linux/kernel/trace/trace_syscalls.c
Masami Hiramatsu bd1a5c849b tracing: Ftrace dynamic ftrace_event_call support
Add dynamic ftrace_event_call support to ftrace. Trace engines can add
new ftrace_event_call to ftrace on the fly. Each operator function of
the call takes an ftrace_event_call data structure as an argument,
because these functions may be shared among several ftrace_event_calls.

Changes from v13:
 - Define remove_subsystem_dir() always (revirt a2ca5e03), because
   trace_remove_event_call() uses it.
 - Modify syscall tracer because of ftrace_event_call change.

[fweisbec@gmail.com: Fixed conflict against latest tracing/core]

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Przemysław Pawełczyk <przemyslaw@pawelczyk.it>
Cc: Roland McGrath <roland@redhat.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Vegard Nossum <vegard.nossum@gmail.com>
LKML-Reference: <20090813203453.31965.71901.stgit@localhost.localdomain>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-08-27 00:46:40 +02:00

516 lines
12 KiB
C

#include <trace/syscall.h>
#include <trace/events/syscalls.h>
#include <linux/kernel.h>
#include <linux/ftrace.h>
#include <linux/perf_counter.h>
#include <asm/syscall.h>
#include "trace_output.h"
#include "trace.h"
static DEFINE_MUTEX(syscall_trace_lock);
static int sys_refcount_enter;
static int sys_refcount_exit;
static DECLARE_BITMAP(enabled_enter_syscalls, FTRACE_SYSCALL_MAX);
static DECLARE_BITMAP(enabled_exit_syscalls, FTRACE_SYSCALL_MAX);
enum print_line_t
print_syscall_enter(struct trace_iterator *iter, int flags)
{
struct trace_seq *s = &iter->seq;
struct trace_entry *ent = iter->ent;
struct syscall_trace_enter *trace;
struct syscall_metadata *entry;
int i, ret, syscall;
trace = (typeof(trace))ent;
syscall = trace->nr;
entry = syscall_nr_to_meta(syscall);
if (!entry)
goto end;
if (entry->enter_id != ent->type) {
WARN_ON_ONCE(1);
goto end;
}
ret = trace_seq_printf(s, "%s(", entry->name);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
for (i = 0; i < entry->nb_args; i++) {
/* parameter types */
if (trace_flags & TRACE_ITER_VERBOSE) {
ret = trace_seq_printf(s, "%s ", entry->types[i]);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
}
/* parameter values */
ret = trace_seq_printf(s, "%s: %lx%s", entry->args[i],
trace->args[i],
i == entry->nb_args - 1 ? "" : ", ");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
}
ret = trace_seq_putc(s, ')');
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
end:
ret = trace_seq_putc(s, '\n');
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
return TRACE_TYPE_HANDLED;
}
enum print_line_t
print_syscall_exit(struct trace_iterator *iter, int flags)
{
struct trace_seq *s = &iter->seq;
struct trace_entry *ent = iter->ent;
struct syscall_trace_exit *trace;
int syscall;
struct syscall_metadata *entry;
int ret;
trace = (typeof(trace))ent;
syscall = trace->nr;
entry = syscall_nr_to_meta(syscall);
if (!entry) {
trace_seq_printf(s, "\n");
return TRACE_TYPE_HANDLED;
}
if (entry->exit_id != ent->type) {
WARN_ON_ONCE(1);
return TRACE_TYPE_UNHANDLED;
}
ret = trace_seq_printf(s, "%s -> 0x%lx\n", entry->name,
trace->ret);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
return TRACE_TYPE_HANDLED;
}
extern char *__bad_type_size(void);
#define SYSCALL_FIELD(type, name) \
sizeof(type) != sizeof(trace.name) ? \
__bad_type_size() : \
#type, #name, offsetof(typeof(trace), name), sizeof(trace.name)
int syscall_enter_format(struct ftrace_event_call *call, struct trace_seq *s)
{
int i;
int nr;
int ret;
struct syscall_metadata *entry;
struct syscall_trace_enter trace;
int offset = offsetof(struct syscall_trace_enter, args);
nr = syscall_name_to_nr(call->data);
entry = syscall_nr_to_meta(nr);
if (!entry)
return 0;
ret = trace_seq_printf(s, "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n",
SYSCALL_FIELD(int, nr));
if (!ret)
return 0;
for (i = 0; i < entry->nb_args; i++) {
ret = trace_seq_printf(s, "\tfield:%s %s;", entry->types[i],
entry->args[i]);
if (!ret)
return 0;
ret = trace_seq_printf(s, "\toffset:%d;\tsize:%zu;\n", offset,
sizeof(unsigned long));
if (!ret)
return 0;
offset += sizeof(unsigned long);
}
trace_seq_puts(s, "\nprint fmt: \"");
for (i = 0; i < entry->nb_args; i++) {
ret = trace_seq_printf(s, "%s: 0x%%0%zulx%s", entry->args[i],
sizeof(unsigned long),
i == entry->nb_args - 1 ? "" : ", ");
if (!ret)
return 0;
}
trace_seq_putc(s, '"');
for (i = 0; i < entry->nb_args; i++) {
ret = trace_seq_printf(s, ", ((unsigned long)(REC->%s))",
entry->args[i]);
if (!ret)
return 0;
}
return trace_seq_putc(s, '\n');
}
int syscall_exit_format(struct ftrace_event_call *call, struct trace_seq *s)
{
int ret;
struct syscall_trace_exit trace;
ret = trace_seq_printf(s,
"\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
"\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n",
SYSCALL_FIELD(int, nr),
SYSCALL_FIELD(unsigned long, ret));
if (!ret)
return 0;
return trace_seq_printf(s, "\nprint fmt: \"0x%%lx\", REC->ret\n");
}
int syscall_enter_define_fields(struct ftrace_event_call *call)
{
struct syscall_trace_enter trace;
struct syscall_metadata *meta;
int ret;
int nr;
int i;
int offset = offsetof(typeof(trace), args);
nr = syscall_name_to_nr(call->data);
meta = syscall_nr_to_meta(nr);
if (!meta)
return 0;
ret = trace_define_common_fields(call);
if (ret)
return ret;
for (i = 0; i < meta->nb_args; i++) {
ret = trace_define_field(call, (char *)meta->types[i],
(char *)meta->args[i], offset,
sizeof(unsigned long), 0,
FILTER_OTHER);
offset += sizeof(unsigned long);
}
return ret;
}
int syscall_exit_define_fields(struct ftrace_event_call *call)
{
struct syscall_trace_exit trace;
int ret;
ret = trace_define_common_fields(call);
if (ret)
return ret;
ret = trace_define_field(call, SYSCALL_FIELD(unsigned long, ret), 0,
FILTER_OTHER);
return ret;
}
void ftrace_syscall_enter(struct pt_regs *regs, long id)
{
struct syscall_trace_enter *entry;
struct syscall_metadata *sys_data;
struct ring_buffer_event *event;
int size;
int syscall_nr;
syscall_nr = syscall_get_nr(current, regs);
if (!test_bit(syscall_nr, enabled_enter_syscalls))
return;
sys_data = syscall_nr_to_meta(syscall_nr);
if (!sys_data)
return;
size = sizeof(*entry) + sizeof(unsigned long) * sys_data->nb_args;
event = trace_current_buffer_lock_reserve(sys_data->enter_id, size,
0, 0);
if (!event)
return;
entry = ring_buffer_event_data(event);
entry->nr = syscall_nr;
syscall_get_arguments(current, regs, 0, sys_data->nb_args, entry->args);
if (!filter_current_check_discard(sys_data->enter_event, entry, event))
trace_current_buffer_unlock_commit(event, 0, 0);
}
void ftrace_syscall_exit(struct pt_regs *regs, long ret)
{
struct syscall_trace_exit *entry;
struct syscall_metadata *sys_data;
struct ring_buffer_event *event;
int syscall_nr;
syscall_nr = syscall_get_nr(current, regs);
if (!test_bit(syscall_nr, enabled_exit_syscalls))
return;
sys_data = syscall_nr_to_meta(syscall_nr);
if (!sys_data)
return;
event = trace_current_buffer_lock_reserve(sys_data->exit_id,
sizeof(*entry), 0, 0);
if (!event)
return;
entry = ring_buffer_event_data(event);
entry->nr = syscall_nr;
entry->ret = syscall_get_return_value(current, regs);
if (!filter_current_check_discard(sys_data->exit_event, entry, event))
trace_current_buffer_unlock_commit(event, 0, 0);
}
int reg_event_syscall_enter(struct ftrace_event_call *call)
{
int ret = 0;
int num;
char *name;
name = (char *)call->data;
num = syscall_name_to_nr(name);
if (num < 0 || num >= FTRACE_SYSCALL_MAX)
return -ENOSYS;
mutex_lock(&syscall_trace_lock);
if (!sys_refcount_enter)
ret = register_trace_sys_enter(ftrace_syscall_enter);
if (ret) {
pr_info("event trace: Could not activate"
"syscall entry trace point");
} else {
set_bit(num, enabled_enter_syscalls);
sys_refcount_enter++;
}
mutex_unlock(&syscall_trace_lock);
return ret;
}
void unreg_event_syscall_enter(struct ftrace_event_call *call)
{
int num;
char *name;
name = (char *)call->data;
num = syscall_name_to_nr(name);
if (num < 0 || num >= FTRACE_SYSCALL_MAX)
return;
mutex_lock(&syscall_trace_lock);
sys_refcount_enter--;
clear_bit(num, enabled_enter_syscalls);
if (!sys_refcount_enter)
unregister_trace_sys_enter(ftrace_syscall_enter);
mutex_unlock(&syscall_trace_lock);
}
int reg_event_syscall_exit(struct ftrace_event_call *call)
{
int ret = 0;
int num;
char *name;
name = (char *)call->data;
num = syscall_name_to_nr(name);
if (num < 0 || num >= FTRACE_SYSCALL_MAX)
return -ENOSYS;
mutex_lock(&syscall_trace_lock);
if (!sys_refcount_exit)
ret = register_trace_sys_exit(ftrace_syscall_exit);
if (ret) {
pr_info("event trace: Could not activate"
"syscall exit trace point");
} else {
set_bit(num, enabled_exit_syscalls);
sys_refcount_exit++;
}
mutex_unlock(&syscall_trace_lock);
return ret;
}
void unreg_event_syscall_exit(struct ftrace_event_call *call)
{
int num;
char *name;
name = (char *)call->data;
num = syscall_name_to_nr(name);
if (num < 0 || num >= FTRACE_SYSCALL_MAX)
return;
mutex_lock(&syscall_trace_lock);
sys_refcount_exit--;
clear_bit(num, enabled_exit_syscalls);
if (!sys_refcount_exit)
unregister_trace_sys_exit(ftrace_syscall_exit);
mutex_unlock(&syscall_trace_lock);
}
struct trace_event event_syscall_enter = {
.trace = print_syscall_enter,
};
struct trace_event event_syscall_exit = {
.trace = print_syscall_exit,
};
#ifdef CONFIG_EVENT_PROFILE
static DECLARE_BITMAP(enabled_prof_enter_syscalls, FTRACE_SYSCALL_MAX);
static DECLARE_BITMAP(enabled_prof_exit_syscalls, FTRACE_SYSCALL_MAX);
static int sys_prof_refcount_enter;
static int sys_prof_refcount_exit;
static void prof_syscall_enter(struct pt_regs *regs, long id)
{
struct syscall_trace_enter *rec;
struct syscall_metadata *sys_data;
int syscall_nr;
int size;
syscall_nr = syscall_get_nr(current, regs);
if (!test_bit(syscall_nr, enabled_prof_enter_syscalls))
return;
sys_data = syscall_nr_to_meta(syscall_nr);
if (!sys_data)
return;
/* get the size after alignment with the u32 buffer size field */
size = sizeof(unsigned long) * sys_data->nb_args + sizeof(*rec);
size = ALIGN(size + sizeof(u32), sizeof(u64));
size -= sizeof(u32);
do {
char raw_data[size];
/* zero the dead bytes from align to not leak stack to user */
*(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
rec = (struct syscall_trace_enter *) raw_data;
tracing_generic_entry_update(&rec->ent, 0, 0);
rec->ent.type = sys_data->enter_id;
rec->nr = syscall_nr;
syscall_get_arguments(current, regs, 0, sys_data->nb_args,
(unsigned long *)&rec->args);
perf_tpcounter_event(sys_data->enter_id, 0, 1, rec, size);
} while(0);
}
int reg_prof_syscall_enter(char *name)
{
int ret = 0;
int num;
num = syscall_name_to_nr(name);
if (num < 0 || num >= FTRACE_SYSCALL_MAX)
return -ENOSYS;
mutex_lock(&syscall_trace_lock);
if (!sys_prof_refcount_enter)
ret = register_trace_sys_enter(prof_syscall_enter);
if (ret) {
pr_info("event trace: Could not activate"
"syscall entry trace point");
} else {
set_bit(num, enabled_prof_enter_syscalls);
sys_prof_refcount_enter++;
}
mutex_unlock(&syscall_trace_lock);
return ret;
}
void unreg_prof_syscall_enter(char *name)
{
int num;
num = syscall_name_to_nr(name);
if (num < 0 || num >= FTRACE_SYSCALL_MAX)
return;
mutex_lock(&syscall_trace_lock);
sys_prof_refcount_enter--;
clear_bit(num, enabled_prof_enter_syscalls);
if (!sys_prof_refcount_enter)
unregister_trace_sys_enter(prof_syscall_enter);
mutex_unlock(&syscall_trace_lock);
}
static void prof_syscall_exit(struct pt_regs *regs, long ret)
{
struct syscall_metadata *sys_data;
struct syscall_trace_exit rec;
int syscall_nr;
syscall_nr = syscall_get_nr(current, regs);
if (!test_bit(syscall_nr, enabled_prof_exit_syscalls))
return;
sys_data = syscall_nr_to_meta(syscall_nr);
if (!sys_data)
return;
tracing_generic_entry_update(&rec.ent, 0, 0);
rec.ent.type = sys_data->exit_id;
rec.nr = syscall_nr;
rec.ret = syscall_get_return_value(current, regs);
perf_tpcounter_event(sys_data->exit_id, 0, 1, &rec, sizeof(rec));
}
int reg_prof_syscall_exit(char *name)
{
int ret = 0;
int num;
num = syscall_name_to_nr(name);
if (num < 0 || num >= FTRACE_SYSCALL_MAX)
return -ENOSYS;
mutex_lock(&syscall_trace_lock);
if (!sys_prof_refcount_exit)
ret = register_trace_sys_exit(prof_syscall_exit);
if (ret) {
pr_info("event trace: Could not activate"
"syscall entry trace point");
} else {
set_bit(num, enabled_prof_exit_syscalls);
sys_prof_refcount_exit++;
}
mutex_unlock(&syscall_trace_lock);
return ret;
}
void unreg_prof_syscall_exit(char *name)
{
int num;
num = syscall_name_to_nr(name);
if (num < 0 || num >= FTRACE_SYSCALL_MAX)
return;
mutex_lock(&syscall_trace_lock);
sys_prof_refcount_exit--;
clear_bit(num, enabled_prof_exit_syscalls);
if (!sys_prof_refcount_exit)
unregister_trace_sys_exit(prof_syscall_exit);
mutex_unlock(&syscall_trace_lock);
}
#endif