hw-breakpoints: Fix broken hw-breakpoint sample module
Frederic Weisbecker [Tue, 10 Nov 2009 09:17:07 +0000 (10:17 +0100)]
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>

kernel/hw_breakpoint.c
kernel/kallsyms.c
samples/hw_breakpoint/data_breakpoint.c

index e662dc9..9ea9414 100644 (file)
@@ -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,
index 8b6b8b6..8e5288a 100644 (file)
@@ -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),
index 9cbdbb8..5bc9819 100644 (file)
 #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);
 }