ret = trace_probe_init(&tu->tp, event, group, true, nargs);
if (ret < 0)
goto error;
dyn_event_init(&tu->devent, &trace_uprobe_ops);
tu->consumer.handler = uprobe_dispatcher;
if (is_ret)
tu->consumer.ret_handler = uretprobe_dispatcher;
init_trace_uprobe_filter(tu->tp.event->filter);
return tu;
error:
free_percpu(tu->nhits);
kfree(tu);
return ERR_PTR(ret);
}
static void free_trace_uprobe(struct trace_uprobe *tu)
{
if (!tu)
return;
path_put(&tu->path);
trace_probe_cleanup(&tu->tp);
kfree(tu->filename);
free_percpu(tu->nhits);
kfree(tu);
}
static struct trace_uprobe *find_probe_event(const char *event, const char *group)
{
struct dyn_event *pos;
struct trace_uprobe *tu;
for_each_trace_uprobe(tu, pos)
if (strcmp(trace_probe_name(&tu->tp), event) == 0 &&
strcmp(trace_probe_group_name(&tu->tp), group) == 0)
return tu;
return NULL;
}
static int unregister_trace_uprobe(struct trace_uprobe *tu)
{
int ret;
if (trace_probe_has_sibling(&tu->tp))
goto unreg;
if (trace_event_dyn_busy(trace_probe_event_call(&tu->tp)))
return -EBUSY;
ret = unregister_uprobe_event(tu);
if (ret)
return ret;
unreg:
dyn_event_remove(&tu->devent);
trace_probe_unlink(&tu->tp);
free_trace_uprobe(tu);
return 0;
}
static bool trace_uprobe_has_same_uprobe(struct trace_uprobe *orig,
struct trace_uprobe *comp)
{
struct trace_probe_event *tpe = orig->tp.event;
struct inode *comp_inode = d_real_inode(comp->path.dentry);
int i;
list_for_each_entry(orig, &tpe->probes, tp.list) {
if (comp_inode != d_real_inode(orig->path.dentry) ||
comp->offset != orig->offset)
continue;
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_uprobe(struct trace_uprobe *tu, struct trace_uprobe *to)
{
int ret;
ret = trace_probe_compare_arg_type(&tu->tp, &to->tp);
if (ret) {
trace_probe_log_set_index(ret + 1);
trace_probe_log_err(0, DIFF_ARG_TYPE);
return -EEXIST;
}
if (trace_uprobe_has_same_uprobe(to, tu)) {
trace_probe_log_set_index(0);
trace_probe_log_err(0, SAME_PROBE);
return -EEXIST;
}
ret = trace_probe_append(&tu->tp, &to->tp);
if (!ret)
dyn_event_add(&tu->devent, trace_probe_event_call(&tu->tp));
return ret;
}
static int validate_ref_ctr_offset(struct trace_uprobe *new)
{
struct dyn_event *pos;
struct trace_uprobe *tmp;
struct inode *new_inode = d_real_inode(new->path.dentry);
for_each_trace_uprobe(tmp, pos) {
if (new_inode == d_real_inode(tmp->path.dentry) &&
new->offset == tmp->offset &&
new->ref_ctr_offset != tmp->ref_ctr_offset) {
pr_warn("Reference counter offset mismatch.");
return -EINVAL;
}
}
return 0;
}
static int register_trace_uprobe(struct trace_uprobe *tu)
{
struct trace_uprobe *old_tu;
int ret;
guard(mutex)(&event_mutex);
ret = validate_ref_ctr_offset(tu);
if (ret)
return ret;
old_tu = find_probe_event(trace_probe_name(&tu->tp),
trace_probe_group_name(&tu->tp));
if (old_tu) {
if (is_ret_probe(tu) != is_ret_probe(old_tu)) {
trace_probe_log_set_index(0);
trace_probe_log_err(0, DIFF_PROBE_TYPE);
return -EEXIST;
}
return append_trace_uprobe(tu, old_tu);
}
ret = register_uprobe_event(tu);
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);
return ret;
}
dyn_event_add(&tu->devent, trace_probe_event_call(&tu->tp));
return ret;
}
DEFINE_FREE(free_trace_uprobe, struct trace_uprobe *, if (_T) free_trace_uprobe(_T))
static int __trace_uprobe_create(int argc, const char **argv)
{
struct traceprobe_parse_context *ctx __free(traceprobe_parse_context) = NULL;
struct trace_uprobe *tu __free(free_trace_uprobe) = NULL;
const char *trlog __free(trace_probe_log_clear) = NULL;
const char *event = NULL, *group = UPROBE_EVENT_SYSTEM;
struct path path __free(path_put) = {};
unsigned long offset, ref_ctr_offset;
char *filename __free(kfree) = NULL;
char *arg, *rctr, *rctr_end, *tmp;
char *gbuf __free(kfree) = NULL;
char *buf __free(kfree) = NULL;
enum probe_print_type ptype;
bool is_return = false;
int i, ret;
ref_ctr_offset = 0;
switch (argv[0][0]) {
case 'r':
is_return = true;
break;
case 'p':
break;
default:
return -ECANCELED;
}
if (argc < 2)
return -ECANCELED;
trlog = trace_probe_log_init("trace_uprobe", argc, argv);
if (argc - 2 > MAX_TRACE_ARGS) {
trace_probe_log_set_index(2);
trace_probe_log_err(0, TOO_MANY_ARGS);
return -E2BIG;
}
if (argv[0][1] == ':')
event = &argv[0][2];
if (!strchr(argv[1], '/'))
return -ECANCELED;
filename = kstrdup(argv[1], GFP_KERNEL);
if (!filename)
return -ENOMEM;
arg = strrchr(filename, ':');
if (!arg || !isdigit(arg[1]))
return -ECANCELED;
trace_probe_log_set_index(1);
*arg++ = '\0';
ret = kern_path(filename, LOOKUP_FOLLOW, &path);
if (ret) {
trace_probe_log_err(0, FILE_NOT_FOUND);
return ret;
}
if (!d_is_reg(path.dentry)) {
trace_probe_log_err(0, NO_REGULAR_FILE);
return -EINVAL;
}
rctr = strchr(arg, '(');
if (rctr) {
rctr_end = strchr(rctr, ')');
if (!rctr_end) {
rctr_end = rctr + strlen(rctr);
trace_probe_log_err(rctr_end - filename,
REFCNT_OPEN_BRACE);
return -EINVAL;
} else if (rctr_end[1] != '\0') {
trace_probe_log_err(rctr_end + 1 - filename,
BAD_REFCNT_SUFFIX);
return -EINVAL;
}
*rctr++ = '\0';
*rctr_end = '\0';
ret = kstrtoul(rctr, 0, &ref_ctr_offset);
if (ret) {
trace_probe_log_err(rctr - filename, BAD_REFCNT);
return ret;
}
}
tmp = strchr(arg, '%');
if (tmp) {
if (!strcmp(tmp, "%return")) {
*tmp = '\0';
is_return = true;
} else {
trace_probe_log_err(tmp - filename, BAD_ADDR_SUFFIX);
return -EINVAL;
}
}
ret = kstrtoul(arg, 0, &offset);
if (ret) {
trace_probe_log_err(arg - filename, BAD_UPROBE_OFFS);
return ret;
}
trace_probe_log_set_index(0);
if (event) {
gbuf = kmalloc(MAX_EVENT_NAME_LEN, GFP_KERNEL);
if (!gbuf)
return -ENOMEM;
ret = traceprobe_parse_event_name(&event, &group, gbuf,
event - argv[0]);
if (ret)
return ret;
}
if (!event) {
char *tail;
char *ptr;
tail = kstrdup(kbasename(filename), GFP_KERNEL);
if (!tail)
return -ENOMEM;
ptr = strpbrk(tail, ".-_");
if (ptr)
*ptr = '\0';
buf = kmalloc(MAX_EVENT_NAME_LEN, GFP_KERNEL);
if (!buf)
return -ENOMEM;
snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset);
event = buf;
kfree(tail);
}
argc -= 2;
argv += 2;
tu = alloc_trace_uprobe(group, event, argc, is_return);
if (IS_ERR(tu)) {
ret = PTR_ERR(tu);
WARN_ON_ONCE(ret != -ENOMEM);
return ret;
}
tu->offset = offset;
tu->ref_ctr_offset = ref_ctr_offset;
tu->path = path;
memset(&path, 0, sizeof(path));
tu->filename = no_free_ptr(filename);
ctx = kzalloc_obj(*ctx);
if (!ctx)
return -ENOMEM;
ctx->flags = (is_return ? TPARG_FL_RETURN : 0) | TPARG_FL_USER;
for (i = 0; i < argc; i++) {
trace_probe_log_set_index(i + 2);
ret = traceprobe_parse_probe_arg(&tu->tp, i, argv[i], ctx);
if (ret)
return ret;
}
ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
ret = traceprobe_set_print_fmt(&tu->tp, ptype);
if (ret < 0)
return ret;
ret = register_trace_uprobe(tu);
if (!ret)
tu = NULL;
return ret;
}
int trace_uprobe_create(const char *raw_command)
{
return trace_probe_create(raw_command, __trace_uprobe_create);
}
static int create_or_delete_trace_uprobe(const char *raw_command)
{
int ret;
if (raw_command[0] == '-')
return dyn_event_release(raw_command, &trace_uprobe_ops);
ret = dyn_event_create(raw_command, &trace_uprobe_ops);
return ret == -ECANCELED ? -EINVAL : ret;
}
static int trace_uprobe_release(struct dyn_event *ev)
{
struct trace_uprobe *tu = to_trace_uprobe(ev);
return unregister_trace_uprobe(tu);
}
static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev)
{
struct trace_uprobe *tu = to_trace_uprobe(ev);
char c = is_ret_probe(tu) ? 'r' : 'p';
int i;
seq_printf(m, "%c:%s/%s %s:0x%0*lx", c, trace_probe_group_name(&tu->tp),
trace_probe_name(&tu->tp), tu->filename,
(int)(sizeof(void *) * 2), tu->offset);
if (tu->ref_ctr_offset)
seq_printf(m, "(0x%lx)", tu->ref_ctr_offset);
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 int probes_seq_show(struct seq_file *m, void *v)
{
struct dyn_event *ev = v;
if (!is_trace_uprobe(ev))
return 0;
return trace_uprobe_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_uprobe_ops);
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 trace_parse_run_command(file, buffer, count, ppos,
create_or_delete_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,
};
static int probes_profile_seq_show(struct seq_file *m, void *v)
{
struct dyn_event *ev = v;
struct trace_uprobe *tu;
unsigned long nhits;
int cpu;
if (!is_trace_uprobe(ev))
return 0;
tu = to_trace_uprobe(ev);
nhits = 0;
for_each_possible_cpu(cpu) {
nhits += per_cpu(*tu->nhits, cpu);
}
seq_printf(m, " %s %-44s %15lu\n", tu->filename,
trace_probe_name(&tu->tp), nhits);
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 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;
int dsize;
};
static struct uprobe_cpu_buffer __percpu *uprobe_cpu_buffer;
static int uprobe_buffer_refcnt;
#define MAX_UCB_BUFFER_SIZE PAGE_SIZE
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);
mutex_lock(&ucb->mutex);
return ucb;
}
static void uprobe_buffer_put(struct uprobe_cpu_buffer *ucb)
{
if (!ucb)
return;
mutex_unlock(&ucb->mutex);
}
static struct uprobe_cpu_buffer *prepare_uprobe_buffer(struct trace_uprobe *tu,
struct pt_regs *regs,
struct uprobe_cpu_buffer **ucbp)
{
struct uprobe_cpu_buffer *ucb;
int dsize, esize;
if (*ucbp)
return *ucbp;
esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
dsize = __get_data_size(&tu->tp, regs, NULL);
ucb = uprobe_buffer_get();
ucb->dsize = tu->tp.size + dsize;
if (WARN_ON_ONCE(ucb->dsize > MAX_UCB_BUFFER_SIZE)) {
ucb->dsize = MAX_UCB_BUFFER_SIZE;
dsize = MAX_UCB_BUFFER_SIZE - tu->tp.size;
}
store_trace_args(ucb->buf, &tu->tp, regs, NULL, esize, dsize);
*ucbp = ucb;
return ucb;
}
static void __uprobe_trace_func(struct trace_uprobe *tu,
unsigned long func, struct pt_regs *regs,
struct uprobe_cpu_buffer *ucb,
struct trace_event_file *trace_file)
{
struct uprobe_trace_entry_head *entry;
struct trace_event_buffer fbuffer;
void *data;
int size, esize;
struct trace_event_call *call = trace_probe_event_call(&tu->tp);
WARN_ON(call != trace_file->event_call);
if (trace_trigger_soft_disabled(trace_file))
return;
esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
size = esize + ucb->dsize;
entry = trace_event_buffer_reserve(&fbuffer, trace_file, size);
if (!entry)
return;
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, ucb->dsize);
trace_event_buffer_commit(&fbuffer);
}
static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs,
struct uprobe_cpu_buffer **ucbp)
{
struct event_file_link *link;
struct uprobe_cpu_buffer *ucb;
if (is_ret_probe(tu))
return 0;
ucb = prepare_uprobe_buffer(tu, regs, ucbp);
rcu_read_lock();
trace_probe_for_each_link_rcu(link, &tu->tp)
__uprobe_trace_func(tu, 0, regs, ucb, 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 **ucbp)
{
struct event_file_link *link;
struct uprobe_cpu_buffer *ucb;
ucb = prepare_uprobe_buffer(tu, regs, ucbp);
rcu_read_lock();
trace_probe_for_each_link_rcu(link, &tu->tp)
__uprobe_trace_func(tu, func, regs, ucb, link->file);
rcu_read_unlock();
}
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;
entry = (struct uprobe_trace_entry_head *)iter->ent;
tu = trace_uprobe_primary_from_call(
container_of(event, struct trace_event_call, event));
if (unlikely(!tu))
goto out;
if (is_ret_probe(tu)) {
trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)",
trace_probe_name(&tu->tp),
entry->vaddr[1], entry->vaddr[0]);
data = DATAOF_TRACE_ENTRY(entry, true);
} else {
trace_seq_printf(s, "%s: (0x%lx)",
trace_probe_name(&tu->tp),
entry->vaddr[0]);
data = DATAOF_TRACE_ENTRY(entry, false);
}
if (trace_probe_print_args(s, tu->tp.args, tu->tp.nr_args, data, entry) < 0)
goto out;
trace_seq_putc(s, '\n');
out:
return trace_handle_return(s);
}
typedef bool (*filter_func_t)(struct uprobe_consumer *self, struct mm_struct *mm);
static int trace_uprobe_enable(struct trace_uprobe *tu, filter_func_t filter)
{
struct inode *inode = d_real_inode(tu->path.dentry);
struct uprobe *uprobe;
tu->consumer.filter = filter;
uprobe = uprobe_register(inode, tu->offset, tu->ref_ctr_offset, &tu->consumer);
if (IS_ERR(uprobe))
return PTR_ERR(uprobe);
tu->uprobe = uprobe;
return 0;
}
static void __probe_event_disable(struct trace_probe *tp)
{
struct trace_uprobe *tu;
bool sync = false;
tu = container_of(tp, struct trace_uprobe, tp);
WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter));
list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) {
if (!tu->uprobe)
continue;
uprobe_unregister_nosync(tu->uprobe, &tu->consumer);
sync = true;
tu->uprobe = NULL;
}
if (sync)
uprobe_unregister_sync();
}
static int probe_event_enable(struct trace_event_call *call,
struct trace_event_file *file, filter_func_t filter)
{
struct trace_probe *tp;
struct trace_uprobe *tu;
bool enabled;
int ret;
tp = trace_probe_primary_from_call(call);
if (WARN_ON_ONCE(!tp))
return -ENODEV;
enabled = trace_probe_is_enabled(tp);
if (file) {
if (trace_probe_test_flag(tp, TP_FLAG_PROFILE))
return -EINTR;
ret = trace_probe_add_file(tp, file);
if (ret < 0)
return ret;
} else {
if (trace_probe_test_flag(tp, TP_FLAG_TRACE))
return -EINTR;
trace_probe_set_flag(tp, TP_FLAG_PROFILE);
}
tu = container_of(tp, struct trace_uprobe, tp);
WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter));
if (enabled)
return 0;
ret = uprobe_buffer_enable();
if (ret)
goto err_flags;
list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) {
ret = trace_uprobe_enable(tu, filter);
if (ret) {
__probe_event_disable(tp);
goto err_buffer;
}
}
return 0;
err_buffer:
uprobe_buffer_disable();
err_flags:
if (file)
trace_probe_remove_file(tp, file);
else
trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
return ret;
}
static void probe_event_disable(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;
if (!trace_probe_is_enabled(tp))
return;
if (file) {
if (trace_probe_remove_file(tp, file) < 0)
return;
if (trace_probe_is_enabled(tp))
return;
} else
trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
__probe_event_disable(tp);
uprobe_buffer_disable();
}
static int uprobe_event_define_fields(struct trace_event_call *event_call)
{
int ret, size;
struct uprobe_trace_entry_head field;
struct trace_uprobe *tu;
tu = trace_uprobe_primary_from_call(event_call);
if (unlikely(!tu))
return -ENODEV;
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);
}
return traceprobe_define_arg_fields(event_call, size, &tu->tp);
}
#ifdef CONFIG_PERF_EVENTS
static bool
__uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm)
{
struct perf_event *event;
list_for_each_entry(event, &filter->perf_events, hw.tp_list) {
if (event->hw.target->mm == mm)
return true;
}
return false;
}
static inline bool
trace_uprobe_filter_event(struct trace_uprobe_filter *filter,
struct perf_event *event)
{
return __uprobe_perf_filter(filter, event->hw.target->mm);
}
static bool trace_uprobe_filter_remove(struct trace_uprobe_filter *filter,
struct perf_event *event)
{
bool done;
write_lock(&filter->rwlock);
if (event->hw.target) {
list_del(&event->hw.tp_list);
done = filter->nr_systemwide ||
(event->hw.target->flags & PF_EXITING) ||
trace_uprobe_filter_event(filter, event);
} else {
filter->nr_systemwide--;
done = filter->nr_systemwide;
}
write_unlock(&filter->rwlock);
return done;
}
static bool trace_uprobe_filter_add(struct trace_uprobe_filter *filter,
struct perf_event *event)
{
bool done;
write_lock(&filter->rwlock);
if (event->hw.target) {
done = filter->nr_systemwide ||
event->parent || event->attr.enable_on_exec ||
trace_uprobe_filter_event(filter, event);
list_add(&event->hw.tp_list, &filter->perf_events);
} else {
done = filter->nr_systemwide;
filter->nr_systemwide++;
}
write_unlock(&filter->rwlock);
return done;
}
static int uprobe_perf_close(struct trace_event_call *call,
struct perf_event *event)
{
struct trace_probe *tp;
struct trace_uprobe *tu;
int ret = 0;
tp = trace_probe_primary_from_call(call);
if (WARN_ON_ONCE(!tp))
return -ENODEV;
tu = container_of(tp, struct trace_uprobe, tp);
if (trace_uprobe_filter_remove(tu->tp.event->filter, event))
return 0;
list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) {
ret = uprobe_apply(tu->uprobe, &tu->consumer, false);
if (ret)
break;
}
return ret;
}
static int uprobe_perf_open(struct trace_event_call *call,
struct perf_event *event)
{
struct trace_probe *tp;
struct trace_uprobe *tu;
int err = 0;
tp = trace_probe_primary_from_call(call);
if (WARN_ON_ONCE(!tp))
return -ENODEV;
tu = container_of(tp, struct trace_uprobe, tp);
if (trace_uprobe_filter_add(tu->tp.event->filter, event))
return 0;
list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) {
err = uprobe_apply(tu->uprobe, &tu->consumer, true);
if (err) {
uprobe_perf_close(call, event);
break;
}
}
return err;
}
static bool uprobe_perf_filter(struct uprobe_consumer *uc, struct mm_struct *mm)
{
struct trace_uprobe_filter *filter;
struct trace_uprobe *tu;
int ret;
tu = container_of(uc, struct trace_uprobe, consumer);
filter = tu->tp.event->filter;
if (READ_ONCE(filter->nr_systemwide))
return true;
read_lock(&filter->rwlock);
ret = __uprobe_perf_filter(filter, mm);
read_unlock(&filter->rwlock);
return ret;
}
static void __uprobe_perf_func(struct trace_uprobe *tu,
unsigned long func, struct pt_regs *regs,
struct uprobe_cpu_buffer **ucbp)
{
struct trace_event_call *call = trace_probe_event_call(&tu->tp);
struct uprobe_trace_entry_head *entry;
struct uprobe_cpu_buffer *ucb;
struct hlist_head *head;
void *data;
int size, esize;
int rctx;
#ifdef CONFIG_BPF_EVENTS
if (bpf_prog_array_valid(call)) {
const struct bpf_prog_array *array;
u32 ret;
rcu_read_lock_trace();
array = rcu_dereference_check(call->prog_array, rcu_read_lock_trace_held());
ret = bpf_prog_run_array_uprobe(array, regs, bpf_prog_run);
rcu_read_unlock_trace();
if (!ret)
return;
}
#endif
esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
ucb = prepare_uprobe_buffer(tu, regs, ucbp);
size = esize + ucb->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_alloc(size, 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, ucb->dsize);
if (size - esize > ucb->dsize)
memset(data + ucb->dsize, 0, size - esize - ucb->dsize);
perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
head, NULL);
out:
preempt_enable();
}
static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs,
struct uprobe_cpu_buffer **ucbp)
{
if (!uprobe_perf_filter(&tu->consumer, current->mm))
return UPROBE_HANDLER_REMOVE;
if (!is_ret_probe(tu))
__uprobe_perf_func(tu, 0, regs, ucbp);
return 0;
}
static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func,
struct pt_regs *regs,
struct uprobe_cpu_buffer **ucbp)
{
__uprobe_perf_func(tu, func, regs, ucbp);
}
int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type,
const char **filename, 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_uprobe *tu;
if (perf_type_tracepoint)
tu = find_probe_event(pevent, group);
else
tu = trace_uprobe_primary_from_call(event->tp_event);
if (!tu)
return -EINVAL;
*fd_type = is_ret_probe(tu) ? BPF_FD_TYPE_URETPROBE
: BPF_FD_TYPE_UPROBE;
*filename = tu->filename;
*probe_offset = tu->offset;
*probe_addr = tu->ref_ctr_offset;
return 0;
}
#endif
static int
trace_uprobe_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 probe_event_enable(event, file, NULL);
case TRACE_REG_UNREGISTER:
probe_event_disable(event, file);
return 0;
#ifdef CONFIG_PERF_EVENTS
case TRACE_REG_PERF_REGISTER:
return probe_event_enable(event, NULL, uprobe_perf_filter);
case TRACE_REG_PERF_UNREGISTER:
probe_event_disable(event, NULL);
return 0;
case TRACE_REG_PERF_OPEN:
return uprobe_perf_open(event, data);
case TRACE_REG_PERF_CLOSE:
return uprobe_perf_close(event, data);
#endif
default:
return 0;
}
}
static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs,
__u64 *data)
{
struct trace_uprobe *tu;
struct uprobe_dispatch_data udd;
struct uprobe_cpu_buffer *ucb = NULL;
unsigned int flags;
int ret = 0;
tu = container_of(con, struct trace_uprobe, consumer);
this_cpu_inc(*tu->nhits);
udd.tu = tu;
udd.bp_addr = instruction_pointer(regs);
current->utask->vaddr = (unsigned long) &udd;
if (WARN_ON_ONCE(!uprobe_cpu_buffer))
return 0;
flags = trace_probe_load_flag(&tu->tp);
if (flags & TP_FLAG_TRACE)
ret |= uprobe_trace_func(tu, regs, &ucb);
#ifdef CONFIG_PERF_EVENTS
if (flags & TP_FLAG_PROFILE)
ret |= uprobe_perf_func(tu, regs, &ucb);
#endif
uprobe_buffer_put(ucb);
return ret;
}
static int uretprobe_dispatcher(struct uprobe_consumer *con,
unsigned long func, struct pt_regs *regs,
__u64 *data)
{
struct trace_uprobe *tu;
struct uprobe_dispatch_data udd;
struct uprobe_cpu_buffer *ucb = NULL;
unsigned int flags;
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;
flags = trace_probe_load_flag(&tu->tp);
if (flags & TP_FLAG_TRACE)
uretprobe_trace_func(tu, func, regs, &ucb);
#ifdef CONFIG_PERF_EVENTS
if (flags & TP_FLAG_PROFILE)
uretprobe_perf_func(tu, func, regs, &ucb);
#endif
uprobe_buffer_put(ucb);
return 0;
}
static struct trace_event_functions uprobe_funcs = {
.trace = print_uprobe_event
};
static struct trace_event_fields uprobe_fields_array[] = {
{ .type = TRACE_FUNCTION_TYPE,
.define_fields = uprobe_event_define_fields },
{}
};
static inline void init_trace_event_call(struct trace_uprobe *tu)
{
struct trace_event_call *call = trace_probe_event_call(&tu->tp);
call->event.funcs = &uprobe_funcs;
call->class->fields_array = uprobe_fields_array;
call->flags = TRACE_EVENT_FL_UPROBE | TRACE_EVENT_FL_CAP_ANY;
call->class->reg = trace_uprobe_register;
}
static int register_uprobe_event(struct trace_uprobe *tu)
{
init_trace_event_call(tu);
return trace_probe_register_event_call(&tu->tp);
}
static int unregister_uprobe_event(struct trace_uprobe *tu)
{
return trace_probe_unregister_event_call(&tu->tp);
}
#ifdef CONFIG_PERF_EVENTS
struct trace_event_call *
create_local_trace_uprobe(char *name, unsigned long offs,
unsigned long ref_ctr_offset, bool is_return)
{
enum probe_print_type ptype;
struct trace_uprobe *tu;
struct path path;
int ret;
ret = kern_path(name, LOOKUP_FOLLOW, &path);
if (ret)
return ERR_PTR(ret);
if (!d_is_reg(path.dentry)) {
path_put(&path);
return ERR_PTR(-EINVAL);
}
tu = alloc_trace_uprobe(UPROBE_EVENT_SYSTEM, "DUMMY_EVENT", 0,
is_return);
if (IS_ERR(tu)) {
pr_info("Failed to allocate trace_uprobe.(%d)\n",
(int)PTR_ERR(tu));
path_put(&path);
return ERR_CAST(tu);
}
tu->offset = offs;
tu->path = path;
tu->ref_ctr_offset = ref_ctr_offset;
tu->filename = kstrdup(name, GFP_KERNEL);
if (!tu->filename) {
ret = -ENOMEM;
goto error;
}
init_trace_event_call(tu);
ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
if (traceprobe_set_print_fmt(&tu->tp, ptype) < 0) {
ret = -ENOMEM;
goto error;
}
return trace_probe_event_call(&tu->tp);
error:
free_trace_uprobe(tu);
return ERR_PTR(ret);
}
void destroy_local_trace_uprobe(struct trace_event_call *event_call)
{
struct trace_uprobe *tu;
tu = trace_uprobe_primary_from_call(event_call);
free_trace_uprobe(tu);
}
#endif
static __init int init_uprobe_trace(void)
{
int ret;
ret = dyn_event_register(&trace_uprobe_ops);
if (ret)
return ret;
ret = tracing_init_dentry();
if (ret)
return 0;
trace_create_file("uprobe_events", TRACE_MODE_WRITE, NULL,
NULL, &uprobe_events_ops);
trace_create_file("uprobe_profile", TRACE_MODE_READ, NULL,
NULL, &uprobe_profile_ops);
return 0;
}
fs_initcall(init_uprobe_trace);
