hw-breakpoints: Fix broken hw-breakpoint sample module

The hw-breakpoint sample module has been broken during the
hw-breakpoint internals refactoring. Propagate the changes
to it.

Reported-by: "K. Prasad" <prasad@linux.vnet.ibm.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>

3 files changed, 27 insertions, 20 deletions

diff --git a/kernel/hw_breakpoint.c b/kernel/hw_breakpoint.c
index e662dc991c96..9ea9414e0e58 100644
--- a/kernel/hw_breakpoint.c
+++ b/kernel/hw_breakpoint.c
@@ -454,6 +454,7 @@ fail:
         /* return the error if any */
         return ERR_PTR(err);
 }
+EXPORT_SYMBOL_GPL(register_wide_hw_breakpoint);
 
 /**
  * unregister_wide_hw_breakpoint - unregister a wide breakpoint in the kernel
@@ -470,7 +471,7 @@ void unregister_wide_hw_breakpoint(struct perf_event **cpu_events)
         }
         free_percpu(cpu_events);
 }
-
+EXPORT_SYMBOL_GPL(unregister_wide_hw_breakpoint);
 
 static struct notifier_block hw_breakpoint_exceptions_nb = {
         .notifier_call = hw_breakpoint_exceptions_notify,
diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index 8b6b8b697c68..8e5288a8a355 100644
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -181,6 +181,7 @@ unsigned long kallsyms_lookup_name(const char *name)
         }
         return module_kallsyms_lookup_name(name);
 }
+EXPORT_SYMBOL_GPL(kallsyms_lookup_name);
 
 int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *,
                                       unsigned long),
diff --git a/samples/hw_breakpoint/data_breakpoint.c b/samples/hw_breakpoint/data_breakpoint.c
index 9cbdbb871b7a..5bc9819a819e 100644
--- a/samples/hw_breakpoint/data_breakpoint.c
+++ b/samples/hw_breakpoint/data_breakpoint.c
@@ -27,18 +27,19 @@
 #include <linux/module.h>       /* Needed by all modules */
 #include <linux/kernel.h>       /* Needed for KERN_INFO */
 #include <linux/init.h>         /* Needed for the macros */
+#include <linux/kallsyms.h>
 
-#include <asm/hw_breakpoint.h>
+#include <linux/perf_event.h>
+#include <linux/hw_breakpoint.h>
 
-struct hw_breakpoint sample_hbp;
+struct perf_event **sample_hbp;
 
 static char ksym_name[KSYM_NAME_LEN] = "pid_max";
 module_param_string(ksym, ksym_name, KSYM_NAME_LEN, S_IRUGO);
 MODULE_PARM_DESC(ksym, "Kernel symbol to monitor; this module will report any"
                         " write operations on the kernel symbol");
 
-void sample_hbp_handler(struct hw_breakpoint *temp, struct pt_regs
-                                                                *temp_regs)
+static void sample_hbp_handler(struct perf_event *temp, void *data)
 {
         printk(KERN_INFO "%s value is changed\n", ksym_name);
         dump_stack();
@@ -48,30 +49,34 @@ void sample_hbp_handler(struct hw_breakpoint *temp, struct pt_regs
 static int __init hw_break_module_init(void)
 {
         int ret;
+        unsigned long addr;
 
-#ifdef CONFIG_X86
-        sample_hbp.info.name = ksym_name;
-        sample_hbp.info.type = HW_BREAKPOINT_WRITE;
-        sample_hbp.info.len = HW_BREAKPOINT_LEN_4;
-#endif /* CONFIG_X86 */
+        addr = kallsyms_lookup_name(ksym_name);
 
-        sample_hbp.triggered = (void *)sample_hbp_handler;
+        sample_hbp = register_wide_hw_breakpoint(addr, HW_BREAKPOINT_LEN_4,
+                                                 HW_BREAKPOINT_W | HW_BREAKPOINT_R,
+                                                 sample_hbp_handler, true);
+        if (IS_ERR(sample_hbp)) {
+                ret = PTR_ERR(sample_hbp);
+                goto fail;
+        } else if (!sample_hbp) {
+                ret = -EINVAL;
+                goto fail;
+        }
 
-        ret = register_kernel_hw_breakpoint(&sample_hbp);
-
-        if (ret < 0) {
-                printk(KERN_INFO "Breakpoint registration failed\n");
-                return ret;
-        } else
-                printk(KERN_INFO "HW Breakpoint for %s write installed\n",
-                                                                ksym_name);
+        printk(KERN_INFO "HW Breakpoint for %s write installed\n", ksym_name);
 
         return 0;
+
+fail:
+        printk(KERN_INFO "Breakpoint registration failed\n");
+
+        return ret;
 }
 
 static void __exit hw_break_module_exit(void)
 {
-        unregister_kernel_hw_breakpoint(&sample_hbp);
+        unregister_wide_hw_breakpoint(sample_hbp);
         printk(KERN_INFO "HW Breakpoint for %s write uninstalled\n", ksym_name);
 }