/* Quick disabling of function tracer. */
int function_trace_stop;
+/* By default, current tracing type is normal tracing. */
+enum ftrace_tracing_type_t ftrace_tracing_type = FTRACE_TYPE_ENTER;
+
/*
* ftrace_disabled is set when an anomaly is discovered.
* ftrace_disabled is much stronger than ftrace_enabled.
{
struct dyn_ftrace *rec;
- if (!ftrace_enabled || ftrace_disabled)
+ if (ftrace_disabled)
return NULL;
rec = ftrace_alloc_dyn_node(ip);
return rec;
}
-#define FTRACE_ADDR ((long)(ftrace_caller))
+static void print_ip_ins(const char *fmt, unsigned char *p)
+{
+ int i;
+
+ printk(KERN_CONT "%s", fmt);
+
+ for (i = 0; i < MCOUNT_INSN_SIZE; i++)
+ printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
+}
+
+static void ftrace_bug(int failed, unsigned long ip)
+{
+ switch (failed) {
+ case -EFAULT:
+ FTRACE_WARN_ON_ONCE(1);
+ pr_info("ftrace faulted on modifying ");
+ print_ip_sym(ip);
+ break;
+ case -EINVAL:
+ FTRACE_WARN_ON_ONCE(1);
+ pr_info("ftrace failed to modify ");
+ print_ip_sym(ip);
+ print_ip_ins(" actual: ", (unsigned char *)ip);
+ printk(KERN_CONT "\n");
+ break;
+ case -EPERM:
+ FTRACE_WARN_ON_ONCE(1);
+ pr_info("ftrace faulted on writing ");
+ print_ip_sym(ip);
+ break;
+ default:
+ FTRACE_WARN_ON_ONCE(1);
+ pr_info("ftrace faulted on unknown error ");
+ print_ip_sym(ip);
+ }
+}
+
static int
-__ftrace_replace_code(struct dyn_ftrace *rec,
- unsigned char *old, unsigned char *new, int enable)
+__ftrace_replace_code(struct dyn_ftrace *rec, int enable)
{
unsigned long ip, fl;
+ unsigned long ftrace_addr;
+
+#ifdef CONFIG_FUNCTION_RET_TRACER
+ if (ftrace_tracing_type == FTRACE_TYPE_ENTER)
+ ftrace_addr = (unsigned long)ftrace_caller;
+ else
+ ftrace_addr = (unsigned long)ftrace_return_caller;
+#else
+ ftrace_addr = (unsigned long)ftrace_caller;
+#endif
ip = rec->ip;
- if (ftrace_filtered && enable) {
+ /*
+ * If this record is not to be traced and
+ * it is not enabled then do nothing.
+ *
+ * If this record is not to be traced and
+ * it is enabled then disabled it.
+ *
+ */
+ if (rec->flags & FTRACE_FL_NOTRACE) {
+ if (rec->flags & FTRACE_FL_ENABLED)
+ rec->flags &= ~FTRACE_FL_ENABLED;
+ else
+ return 0;
+
+ } else if (ftrace_filtered && enable) {
/*
- * If filtering is on:
- *
- * If this record is set to be filtered and
- * is enabled then do nothing.
- *
- * If this record is set to be filtered and
- * it is not enabled, enable it.
- *
- * If this record is not set to be filtered
- * and it is not enabled do nothing.
- *
- * If this record is set not to trace then
- * do nothing.
- *
- * If this record is set not to trace and
- * it is enabled then disable it.
- *
- * If this record is not set to be filtered and
- * it is enabled, disable it.
+ * Filtering is on:
*/
- fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_NOTRACE |
- FTRACE_FL_ENABLED);
+ fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_ENABLED);
- if ((fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED)) ||
- (fl == (FTRACE_FL_FILTER | FTRACE_FL_NOTRACE)) ||
- !fl || (fl == FTRACE_FL_NOTRACE))
+ /* Record is filtered and enabled, do nothing */
+ if (fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED))
return 0;
- /*
- * If it is enabled disable it,
- * otherwise enable it!
- */
- if (fl & FTRACE_FL_ENABLED) {
- /* swap new and old */
- new = old;
- old = ftrace_call_replace(ip, FTRACE_ADDR);
+ /* Record is not filtered and is not enabled do nothing */
+ if (!fl)
+ return 0;
+
+ /* Record is not filtered but enabled, disable it */
+ if (fl == FTRACE_FL_ENABLED)
rec->flags &= ~FTRACE_FL_ENABLED;
- } else {
- new = ftrace_call_replace(ip, FTRACE_ADDR);
+ else
+ /* Otherwise record is filtered but not enabled, enable it */
rec->flags |= FTRACE_FL_ENABLED;
- }
} else {
+ /* Disable or not filtered */
if (enable) {
- /*
- * If this record is set not to trace and is
- * not enabled, do nothing.
- */
- fl = rec->flags & (FTRACE_FL_NOTRACE | FTRACE_FL_ENABLED);
- if (fl == FTRACE_FL_NOTRACE)
- return 0;
-
- new = ftrace_call_replace(ip, FTRACE_ADDR);
- } else
- old = ftrace_call_replace(ip, FTRACE_ADDR);
-
- if (enable) {
+ /* if record is enabled, do nothing */
if (rec->flags & FTRACE_FL_ENABLED)
return 0;
+
rec->flags |= FTRACE_FL_ENABLED;
+
} else {
+
+ /* if record is not enabled do nothing */
if (!(rec->flags & FTRACE_FL_ENABLED))
return 0;
+
rec->flags &= ~FTRACE_FL_ENABLED;
}
}
- return ftrace_modify_code(ip, old, new);
+ if (rec->flags & FTRACE_FL_ENABLED)
+ return ftrace_make_call(rec, ftrace_addr);
+ else
+ return ftrace_make_nop(NULL, rec, ftrace_addr);
}
static void ftrace_replace_code(int enable)
{
int i, failed;
- unsigned char *new = NULL, *old = NULL;
struct dyn_ftrace *rec;
struct ftrace_page *pg;
- if (enable)
- old = ftrace_nop_replace();
- else
- new = ftrace_nop_replace();
-
for (pg = ftrace_pages_start; pg; pg = pg->next) {
for (i = 0; i < pg->index; i++) {
rec = &pg->records[i];
- /* don't modify code that has already faulted */
- if (rec->flags & FTRACE_FL_FAILED)
+ /*
+ * Skip over free records and records that have
+ * failed.
+ */
+ if (rec->flags & FTRACE_FL_FREE ||
+ rec->flags & FTRACE_FL_FAILED)
continue;
/* ignore updates to this record's mcount site */
unfreeze_record(rec);
}
- failed = __ftrace_replace_code(rec, old, new, enable);
+ failed = __ftrace_replace_code(rec, enable);
if (failed && (rec->flags & FTRACE_FL_CONVERTED)) {
rec->flags |= FTRACE_FL_FAILED;
if ((system_state == SYSTEM_BOOTING) ||
!core_kernel_text(rec->ip)) {
ftrace_free_rec(rec);
- }
+ } else
+ ftrace_bug(failed, rec->ip);
}
}
}
}
-static void print_ip_ins(const char *fmt, unsigned char *p)
-{
- int i;
-
- printk(KERN_CONT "%s", fmt);
-
- for (i = 0; i < MCOUNT_INSN_SIZE; i++)
- printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
-}
-
static int
-ftrace_code_disable(struct dyn_ftrace *rec)
+ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
{
unsigned long ip;
- unsigned char *nop, *call;
int ret;
ip = rec->ip;
- nop = ftrace_nop_replace();
- call = ftrace_call_replace(ip, mcount_addr);
-
- ret = ftrace_modify_code(ip, call, nop);
+ ret = ftrace_make_nop(mod, rec, mcount_addr);
if (ret) {
- switch (ret) {
- case -EFAULT:
- FTRACE_WARN_ON_ONCE(1);
- pr_info("ftrace faulted on modifying ");
- print_ip_sym(ip);
- break;
- case -EINVAL:
- FTRACE_WARN_ON_ONCE(1);
- pr_info("ftrace failed to modify ");
- print_ip_sym(ip);
- print_ip_ins(" expected: ", call);
- print_ip_ins(" actual: ", (unsigned char *)ip);
- print_ip_ins(" replace: ", nop);
- printk(KERN_CONT "\n");
- break;
- case -EPERM:
- FTRACE_WARN_ON_ONCE(1);
- pr_info("ftrace faulted on writing ");
- print_ip_sym(ip);
- break;
- default:
- FTRACE_WARN_ON_ONCE(1);
- pr_info("ftrace faulted on unknown error ");
- print_ip_sym(ip);
- }
-
+ ftrace_bug(ret, ip);
rec->flags |= FTRACE_FL_FAILED;
return 0;
}
mutex_lock(&ftrace_start_lock);
ftrace_start_up++;
- if (ftrace_start_up == 1)
- command |= FTRACE_ENABLE_CALLS;
+ command |= FTRACE_ENABLE_CALLS;
if (saved_ftrace_func != ftrace_trace_function) {
saved_ftrace_func = ftrace_trace_function;
static unsigned long ftrace_update_cnt;
unsigned long ftrace_update_tot_cnt;
-static int ftrace_update_code(void)
+static int ftrace_update_code(struct module *mod)
{
struct dyn_ftrace *p, *t;
cycle_t start, stop;
list_del_init(&p->list);
/* convert record (i.e, patch mcount-call with NOP) */
- if (ftrace_code_disable(p)) {
+ if (ftrace_code_disable(mod, p)) {
p->flags |= FTRACE_FL_CONVERTED;
ftrace_update_cnt++;
} else
cnt = num_to_init / ENTRIES_PER_PAGE;
pr_info("ftrace: allocating %ld entries in %d pages\n",
- num_to_init, cnt);
+ num_to_init, cnt + 1);
for (i = 0; i < cnt; i++) {
pg->next = (void *)get_zeroed_page(GFP_KERNEL);
void *p = NULL;
loff_t l = -1;
- if (*pos != iter->pos) {
- for (p = t_next(m, p, &l); p && l < *pos; p = t_next(m, p, &l))
- ;
- } else {
- l = *pos;
- p = t_next(m, p, &l);
- }
+ if (*pos > iter->pos)
+ *pos = iter->pos;
+
+ l = *pos;
+ p = t_next(m, p, &l);
return p;
}
static int t_show(struct seq_file *m, void *v)
{
+ struct ftrace_iterator *iter = m->private;
struct dyn_ftrace *rec = v;
char str[KSYM_SYMBOL_LEN];
+ int ret = 0;
if (!rec)
return 0;
kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
- seq_printf(m, "%s\n", str);
+ ret = seq_printf(m, "%s\n", str);
+ if (ret < 0) {
+ iter->pos--;
+ iter->idx--;
+ }
return 0;
}
return -ENOMEM;
iter->pg = ftrace_pages_start;
- iter->pos = -1;
+ iter->pos = 0;
ret = seq_open(file, &show_ftrace_seq_ops);
if (!ret) {
if (file->f_mode & FMODE_READ) {
iter->pg = ftrace_pages_start;
- iter->pos = -1;
+ iter->pos = 0;
iter->flags = enable ? FTRACE_ITER_FILTER :
FTRACE_ITER_NOTRACE;
mutex_lock(&ftrace_sysctl_lock);
mutex_lock(&ftrace_start_lock);
- if (iter->filtered && ftrace_start_up && ftrace_enabled)
+ if (ftrace_start_up && ftrace_enabled)
ftrace_run_update_code(FTRACE_ENABLE_CALLS);
mutex_unlock(&ftrace_start_lock);
mutex_unlock(&ftrace_sysctl_lock);
fs_initcall(ftrace_init_debugfs);
-static int ftrace_convert_nops(unsigned long *start,
+static int ftrace_convert_nops(struct module *mod,
+ unsigned long *start,
unsigned long *end)
{
unsigned long *p;
p = start;
while (p < end) {
addr = ftrace_call_adjust(*p++);
+ /*
+ * Some architecture linkers will pad between
+ * the different mcount_loc sections of different
+ * object files to satisfy alignments.
+ * Skip any NULL pointers.
+ */
+ if (!addr)
+ continue;
ftrace_record_ip(addr);
}
/* disable interrupts to prevent kstop machine */
local_irq_save(flags);
- ftrace_update_code();
+ ftrace_update_code(mod);
local_irq_restore(flags);
mutex_unlock(&ftrace_start_lock);
return 0;
}
-void ftrace_init_module(unsigned long *start, unsigned long *end)
+void ftrace_init_module(struct module *mod,
+ unsigned long *start, unsigned long *end)
{
if (ftrace_disabled || start == end)
return;
- ftrace_convert_nops(start, end);
+ ftrace_convert_nops(mod, start, end);
}
extern unsigned long __start_mcount_loc[];
last_ftrace_enabled = ftrace_enabled = 1;
- ret = ftrace_convert_nops(__start_mcount_loc,
+ ret = ftrace_convert_nops(NULL,
+ __start_mcount_loc,
__stop_mcount_loc);
return;
return -1;
mutex_lock(&ftrace_sysctl_lock);
+
+ if (ftrace_tracing_type == FTRACE_TYPE_RETURN) {
+ ret = -EBUSY;
+ goto out;
+ }
+
ret = __register_ftrace_function(ops);
ftrace_startup();
- mutex_unlock(&ftrace_sysctl_lock);
+out:
+ mutex_unlock(&ftrace_sysctl_lock);
return ret;
}
}
#ifdef CONFIG_FUNCTION_RET_TRACER
+
+/* The callback that hooks the return of a function */
trace_function_return_t ftrace_function_return =
(trace_function_return_t)ftrace_stub;
-void register_ftrace_return(trace_function_return_t func)
+
+int register_ftrace_return(trace_function_return_t func)
{
+ int ret = 0;
+
+ mutex_lock(&ftrace_sysctl_lock);
+
+ /*
+ * Don't launch return tracing if normal function
+ * tracing is already running.
+ */
+ if (ftrace_trace_function != ftrace_stub) {
+ ret = -EBUSY;
+ goto out;
+ }
+
+ ftrace_tracing_type = FTRACE_TYPE_RETURN;
ftrace_function_return = func;
+ ftrace_startup();
+
+out:
+ mutex_unlock(&ftrace_sysctl_lock);
+ return ret;
}
void unregister_ftrace_return(void)
{
+ mutex_lock(&ftrace_sysctl_lock);
+
ftrace_function_return = (trace_function_return_t)ftrace_stub;
+ ftrace_shutdown();
+ /* Restore normal tracing type */
+ ftrace_tracing_type = FTRACE_TYPE_ENTER;
+
+ mutex_unlock(&ftrace_sysctl_lock);
}
#endif
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff