* that variable.
*
* Copyright (C) IBM Corporation, 2009
+ *
+ * Author: K.Prasad <prasad@linux.vnet.ibm.com>
*/
#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 *bp, int nmi,
+ struct perf_sample_data *data,
+ struct pt_regs *regs)
{
printk(KERN_INFO "%s value is changed\n", ksym_name);
dump_stack();
static int __init hw_break_module_init(void)
{
int ret;
+ struct perf_event_attr attr;
-#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 */
-
- sample_hbp.triggered = (void *)sample_hbp_handler;
+ hw_breakpoint_init(&attr);
+ attr.bp_addr = kallsyms_lookup_name(ksym_name);
+ attr.bp_len = HW_BREAKPOINT_LEN_4;
+ attr.bp_type = HW_BREAKPOINT_W | HW_BREAKPOINT_R;
- ret = register_kernel_hw_breakpoint(&sample_hbp);
+ sample_hbp = register_wide_hw_breakpoint(&attr, sample_hbp_handler);
+ if (IS_ERR(sample_hbp)) {
+ ret = PTR_ERR(sample_hbp);
+ goto fail;
+ }
- 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);
}