]> nv-tegra.nvidia Code Review - linux-2.6.git/blobdiff - kernel/trace/trace.c
Merge branch 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-2.6.git] / kernel / trace / trace.c
index 31118ae16f03faef7f3e5b0fe7301e9ae56fc3b6..06ba26747d7e223b44ee67935b9ea33ff25752f8 100644 (file)
@@ -313,7 +313,6 @@ static const char *trace_options[] = {
        "bin",
        "block",
        "stacktrace",
-       "sched-tree",
        "trace_printk",
        "ftrace_preempt",
        "branch",
@@ -1151,6 +1150,22 @@ void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
        __ftrace_trace_stack(tr->buffer, flags, skip, pc);
 }
 
+/**
+ * trace_dump_stack - record a stack back trace in the trace buffer
+ */
+void trace_dump_stack(void)
+{
+       unsigned long flags;
+
+       if (tracing_disabled || tracing_selftest_running)
+               return;
+
+       local_save_flags(flags);
+
+       /* skipping 3 traces, seems to get us at the caller of this function */
+       __ftrace_trace_stack(global_trace.buffer, flags, 3, preempt_count());
+}
+
 void
 ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc)
 {
@@ -2316,67 +2331,49 @@ static const struct file_operations tracing_cpumask_fops = {
        .write          = tracing_cpumask_write,
 };
 
-static ssize_t
-tracing_trace_options_read(struct file *filp, char __user *ubuf,
-                      size_t cnt, loff_t *ppos)
+static int tracing_trace_options_show(struct seq_file *m, void *v)
 {
        struct tracer_opt *trace_opts;
        u32 tracer_flags;
-       int len = 0;
-       char *buf;
-       int r = 0;
        int i;
 
-
-       /* calculate max size */
-       for (i = 0; trace_options[i]; i++) {
-               len += strlen(trace_options[i]);
-               len += 3; /* "no" and newline */
-       }
-
        mutex_lock(&trace_types_lock);
        tracer_flags = current_trace->flags->val;
        trace_opts = current_trace->flags->opts;
 
-       /*
-        * Increase the size with names of options specific
-        * of the current tracer.
-        */
-       for (i = 0; trace_opts[i].name; i++) {
-               len += strlen(trace_opts[i].name);
-               len += 3; /* "no" and newline */
-       }
-
-       /* +1 for \0 */
-       buf = kmalloc(len + 1, GFP_KERNEL);
-       if (!buf) {
-               mutex_unlock(&trace_types_lock);
-               return -ENOMEM;
-       }
-
        for (i = 0; trace_options[i]; i++) {
                if (trace_flags & (1 << i))
-                       r += sprintf(buf + r, "%s\n", trace_options[i]);
+                       seq_printf(m, "%s\n", trace_options[i]);
                else
-                       r += sprintf(buf + r, "no%s\n", trace_options[i]);
+                       seq_printf(m, "no%s\n", trace_options[i]);
        }
 
        for (i = 0; trace_opts[i].name; i++) {
                if (tracer_flags & trace_opts[i].bit)
-                       r += sprintf(buf + r, "%s\n",
-                               trace_opts[i].name);
+                       seq_printf(m, "%s\n", trace_opts[i].name);
                else
-                       r += sprintf(buf + r, "no%s\n",
-                               trace_opts[i].name);
+                       seq_printf(m, "no%s\n", trace_opts[i].name);
        }
        mutex_unlock(&trace_types_lock);
 
-       WARN_ON(r >= len + 1);
+       return 0;
+}
 
-       r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+static int __set_tracer_option(struct tracer *trace,
+                              struct tracer_flags *tracer_flags,
+                              struct tracer_opt *opts, int neg)
+{
+       int ret;
 
-       kfree(buf);
-       return r;
+       ret = trace->set_flag(tracer_flags->val, opts->bit, !neg);
+       if (ret)
+               return ret;
+
+       if (neg)
+               tracer_flags->val &= ~opts->bit;
+       else
+               tracer_flags->val |= opts->bit;
+       return 0;
 }
 
 /* Try to assign a tracer specific option */
@@ -2384,33 +2381,17 @@ static int set_tracer_option(struct tracer *trace, char *cmp, int neg)
 {
        struct tracer_flags *tracer_flags = trace->flags;
        struct tracer_opt *opts = NULL;
-       int ret = 0, i = 0;
-       int len;
+       int i;
 
        for (i = 0; tracer_flags->opts[i].name; i++) {
                opts = &tracer_flags->opts[i];
-               len = strlen(opts->name);
 
-               if (strncmp(cmp, opts->name, len) == 0) {
-                       ret = trace->set_flag(tracer_flags->val,
-                               opts->bit, !neg);
-                       break;
-               }
+               if (strcmp(cmp, opts->name) == 0)
+                       return __set_tracer_option(trace, trace->flags,
+                                                  opts, neg);
        }
-       /* Not found */
-       if (!tracer_flags->opts[i].name)
-               return -EINVAL;
-
-       /* Refused to handle */
-       if (ret)
-               return ret;
-
-       if (neg)
-               tracer_flags->val &= ~opts->bit;
-       else
-               tracer_flags->val |= opts->bit;
 
-       return 0;
+       return -EINVAL;
 }
 
 static void set_tracer_flags(unsigned int mask, int enabled)
@@ -2430,7 +2411,7 @@ tracing_trace_options_write(struct file *filp, const char __user *ubuf,
                        size_t cnt, loff_t *ppos)
 {
        char buf[64];
-       char *cmp = buf;
+       char *cmp;
        int neg = 0;
        int ret;
        int i;
@@ -2442,16 +2423,15 @@ tracing_trace_options_write(struct file *filp, const char __user *ubuf,
                return -EFAULT;
 
        buf[cnt] = 0;
+       cmp = strstrip(buf);
 
-       if (strncmp(buf, "no", 2) == 0) {
+       if (strncmp(cmp, "no", 2) == 0) {
                neg = 1;
                cmp += 2;
        }
 
        for (i = 0; trace_options[i]; i++) {
-               int len = strlen(trace_options[i]);
-
-               if (strncmp(cmp, trace_options[i], len) == 0) {
+               if (strcmp(cmp, trace_options[i]) == 0) {
                        set_tracer_flags(1 << i, !neg);
                        break;
                }
@@ -2471,9 +2451,18 @@ tracing_trace_options_write(struct file *filp, const char __user *ubuf,
        return cnt;
 }
 
+static int tracing_trace_options_open(struct inode *inode, struct file *file)
+{
+       if (tracing_disabled)
+               return -ENODEV;
+       return single_open(file, tracing_trace_options_show, NULL);
+}
+
 static const struct file_operations tracing_iter_fops = {
-       .open           = tracing_open_generic,
-       .read           = tracing_trace_options_read,
+       .open           = tracing_trace_options_open,
+       .read           = seq_read,
+       .llseek         = seq_lseek,
+       .release        = single_release,
        .write          = tracing_trace_options_write,
 };
 
@@ -3392,21 +3381,18 @@ tracing_mark_write(struct file *filp, const char __user *ubuf,
        return cnt;
 }
 
-static ssize_t tracing_clock_read(struct file *filp, char __user *ubuf,
-                                 size_t cnt, loff_t *ppos)
+static int tracing_clock_show(struct seq_file *m, void *v)
 {
-       char buf[64];
-       int bufiter = 0;
        int i;
 
        for (i = 0; i < ARRAY_SIZE(trace_clocks); i++)
-               bufiter += snprintf(buf + bufiter, sizeof(buf) - bufiter,
+               seq_printf(m,
                        "%s%s%s%s", i ? " " : "",
                        i == trace_clock_id ? "[" : "", trace_clocks[i].name,
                        i == trace_clock_id ? "]" : "");
-       bufiter += snprintf(buf + bufiter, sizeof(buf) - bufiter, "\n");
+       seq_putc(m, '\n');
 
-       return simple_read_from_buffer(ubuf, cnt, ppos, buf, bufiter);
+       return 0;
 }
 
 static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf,
@@ -3448,6 +3434,13 @@ static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf,
        return cnt;
 }
 
+static int tracing_clock_open(struct inode *inode, struct file *file)
+{
+       if (tracing_disabled)
+               return -ENODEV;
+       return single_open(file, tracing_clock_show, NULL);
+}
+
 static const struct file_operations tracing_max_lat_fops = {
        .open           = tracing_open_generic,
        .read           = tracing_max_lat_read,
@@ -3486,8 +3479,10 @@ static const struct file_operations tracing_mark_fops = {
 };
 
 static const struct file_operations trace_clock_fops = {
-       .open           = tracing_open_generic,
-       .read           = tracing_clock_read,
+       .open           = tracing_clock_open,
+       .read           = seq_read,
+       .llseek         = seq_lseek,
+       .release        = single_release,
        .write          = tracing_clock_write,
 };
 
@@ -3948,39 +3943,16 @@ trace_options_write(struct file *filp, const char __user *ubuf, size_t cnt,
        if (ret < 0)
                return ret;
 
-       ret = 0;
-       switch (val) {
-       case 0:
-               /* do nothing if already cleared */
-               if (!(topt->flags->val & topt->opt->bit))
-                       break;
-
-               mutex_lock(&trace_types_lock);
-               if (current_trace->set_flag)
-                       ret = current_trace->set_flag(topt->flags->val,
-                                                     topt->opt->bit, 0);
-               mutex_unlock(&trace_types_lock);
-               if (ret)
-                       return ret;
-               topt->flags->val &= ~topt->opt->bit;
-               break;
-       case 1:
-               /* do nothing if already set */
-               if (topt->flags->val & topt->opt->bit)
-                       break;
+       if (val != 0 && val != 1)
+               return -EINVAL;
 
+       if (!!(topt->flags->val & topt->opt->bit) != val) {
                mutex_lock(&trace_types_lock);
-               if (current_trace->set_flag)
-                       ret = current_trace->set_flag(topt->flags->val,
-                                                     topt->opt->bit, 1);
+               ret = __set_tracer_option(current_trace, topt->flags,
+                                         topt->opt, val);
                mutex_unlock(&trace_types_lock);
                if (ret)
                        return ret;
-               topt->flags->val |= topt->opt->bit;
-               break;
-
-       default:
-               return -EINVAL;
        }
 
        *ppos += cnt;