1 files changed, 431 insertions, 99 deletions

diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 5e579645ac86..9fbce6c9d2e1 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -1,30 +1,18 @@
 #include <trace/syscall.h>
+#include <trace/events/syscalls.h>
 #include <linux/kernel.h>
+#include <linux/ftrace.h>
+#include <linux/perf_event.h>
 #include <asm/syscall.h>
 
 #include "trace_output.h"
 #include "trace.h"
 
-/* Keep a counter of the syscall tracing users */
-static int refcount;
-
-/* Prevent from races on thread flags toggling */
 static DEFINE_MUTEX(syscall_trace_lock);
-
-/* Option to display the parameters types */
-enum {
-        TRACE_SYSCALLS_OPT_TYPES = 0x1,
-};
-
-static struct tracer_opt syscalls_opts[] = {
-        { TRACER_OPT(syscall_arg_type, TRACE_SYSCALLS_OPT_TYPES) },
-        { }
-};
-
-static struct tracer_flags syscalls_flags = {
-        .val = 0, /* By default: no parameters types */
-        .opts = syscalls_opts
-};
+static int sys_refcount_enter;
+static int sys_refcount_exit;
+static DECLARE_BITMAP(enabled_enter_syscalls, NR_syscalls);
+static DECLARE_BITMAP(enabled_exit_syscalls, NR_syscalls);
 
 enum print_line_t
 print_syscall_enter(struct trace_iterator *iter, int flags)
@@ -35,35 +23,46 @@ print_syscall_enter(struct trace_iterator *iter, int flags)
         struct syscall_metadata *entry;
         int i, ret, syscall;
 
-        trace_assign_type(trace, ent);
-
+        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 (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;
 }
 
@@ -77,16 +76,20 @@ print_syscall_exit(struct trace_iterator *iter, int flags)
         struct syscall_metadata *entry;
         int ret;
 
-        trace_assign_type(trace, ent);
-
+        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)
@@ -95,62 +98,140 @@ print_syscall_exit(struct trace_iterator *iter, int flags)
         return TRACE_TYPE_HANDLED;
 }
 
-void start_ftrace_syscalls(void)
+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)
 {
-        unsigned long flags;
-        struct task_struct *g, *t;
+        int i;
+        int nr;
+        int ret;
+        struct syscall_metadata *entry;
+        struct syscall_trace_enter trace;
+        int offset = offsetof(struct syscall_trace_enter, args);
 
-        mutex_lock(&syscall_trace_lock);
+        nr = syscall_name_to_nr(call->data);
+        entry = syscall_nr_to_meta(nr);
 
-        /* Don't enable the flag on the tasks twice */
-        if (++refcount != 1)
-                goto unlock;
+        if (!entry)
+                return 0;
 
-        arch_init_ftrace_syscalls();
-        read_lock_irqsave(&tasklist_lock, flags);
+        ret = trace_seq_printf(s, "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n",
+                               SYSCALL_FIELD(int, nr));
+        if (!ret)
+                return 0;
 
-        do_each_thread(g, t) {
-                set_tsk_thread_flag(t, TIF_SYSCALL_FTRACE);
-        } while_each_thread(g, t);
+        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);
+        }
 
-        read_unlock_irqrestore(&tasklist_lock, flags);
+        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, '"');
 
-unlock:
-        mutex_unlock(&syscall_trace_lock);
+        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');
 }
 
-void stop_ftrace_syscalls(void)
+int syscall_exit_format(struct ftrace_event_call *call, struct trace_seq *s)
 {
-        unsigned long flags;
-        struct task_struct *g, *t;
+        int ret;
+        struct syscall_trace_exit trace;
 
-        mutex_lock(&syscall_trace_lock);
+        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;
 
-        /* There are perhaps still some users */
-        if (--refcount)
-                goto unlock;
+        return trace_seq_printf(s, "\nprint fmt: \"0x%%lx\", REC->ret\n");
+}
 
-        read_lock_irqsave(&tasklist_lock, flags);
+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, meta->types[i],
+                                         meta->args[i], offset,
+                                         sizeof(unsigned long), 0,
+                                         FILTER_OTHER);
+                offset += sizeof(unsigned long);
+        }
 
-        do_each_thread(g, t) {
-                clear_tsk_thread_flag(t, TIF_SYSCALL_FTRACE);
-        } while_each_thread(g, t);
+        return ret;
+}
 
-        read_unlock_irqrestore(&tasklist_lock, flags);
+int syscall_exit_define_fields(struct ftrace_event_call *call)
+{
+        struct syscall_trace_exit trace;
+        int ret;
 
-unlock:
-        mutex_unlock(&syscall_trace_lock);
+        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)
+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;
 
         sys_data = syscall_nr_to_meta(syscall_nr);
         if (!sys_data)
@@ -158,8 +239,8 @@ void ftrace_syscall_enter(struct pt_regs *regs)
 
         size = sizeof(*entry) + sizeof(unsigned long) * sys_data->nb_args;
 
-        event = trace_current_buffer_lock_reserve(TRACE_SYSCALL_ENTER, size,
-                                                        0, 0);
+        event = trace_current_buffer_lock_reserve(&buffer, sys_data->enter_id,
+                                                  size, 0, 0);
         if (!event)
                 return;
 
@@ -167,24 +248,30 @@ void ftrace_syscall_enter(struct pt_regs *regs)
         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)
+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;
 
         sys_data = syscall_nr_to_meta(syscall_nr);
         if (!sys_data)
                 return;
 
-        event = trace_current_buffer_lock_reserve(TRACE_SYSCALL_EXIT,
+        event = trace_current_buffer_lock_reserve(&buffer, sys_data->exit_id,
                                 sizeof(*entry), 0, 0);
         if (!event)
                 return;
@@ -193,58 +280,303 @@ void ftrace_syscall_exit(struct pt_regs *regs)
         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);
 }
 
-static int init_syscall_tracer(struct trace_array *tr)
+int reg_event_syscall_enter(void *ptr)
 {
-        start_ftrace_syscalls();
+        int ret = 0;
+        int num;
+        char *name;
+
+        name = (char *)ptr;
+        num = syscall_name_to_nr(name);
+        if (num < 0 || num >= NR_syscalls)
+                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(void *ptr)
+{
+        int num;
+        char *name;
 
-        return 0;
+        name = (char *)ptr;
+        num = syscall_name_to_nr(name);
+        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_sys_enter(ftrace_syscall_enter);
+        mutex_unlock(&syscall_trace_lock);
 }
 
-static void reset_syscall_tracer(struct trace_array *tr)
+int reg_event_syscall_exit(void *ptr)
 {
-        stop_ftrace_syscalls();
-        tracing_reset_online_cpus(tr);
+        int ret = 0;
+        int num;
+        char *name;
+
+        name = (char *)ptr;
+        num = syscall_name_to_nr(name);
+        if (num < 0 || num >= NR_syscalls)
+                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;
 }
 
-static struct trace_event syscall_enter_event = {
-        .type           = TRACE_SYSCALL_ENTER,
-        .trace          = print_syscall_enter,
-};
+void unreg_event_syscall_exit(void *ptr)
+{
+        int num;
+        char *name;
+
+        name = (char *)ptr;
+        num = syscall_name_to_nr(name);
+        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_sys_exit(ftrace_syscall_exit);
+        mutex_unlock(&syscall_trace_lock);
+}
 
-static struct trace_event syscall_exit_event = {
-        .type           = TRACE_SYSCALL_EXIT,
-        .trace          = print_syscall_exit,
+struct trace_event event_syscall_enter = {
+        .trace                  = print_syscall_enter,
 };
 
-static struct tracer syscall_tracer __read_mostly = {
-        .name           = "syscall",
-        .init           = init_syscall_tracer,
-        .reset          = reset_syscall_tracer,
-        .flags          = &syscalls_flags,
+struct trace_event event_syscall_exit = {
+        .trace                  = print_syscall_exit,
 };
 
-__init int register_ftrace_syscalls(void)
+#ifdef CONFIG_EVENT_PROFILE
+
+static DECLARE_BITMAP(enabled_prof_enter_syscalls, NR_syscalls);
+static DECLARE_BITMAP(enabled_prof_exit_syscalls, NR_syscalls);
+static int sys_prof_refcount_enter;
+static int sys_prof_refcount_exit;
+
+static void prof_syscall_enter(struct pt_regs *regs, long id)
 {
-        int ret;
+        struct syscall_metadata *sys_data;
+        struct syscall_trace_enter *rec;
+        unsigned long flags;
+        char *raw_data;
+        int syscall_nr;
+        int size;
+        int cpu;
 
-        ret = register_ftrace_event(&syscall_enter_event);
-        if (!ret) {
-                printk(KERN_WARNING "event %d failed to register\n",
-                       syscall_enter_event.type);
-                WARN_ON_ONCE(1);
+        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);
+
+        if (WARN_ONCE(size > FTRACE_MAX_PROFILE_SIZE,
+                      "profile buffer not large enough"))
+                return;
+
+        /* Protect the per cpu buffer, begin the rcu read side */
+        local_irq_save(flags);
+
+        cpu = smp_processor_id();
+
+        if (in_nmi())
+                raw_data = rcu_dereference(trace_profile_buf_nmi);
+        else
+                raw_data = rcu_dereference(trace_profile_buf);
+
+        if (!raw_data)
+                goto end;
+
+        raw_data = per_cpu_ptr(raw_data, cpu);
+
+        /* 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_tp_event(sys_data->enter_id, 0, 1, rec, size);
+
+end:
+        local_irq_restore(flags);
+}
+
+int reg_prof_syscall_enter(char *name)
+{
+        int ret = 0;
+        int num;
+
+        num = syscall_name_to_nr(name);
+        if (num < 0 || num >= NR_syscalls)
+                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;
+}
 
-        ret = register_ftrace_event(&syscall_exit_event);
-        if (!ret) {
-                printk(KERN_WARNING "event %d failed to register\n",
-                       syscall_exit_event.type);
-                WARN_ON_ONCE(1);
+void unreg_prof_syscall_enter(char *name)
+{
+        int num;
+
+        num = syscall_name_to_nr(name);
+        if (num < 0 || num >= NR_syscalls)
+                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;
+        unsigned long flags;
+        int syscall_nr;
+        char *raw_data;
+        int size;
+        int cpu;
+
+        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;
+
+        /* 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 > FTRACE_MAX_PROFILE_SIZE,
+                "exit event has grown above profile buffer size"))
+                return;
+
+        /* Protect the per cpu buffer, begin the rcu read side */
+        local_irq_save(flags);
+        cpu = smp_processor_id();
+
+        if (in_nmi())
+                raw_data = rcu_dereference(trace_profile_buf_nmi);
+        else
+                raw_data = rcu_dereference(trace_profile_buf);
+
+        if (!raw_data)
+                goto end;
+
+        raw_data = per_cpu_ptr(raw_data, cpu);
+
+        /* zero the dead bytes from align to not leak stack to user */
+        *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
+
+        rec = (struct syscall_trace_exit *)raw_data;
+
+        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_tp_event(sys_data->exit_id, 0, 1, rec, size);
+
+end:
+        local_irq_restore(flags);
+}
+
+int reg_prof_syscall_exit(char *name)
+{
+        int ret = 0;
+        int num;
+
+        num = syscall_name_to_nr(name);
+        if (num < 0 || num >= NR_syscalls)
+                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 >= NR_syscalls)
+                return;
 
-        return register_tracer(&syscall_tracer);
+        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);
 }
-device_initcall(register_ftrace_syscalls);
+
+#endif
+
+