diff options
Diffstat (limited to 'samples/hw_breakpoint')
-rw-r--r-- | samples/hw_breakpoint/data_breakpoint.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/samples/hw_breakpoint/data_breakpoint.c b/samples/hw_breakpoint/data_breakpoint.c index c58504774118..418c46fe5ffc 100644 --- a/samples/hw_breakpoint/data_breakpoint.c +++ b/samples/hw_breakpoint/data_breakpoint.c @@ -23,7 +23,7 @@ struct perf_event * __percpu *sample_hbp; -static char ksym_name[KSYM_NAME_LEN] = "pid_max"; +static char ksym_name[KSYM_NAME_LEN] = "jiffies"; 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"); @@ -41,11 +41,15 @@ static int __init hw_break_module_init(void) { int ret; struct perf_event_attr attr; + void *addr = __symbol_get(ksym_name); + + if (!addr) + return -ENXIO; hw_breakpoint_init(&attr); - attr.bp_addr = kallsyms_lookup_name(ksym_name); + attr.bp_addr = (unsigned long)addr; attr.bp_len = HW_BREAKPOINT_LEN_4; - attr.bp_type = HW_BREAKPOINT_W | HW_BREAKPOINT_R; + attr.bp_type = HW_BREAKPOINT_W; sample_hbp = register_wide_hw_breakpoint(&attr, sample_hbp_handler, NULL); if (IS_ERR((void __force *)sample_hbp)) { @@ -66,6 +70,7 @@ fail: static void __exit hw_break_module_exit(void) { unregister_wide_hw_breakpoint(sample_hbp); + symbol_put(ksym_name); printk(KERN_INFO "HW Breakpoint for %s write uninstalled\n", ksym_name); } |