Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wirel...
[safe/jmp/linux-2.6] / kernel / trace / trace_ksym.c
index 9f040e4..8eaf007 100644 (file)
 #include <linux/debugfs.h>
 #include <linux/ftrace.h>
 #include <linux/module.h>
+#include <linux/slab.h>
 #include <linux/fs.h>
 
 #include "trace_output.h"
-#include "trace_stat.h"
 #include "trace.h"
 
 #include <linux/hw_breakpoint.h>
 #include <asm/hw_breakpoint.h>
 
-/*
- * For now, let us restrict the no. of symbols traced simultaneously to number
- * of available hardware breakpoint registers.
- */
-#define KSYM_TRACER_MAX HBP_NUM
+#include <asm/atomic.h>
 
 #define KSYM_TRACER_OP_LEN 3 /* rw- */
 
 struct trace_ksym {
        struct perf_event       **ksym_hbp;
-       unsigned long           ksym_addr;
-       int                     type;
-       int                     len;
+       struct perf_event_attr  attr;
 #ifdef CONFIG_PROFILE_KSYM_TRACER
-       unsigned long           counter;
+       atomic64_t              counter;
 #endif
        struct hlist_node       ksym_hlist;
 };
 
 static struct trace_array *ksym_trace_array;
 
-static unsigned int ksym_filter_entry_count;
 static unsigned int ksym_tracing_enabled;
 
 static HLIST_HEAD(ksym_filter_head);
@@ -71,9 +64,8 @@ void ksym_collect_stats(unsigned long hbp_hit_addr)
 
        rcu_read_lock();
        hlist_for_each_entry_rcu(entry, node, &ksym_filter_head, ksym_hlist) {
-               if ((entry->ksym_addr == hbp_hit_addr) &&
-                   (entry->counter <= MAX_UL_INT)) {
-                       entry->counter++;
+               if (entry->attr.bp_addr == hbp_hit_addr) {
+                       atomic64_inc(&entry->counter);
                        break;
                }
        }
@@ -81,11 +73,12 @@ void ksym_collect_stats(unsigned long hbp_hit_addr)
 }
 #endif /* CONFIG_PROFILE_KSYM_TRACER */
 
-void ksym_hbp_handler(struct perf_event *hbp, void *data)
+void ksym_hbp_handler(struct perf_event *hbp, int nmi,
+                     struct perf_sample_data *data,
+                     struct pt_regs *regs)
 {
        struct ring_buffer_event *event;
        struct ksym_trace_entry *entry;
-       struct pt_regs *regs = data;
        struct ring_buffer *buffer;
        int pc;
 
@@ -181,38 +174,32 @@ int process_new_ksym_entry(char *ksymname, int op, unsigned long addr)
        struct trace_ksym *entry;
        int ret = -ENOMEM;
 
-       if (ksym_filter_entry_count >= KSYM_TRACER_MAX) {
-               printk(KERN_ERR "ksym_tracer: Maximum limit:(%d) reached. No"
-               " new requests for tracing can be accepted now.\n",
-                       KSYM_TRACER_MAX);
-               return -ENOSPC;
-       }
-
        entry = kzalloc(sizeof(struct trace_ksym), GFP_KERNEL);
        if (!entry)
                return -ENOMEM;
 
-       entry->type = op;
-       entry->ksym_addr = addr;
-       entry->len = HW_BREAKPOINT_LEN_4;
+       hw_breakpoint_init(&entry->attr);
+
+       entry->attr.bp_type = op;
+       entry->attr.bp_addr = addr;
+       entry->attr.bp_len = HW_BREAKPOINT_LEN_4;
+
+       entry->ksym_hbp = register_wide_hw_breakpoint(&entry->attr,
+                                       ksym_hbp_handler);
 
-       ret = -EAGAIN;
-       entry->ksym_hbp = register_wide_hw_breakpoint(entry->ksym_addr,
-                                       entry->len, entry->type,
-                                       ksym_hbp_handler, true);
        if (IS_ERR(entry->ksym_hbp)) {
-               entry->ksym_hbp = NULL;
                ret = PTR_ERR(entry->ksym_hbp);
-       }
-
-       if (!entry->ksym_hbp) {
-               printk(KERN_INFO "ksym_tracer request failed. Try again"
-                                       " later!!\n");
+               if (ret == -ENOSPC) {
+                       printk(KERN_ERR "ksym_tracer: Maximum limit reached."
+                       " No new requests for tracing can be accepted now.\n");
+               } else {
+                       printk(KERN_INFO "ksym_tracer request failed. Try again"
+                                        " later!!\n");
+               }
                goto err;
        }
 
        hlist_add_head_rcu(&(entry->ksym_hlist), &ksym_filter_head);
-       ksym_filter_entry_count++;
 
        return 0;
 
@@ -239,12 +226,13 @@ static ssize_t ksym_trace_filter_read(struct file *filp, char __user *ubuf,
        mutex_lock(&ksym_tracer_mutex);
 
        hlist_for_each_entry(entry, node, &ksym_filter_head, ksym_hlist) {
-               ret = trace_seq_printf(s, "%pS:", (void *)entry->ksym_addr);
-               if (entry->type == HW_BREAKPOINT_R)
+               ret = trace_seq_printf(s, "%pS:",
+                               (void *)(unsigned long)entry->attr.bp_addr);
+               if (entry->attr.bp_type == HW_BREAKPOINT_R)
                        ret = trace_seq_puts(s, "r--\n");
-               else if (entry->type == HW_BREAKPOINT_W)
+               else if (entry->attr.bp_type == HW_BREAKPOINT_W)
                        ret = trace_seq_puts(s, "-w-\n");
-               else if (entry->type == (HW_BREAKPOINT_W | HW_BREAKPOINT_R))
+               else if (entry->attr.bp_type == (HW_BREAKPOINT_W | HW_BREAKPOINT_R))
                        ret = trace_seq_puts(s, "rw-\n");
                WARN_ON_ONCE(!ret);
        }
@@ -267,7 +255,6 @@ static void __ksym_trace_reset(void)
        hlist_for_each_entry_safe(entry, node, node1, &ksym_filter_head,
                                                                ksym_hlist) {
                unregister_wide_hw_breakpoint(entry->ksym_hbp);
-               ksym_filter_entry_count--;
                hlist_del_rcu(&(entry->ksym_hlist));
                synchronize_rcu();
                kfree(entry);
@@ -281,21 +268,20 @@ static ssize_t ksym_trace_filter_write(struct file *file,
 {
        struct trace_ksym *entry;
        struct hlist_node *node;
-       char *input_string, *ksymname = NULL;
+       char *buf, *input_string, *ksymname = NULL;
        unsigned long ksym_addr = 0;
        int ret, op, changed = 0;
 
-       input_string = kzalloc(count + 1, GFP_KERNEL);
-       if (!input_string)
+       buf = kzalloc(count + 1, GFP_KERNEL);
+       if (!buf)
                return -ENOMEM;
 
-       if (copy_from_user(input_string, buffer, count)) {
-               kfree(input_string);
-               return -EFAULT;
-       }
-       input_string[count] = '\0';
+       ret = -EFAULT;
+       if (copy_from_user(buf, buffer, count))
+               goto out;
 
-       strstrip(input_string);
+       buf[count] = '\0';
+       input_string = strstrip(buf);
 
        /*
         * Clear all breakpoints if:
@@ -306,68 +292,55 @@ static ssize_t ksym_trace_filter_write(struct file *file,
        if (!input_string[0] || !strcmp(input_string, "0") ||
            !strcmp(input_string, "*:---")) {
                __ksym_trace_reset();
-               kfree(input_string);
-               return count;
+               ret = 0;
+               goto out;
        }
 
        ret = op = parse_ksym_trace_str(input_string, &ksymname, &ksym_addr);
-       if (ret < 0) {
-               kfree(input_string);
-               return ret;
-       }
+       if (ret < 0)
+               goto out;
 
        mutex_lock(&ksym_tracer_mutex);
 
        ret = -EINVAL;
        hlist_for_each_entry(entry, node, &ksym_filter_head, ksym_hlist) {
-               if (entry->ksym_addr == ksym_addr) {
+               if (entry->attr.bp_addr == ksym_addr) {
                        /* Check for malformed request: (6) */
-                       if (entry->type != op)
+                       if (entry->attr.bp_type != op)
                                changed = 1;
                        else
-                               goto out;
+                               goto out_unlock;
                        break;
                }
        }
        if (changed) {
                unregister_wide_hw_breakpoint(entry->ksym_hbp);
-               entry->type = op;
+               entry->attr.bp_type = op;
+               ret = 0;
                if (op > 0) {
                        entry->ksym_hbp =
-                               register_wide_hw_breakpoint(entry->ksym_addr,
-                                       entry->len, entry->type,
-                                       ksym_hbp_handler, true);
+                               register_wide_hw_breakpoint(&entry->attr,
+                                       ksym_hbp_handler);
                        if (IS_ERR(entry->ksym_hbp))
-                               entry->ksym_hbp = NULL;
-
-                       /* modified without problem */
-                       if (entry->ksym_hbp) {
-                               ret = 0;
-                               goto out;
-                       }
-               } else {
-                       ret = 0;
+                               ret = PTR_ERR(entry->ksym_hbp);
+                       else
+                               goto out_unlock;
                }
                /* Error or "symbol:---" case: drop it */
-               ksym_filter_entry_count--;
                hlist_del_rcu(&(entry->ksym_hlist));
                synchronize_rcu();
                kfree(entry);
-               goto out;
+               goto out_unlock;
        } else {
                /* Check for malformed request: (4) */
-               if (op == 0)
-                       goto out;
-               ret = process_new_ksym_entry(ksymname, op, ksym_addr);
+               if (op)
+                       ret = process_new_ksym_entry(ksymname, op, ksym_addr);
        }
-out:
+out_unlock:
        mutex_unlock(&ksym_tracer_mutex);
-
-       kfree(input_string);
-
-       if (!ret)
-               ret = count;
-       return ret;
+out:
+       kfree(buf);
+       return !ret ? count : ret;
 }
 
 static const struct file_operations ksym_tracing_fops = {
@@ -459,102 +432,77 @@ struct tracer ksym_tracer __read_mostly =
        .print_line     = ksym_trace_output
 };
 
-__init static int init_ksym_trace(void)
-{
-       struct dentry *d_tracer;
-       struct dentry *entry;
-
-       d_tracer = tracing_init_dentry();
-       ksym_filter_entry_count = 0;
-
-       entry = debugfs_create_file("ksym_trace_filter", 0644, d_tracer,
-                                   NULL, &ksym_tracing_fops);
-       if (!entry)
-               pr_warning("Could not create debugfs "
-                          "'ksym_trace_filter' file\n");
-
-       return register_tracer(&ksym_tracer);
-}
-device_initcall(init_ksym_trace);
-
-
 #ifdef CONFIG_PROFILE_KSYM_TRACER
-static int ksym_tracer_stat_headers(struct seq_file *m)
+static int ksym_profile_show(struct seq_file *m, void *v)
 {
+       struct hlist_node *node;
+       struct trace_ksym *entry;
+       int access_type = 0;
+       char fn_name[KSYM_NAME_LEN];
+
        seq_puts(m, "  Access Type ");
        seq_puts(m, "  Symbol                                       Counter\n");
        seq_puts(m, "  ----------- ");
        seq_puts(m, "  ------                                       -------\n");
-       return 0;
-}
 
-static int ksym_tracer_stat_show(struct seq_file *m, void *v)
-{
-       struct hlist_node *stat = v;
-       struct trace_ksym *entry;
-       int access_type = 0;
-       char fn_name[KSYM_NAME_LEN];
+       rcu_read_lock();
+       hlist_for_each_entry_rcu(entry, node, &ksym_filter_head, ksym_hlist) {
 
-       entry = hlist_entry(stat, struct trace_ksym, ksym_hlist);
+               access_type = entry->attr.bp_type;
 
-       access_type = entry->type;
+               switch (access_type) {
+               case HW_BREAKPOINT_R:
+                       seq_puts(m, "  R           ");
+                       break;
+               case HW_BREAKPOINT_W:
+                       seq_puts(m, "  W           ");
+                       break;
+               case HW_BREAKPOINT_R | HW_BREAKPOINT_W:
+                       seq_puts(m, "  RW          ");
+                       break;
+               default:
+                       seq_puts(m, "  NA          ");
+               }
 
-       switch (access_type) {
-       case HW_BREAKPOINT_R:
-               seq_puts(m, "  R           ");
-               break;
-       case HW_BREAKPOINT_W:
-               seq_puts(m, "  W           ");
-               break;
-       case HW_BREAKPOINT_R | HW_BREAKPOINT_W:
-               seq_puts(m, "  RW          ");
-               break;
-       default:
-               seq_puts(m, "  NA          ");
+               if (lookup_symbol_name(entry->attr.bp_addr, fn_name) >= 0)
+                       seq_printf(m, "  %-36s", fn_name);
+               else
+                       seq_printf(m, "  %-36s", "<NA>");
+               seq_printf(m, " %15llu\n",
+                          (unsigned long long)atomic64_read(&entry->counter));
        }
-
-       if (lookup_symbol_name(entry->ksym_addr, fn_name) >= 0)
-               seq_printf(m, "  %-36s", fn_name);
-       else
-               seq_printf(m, "  %-36s", "<NA>");
-       seq_printf(m, " %15lu\n", entry->counter);
+       rcu_read_unlock();
 
        return 0;
 }
 
-static void *ksym_tracer_stat_start(struct tracer_stat *trace)
-{
-       return ksym_filter_head.first;
-}
-
-static void *
-ksym_tracer_stat_next(void *v, int idx)
+static int ksym_profile_open(struct inode *node, struct file *file)
 {
-       struct hlist_node *stat = v;
-
-       return stat->next;
+       return single_open(file, ksym_profile_show, NULL);
 }
 
-static struct tracer_stat ksym_tracer_stats = {
-       .name = "ksym_tracer",
-       .stat_start = ksym_tracer_stat_start,
-       .stat_next = ksym_tracer_stat_next,
-       .stat_headers = ksym_tracer_stat_headers,
-       .stat_show = ksym_tracer_stat_show
+static const struct file_operations ksym_profile_fops = {
+       .open           = ksym_profile_open,
+       .read           = seq_read,
+       .llseek         = seq_lseek,
+       .release        = single_release,
 };
+#endif /* CONFIG_PROFILE_KSYM_TRACER */
 
-__init static int ksym_tracer_stat_init(void)
+__init static int init_ksym_trace(void)
 {
-       int ret;
+       struct dentry *d_tracer;
 
-       ret = register_stat_tracer(&ksym_tracer_stats);
-       if (ret) {
-               printk(KERN_WARNING "Warning: could not register "
-                                   "ksym tracer stats\n");
-               return 1;
-       }
+       d_tracer = tracing_init_dentry();
 
-       return 0;
+       trace_create_file("ksym_trace_filter", 0644, d_tracer,
+                         NULL, &ksym_tracing_fops);
+
+#ifdef CONFIG_PROFILE_KSYM_TRACER
+       trace_create_file("ksym_profile", 0444, d_tracer,
+                         NULL, &ksym_profile_fops);
+#endif
+
+       return register_tracer(&ksym_tracer);
 }
-fs_initcall(ksym_tracer_stat_init);
-#endif /* CONFIG_PROFILE_KSYM_TRACER */
+device_initcall(init_ksym_trace);