Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
[safe/jmp/linux-2.6] / kernel / trace / trace_ksym.c
index 7d349d3..94103cd 100644 (file)
 #include <linux/fs.h>
 
 #include "trace_output.h"
-#include "trace_stat.h"
 #include "trace.h"
 
-/* For now, let us restrict the no. of symbols traced simultaneously to number
+#include <linux/hw_breakpoint.h>
+#include <asm/hw_breakpoint.h>
+
+#include <asm/atomic.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
 #define KSYM_TRACER_OP_LEN 3 /* rw- */
 
 struct trace_ksym {
-       struct hw_breakpoint    *ksym_hbp;
-       unsigned long           ksym_addr;
+       struct perf_event       **ksym_hbp;
+       struct perf_event_attr  attr;
 #ifdef CONFIG_PROFILE_KSYM_TRACER
-       unsigned long           counter;
+       atomic64_t              counter;
 #endif
        struct hlist_node       ksym_hlist;
 };
@@ -65,9 +70,8 @@ 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;
                }
        }
@@ -75,35 +79,38 @@ void ksym_collect_stats(unsigned long hbp_hit_addr)
 }
 #endif /* CONFIG_PROFILE_KSYM_TRACER */
 
-void ksym_hbp_handler(struct hw_breakpoint *hbp, struct pt_regs *regs)
+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 trace_array *tr;
        struct ksym_trace_entry *entry;
+       struct ring_buffer *buffer;
        int pc;
 
        if (!ksym_tracing_enabled)
                return;
 
-       tr = ksym_trace_array;
+       buffer = ksym_trace_array->buffer;
+
        pc = preempt_count();
 
-       event = trace_buffer_lock_reserve(tr, TRACE_KSYM,
+       event = trace_buffer_lock_reserve(buffer, TRACE_KSYM,
                                                        sizeof(*entry), 0, pc);
        if (!event)
                return;
 
        entry           = ring_buffer_event_data(event);
        entry->ip       = instruction_pointer(regs);
-       entry->type     = hbp->info.type;
-       strlcpy(entry->ksym_name, hbp->info.name, KSYM_SYMBOL_LEN);
+       entry->type     = hw_breakpoint_type(hbp);
+       entry->addr     = hw_breakpoint_addr(hbp);
        strlcpy(entry->cmd, current->comm, TASK_COMM_LEN);
 
 #ifdef CONFIG_PROFILE_KSYM_TRACER
-       ksym_collect_stats(hbp->info.address);
+       ksym_collect_stats(hw_breakpoint_addr(hbp));
 #endif /* CONFIG_PROFILE_KSYM_TRACER */
 
-       trace_buffer_unlock_commit(tr, event, 0, pc);
+       trace_buffer_unlock_commit(buffer, event, 0, pc);
 }
 
 /* Valid access types are represented as
@@ -119,28 +126,22 @@ static int ksym_trace_get_access_type(char *str)
        int access = 0;
 
        if (str[0] == 'r')
-               access += 4;
-       else if (str[0] != '-')
-               return -EINVAL;
+               access |= HW_BREAKPOINT_R;
 
        if (str[1] == 'w')
-               access += 2;
-       else if (str[1] != '-')
-               return -EINVAL;
+               access |= HW_BREAKPOINT_W;
 
-       if (str[2] != '-')
-               return -EINVAL;
+       if (str[2] == 'x')
+               access |= HW_BREAKPOINT_X;
 
        switch (access) {
-       case 6:
-               access = HW_BREAKPOINT_RW;
-               break;
-       case 2:
-               access = HW_BREAKPOINT_WRITE;
-               break;
+       case HW_BREAKPOINT_R:
+       case HW_BREAKPOINT_W:
+       case HW_BREAKPOINT_W | HW_BREAKPOINT_R:
+               return access;
+       default:
+               return -EINVAL;
        }
-
-       return access;
 }
 
 /*
@@ -160,8 +161,6 @@ static int parse_ksym_trace_str(char *input_string, char **ksymname,
 {
        int ret;
 
-       strstrip(input_string);
-
        *ksymname = strsep(&input_string, ":");
        *addr = kallsyms_lookup_name(*ksymname);
 
@@ -192,36 +191,30 @@ int process_new_ksym_entry(char *ksymname, int op, unsigned long addr)
        if (!entry)
                return -ENOMEM;
 
-       entry->ksym_hbp = kzalloc(sizeof(struct hw_breakpoint), GFP_KERNEL);
-       if (!entry->ksym_hbp)
-               goto err;
+       hw_breakpoint_init(&entry->attr);
 
-       entry->ksym_hbp->info.name = kstrdup(ksymname, GFP_KERNEL);
-       if (!entry->ksym_hbp->info.name)
-               goto err;
+       entry->attr.bp_type = op;
+       entry->attr.bp_addr = addr;
+       entry->attr.bp_len = HW_BREAKPOINT_LEN_4;
 
-       entry->ksym_hbp->info.type = op;
-       entry->ksym_addr = entry->ksym_hbp->info.address = addr;
-#ifdef CONFIG_X86
-       entry->ksym_hbp->info.len = HW_BREAKPOINT_LEN_4;
-#endif
-       entry->ksym_hbp->triggered = (void *)ksym_hbp_handler;
+       entry->ksym_hbp = register_wide_hw_breakpoint(&entry->attr,
+                                       ksym_hbp_handler);
 
-       ret = register_kernel_hw_breakpoint(entry->ksym_hbp);
-       if (ret < 0) {
+       if (IS_ERR(entry->ksym_hbp)) {
+               ret = PTR_ERR(entry->ksym_hbp);
                printk(KERN_INFO "ksym_tracer request failed. Try again"
                                        " later!!\n");
-               ret = -EAGAIN;
                goto err;
        }
+
        hlist_add_head_rcu(&(entry->ksym_hlist), &ksym_filter_head);
        ksym_filter_entry_count++;
+
        return 0;
+
 err:
-       if (entry->ksym_hbp)
-               kfree(entry->ksym_hbp->info.name);
-       kfree(entry->ksym_hbp);
        kfree(entry);
+
        return ret;
 }
 
@@ -242,10 +235,13 @@ 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, "%s:", entry->ksym_hbp->info.name);
-               if (entry->ksym_hbp->info.type == HW_BREAKPOINT_WRITE)
+               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->attr.bp_type == HW_BREAKPOINT_W)
                        ret = trace_seq_puts(s, "-w-\n");
-               else if (entry->ksym_hbp->info.type == HW_BREAKPOINT_RW)
+               else if (entry->attr.bp_type == (HW_BREAKPOINT_W | HW_BREAKPOINT_R))
                        ret = trace_seq_puts(s, "rw-\n");
                WARN_ON_ONCE(!ret);
        }
@@ -259,74 +255,103 @@ static ssize_t ksym_trace_filter_read(struct file *filp, char __user *ubuf,
        return cnt;
 }
 
+static void __ksym_trace_reset(void)
+{
+       struct trace_ksym *entry;
+       struct hlist_node *node, *node1;
+
+       mutex_lock(&ksym_tracer_mutex);
+       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);
+       }
+       mutex_unlock(&ksym_tracer_mutex);
+}
+
 static ssize_t ksym_trace_filter_write(struct file *file,
                                        const char __user *buffer,
                                                size_t count, loff_t *ppos)
 {
        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;
+       ret = -EFAULT;
+       if (copy_from_user(buf, buffer, count))
+               goto out;
+
+       buf[count] = '\0';
+       input_string = strstrip(buf);
+
+       /*
+        * Clear all breakpoints if:
+        * 1: echo > ksym_trace_filter
+        * 2: echo 0 > ksym_trace_filter
+        * 3: echo "*:---" > ksym_trace_filter
+        */
+       if (!input_string[0] || !strcmp(input_string, "0") ||
+           !strcmp(input_string, "*:---")) {
+               __ksym_trace_reset();
+               ret = 0;
+               goto out;
        }
-       input_string[count] = '\0';
 
        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->ksym_hbp->info.type != op)
+                       if (entry->attr.bp_type != op)
                                changed = 1;
                        else
-                               goto out;
+                               goto out_unlock;
                        break;
                }
        }
        if (changed) {
-               unregister_kernel_hw_breakpoint(entry->ksym_hbp);
-               entry->ksym_hbp->info.type = op;
+               unregister_wide_hw_breakpoint(entry->ksym_hbp);
+               entry->attr.bp_type = op;
+               ret = 0;
                if (op > 0) {
-                       ret = register_kernel_hw_breakpoint(entry->ksym_hbp);
-                       if (ret == 0)
-                               goto out;
+                       entry->ksym_hbp =
+                               register_wide_hw_breakpoint(&entry->attr,
+                                       ksym_hbp_handler);
+                       if (IS_ERR(entry->ksym_hbp))
+                               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->ksym_hbp->info.name);
-               kfree(entry->ksym_hbp);
                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 = {
@@ -337,23 +362,8 @@ static const struct file_operations ksym_tracing_fops = {
 
 static void ksym_trace_reset(struct trace_array *tr)
 {
-       struct trace_ksym *entry;
-       struct hlist_node *node, *node1;
-
        ksym_tracing_enabled = 0;
-
-       mutex_lock(&ksym_tracer_mutex);
-       hlist_for_each_entry_safe(entry, node, node1, &ksym_filter_head,
-                                                               ksym_hlist) {
-               unregister_kernel_hw_breakpoint(entry->ksym_hbp);
-               ksym_filter_entry_count--;
-               hlist_del_rcu(&(entry->ksym_hlist));
-               synchronize_rcu();
-               kfree(entry->ksym_hbp->info.name);
-               kfree(entry->ksym_hbp);
-               kfree(entry);
-       }
-       mutex_unlock(&ksym_tracer_mutex);
+       __ksym_trace_reset();
 }
 
 static int ksym_trace_init(struct trace_array *tr)
@@ -370,13 +380,12 @@ static int ksym_trace_init(struct trace_array *tr)
 
 static void ksym_trace_print_header(struct seq_file *m)
 {
-
        seq_puts(m,
-                "#       TASK-PID      CPU#      Symbol         Type    "
-                "Function         \n");
+                "#       TASK-PID   CPU#      Symbol                    "
+                "Type    Function\n");
        seq_puts(m,
-                "#          |           |          |              |         "
-                "|            \n");
+                "#          |        |          |                       "
+                " |         |\n");
 }
 
 static enum print_line_t ksym_trace_output(struct trace_iterator *iter)
@@ -392,16 +401,19 @@ static enum print_line_t ksym_trace_output(struct trace_iterator *iter)
 
        trace_assign_type(field, entry);
 
-       ret = trace_seq_printf(s, "%-15s %-5d %-3d %-20s ", field->cmd,
-                               entry->pid, iter->cpu, field->ksym_name);
+       ret = trace_seq_printf(s, "%11s-%-5d [%03d] %pS", field->cmd,
+                               entry->pid, iter->cpu, (char *)field->addr);
        if (!ret)
                return TRACE_TYPE_PARTIAL_LINE;
 
        switch (field->type) {
-       case HW_BREAKPOINT_WRITE:
+       case HW_BREAKPOINT_R:
+               ret = trace_seq_printf(s, " R  ");
+               break;
+       case HW_BREAKPOINT_W:
                ret = trace_seq_printf(s, " W  ");
                break;
-       case HW_BREAKPOINT_RW:
+       case HW_BREAKPOINT_R | HW_BREAKPOINT_W:
                ret = trace_seq_printf(s, " RW ");
                break;
        default:
@@ -412,7 +424,7 @@ static enum print_line_t ksym_trace_output(struct trace_iterator *iter)
                return TRACE_TYPE_PARTIAL_LINE;
 
        sprint_symbol(str, field->ip);
-       ret = trace_seq_printf(s, "%-20s\n", str);
+       ret = trace_seq_printf(s, "%s\n", str);
        if (!ret)
                return TRACE_TYPE_PARTIAL_LINE;
 
@@ -431,98 +443,77 @@ 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)
-{
-       seq_printf(m, "   Access type    ");
-       seq_printf(m, "            Symbol                     Counter     \n");
-       return 0;
-}
-
-static int ksym_tracer_stat_show(struct seq_file *m, void *v)
+static int ksym_profile_show(struct seq_file *m, void *v)
 {
-       struct hlist_node *stat = v;
+       struct hlist_node *node;
        struct trace_ksym *entry;
        int access_type = 0;
        char fn_name[KSYM_NAME_LEN];
 
-       entry = hlist_entry(stat, struct trace_ksym, ksym_hlist);
+       seq_puts(m, "  Access Type ");
+       seq_puts(m, "  Symbol                                       Counter\n");
+       seq_puts(m, "  ----------- ");
+       seq_puts(m, "  ------                                       -------\n");
 
-       if (entry->ksym_hbp)
-               access_type = entry->ksym_hbp->info.type;
+       rcu_read_lock();
+       hlist_for_each_entry_rcu(entry, node, &ksym_filter_head, ksym_hlist) {
 
-       switch (access_type) {
-       case HW_BREAKPOINT_WRITE:
-               seq_printf(m, "     W     ");
-               break;
-       case HW_BREAKPOINT_RW:
-               seq_printf(m, "     RW    ");
-               break;
-       default:
-               seq_printf(m, "     NA    ");
-       }
+               access_type = entry->attr.bp_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          ");
+               }
 
-       if (lookup_symbol_name(entry->ksym_addr, fn_name) >= 0)
-               seq_printf(m, "               %s                 ", fn_name);
-       else
-               seq_printf(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));
+       }
+       rcu_read_unlock();
 
-       seq_printf(m, "%15lu\n", entry->counter);
        return 0;
 }
 
-static void *ksym_tracer_stat_start(struct tracer_stat *trace)
+static int ksym_profile_open(struct inode *node, struct file *file)
 {
-       return &(ksym_filter_head.first);
-}
-
-static void *
-ksym_tracer_stat_next(void *v, int idx)
-{
-       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);