#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;
};
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;
}
}
}
#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
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;
}
/*
{
int ret;
- strstrip(input_string);
-
*ksymname = strsep(&input_string, ":");
*addr = kallsyms_lookup_name(*ksymname);
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;
}
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);
}
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 = {
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)
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)
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:
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;
.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);