#include <trace/syscall.h>
+#include <trace/events/syscalls.h>
+#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/ftrace.h>
+#include <linux/perf_event.h>
#include <asm/syscall.h>
#include "trace_output.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);
+static DECLARE_BITMAP(enabled_enter_syscalls, NR_syscalls);
+static DECLARE_BITMAP(enabled_exit_syscalls, NR_syscalls);
-/* Option to display the parameters types */
-enum {
- TRACE_SYSCALLS_OPT_TYPES = 0x1,
-};
+extern unsigned long __start_syscalls_metadata[];
+extern unsigned long __stop_syscalls_metadata[];
-static struct tracer_opt syscalls_opts[] = {
- { TRACER_OPT(syscall_arg_type, TRACE_SYSCALLS_OPT_TYPES) },
- { }
-};
+static struct syscall_metadata **syscalls_metadata;
-static struct tracer_flags syscalls_flags = {
- .val = 0, /* By default: no parameters types */
- .opts = syscalls_opts
-};
+static struct syscall_metadata *find_syscall_meta(unsigned long syscall)
+{
+ struct syscall_metadata *start;
+ struct syscall_metadata *stop;
+ char str[KSYM_SYMBOL_LEN];
+
+
+ start = (struct syscall_metadata *)__start_syscalls_metadata;
+ stop = (struct syscall_metadata *)__stop_syscalls_metadata;
+ kallsyms_lookup(syscall, NULL, NULL, NULL, str);
+
+ for ( ; start < stop; start++) {
+ /*
+ * Only compare after the "sys" prefix. Archs that use
+ * syscall wrappers may have syscalls symbols aliases prefixed
+ * with "SyS" instead of "sys", leading to an unwanted
+ * mismatch.
+ */
+ if (start->name && !strcmp(start->name + 3, str + 3))
+ return start;
+ }
+ return NULL;
+}
+
+static struct syscall_metadata *syscall_nr_to_meta(int nr)
+{
+ if (!syscalls_metadata || nr >= NR_syscalls || nr < 0)
+ return NULL;
+
+ return syscalls_metadata[nr];
+}
enum print_line_t
print_syscall_enter(struct trace_iterator *iter, int flags)
if (!entry)
goto end;
- if (entry->enter_id != ent->type) {
+ if (entry->enter_event->id != ent->type) {
WARN_ON_ONCE(1);
goto end;
}
for (i = 0; i < entry->nb_args; i++) {
/* parameter types */
- if (syscalls_flags.val & TRACE_SYSCALLS_OPT_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],
+ ret = trace_seq_printf(s, "%s: %lx%s", entry->args[i],
trace->args[i],
- i == entry->nb_args - 1 ? ")" : ",");
+ 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:
- trace_seq_printf(s, "\n");
+ ret = trace_seq_putc(s, '\n');
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+
return TRACE_TYPE_HANDLED;
}
return TRACE_TYPE_HANDLED;
}
- if (entry->exit_id != ent->type) {
+ if (entry->exit_event->id != ent->type) {
WARN_ON_ONCE(1);
return TRACE_TYPE_UNHANDLED;
}
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), is_signed_type(type)
+
+static
+int __set_enter_print_fmt(struct syscall_metadata *entry, char *buf, int len)
+{
+ int i;
+ int pos = 0;
+
+ /* When len=0, we just calculate the needed length */
+#define LEN_OR_ZERO (len ? len - pos : 0)
+
+ pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
+ for (i = 0; i < entry->nb_args; i++) {
+ pos += snprintf(buf + pos, LEN_OR_ZERO, "%s: 0x%%0%zulx%s",
+ entry->args[i], sizeof(unsigned long),
+ i == entry->nb_args - 1 ? "" : ", ");
+ }
+ pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
+
+ for (i = 0; i < entry->nb_args; i++) {
+ pos += snprintf(buf + pos, LEN_OR_ZERO,
+ ", ((unsigned long)(REC->%s))", entry->args[i]);
+ }
+
+#undef LEN_OR_ZERO
+
+ /* return the length of print_fmt */
+ return pos;
+}
+
+static int set_syscall_print_fmt(struct ftrace_event_call *call)
+{
+ char *print_fmt;
+ int len;
+ struct syscall_metadata *entry = call->data;
+
+ if (entry->enter_event != call) {
+ call->print_fmt = "\"0x%lx\", REC->ret";
+ return 0;
+ }
+
+ /* First: called with 0 length to calculate the needed length */
+ len = __set_enter_print_fmt(entry, NULL, 0);
+
+ print_fmt = kmalloc(len + 1, GFP_KERNEL);
+ if (!print_fmt)
+ return -ENOMEM;
+
+ /* Second: actually write the @print_fmt */
+ __set_enter_print_fmt(entry, print_fmt, len + 1);
+ call->print_fmt = print_fmt;
+
+ return 0;
+}
+
+static void free_syscall_print_fmt(struct ftrace_event_call *call)
+{
+ struct syscall_metadata *entry = call->data;
+
+ if (entry->enter_event == call)
+ kfree(call->print_fmt);
+}
+
+int syscall_enter_define_fields(struct ftrace_event_call *call)
+{
+ struct syscall_trace_enter trace;
+ struct syscall_metadata *meta = call->data;
+ int ret;
+ int i;
+ int offset = offsetof(typeof(trace), args);
+
+ ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER);
+ if (ret)
+ return ret;
+
+ for (i = 0; i < meta->nb_args; i++) {
+ ret = trace_define_field(call, meta->types[i],
+ 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_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER);
+ if (ret)
+ return ret;
+
+ ret = trace_define_field(call, SYSCALL_FIELD(long, ret),
+ 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;
+ struct ring_buffer *buffer;
int size;
int syscall_nr;
syscall_nr = syscall_get_nr(current, regs);
+ if (syscall_nr < 0)
+ return;
if (!test_bit(syscall_nr, enabled_enter_syscalls))
return;
size = sizeof(*entry) + sizeof(unsigned long) * sys_data->nb_args;
- event = trace_current_buffer_lock_reserve(sys_data->enter_id, size,
- 0, 0);
+ event = trace_current_buffer_lock_reserve(&buffer,
+ sys_data->enter_event->id, size, 0, 0);
if (!event)
return;
entry->nr = syscall_nr;
syscall_get_arguments(current, regs, 0, sys_data->nb_args, entry->args);
- trace_current_buffer_unlock_commit(event, 0, 0);
- trace_wake_up();
+ if (!filter_current_check_discard(buffer, sys_data->enter_event,
+ entry, event))
+ trace_current_buffer_unlock_commit(buffer, 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;
+ struct ring_buffer *buffer;
int syscall_nr;
syscall_nr = syscall_get_nr(current, regs);
+ if (syscall_nr < 0)
+ return;
if (!test_bit(syscall_nr, enabled_exit_syscalls))
return;
if (!sys_data)
return;
- event = trace_current_buffer_lock_reserve(sys_data->exit_id,
- sizeof(*entry), 0, 0);
+ event = trace_current_buffer_lock_reserve(&buffer,
+ sys_data->exit_event->id, sizeof(*entry), 0, 0);
if (!event)
return;
entry->nr = syscall_nr;
entry->ret = syscall_get_return_value(current, regs);
- trace_current_buffer_unlock_commit(event, 0, 0);
- trace_wake_up();
+ if (!filter_current_check_discard(buffer, sys_data->exit_event,
+ entry, event))
+ trace_current_buffer_unlock_commit(buffer, event, 0, 0);
}
-int reg_event_syscall_enter(void *ptr)
+int reg_event_syscall_enter(struct ftrace_event_call *call)
{
int ret = 0;
int num;
- char *name;
- name = (char *)ptr;
- num = syscall_name_to_nr(name);
- if (num < 0 || num >= FTRACE_SYSCALL_MAX)
+ num = ((struct syscall_metadata *)call->data)->syscall_nr;
+ if (num < 0 || num >= NR_syscalls)
return -ENOSYS;
mutex_lock(&syscall_trace_lock);
if (!sys_refcount_enter)
- ret = register_trace_syscall_enter(ftrace_syscall_enter);
- if (ret) {
- pr_info("event trace: Could not activate"
- "syscall entry trace point");
- } else {
+ ret = register_trace_sys_enter(ftrace_syscall_enter);
+ if (!ret) {
set_bit(num, enabled_enter_syscalls);
sys_refcount_enter++;
}
return ret;
}
-void unreg_event_syscall_enter(void *ptr)
+void unreg_event_syscall_enter(struct ftrace_event_call *call)
{
int num;
- char *name;
- name = (char *)ptr;
- num = syscall_name_to_nr(name);
- if (num < 0 || num >= FTRACE_SYSCALL_MAX)
+ num = ((struct syscall_metadata *)call->data)->syscall_nr;
+ if (num < 0 || num >= NR_syscalls)
return;
mutex_lock(&syscall_trace_lock);
sys_refcount_enter--;
clear_bit(num, enabled_enter_syscalls);
if (!sys_refcount_enter)
- unregister_trace_syscall_enter(ftrace_syscall_enter);
+ unregister_trace_sys_enter(ftrace_syscall_enter);
mutex_unlock(&syscall_trace_lock);
}
-int reg_event_syscall_exit(void *ptr)
+int reg_event_syscall_exit(struct ftrace_event_call *call)
{
int ret = 0;
int num;
- char *name;
- name = (char *)ptr;
- num = syscall_name_to_nr(name);
- if (num < 0 || num >= FTRACE_SYSCALL_MAX)
+ num = ((struct syscall_metadata *)call->data)->syscall_nr;
+ if (num < 0 || num >= NR_syscalls)
return -ENOSYS;
mutex_lock(&syscall_trace_lock);
if (!sys_refcount_exit)
- ret = register_trace_syscall_exit(ftrace_syscall_exit);
- if (ret) {
- pr_info("event trace: Could not activate"
- "syscall exit trace point");
- } else {
+ ret = register_trace_sys_exit(ftrace_syscall_exit);
+ if (!ret) {
set_bit(num, enabled_exit_syscalls);
sys_refcount_exit++;
}
return ret;
}
-void unreg_event_syscall_exit(void *ptr)
+void unreg_event_syscall_exit(struct ftrace_event_call *call)
{
int num;
- char *name;
- name = (char *)ptr;
- num = syscall_name_to_nr(name);
- if (num < 0 || num >= FTRACE_SYSCALL_MAX)
+ num = ((struct syscall_metadata *)call->data)->syscall_nr;
+ if (num < 0 || num >= NR_syscalls)
return;
mutex_lock(&syscall_trace_lock);
sys_refcount_exit--;
clear_bit(num, enabled_exit_syscalls);
if (!sys_refcount_exit)
- unregister_trace_syscall_exit(ftrace_syscall_exit);
+ unregister_trace_sys_exit(ftrace_syscall_exit);
+ mutex_unlock(&syscall_trace_lock);
+}
+
+int init_syscall_trace(struct ftrace_event_call *call)
+{
+ int id;
+
+ if (set_syscall_print_fmt(call) < 0)
+ return -ENOMEM;
+
+ id = trace_event_raw_init(call);
+
+ if (id < 0) {
+ free_syscall_print_fmt(call);
+ return id;
+ }
+
+ return id;
+}
+
+unsigned long __init arch_syscall_addr(int nr)
+{
+ return (unsigned long)sys_call_table[nr];
+}
+
+int __init init_ftrace_syscalls(void)
+{
+ struct syscall_metadata *meta;
+ unsigned long addr;
+ int i;
+
+ syscalls_metadata = kzalloc(sizeof(*syscalls_metadata) *
+ NR_syscalls, GFP_KERNEL);
+ if (!syscalls_metadata) {
+ WARN_ON(1);
+ return -ENOMEM;
+ }
+
+ for (i = 0; i < NR_syscalls; i++) {
+ addr = arch_syscall_addr(i);
+ meta = find_syscall_meta(addr);
+ if (!meta)
+ continue;
+
+ meta->syscall_nr = i;
+ syscalls_metadata[i] = meta;
+ }
+
+ return 0;
+}
+core_initcall(init_ftrace_syscalls);
+
+#ifdef CONFIG_PERF_EVENTS
+
+static DECLARE_BITMAP(enabled_perf_enter_syscalls, NR_syscalls);
+static DECLARE_BITMAP(enabled_perf_exit_syscalls, NR_syscalls);
+static int sys_perf_refcount_enter;
+static int sys_perf_refcount_exit;
+
+static void perf_syscall_enter(struct pt_regs *regs, long id)
+{
+ struct syscall_metadata *sys_data;
+ struct syscall_trace_enter *rec;
+ unsigned long flags;
+ int syscall_nr;
+ int rctx;
+ int size;
+
+ syscall_nr = syscall_get_nr(current, regs);
+ if (!test_bit(syscall_nr, enabled_perf_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);
+
+ if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
+ "perf buffer not large enough"))
+ return;
+
+ rec = (struct syscall_trace_enter *)perf_trace_buf_prepare(size,
+ sys_data->enter_event->id, &rctx, &flags);
+ if (!rec)
+ return;
+
+ rec->nr = syscall_nr;
+ syscall_get_arguments(current, regs, 0, sys_data->nb_args,
+ (unsigned long *)&rec->args);
+ perf_trace_buf_submit(rec, size, rctx, 0, 1, flags, regs);
+}
+
+int perf_sysenter_enable(struct ftrace_event_call *call)
+{
+ int ret = 0;
+ int num;
+
+ num = ((struct syscall_metadata *)call->data)->syscall_nr;
+
+ mutex_lock(&syscall_trace_lock);
+ if (!sys_perf_refcount_enter)
+ ret = register_trace_sys_enter(perf_syscall_enter);
+ if (ret) {
+ pr_info("event trace: Could not activate"
+ "syscall entry trace point");
+ } else {
+ set_bit(num, enabled_perf_enter_syscalls);
+ sys_perf_refcount_enter++;
+ }
+ mutex_unlock(&syscall_trace_lock);
+ return ret;
+}
+
+void perf_sysenter_disable(struct ftrace_event_call *call)
+{
+ int num;
+
+ num = ((struct syscall_metadata *)call->data)->syscall_nr;
+
+ mutex_lock(&syscall_trace_lock);
+ sys_perf_refcount_enter--;
+ clear_bit(num, enabled_perf_enter_syscalls);
+ if (!sys_perf_refcount_enter)
+ unregister_trace_sys_enter(perf_syscall_enter);
+ mutex_unlock(&syscall_trace_lock);
+}
+
+static void perf_syscall_exit(struct pt_regs *regs, long ret)
+{
+ struct syscall_metadata *sys_data;
+ struct syscall_trace_exit *rec;
+ unsigned long flags;
+ int syscall_nr;
+ int rctx;
+ int size;
+
+ syscall_nr = syscall_get_nr(current, regs);
+ if (!test_bit(syscall_nr, enabled_perf_exit_syscalls))
+ return;
+
+ sys_data = syscall_nr_to_meta(syscall_nr);
+ if (!sys_data)
+ return;
+
+ /* We can probably do that at build time */
+ size = ALIGN(sizeof(*rec) + sizeof(u32), sizeof(u64));
+ size -= sizeof(u32);
+
+ /*
+ * Impossible, but be paranoid with the future
+ * How to put this check outside runtime?
+ */
+ if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
+ "exit event has grown above perf buffer size"))
+ return;
+
+ rec = (struct syscall_trace_exit *)perf_trace_buf_prepare(size,
+ sys_data->exit_event->id, &rctx, &flags);
+ if (!rec)
+ return;
+
+ rec->nr = syscall_nr;
+ rec->ret = syscall_get_return_value(current, regs);
+
+ perf_trace_buf_submit(rec, size, rctx, 0, 1, flags, regs);
+}
+
+int perf_sysexit_enable(struct ftrace_event_call *call)
+{
+ int ret = 0;
+ int num;
+
+ num = ((struct syscall_metadata *)call->data)->syscall_nr;
+
+ mutex_lock(&syscall_trace_lock);
+ if (!sys_perf_refcount_exit)
+ ret = register_trace_sys_exit(perf_syscall_exit);
+ if (ret) {
+ pr_info("event trace: Could not activate"
+ "syscall exit trace point");
+ } else {
+ set_bit(num, enabled_perf_exit_syscalls);
+ sys_perf_refcount_exit++;
+ }
+ mutex_unlock(&syscall_trace_lock);
+ return ret;
+}
+
+void perf_sysexit_disable(struct ftrace_event_call *call)
+{
+ int num;
+
+ num = ((struct syscall_metadata *)call->data)->syscall_nr;
+
+ mutex_lock(&syscall_trace_lock);
+ sys_perf_refcount_exit--;
+ clear_bit(num, enabled_perf_exit_syscalls);
+ if (!sys_perf_refcount_exit)
+ unregister_trace_sys_exit(perf_syscall_exit);
mutex_unlock(&syscall_trace_lock);
}
-struct trace_event event_syscall_enter = {
- .trace = print_syscall_enter,
-};
+#endif /* CONFIG_PERF_EVENTS */
-struct trace_event event_syscall_exit = {
- .trace = print_syscall_exit,
-};