diff options
Diffstat (limited to 'kernel/trace')
| -rw-r--r-- | kernel/trace/Kconfig | 38 | ||||
| -rw-r--r-- | kernel/trace/Makefile | 2 | ||||
| -rw-r--r-- | kernel/trace/ring_buffer.c | 15 | ||||
| -rw-r--r-- | kernel/trace/trace.h | 38 | ||||
| -rw-r--r-- | kernel/trace/trace_entries.h | 16 | ||||
| -rw-r--r-- | kernel/trace/trace_event_profile.c | 43 | ||||
| -rw-r--r-- | kernel/trace/trace_events.c | 168 | ||||
| -rw-r--r-- | kernel/trace/trace_events_filter.c | 310 | ||||
| -rw-r--r-- | kernel/trace/trace_export.c | 39 | ||||
| -rw-r--r-- | kernel/trace/trace_kprobe.c | 1523 | ||||
| -rw-r--r-- | kernel/trace/trace_ksym.c | 550 | ||||
| -rw-r--r-- | kernel/trace/trace_selftest.c | 55 | ||||
| -rw-r--r-- | kernel/trace/trace_syscalls.c | 195 |
13 files changed, 2645 insertions, 347 deletions
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index b416512ad17..d006554888d 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -339,6 +339,27 @@ config POWER_TRACER power management decisions, specifically the C-state and P-state behavior. +config KSYM_TRACER + bool "Trace read and write access on kernel memory locations" + depends on HAVE_HW_BREAKPOINT + select TRACING + help + This tracer helps find read and write operations on any given kernel + symbol i.e. /proc/kallsyms. + +config PROFILE_KSYM_TRACER + bool "Profile all kernel memory accesses on 'watched' variables" + depends on KSYM_TRACER + help + This tracer profiles kernel accesses on variables watched through the + ksym tracer ftrace plugin. Depending upon the hardware, all read + and write operations on kernel variables can be monitored for + accesses. + + The results will be displayed in: + /debugfs/tracing/profile_ksym + + Say N if unsure. config STACK_TRACER bool "Trace max stack" @@ -428,6 +449,23 @@ config BLK_DEV_IO_TRACE If unsure, say N. +config KPROBE_EVENT + depends on KPROBES + depends on X86 + bool "Enable kprobes-based dynamic events" + select TRACING + default y + help + This allows the user to add tracing events (similar to tracepoints) on the fly + via the ftrace interface. See Documentation/trace/kprobetrace.txt + for more details. + + Those events can be inserted wherever kprobes can probe, and record + various register and memory values. + + This option is also required by perf-probe subcommand of perf tools. If + you want to use perf tools, this option is strongly recommended. + config DYNAMIC_FTRACE bool "enable/disable ftrace tracepoints dynamically" depends on FUNCTION_TRACER diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 26f03ac07c2..cd9ecd89ec7 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -53,6 +53,8 @@ obj-$(CONFIG_EVENT_TRACING) += trace_export.o obj-$(CONFIG_FTRACE_SYSCALLS) += trace_syscalls.o obj-$(CONFIG_EVENT_PROFILE) += trace_event_profile.o obj-$(CONFIG_EVENT_TRACING) += trace_events_filter.o +obj-$(CONFIG_KPROBE_EVENT) += trace_kprobe.o +obj-$(CONFIG_KSYM_TRACER) += trace_ksym.o obj-$(CONFIG_EVENT_TRACING) += power-traces.o libftrace-y := ftrace.o diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index a72c6e03dee..a1ca4956ab5 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -397,18 +397,21 @@ int ring_buffer_print_page_header(struct trace_seq *s) int ret; ret = trace_seq_printf(s, "\tfield: u64 timestamp;\t" - "offset:0;\tsize:%u;\n", - (unsigned int)sizeof(field.time_stamp)); + "offset:0;\tsize:%u;\tsigned:%u;\n", + (unsigned int)sizeof(field.time_stamp), + (unsigned int)is_signed_type(u64)); ret = trace_seq_printf(s, "\tfield: local_t commit;\t" - "offset:%u;\tsize:%u;\n", + "offset:%u;\tsize:%u;\tsigned:%u;\n", (unsigned int)offsetof(typeof(field), commit), - (unsigned int)sizeof(field.commit)); + (unsigned int)sizeof(field.commit), + (unsigned int)is_signed_type(long)); ret = trace_seq_printf(s, "\tfield: char data;\t" - "offset:%u;\tsize:%u;\n", + "offset:%u;\tsize:%u;\tsigned:%u;\n", (unsigned int)offsetof(typeof(field), data), - (unsigned int)BUF_PAGE_SIZE); + (unsigned int)BUF_PAGE_SIZE, + (unsigned int)is_signed_type(char)); return ret; } diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index acef8b4636f..1d7f4830a80 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -11,6 +11,7 @@ #include <linux/ftrace.h> #include <trace/boot.h> #include <linux/kmemtrace.h> +#include <linux/hw_breakpoint.h> #include <linux/trace_seq.h> #include <linux/ftrace_event.h> @@ -37,6 +38,7 @@ enum trace_type { TRACE_KMEM_ALLOC, TRACE_KMEM_FREE, TRACE_BLK, + TRACE_KSYM, __TRACE_LAST_TYPE, }; @@ -98,9 +100,32 @@ struct syscall_trace_enter { struct syscall_trace_exit { struct trace_entry ent; int nr; - unsigned long ret; + long ret; }; +struct kprobe_trace_entry { + struct trace_entry ent; + unsigned long ip; + int nargs; + unsigned long args[]; +}; + +#define SIZEOF_KPROBE_TRACE_ENTRY(n) \ + (offsetof(struct kprobe_trace_entry, args) + \ + (sizeof(unsigned long) * (n))) + +struct kretprobe_trace_entry { + struct trace_entry ent; + unsigned long func; + unsigned long ret_ip; + int nargs; + unsigned long args[]; +}; + +#define SIZEOF_KRETPROBE_TRACE_ENTRY(n) \ + (offsetof(struct kretprobe_trace_entry, args) + \ + (sizeof(unsigned long) * (n))) + /* * trace_flag_type is an enumeration that holds different * states when a trace occurs. These are: @@ -209,6 +234,7 @@ extern void __ftrace_bad_type(void); TRACE_KMEM_ALLOC); \ IF_ASSIGN(var, ent, struct kmemtrace_free_entry, \ TRACE_KMEM_FREE); \ + IF_ASSIGN(var, ent, struct ksym_trace_entry, TRACE_KSYM);\ __ftrace_bad_type(); \ } while (0) @@ -364,6 +390,8 @@ int register_tracer(struct tracer *type); void unregister_tracer(struct tracer *type); int is_tracing_stopped(void); +extern int process_new_ksym_entry(char *ksymname, int op, unsigned long addr); + extern unsigned long nsecs_to_usecs(unsigned long nsecs); #ifdef CONFIG_TRACER_MAX_TRACE @@ -438,6 +466,8 @@ extern int trace_selftest_startup_branch(struct tracer *trace, struct trace_array *tr); extern int trace_selftest_startup_hw_branches(struct tracer *trace, struct trace_array *tr); +extern int trace_selftest_startup_ksym(struct tracer *trace, + struct trace_array *tr); #endif /* CONFIG_FTRACE_STARTUP_TEST */ extern void *head_page(struct trace_array_cpu *data); @@ -683,7 +713,6 @@ struct event_filter { int n_preds; struct filter_pred **preds; char *filter_string; - bool no_reset; }; struct event_subsystem { @@ -703,7 +732,7 @@ typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event, typedef int (*regex_match_func)(char *str, struct regex *r, int len); enum regex_type { - MATCH_FULL, + MATCH_FULL = 0, MATCH_FRONT_ONLY, MATCH_MIDDLE_ONLY, MATCH_END_ONLY, @@ -744,7 +773,8 @@ filter_check_discard(struct ftrace_event_call *call, void *rec, struct ring_buffer *buffer, struct ring_buffer_event *event) { - if (unlikely(call->filter_active) && !filter_match_preds(call, rec)) { + if (unlikely(call->filter_active) && + !filter_match_preds(call->filter, rec)) { ring_buffer_discard_commit(buffer, event); return 1; } diff --git a/kernel/trace/trace_entries.h b/kernel/trace/trace_entries.h index ead3d724599..c16a08f399d 100644 --- a/kernel/trace/trace_entries.h +++ b/kernel/trace/trace_entries.h @@ -364,3 +364,19 @@ FTRACE_ENTRY(kmem_free, kmemtrace_free_entry, F_printk("type:%u call_site:%lx ptr:%p", __entry->type_id, __entry->call_site, __entry->ptr) ); + +FTRACE_ENTRY(ksym_trace, ksym_trace_entry, + + TRACE_KSYM, + + F_STRUCT( + __field( unsigned long, ip ) + __field( unsigned char, type ) + __array( char , cmd, TASK_COMM_LEN ) + __field( unsigned long, addr ) + ), + + F_printk("ip: %pF type: %d ksym_name: %pS cmd: %s", + (void *)__entry->ip, (unsigned int)__entry->type, + (void *)__entry->addr, __entry->cmd) +); diff --git a/kernel/trace/trace_event_profile.c b/kernel/trace/trace_event_profile.c index 8d5c171cc99..d9c60f80aa0 100644 --- a/kernel/trace/trace_event_profile.c +++ b/kernel/trace/trace_event_profile.c @@ -8,17 +8,14 @@ #include <linux/module.h> #include "trace.h" -/* - * We can't use a size but a type in alloc_percpu() - * So let's create a dummy type that matches the desired size - */ -typedef struct {char buf[FTRACE_MAX_PROFILE_SIZE];} profile_buf_t; -char *trace_profile_buf; -EXPORT_SYMBOL_GPL(trace_profile_buf); +char *perf_trace_buf; +EXPORT_SYMBOL_GPL(perf_trace_buf); + +char *perf_trace_buf_nmi; +EXPORT_SYMBOL_GPL(perf_trace_buf_nmi); -char *trace_profile_buf_nmi; -EXPORT_SYMBOL_GPL(trace_profile_buf_nmi); +typedef typeof(char [FTRACE_MAX_PROFILE_SIZE]) perf_trace_t ; /* Count the events in use (per event id, not per instance) */ static int total_profile_count; @@ -32,20 +29,20 @@ static int ftrace_profile_enable_event(struct ftrace_event_call *event) return 0; if (!total_profile_count) { - buf = (char *)alloc_percpu(profile_buf_t); + buf = (char *)alloc_percpu(perf_trace_t); if (!buf) goto fail_buf; - rcu_assign_pointer(trace_profile_buf, buf); + rcu_assign_pointer(perf_trace_buf, buf); - buf = (char *)alloc_percpu(profile_buf_t); + buf = (char *)alloc_percpu(perf_trace_t); if (!buf) goto fail_buf_nmi; - rcu_assign_pointer(trace_profile_buf_nmi, buf); + rcu_assign_pointer(perf_trace_buf_nmi, buf); } - ret = event->profile_enable(); + ret = event->profile_enable(event); if (!ret) { total_profile_count++; return 0; @@ -53,10 +50,10 @@ static int ftrace_profile_enable_event(struct ftrace_event_call *event) fail_buf_nmi: if (!total_profile_count) { - free_percpu(trace_profile_buf_nmi); - free_percpu(trace_profile_buf); - trace_profile_buf_nmi = NULL; - trace_profile_buf = NULL; + free_percpu(perf_trace_buf_nmi); + free_percpu(perf_trace_buf); + perf_trace_buf_nmi = NULL; + perf_trace_buf = NULL; } fail_buf: atomic_dec(&event->profile_count); @@ -89,14 +86,14 @@ static void ftrace_profile_disable_event(struct ftrace_event_call *event) if (!atomic_add_negative(-1, &event->profile_count)) return; - event->profile_disable(); + event->profile_disable(event); if (!--total_profile_count) { - buf = trace_profile_buf; - rcu_assign_pointer(trace_profile_buf, NULL); + buf = perf_trace_buf; + rcu_assign_pointer(perf_trace_buf, NULL); - nmi_buf = trace_profile_buf_nmi; - rcu_assign_pointer(trace_profile_buf_nmi, NULL); + nmi_buf = perf_trace_buf_nmi; + rcu_assign_pointer(perf_trace_buf_nmi, NULL); /* * Ensure every events in profiling have finished before diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 5e9ffc33f6d..1d18315dc83 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -93,9 +93,7 @@ int trace_define_common_fields(struct ftrace_event_call *call) } EXPORT_SYMBOL_GPL(trace_define_common_fields); -#ifdef CONFIG_MODULES - -static void trace_destroy_fields(struct ftrace_event_call *call) +void trace_destroy_fields(struct ftrace_event_call *call) { struct ftrace_event_field *field, *next; @@ -107,8 +105,6 @@ static void trace_destroy_fields(struct ftrace_event_call *call) } } -#endif /* CONFIG_MODULES */ - static void ftrace_event_enable_disable(struct ftrace_event_call *call, int enable) { @@ -117,14 +113,14 @@ static void ftrace_event_enable_disable(struct ftrace_event_call *call, if (call->enabled) { call->enabled = 0; tracing_stop_cmdline_record(); - call->unregfunc(call->data); + call->unregfunc(call); } break; case 1: if (!call->enabled) { call->enabled = 1; tracing_start_cmdline_record(); - call->regfunc(call->data); + call->regfunc(call); } break; } @@ -507,7 +503,7 @@ extern char *__bad_type_size(void); #define FIELD(type, name) \ sizeof(type) != sizeof(field.name) ? __bad_type_size() : \ #type, "common_" #name, offsetof(typeof(field), name), \ - sizeof(field.name) + sizeof(field.name), is_signed_type(type) static int trace_write_header(struct trace_seq *s) { @@ -515,17 +511,17 @@ static int trace_write_header(struct trace_seq *s) /* struct trace_entry */ return trace_seq_printf(s, - "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n" - "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n" - "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n" - "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n" - "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n" - "\n", - FIELD(unsigned short, type), - FIELD(unsigned char, flags), - FIELD(unsigned char, preempt_count), - FIELD(int, pid), - FIELD(int, lock_depth)); + "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\tsigned:%u;\n" + "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\tsigned:%u;\n" + "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\tsigned:%u;\n" + "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\tsigned:%u;\n" + "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\tsigned:%u;\n" + "\n", + FIELD(unsigned short, type), + FIELD(unsigned char, flags), + FIELD(unsigned char, preempt_count), + FIELD(int, pid), + FIELD(int, lock_depth)); } static ssize_t @@ -937,27 +933,46 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events, return 0; } -#define for_each_event(event, start, end) \ - for (event = start; \ - (unsigned long)event < (unsigned long)end; \ - event++) +static int __trace_add_event_call(struct ftrace_event_call *call) +{ + struct dentry *d_events; + int ret; -#ifdef CONFIG_MODULES + if (!call->name) + return -EINVAL; -static LIST_HEAD(ftrace_module_file_list); + if (call->raw_init) { + ret = call->raw_init(call); + if (ret < 0) { + if (ret != -ENOSYS) + pr_warning("Could not initialize trace " + "events/%s\n", call->name); + return ret; + } + } -/* - * Modules must own their file_operations to keep up with - * reference counting. - */ -struct ftrace_module_file_ops { - struct list_head list; - struct module *mod; - struct file_operations id; - struct file_operations enable; - struct file_operations format; - struct file_operations filter; -}; + d_events = event_trace_events_dir(); + if (!d_events) + return -ENOENT; + + ret = event_create_dir(call, d_events, &ftrace_event_id_fops, + &ftrace_enable_fops, &ftrace_event_filter_fops, + &ftrace_event_format_fops); + if (!ret) + list_add(&call->list, &ftrace_events); + + return ret; +} + +/* Add an additional event_call dynamically */ +int trace_add_event_call(struct ftrace_event_call *call) +{ + int ret; + mutex_lock(&event_mutex); + ret = __trace_add_event_call(call); + mutex_unlock(&event_mutex); + return ret; +} static void remove_subsystem_dir(const char *name) { @@ -985,6 +1000,53 @@ static void remove_subsystem_dir(const char *name) } } +/* + * Must be called under locking both of event_mutex and trace_event_mutex. + */ +static void __trace_remove_event_call(struct ftrace_event_call *call) +{ + ftrace_event_enable_disable(call, 0); + if (call->event) + __unregister_ftrace_event(call->event); + debugfs_remove_recursive(call->dir); + list_del(&call->list); + trace_destroy_fields(call); + destroy_preds(call); + remove_subsystem_dir(call->system); +} + +/* Remove an event_call */ +void trace_remove_event_call(struct ftrace_event_call *call) +{ + mutex_lock(&event_mutex); + down_write(&trace_event_mutex); + __trace_remove_event_call(call); + up_write(&trace_event_mutex); + mutex_unlock(&event_mutex); +} + +#define for_each_event(event, start, end) \ + for (event = start; \ + (unsigned long)event < (unsigned long)end; \ + event++) + +#ifdef CONFIG_MODULES + +static LIST_HEAD(ftrace_module_file_list); + +/* + * Modules must own their file_operations to keep up with + * reference counting. + */ +struct ftrace_module_file_ops { + struct list_head list; + struct module *mod; + struct file_operations id; + struct file_operations enable; + struct file_operations format; + struct file_operations filter; +}; + static struct ftrace_module_file_ops * trace_create_file_ops(struct module *mod) { @@ -1042,7 +1104,7 @@ static void trace_module_add_events(struct module *mod) if (!call->name) continue; if (call->raw_init) { - ret = call->raw_init(); + ret = call->raw_init(call); if (ret < 0) { if (ret != -ENOSYS) pr_warning("Could not initialize trace " @@ -1060,10 +1122,11 @@ static void trace_module_add_events(struct module *mod) return; } call->mod = mod; - list_add(&call->list, &ftrace_events); - event_create_dir(call, d_events, - &file_ops->id, &file_ops->enable, - &file_ops->filter, &file_ops->format); + ret = event_create_dir(call, d_events, + &file_ops->id, &file_ops->enable, + &file_ops->filter, &file_ops->format); + if (!ret) + list_add(&call->list, &ftrace_events); } } @@ -1077,14 +1140,7 @@ static void trace_module_remove_events(struct module *mod) list_for_each_entry_safe(call, p, &ftrace_events, list) { if (call->mod == mod) { found = true; - ftrace_event_enable_disable(call, 0); - if (call->event) - __unregister_ftrace_event(call->event); - debugfs_remove_recursive(call->dir); - list_del(&call->list); - trace_destroy_fields(call); - destroy_preds(call); - remove_subsystem_dir(call->system); + __trace_remove_event_call(call); } } @@ -1202,7 +1258,7 @@ static __init int event_trace_init(void) if (!call->name) continue; if (call->raw_init) { - ret = call->raw_init(); + ret = call->raw_init(call); if (ret < 0) { if (ret != -ENOSYS) pr_warning("Could not initialize trace " @@ -1210,10 +1266,12 @@ static __init int event_trace_init(void) continue; } } - list_add(&call->list, &ftrace_events); - event_create_dir(call, d_events, &ftrace_event_id_fops, - &ftrace_enable_fops, &ftrace_event_filter_fops, - &ftrace_event_format_fops); + ret = event_create_dir(call, d_events, &ftrace_event_id_fops, + &ftrace_enable_fops, + &ftrace_event_filter_fops, + &ftrace_event_format_fops); + if (!ret) + list_add(&call->list, &ftrace_events); } while (true) { diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index 92672016da2..50504cb228d 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -21,6 +21,7 @@ #include <linux/module.h> #include <linux/ctype.h> #include <linux/mutex.h> +#include <linux/perf_event.h> #include "trace.h" #include "trace_output.h" @@ -29,6 +30,7 @@ enum filter_op_ids { OP_OR, OP_AND, + OP_GLOB, OP_NE, OP_EQ, OP_LT, @@ -46,16 +48,17 @@ struct filter_op { }; static struct filter_op filter_ops[] = { - { OP_OR, "||", 1 }, - { OP_AND, "&&", 2 }, - { OP_NE, "!=", 4 }, - { OP_EQ, "==", 4 }, - { OP_LT, "<", 5 }, - { OP_LE, "<=", 5 }, - { OP_GT, ">", 5 }, - { OP_GE, ">=", 5 }, - { OP_NONE, "OP_NONE", 0 }, - { OP_OPEN_PAREN, "(", 0 }, + { OP_OR, "||", 1 }, + { OP_AND, "&&", 2 }, + { OP_GLOB, "~", 4 }, + { OP_NE, "!=", 4 }, + { OP_EQ, "==", 4 }, + { OP_LT, "<", 5 }, + { OP_LE, "<=", 5 }, + { OP_GT, ">", 5 }, + { OP_GE, ">=", 5 }, + { OP_NONE, "OP_NONE", 0 }, + { OP_OPEN_PAREN, "(", 0 }, }; enum { @@ -329,22 +332,18 @@ enum regex_type filter_parse_regex(char *buff, int len, char **search, int *not) return type; } -static int filter_build_regex(struct filter_pred *pred) +static void filter_build_regex(struct filter_pred *pred) { struct regex *r = &pred->regex; - char *search, *dup; - enum regex_type type; - int not; - - type = filter_parse_regex(r->pattern, r->len, &search, ¬); - dup = kstrdup(search, GFP_KERNEL); - if (!dup) - return -ENOMEM; - - strcpy(r->pattern, dup); - kfree(dup); - - r->len = strlen(r->pattern); + char *search; + enum regex_type type = MATCH_FULL; + int not = 0; + + if (pred->op == OP_GLOB) { + type = filter_parse_regex(r->pattern, r->len, &search, ¬); + r->len = strlen(search); + memmove(r->pattern, search, r->len+1); + } switch (type) { case MATCH_FULL: @@ -362,14 +361,11 @@ static int filter_build_regex(struct filter_pred *pred) } pred->not ^= not; - - return 0; } /* return 1 if event matches, 0 otherwise (discard) */ -int filter_match_preds(struct ftrace_event_call *call, void *rec) +int filter_match_preds(struct event_filter *filter, void *rec) { - struct event_filter *filter = call->filter; int match, top = 0, val1 = 0, val2 = 0; int stack[MAX_FILTER_PRED]; struct filter_pred *pred; @@ -542,9 +538,8 @@ static void filter_disable_preds(struct ftrace_event_call *call) filter->preds[i]->fn = filter_pred_none; } -void destroy_preds(struct ftrace_event_call *call) +static void __free_preds(struct event_filter *filter) { - struct event_filter *filter = call->filter; int i; if (!filter) @@ -557,21 +552,24 @@ void destroy_preds(struct ftrace_event_call *call) kfree(filter->preds); kfree(filter->filter_string); kfree(filter); +} + +void destroy_preds(struct ftrace_event_call *call) +{ + __free_preds(call->filter); call->filter = NULL; + call->filter_active = 0; } -static int init_preds(struct ftrace_event_call *call) +static struct event_filter *__alloc_preds(void) { struct event_filter *filter; struct filter_pred *pred; int i; - if (call->filter) - return 0; - - filter = call->filter = kzalloc(sizeof(*filter), GFP_KERNEL); - if (!call->filter) - return -ENOMEM; + filter = kzalloc(sizeof(*filter), GFP_KERNEL); + if (!filter) + return ERR_PTR(-ENOMEM); filter->n_preds = 0; @@ -587,12 +585,24 @@ static int init_preds(struct ftrace_event_call *call) filter->preds[i] = pred; } - return 0; + return filter; oom: - destroy_preds(call); + __free_preds(filter); + return ERR_PTR(-ENOMEM); +} + +static int init_preds(struct ftrace_event_call *call) +{ + if (call->filter) + return 0; - return -ENOMEM; + call->filter_active = 0; + call->filter = __alloc_preds(); + if (IS_ERR(call->filter)) + return PTR_ERR(call->filter); + + return 0; } static int init_subsystem_preds(struct event_subsystem *system) @@ -615,14 +625,7 @@ static int init_subsystem_preds(struct event_subsystem *system) return 0; } -enum { - FILTER_DISABLE_ALL, - FILTER_INIT_NO_RESET, - FILTER_SKIP_NO_RESET, -}; - -static void filter_free_subsystem_preds(struct event_subsystem *system, - int flag) +static void filter_free_subsystem_preds(struct event_subsystem *system) { struct ftrace_event_call *call; @@ -633,14 +636,6 @@ static void filter_free_subsystem_preds(struct event_subsystem *system, if (strcmp(call->system, system->name) != 0) continue; - if (flag == FILTER_INIT_NO_RESET) { - call->filter->no_reset = false; - continue; - } - - if (flag == FILTER_SKIP_NO_RESET && call->filter->no_reset) - continue; - filter_disable_preds(call); remove_filter_string(call->filter); } @@ -648,10 +643,10 @@ static void filter_free_subsystem_preds(struct event_subsystem *system, static int filter_add_pred_fn(struct filter_parse_state *ps, struct ftrace_event_call *call, + struct event_filter *filter, struct filter_pred *pred, filter_pred_fn_t fn) { - struct event_filter *filter = call->filter; int idx, err; if (filter->n_preds == MAX_FILTER_PRED) { @@ -666,7 +661,6 @@ static int filter_add_pred_fn(struct filter_parse_state *ps, return err; filter->n_preds++; - call->filter_active = 1; return 0; } @@ -691,7 +685,10 @@ static bool is_string_field(struct ftrace_event_field *field) static int is_legal_op(struct ftrace_event_field *field, int op) { - if (is_string_field(field) && (op != OP_EQ && op != OP_NE)) + if (is_string_field(field) && + (op != OP_EQ && op != OP_NE && op != OP_GLOB)) + return 0; + if (!is_string_field(field) && op == OP_GLOB) return 0; return 1; @@ -742,6 +739,7 @@ static filter_pred_fn_t select_comparison_fn(int op, int field_size, static int filter_add_pred(struct filter_parse_state *ps, struct ftrace_event_call *call, + struct event_filter *filter, struct filter_pred *pred, bool dry_run) { @@ -776,15 +774,13 @@ static int filter_add_pred(struct filter_parse_state *ps, } if (is_string_field(field)) { - ret = filter_build_regex(pred); - if (ret) - return ret; + filter_build_regex(pred); if (field->filter_type == FILTER_STATIC_STRING) { fn = filter_pred_string; pred->regex.field_len = field->size; } else if (field->filter_type == FILTER_DYN_STRING) - fn = filter_pred_strloc; + fn = filter_pred_strloc; else { fn = filter_pred_pchar; pred->regex.field_len = strlen(pred->regex.pattern); @@ -813,45 +809,7 @@ static int filter_add_pred(struct filter_parse_state *ps, add_pred_fn: if (!dry_run) - return filter_add_pred_fn(ps, call, pred, fn); - return 0; -} - -static int filter_add_subsystem_pred(struct filter_parse_state *ps, - struct event_subsystem *system, - struct filter_pred *pred, - char *filter_string, - bool dry_run) -{ - struct ftrace_event_call *call; - int err = 0; - bool fail = true; - - list_for_each_entry(call, &ftrace_events, list) { - - if (!call->define_fields) - continue; - - if (strcmp(call->system, system->name)) - continue; - - if (call->filter->no_reset) - continue; - - err = filter_add_pred(ps, call, pred, dry_run); - if (err) - call->filter->no_reset = true; - else - fail = false; - - if (!dry_run) - replace_filter_string(call->filter, filter_string); - } - - if (fail) { - parse_error(ps, FILT_ERR_BAD_SUBSYS_FILTER, 0); - return err; - } + return filter_add_pred_fn(ps, call, filter, pred, fn); return 0; } @@ -1209,8 +1167,8 @@ static int check_preds(struct filter_parse_state *ps) return 0; } -static int replace_preds(struct event_subsystem *system, - struct ftrace_event_call *call, +static int replace_preds(struct ftrace_event_call *call, + struct event_filter *filter, struct filter_parse_state *ps, char *filter_string, bool dry_run) @@ -1257,11 +1215,7 @@ static int replace_preds(struct event_subsystem *system, add_pred: if (!pred) return -ENOMEM; - if (call) - err = filter_add_pred(ps, call, pred, false); - else - err = filter_add_subsystem_pred(ps, system, pred, - filter_string, dry_run); + err = filter_add_pred(ps, call, filter, pred, dry_run); filter_free_pred(pred); if (err) return err; @@ -1272,10 +1226,50 @@ add_pred: return 0; } -int apply_event_filter(struct ftrace_event_call *call, char *filter_string) +static int replace_system_preds(struct event_subsystem *system, + struct filter_parse_state *ps, + char *filter_string) { + struct ftrace_event_call *call; + bool fail = true; int err; + list_for_each_entry(call, &ftrace_events, list) { + struct event_filter *filter = call->filter; + + if (!call->define_fields) + continue; + + if (strcmp(call->system, system->name) != 0) + continue; + + /* try to see if the filter can be applied */ + err = replace_preds(call, filter, ps, filter_string, true); + if (err) + continue; + + /* really apply the filter */ + filter_disable_preds(call); + err = replace_preds(call, filter, ps, filter_string, false); + if (err) + filter_disable_preds(call); + else { + call->filter_active = 1; + replace_filter_string(filter, filter_string); + } + fail = false; + } + + if (fail) { + parse_error(ps, FILT_ERR_BAD_SUBSYS_FILTER, 0); + return -EINVAL; + } + return 0; +} + +int apply_event_filter(struct ftrace_event_call *call, char *filter_string) +{ + int err; struct filter_parse_state *ps; mutex_lock(&event_mutex); @@ -1287,8 +1281,7 @@ int apply_event_filter(struct ftrace_event_call *call, char *filter_string) if (!strcmp(strstrip(filter_string), "0")) { filter_disable_preds(call); remove_filter_string(call->filter); - mutex_unlock(&event_mutex); - return 0; + goto out_unlock; } err = -ENOMEM; @@ -1306,10 +1299,11 @@ int apply_event_filter(struct ftrace_event_call *call, char *filter_string) goto out; } - err = replace_preds(NULL, call, ps, filter_string, false); + err = replace_preds(call, call->filter, ps, filter_string, false); if (err) append_filter_err(ps, call->filter); - + else + call->filter_active = 1; out: filter_opstack_clear(ps); postfix_clear(ps); @@ -1324,7 +1318,6 @@ int apply_subsystem_event_filter(struct event_subsystem *system, char *filter_string) { int err; - struct filter_parse_state *ps; mutex_lock(&event_mutex); @@ -1334,10 +1327,9 @@ int apply_subsystem_event_filter(struct event_subsystem *system, goto out_unlock; if (!strcmp(strstrip(filter_string), "0")) { - filter_free_subsystem_preds(system, FILTER_DISABLE_ALL); + filter_free_subsystem_preds(system); remove_filter_string(system->filter); - mutex_unlock(&event_mutex); - return 0; + goto out_unlock; } err = -ENOMEM; @@ -1354,31 +1346,87 @@ int apply_subsystem_event_filter(struct event_subsystem *system, goto out; } - filter_free_subsystem_preds(system, FILTER_INIT_NO_RESET); - - /* try to see the filter can be applied to which events */ - err = replace_preds(system, NULL, ps, filter_string, true); - if (err) { + err = replace_system_preds(system, ps, filter_string); + if (err) append_filter_err(ps, system->filter); - goto out; + +out: + filter_opstack_clear(ps); + postfix_clear(ps); + kfree(ps); +out_unlock: + mutex_unlock(&event_mutex); + + return err; +} + +#ifdef CONFIG_EVENT_PROFILE + +void ftrace_profile_free_filter(struct perf_event *event) +{ + struct event_filter *filter = event->filter; + + event->filter = NULL; + __free_preds(filter); +} + +int ftrace_profile_set_filter(struct perf_event *event, int event_id, + char *filter_str) +{ + int err; + struct event_filter *filter; + struct filter_parse_state *ps; + struct ftrace_event_call *call = NULL; + + mutex_lock(&event_mutex); + + list_for_each_entry(call, &ftrace_events, list) { + if (call->id == event_id) + break; } - filter_free_subsystem_preds(system, FILTER_SKIP_NO_RESET); + err = -EINVAL; + if (!call) + goto out_unlock; - /* really apply the filter to the events */ - err = replace_preds(system, NULL, ps, filter_string, false); - if (err) { - append_filter_err(ps, system->filter); - filter_free_subsystem_preds(system, 2); + err = -EEXIST; + if (event->filter) + goto out_unlock; + + filter = __alloc_preds(); + if (IS_ERR(filter)) { + err = PTR_ERR(filter); + goto out_unlock; } -out: + err = -ENOMEM; + ps = kzalloc(sizeof(*ps), GFP_KERNEL); + if (!ps) + goto free_preds; + + parse_init(ps, filter_ops, filter_str); + err = filter_parse(ps); + if (err) + goto free_ps; + + err = replace_preds(call, filter, ps, filter_str, false); + if (!err) + event->filter = filter; + +free_ps: filter_opstack_clear(ps); postfix_clear(ps); kfree(ps); + +free_preds: + if (err) + __free_preds(filter); + out_unlock: mutex_unlock(&event_mutex); return err; } +#endif /* CONFIG_EVENT_PROFILE */ + diff --git a/kernel/trace/trace_export.c b/kernel/trace/trace_export.c index c74848ddb85..dff8c84ddf1 100644 --- a/kernel/trace/trace_export.c +++ b/kernel/trace/trace_export.c @@ -66,44 +66,47 @@ static void __always_unused ____ftrace_check_##name(void) \ #undef __field #define __field(type, item) \ ret = trace_seq_printf(s, "\tfield:" #type " " #item ";\t" \ - "offset:%zu;\tsize:%zu;\n", \ + "offset:%zu;\tsize:%zu;\tsigned:%u;\n", \ offsetof(typeof(field), item), \ - sizeof(field.item)); \ + sizeof(field.item), is_signed_type(type)); \ if (!ret) \ return 0; #undef __field_desc #define __field_desc(type, container, item) \ ret = trace_seq_printf(s, "\tfield:" #type " " #item ";\t" \ - "offset:%zu;\tsize:%zu;\n", \ + "offset:%zu;\tsize:%zu;\tsigned:%u;\n", \ offsetof(typeof(field), container.item), \ - sizeof(field.container.item)); \ + sizeof(field.container.item), \ + is_signed_type(type)); \ if (!ret) \ return 0; #undef __array #define __array(type, item, len) \ ret = trace_seq_printf(s, "\tfield:" #type " " #item "[" #len "];\t" \ - "offset:%zu;\tsize:%zu;\n", \ - offsetof(typeof(field), item), \ - sizeof(field.item)); \ + "offset:%zu;\tsize:%zu;\tsigned:%u;\n", \ + offsetof(typeof(field), item), \ + sizeof(field.item), is_signed_type(type)); \ if (!ret) \ return 0; #undef __array_desc #define __array_desc(type, container, item, len) \ ret = trace_seq_printf(s, "\tfield:" #type " " #item "[" #len "];\t" \ - "offset:%zu;\tsize:%zu;\n", \ + "offset:%zu;\tsize:%zu;\tsigned:%u;\n", \ offsetof(typeof(field), container.item), \ - sizeof(field.container.item)); \ + sizeof(field.container.item), \ + is_signed_type(type)); \ if (!ret) \ return 0; #undef __dynamic_array #define __dynamic_array(type, item) \ ret = trace_seq_printf(s, "\tfield:" #type " " #item ";\t" \ - "offset:%zu;\tsize:0;\n", \ - offsetof(typeof(field), item)); \ + "offset:%zu;\tsize:0;\tsigned:%u;\n", \ + offsetof(typeof(field), item), \ + is_signed_type(type)); \ if (!ret) \ return 0; @@ -131,7 +134,6 @@ ftrace_format_##name(struct ftrace_event_call *unused, \ #include "trace_entries.h" - #undef __field #define __field(type, item) \ ret = trace_define_field(event_call, #type, #item, \ @@ -193,6 +195,11 @@ ftrace_define_fields_##name(struct ftrace_event_call *event_call) \ #include "trace_entries.h" +static int ftrace_raw_init_event(struct ftrace_event_call *call) +{ + INIT_LIST_HEAD(&call->fields); + return 0; +} #undef __field #define __field(type, item) @@ -211,7 +218,6 @@ ftrace_define_fields_##name(struct ftrace_event_call *event_call) \ #undef FTRACE_ENTRY #define FTRACE_ENTRY(call, struct_name, type, tstruct, print) \ -static int ftrace_raw_init_event_##call(void); \ \ struct ftrace_event_call __used \ __attribute__((__aligned__(4))) \ @@ -219,14 +225,9 @@ __attribute__((section("_ftrace_events"))) event_##call = { \ .name = #call, \ .id = type, \ .system = __stringify(TRACE_SYSTEM), \ - .raw_init = ftrace_raw_init_event_##call, \ + .raw_init = ftrace_raw_init_event, \ .show_format = ftrace_format_##call, \ .define_fields = ftrace_define_fields_##call, \ }; \ -static int ftrace_raw_init_event_##call(void) \ -{ \ - INIT_LIST_HEAD(&event_##call.fields); \ - return 0; \ -} \ #include "trace_entries.h" diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c new file mode 100644 index 00000000000..aff5f80b59b --- /dev/null +++ b/kernel/trace/trace_kprobe.c @@ -0,0 +1,1523 @@ +/* + * Kprobes-based tracing events + * + * Created by Masami Hiramatsu <mhiramat@redhat.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <linux/module.h> +#include <linux/uaccess.h> +#include <linux/kprobes.h> +#include <linux/seq_file.h> +#include <linux/slab.h> +#include <linux/smp.h> +#include <linux/debugfs.h> +#include <linux/types.h> +#include <linux/string.h> +#include <linux/ctype.h> +#include <linux/ptrace.h> +#include <linux/perf_event.h> + +#include "trace.h" +#include "trace_output.h" + +#define MAX_TRACE_ARGS 128 +#define MAX_ARGSTR_LEN 63 +#define MAX_EVENT_NAME_LEN 64 +#define KPROBE_EVENT_SYSTEM "kprobes" + +/* Reserved field names */ +#define FIELD_STRING_IP "__probe_ip" +#define FIELD_STRING_NARGS "__probe_nargs" +#define FIELD_STRING_RETIP "__probe_ret_ip" +#define FIELD_STRING_FUNC "__probe_func" + +const char *reserved_field_names[] = { + "common_type", + "common_flags", + "common_preempt_count", + "common_pid", + "common_tgid", + "common_lock_depth", + FIELD_STRING_IP, + FIELD_STRING_NARGS, + FIELD_STRING_RETIP, + FIELD_STRING_FUNC, +}; + +struct fetch_func { + unsigned long (*func)(struct pt_regs *, void *); + void *data; +}; + +static __kprobes unsigned long call_fetch(struct fetch_func *f, + struct pt_regs *regs) +{ + return f->func(regs, f->data); +} + +/* fetch handlers */ +static __kprobes unsigned long fetch_register(struct pt_regs *regs, + void *offset) +{ + return regs_get_register(regs, (unsigned int)((unsigned long)offset)); +} + +static __kprobes unsigned long fetch_stack(struct pt_regs *regs, + void *num) +{ + return regs_get_kernel_stack_nth(regs, + (unsigned int)((unsigned long)num)); +} + +static __kprobes unsigned long fetch_memory(struct pt_regs *regs, void *addr) +{ + unsigned long retval; + + if (probe_kernel_address(addr, retval)) + return 0; + return retval; +} + +static __kprobes unsigned long fetch_argument(struct pt_regs *regs, void *num) +{ + return regs_get_argument_nth(regs, (unsigned int)((unsigned long)num)); +} + +static __kprobes unsigned long fetch_retvalue(struct pt_regs *regs, + void *dummy) +{ + return regs_return_value(regs); +} + +static __kprobes unsigned long fetch_stack_address(struct pt_regs *regs, + void *dummy) +{ + return kernel_stack_pointer(regs); +} + +/* Memory fetching by symbol */ +struct symbol_cache { + char *symbol; + long offset; + unsigned long addr; +}; + +static unsigned long update_symbol_cache(struct symbol_cache *sc) +{ + sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol); + if (sc->addr) + sc->addr += sc->offset; + return sc->addr; +} + +static void free_symbol_cache(struct symbol_cache *sc) +{ + kfree(sc->symbol); + kfree(sc); +} + +static struct symbol_cache *alloc_symbol_cache(const char *sym, long offset) +{ + struct symbol_cache *sc; + + if (!sym || strlen(sym) == 0) + return NULL; + sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL); + if (!sc) + return NULL; + + sc->symbol = kstrdup(sym, GFP_KERNEL); + if (!sc->symbol) { + kfree(sc); + return NULL; + } + sc->offset = offset; + + update_symbol_cache(sc); + return sc; +} + +static __kprobes unsigned long fetch_symbol(struct pt_regs *regs, void *data) +{ + struct symbol_cache *sc = data; + + if (sc->addr) + return fetch_memory(regs, (void *)sc->addr); + else + return 0; +} + +/* Special indirect memory access interface */ +struct indirect_fetch_data { + struct fetch_func orig; + long offset; +}; + +static __kprobes unsigned long fetch_indirect(struct pt_regs *regs, void *data) +{ + struct indirect_fetch_data *ind = data; + unsigned long addr; + + addr = call_fetch(&ind->orig, regs); + if (addr) { + addr += ind->offset; + return fetch_memory(regs, (void *)addr); + } else + return 0; +} + +static __kprobes void free_indirect_fetch_data(struct indirect_fetch_data *data) +{ + if (data->orig.func == fetch_indirect) + free_indirect_fetch_data(data->orig.data); + else if (data->orig.func == fetch_symbol) + free_symbol_cache(data->orig.data); + kfree(data); +} + +/** + * Kprobe event core functions + */ + +struct probe_arg { + struct fetch_func fetch; + const char *name; +}; + +/* Flags for trace_probe */ +#define TP_FLAG_TRACE 1 +#define TP_FLAG_PROFILE 2 + +struct trace_probe { + struct list_head list; + struct kretprobe rp; /* Use rp.kp for kprobe use */ + unsigned long nhit; + unsigned int flags; /* For TP_FLAG_* */ + const char *symbol; /* symbol name */ + struct ftrace_event_call call; + struct trace_event event; + unsigned int nr_args; + struct probe_arg args[]; +}; + +#define SIZEOF_TRACE_PROBE(n) \ + (offsetof(struct trace_probe, args) + \ + (sizeof(struct probe_arg) * (n))) + +static __kprobes int probe_is_return(struct trace_probe *tp) +{ + return tp->rp.handler != NULL; +} + +static __kprobes const char *probe_symbol(struct trace_probe *tp) +{ + return tp->symbol ? tp->symbol : "unknown"; +} + +static int probe_arg_string(char *buf, size_t n, struct fetch_func *ff) +{ + int ret = -EINVAL; + + if (ff->func == fetch_argument) + ret = snprintf(buf, n, "$arg%lu", (unsigned long)ff->data); + else if (ff->func == fetch_register) { + const char *name; + name = regs_query_register_name((unsigned int)((long)ff->data)); + ret = snprintf(buf, n, "%%%s", name); + } else if (ff->func == fetch_stack) + ret = snprintf(buf, n, "$stack%lu", (unsigned long)ff->data); + else if (ff->func == fetch_memory) + ret = snprintf(buf, n, "@0x%p", ff->data); + else if (ff->func == fetch_symbol) { + struct symbol_cache *sc = ff->data; + if (sc->offset) + ret = snprintf(buf, n, "@%s%+ld", sc->symbol, + sc->offset); + else + ret = snprintf(buf, n, "@%s", sc->symbol); + } else if (ff->func == fetch_retvalue) + ret = snprintf(buf, n, "$retval"); + else if (ff->func == fetch_stack_address) + ret = snprintf(buf, n, "$stack"); + else if (ff->func == fetch_indirect) { + struct indirect_fetch_data *id = ff->data; + size_t l = 0; + ret = snprintf(buf, n, "%+ld(", id->offset); + if (ret >= n) + goto end; + l += ret; + ret = probe_arg_string(buf + l, n - l, &id->orig); + if (ret < 0) + goto end; + l += ret; + ret = snprintf(buf + l, n - l, ")"); + ret += l; + } +end: + if (ret >= n) + return -ENOSPC; + return ret; +} + +static int register_probe_event(struct trace_probe *tp); +static void unregister_probe_event(struct trace_probe *tp); + +static DEFINE_MUTEX(probe_lock); +static LIST_HEAD(probe_list); + +static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs); +static int kretprobe_dispatcher(struct kretprobe_instance *ri, + struct pt_regs *regs); + +/* + * Allocate new trace_probe and initialize it (including kprobes). + */ +static struct trace_probe *alloc_trace_probe(const char *group, + const char *event, + void *addr, + const char *symbol, + unsigned long offs, + int nargs, int is_return) +{ + struct trace_probe *tp; + + tp = kzalloc(SIZEOF_TRACE_PROBE(nargs), GFP_KERNEL); + if (!tp) + return ERR_PTR(-ENOMEM); + + if (symbol) { + tp->symbol = kstrdup(symbol, GFP_KERNEL); + if (!tp->symbol) + goto error; + tp->rp.kp.symbol_name = tp->symbol; + tp->rp.kp.offset = offs; + } else + tp->rp.kp.addr = addr; + + if (is_return) + tp->rp.handler = kretprobe_dispatcher; + else + tp->rp.kp.pre_handler = kprobe_dispatcher; + + if (!event) + goto error; + tp->call.name = kstrdup(event, GFP_KERNEL); + if (!tp->call.name) + goto error; + + if (!group) + goto error; + tp->call.system = kstrdup(group, GFP_KERNEL); + if (!tp->call.system) + goto error; + + INIT_LIST_HEAD(&tp->list); + return tp; +error: + kfree(tp->call.name); + kfree(tp->symbol); + kfree(tp); + return ERR_PTR(-ENOMEM); +} + +static void free_probe_arg(struct probe_arg *arg) +{ + if (arg->fetch.func == fetch_symbol) + free_symbol_cache(arg->fetch.data); + else if (arg->fetch.func == fetch_indirect) + free_indirect_fetch_data(arg->fetch.data); + kfree(arg->name); +} + +static void free_trace_probe(struct trace_probe *tp) +{ + int i; + + for (i = 0; i < tp->nr_args; i++) + free_probe_arg(&tp->args[i]); + + kfree(tp->call.system); + kfree(tp->call.name); + kfree(tp->symbol); + kfree(tp); +} + +static struct trace_probe *find_probe_event(const char *event, + const char *group) +{ + struct trace_probe *tp; + + list_for_each_entry(tp, &probe_list, list) + if (strcmp(tp->call.name, event) == 0 && + strcmp(tp->call.system, group) == 0) + return tp; + return NULL; +} + +/* Unregister a trace_probe and probe_event: call with locking probe_lock */ +static void unregister_trace_probe(struct trace_probe *tp) +{ + if (probe_is_return(tp)) + unregister_kretprobe(&tp->rp); + else + unregister_kprobe(&tp->rp.kp); + list_del(&tp->list); + unregister_probe_event(tp); +} + +/* Register a trace_probe and probe_event */ +static int register_trace_probe(struct trace_probe *tp) +{ + struct trace_probe *old_tp; + int ret; + + mutex_lock(&probe_lock); + + /* register as an event */ + old_tp = find_probe_event(tp->call.name, tp->call.system); + if (old_tp) { + /* delete old event */ + unregister_trace_probe(old_tp); + free_trace_probe(old_tp); + } + ret = register_probe_event(tp); + if (ret) { + pr_warning("Faild to register probe event(%d)\n", ret); + goto end; + } + + tp->rp.kp.flags |= KPROBE_FLAG_DISABLED; + if (probe_is_return(tp)) + ret = register_kretprobe(&tp->rp); + else + ret = register_kprobe(&tp->rp.kp); + + if (ret) { + pr_warning("Could not insert probe(%d)\n", ret); + if (ret == -EILSEQ) { + pr_warning("Probing address(0x%p) is not an " + "instruction boundary.\n", + tp->rp.kp.addr); + ret = -EINVAL; + } + unregister_probe_event(tp); + } else + list_add_tail(&tp->list, &probe_list); +end: + mutex_unlock(&probe_lock); + return ret; +} + +/* Split symbol and offset. */ +static int split_symbol_offset(char *symbol, unsigned long *offset) +{ + char *tmp; + int ret; + + if (!offset) + return -EINVAL; + + tmp = strchr(symbol, '+'); + if (tmp) { + /* skip sign because strict_strtol doesn't accept '+' */ + ret = strict_strtoul(tmp + 1, 0, offset); + if (ret) + return ret; + *tmp = '\0'; + } else + *offset = 0; + return 0; +} + +#define PARAM_MAX_ARGS 16 +#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) + +static int parse_probe_vars(char *arg, struct fetch_func *ff, int is_return) +{ + int ret = 0; + unsigned long param; + + if (strcmp(arg, "retval") == 0) { + if (is_return) { + ff->func = fetch_retvalue; + ff->data = NULL; + } else + ret = -EINVAL; + } else if (strncmp(arg, "stack", 5) == 0) { + if (arg[5] == '\0') { + ff->func = fetch_stack_address; + ff->data = NULL; + } else if (isdigit(arg[5])) { + ret = strict_strtoul(arg + 5, 10, ¶m); + if (ret || param > PARAM_MAX_STACK) + ret = -EINVAL; + else { + ff->func = fetch_stack; + ff->data = (void *)param; + } + } else + ret = -EINVAL; + } else if (strncmp(arg, "arg", 3) == 0 && isdigit(arg[3])) { + ret = strict_strtoul(arg + 3, 10, ¶m); + if (ret || param > PARAM_MAX_ARGS) + ret = -EINVAL; + else { + ff->func = fetch_argument; + ff->data = (void *)param; + } + } else + ret = -EINVAL; + return ret; +} + +/* Recursive argument parser */ +static int __parse_probe_arg(char *arg, struct fetch_func *ff, int is_return) +{ + int ret = 0; + unsigned long param; + long offset; + char *tmp; + + switch (arg[0]) { + case '$': + ret = parse_probe_vars(arg + 1, ff, is_return); + break; + case '%': /* named register */ + ret = regs_query_register_offset(arg + 1); + if (ret >= 0) { + ff->func = fetch_register; + ff->data = (void *)(unsigned long)ret; + ret = 0; + } + break; + case '@': /* memory or symbol */ + if (isdigit(arg[1])) { + ret = strict_strtoul(arg + 1, 0, ¶m); + if (ret) + break; + ff->func = fetch_memory; + ff->data = (void *)param; + } else { + ret = split_symbol_offset(arg + 1, &offset); + if (ret) + break; + ff->data = alloc_symbol_cache(arg + 1, offset); + if (ff->data) + ff->func = fetch_symbol; + else + ret = -EINVAL; + } + break; + case '+': /* indirect memory */ + case '-': + tmp = strchr(arg, '('); + if (!tmp) { + ret = -EINVAL; + break; + } + *tmp = '\0'; + ret = strict_strtol(arg + 1, 0, &offset); + if (ret) + break; + if (arg[0] == '-') + offset = -offset; + arg = tmp + 1; + tmp = strrchr(arg, ')'); + if (tmp) { + struct indirect_fetch_data *id; + *tmp = '\0'; + id = kzalloc(sizeof(struct indirect_fetch_data), + GFP_KERNEL); + if (!id) + return -ENOMEM; + id->offset = offset; + ret = __parse_probe_arg(arg, &id->orig, is_return); + if (ret) + kfree(id); + else { + ff->func = fetch_indirect; + ff->data = (void *)id; + } + } else + ret = -EINVAL; + break; + default: + /* TODO: support custom handler */ + ret = -EINVAL; + } + return ret; +} + +/* String length checking wrapper */ +static int parse_probe_arg(char *arg, struct fetch_func *ff, int is_return) +{ + if (strlen(arg) > MAX_ARGSTR_LEN) { + pr_info("Argument is too long.: %s\n", arg); + return -ENOSPC; + } + return __parse_probe_arg(arg, ff, is_return); +} + +/* Return 1 if name is reserved or already used by another argument */ +static int conflict_field_name(const char *name, + struct probe_arg *args, int narg) +{ + int i; + for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++) + if (strcmp(reserved_field_names[i], name) == 0) + return 1; + for (i = 0; i < narg; i++) + if (strcmp(args[i].name, name) == 0) + return 1; + return 0; +} + +static int create_trace_probe(int argc, char **argv) +{ + /* + * Argument syntax: + * - Add kprobe: p[:[GRP/]EVENT] KSYM[+OFFS]|KADDR [FETCHARGS] + * - Add kretprobe: r[:[GRP/]EVENT] KSYM[+0] [FETCHARGS] + * Fetch args: + * $argN : fetch Nth of function argument. (N:0-) + * $retval : fetch return value + * $stack : fetch stack address + * $stackN : fetch Nth of stack (N:0-) + * @ADDR : fetch memory at ADDR (ADDR should be in kernel) + * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol) + * %REG : fetch register REG + * Indirect memory fetch: + * +|-offs(ARG) : fetch memory at ARG +|- offs address. + * Alias name of args: + * NAME=FETCHARG : set NAME as alias of FETCHARG. + */ + struct trace_probe *tp; + int i, ret = 0; + int is_return = 0; + char *symbol = NULL, *event = NULL, *arg = NULL, *group = NULL; + unsigned long offset = 0; + void *addr = NULL; + char buf[MAX_EVENT_NAME_LEN]; + + if (argc < 2) { + pr_info("Probe point is not specified.\n"); + return -EINVAL; + } + + if (argv[0][0] == 'p') + is_return = 0; + else if (argv[0][0] == 'r') + is_return = 1; + else { + pr_info("Probe definition must be started with 'p' or 'r'.\n"); + return -EINVAL; + } + + if (argv[0][1] == ':') { + event = &argv[0][2]; + if (strchr(event, '/')) { + group = event; + event = strchr(group, '/') + 1; + event[-1] = '\0'; + if (strlen(group) == 0) { + pr_info("Group name is not specifiled\n"); + return -EINVAL; + } + } + if (strlen(event) == 0) { + pr_info("Event name is not specifiled\n"); + return -EINVAL; + } + } + + if (isdigit(argv[1][0])) { + if (is_return) { + pr_info("Return probe point must be a symbol.\n"); + return -EINVAL; + } + /* an address specified */ + ret = strict_strtoul(&argv[0][2], 0, (unsigned long *)&addr); + if (ret) { + pr_info("Failed to parse address.\n"); + return ret; + } + } else { + /* a symbol specified */ + symbol = argv[1]; + /* TODO: support .init module functions */ + ret = split_symbol_offset(symbol, &offset); + if (ret) { + pr_info("Failed to parse symbol.\n"); + return ret; + } + if (offset && is_return) { + pr_info("Return probe must be used without offset.\n"); + return -EINVAL; + } + } + argc -= 2; argv += 2; + + /* setup a probe */ + if (!group) + group = KPROBE_EVENT_SYSTEM; + if (!event) { + /* Make a new event name */ + if (symbol) + snprintf(buf, MAX_EVENT_NAME_LEN, "%c@%s%+ld", + is_return ? 'r' : 'p', symbol, offset); + else + snprintf(buf, MAX_EVENT_NAME_LEN, "%c@0x%p", + is_return ? 'r' : 'p', addr); + event = buf; + } + tp = alloc_trace_probe(group, event, addr, symbol, offset, argc, + is_return); + if (IS_ERR(tp)) { + pr_info("Failed to allocate trace_probe.(%d)\n", + (int)PTR_ERR(tp)); + return PTR_ERR(tp); + } + + /* parse arguments */ + ret = 0; + for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { + /* Parse argument name */ + arg = strchr(argv[i], '='); + if (arg) + *arg++ = '\0'; + else + arg = argv[i]; + + if (conflict_field_name(argv[i], tp->args, i)) { + pr_info("Argument%d name '%s' conflicts with " + "another field.\n", i, argv[i]); + ret = -EINVAL; + goto error; + } + + tp->args[i].name = kstrdup(argv[i], GFP_KERNEL); + if (!tp->args[i].name) { + pr_info("Failed to allocate argument%d name '%s'.\n", + i, argv[i]); + ret = -ENOMEM; + goto error; + } + + /* Parse fetch argument */ + ret = parse_probe_arg(arg, &tp->args[i].fetch, is_return); + if (ret) { + pr_info("Parse error at argument%d. (%d)\n", i, ret); + kfree(tp->args[i].name); + goto error; + } + + tp->nr_args++; + } + + ret = register_trace_probe(tp); + if (ret) + goto error; + return 0; + +error: + free_trace_probe(tp); + return ret; +} + +static void cleanup_all_probes(void) +{ + struct trace_probe *tp; + + mutex_lock(&probe_lock); + /* TODO: Use batch unregistration */ + while (!list_empty(&probe_list)) { + tp = list_entry(probe_list.next, struct trace_probe, list); + unregister_trace_probe(tp); + free_trace_probe(tp); + } + mutex_unlock(&probe_lock); +} + + +/* Probes listing interfaces */ +static void *probes_seq_start(struct seq_file *m, loff_t *pos) +{ + mutex_lock(&probe_lock); + return seq_list_start(&probe_list, *pos); +} + +static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos) +{ + return seq_list_next(v, &probe_list, pos); +} + +static void probes_seq_stop(struct seq_file *m, void *v) +{ + mutex_unlock(&probe_lock); +} + +static int probes_seq_show(struct seq_file *m, void *v) +{ + struct trace_probe *tp = v; + int i, ret; + char buf[MAX_ARGSTR_LEN + 1]; + + seq_printf(m, "%c", probe_is_return(tp) ? 'r' : 'p'); + seq_printf(m, ":%s/%s", tp->call.system, tp->call.name); + + if (!tp->symbol) + seq_printf(m, " 0x%p", tp->rp.kp.addr); + else if (tp->rp.kp.offset) + seq_printf(m, " %s+%u", probe_symbol(tp), tp->rp.kp.offset); + else + seq_printf(m, " %s", probe_symbol(tp)); + + for (i = 0; i < tp->nr_args; i++) { + ret = probe_arg_string(buf, MAX_ARGSTR_LEN, &tp->args[i].fetch); + if (ret < 0) { + pr_warning("Argument%d decoding error(%d).\n", i, ret); + return ret; + } + seq_printf(m, " %s=%s", tp->args[i].name, buf); + } + seq_printf(m, "\n"); + return 0; +} + +static const struct seq_operations probes_seq_op = { + .start = probes_seq_start, + .next = probes_seq_next, + .stop = probes_seq_stop, + .show = probes_seq_show +}; + +static int probes_open(struct inode *inode, struct file *file) +{ + if ((file->f_mode & FMODE_WRITE) && + (file->f_flags & O_TRUNC)) + cleanup_all_probes(); + + return seq_open(file, &probes_seq_op); +} + +static int command_trace_probe(const char *buf) +{ + char **argv; + int argc = 0, ret = 0; + + argv = argv_split(GFP_KERNEL, buf, &argc); + if (!argv) + return -ENOMEM; + + if (argc) + ret = create_trace_probe(argc, argv); + + argv_free(argv); + return ret; +} + +#define WRITE_BUFSIZE 128 + +static ssize_t probes_write(struct file *file, const char __user *buffer, + size_t count, loff_t *ppos) +{ + char *kbuf, *tmp; + int ret; + size_t done; + size_t size; + + kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL); + if (!kbuf) + return -ENOMEM; + + ret = done = 0; + while (done < count) { + size = count - done; + if (size >= WRITE_BUFSIZE) + size = WRITE_BUFSIZE - 1; + if (copy_from_user(kbuf, buffer + done, size)) { + ret = -EFAULT; + goto out; + } + kbuf[size] = '\0'; + tmp = strchr(kbuf, '\n'); + if (tmp) { + *tmp = '\0'; + size = tmp - kbuf + 1; + } else if (done + size < count) { + pr_warning("Line length is too long: " + "Should be less than %d.", WRITE_BUFSIZE); + ret = -EINVAL; + goto out; + } + done += size; + /* Remove comments */ + tmp = strchr(kbuf, '#'); + if (tmp) + *tmp = '\0'; + + ret = command_trace_probe(kbuf); + if (ret) + goto out; + } + ret = done; +out: + kfree(kbuf); + return ret; +} + +static const struct file_operations kprobe_events_ops = { + .owner = THIS_MODULE, + .open = probes_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, + .write = probes_write, +}; + +/* Probes profiling interfaces */ +static int probes_profile_seq_show(struct seq_file *m, void *v) +{ + struct trace_probe *tp = v; + + seq_printf(m, " %-44s %15lu %15lu\n", tp->call.name, tp->nhit, + tp->rp.kp.nmissed); + + return 0; +} + +static const struct seq_operations profile_seq_op = { + .start = probes_seq_start, + .next = probes_seq_next, + .stop = probes_seq_stop, + .show = probes_profile_seq_show +}; + +static int profile_open(struct inode *inode, struct file *file) +{ + return seq_open(file, &profile_seq_op); +} + +static const struct file_operations kprobe_profile_ops = { + .owner = THIS_MODULE, + .open = profile_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; + +/* Kprobe handler */ +static __kprobes int kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs) +{ + struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp); + struct kprobe_trace_entry *entry; + struct ring_buffer_event *event; + struct ring_buffer *buffer; + int size, i, pc; + unsigned long irq_flags; + struct ftrace_event_call *call = &tp->call; + + tp->nhit++; + + local_save_flags(irq_flags); + pc = preempt_count(); + + size = SIZEOF_KPROBE_TRACE_ENTRY(tp->nr_args); + + event = trace_current_buffer_lock_reserve(&buffer, call->id, size, + irq_flags, pc); + if (!event) + return 0; + + entry = ring_buffer_event_data(event); + entry->nargs = tp->nr_args; + entry->ip = (unsigned long)kp->addr; + for (i = 0; i < tp->nr_args; i++) + entry->args[i] = call_fetch(&tp->args[i].fetch, regs); + + if (!filter_current_check_discard(buffer, call, entry, event)) + trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc); + return 0; +} + +/* Kretprobe handler */ +static __kprobes int kretprobe_trace_func(struct kretprobe_instance *ri, + struct pt_regs *regs) +{ + struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp); + struct kretprobe_trace_entry *entry; + struct ring_buffer_event *event; + struct ring_buffer *buffer; + int size, i, pc; + unsigned long irq_flags; + struct ftrace_event_call *call = &tp->call; + + local_save_flags(irq_flags); + pc = preempt_count(); + + size = SIZEOF_KRETPROBE_TRACE_ENTRY(tp->nr_args); + + event = trace_current_buffer_lock_reserve(&buffer, call->id, size, + irq_flags, pc); + if (!event) + return 0; + + entry = ring_buffer_event_data(event); + entry->nargs = tp->nr_args; + entry->func = (unsigned long)tp->rp.kp.addr; + entry->ret_ip = (unsigned long)ri->ret_addr; + for (i = 0; i < tp->nr_args; i++) + entry->args[i] = call_fetch(&tp->args[i].fetch, regs); + + if (!filter_current_check_discard(buffer, call, entry, event)) + trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc); + + return 0; +} + +/* Event entry printers */ +enum print_line_t +print_kprobe_event(struct trace_iterator *iter, int flags) +{ + struct kprobe_trace_entry *field; + struct trace_seq *s = &iter->seq; + struct trace_event *event; + struct trace_probe *tp; + int i; + + field = (struct kprobe_trace_entry *)iter->ent; + event = ftrace_find_event(field->ent.type); + tp = container_of(event, struct trace_probe, event); + + if (!trace_seq_printf(s, "%s: (", tp->call.name)) + goto partial; + + if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET)) + goto partial; + + if (!trace_seq_puts(s, ")")) + goto partial; + + for (i = 0; i < field->nargs; i++) + if (!trace_seq_printf(s, " %s=%lx", + tp->args[i].name, field->args[i])) + goto partial; + + if (!trace_seq_puts(s, "\n")) + goto partial; + + return TRACE_TYPE_HANDLED; +partial: + return TRACE_TYPE_PARTIAL_LINE; +} + +enum print_line_t +print_kretprobe_event(struct trace_iterator *iter, int flags) +{ + struct kretprobe_trace_entry *field; + struct trace_seq *s = &iter->seq; + struct trace_event *event; + struct trace_probe *tp; + int i; + + field = (struct kretprobe_trace_entry *)iter->ent; + event = ftrace_find_event(field->ent.type); + tp = container_of(event, struct trace_probe, event); + + if (!trace_seq_printf(s, "%s: (", tp->call.name)) + goto partial; + + if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET)) + goto partial; + + if (!trace_seq_puts(s, " <- ")) + goto partial; + + if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET)) + goto partial; + + if (!trace_seq_puts(s, ")")) + goto partial; + + for (i = 0; i < field->nargs; i++) + if (!trace_seq_printf(s, " %s=%lx", + tp->args[i].name, field->args[i])) + goto partial; + + if (!trace_seq_puts(s, "\n")) + goto partial; + + return TRACE_TYPE_HANDLED; +partial: + return TRACE_TYPE_PARTIAL_LINE; +} + +static int probe_event_enable(struct ftrace_event_call *call) +{ + struct trace_probe *tp = (struct trace_probe *)call->data; + + tp->flags |= TP_FLAG_TRACE; + if (probe_is_return(tp)) + return enable_kretprobe(&tp->rp); + else + return enable_kprobe(&tp->rp.kp); +} + +static void probe_event_disable(struct ftrace_event_call *call) +{ + struct trace_probe *tp = (struct trace_probe *)call->data; + + tp->flags &= ~TP_FLAG_TRACE; + if (!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE))) { + if (probe_is_return(tp)) + disable_kretprobe(&tp->rp); + else + disable_kprobe(&tp->rp.kp); + } +} + +static int probe_event_raw_init(struct ftrace_event_call *event_call) +{ + INIT_LIST_HEAD(&event_call->fields); + + return 0; +} + +#undef DEFINE_FIELD +#define DEFINE_FIELD(type, item, name, is_signed) \ + do { \ + ret = trace_define_field(event_call, #type, name, \ + offsetof(typeof(field), item), \ + sizeof(field.item), is_signed, \ + FILTER_OTHER); \ + if (ret) \ + return ret; \ + } while (0) + +static int kprobe_event_define_fields(struct ftrace_event_call *event_call) +{ + int ret, i; + struct kprobe_trace_entry field; + struct trace_probe *tp = (struct trace_probe *)event_call->data; + + ret = trace_define_common_fields(event_call); + if (!ret) + return ret; + + DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0); + DEFINE_FIELD(int, nargs, FIELD_STRING_NARGS, 1); + /* Set argument names as fields */ + for (i = 0; i < tp->nr_args; i++) + DEFINE_FIELD(unsigned long, args[i], tp->args[i].name, 0); + return 0; +} + +static int kretprobe_event_define_fields(struct ftrace_event_call *event_call) +{ + int ret, i; + struct kretprobe_trace_entry field; + struct trace_probe *tp = (struct trace_probe *)event_call->data; + + ret = trace_define_common_fields(event_call); + if (!ret) + return ret; + + DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0); + DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0); + DEFINE_FIELD(int, nargs, FIELD_STRING_NARGS, 1); + /* Set argument names as fields */ + for (i = 0; i < tp->nr_args; i++) + DEFINE_FIELD(unsigned long, args[i], tp->args[i].name, 0); + return 0; +} + +static int __probe_event_show_format(struct trace_seq *s, + struct trace_probe *tp, const char *fmt, + const char *arg) +{ + int i; + + /* Show format */ + if (!trace_seq_printf(s, "\nprint fmt: \"%s", fmt)) + return 0; + + for (i = 0; i < tp->nr_args; i++) + if (!trace_seq_printf(s, " %s=%%lx", tp->args[i].name)) + return 0; + + if (!trace_seq_printf(s, "\", %s", arg)) + return 0; + + for (i = 0; i < tp->nr_args; i++) + if (!trace_seq_printf(s, ", REC->%s", tp->args[i].name)) + return 0; + + return trace_seq_puts(s, "\n"); +} + +#undef SHOW_FIELD +#define SHOW_FIELD(type, item, name) \ + do { \ + ret = trace_seq_printf(s, "\tfield: " #type " %s;\t" \ + "offset:%u;\tsize:%u;\n", name, \ + (unsigned int)offsetof(typeof(field), item),\ + (unsigned int)sizeof(type)); \ + if (!ret) \ + return 0; \ + } while (0) + +static int kprobe_event_show_format(struct ftrace_event_call *call, + struct trace_seq *s) +{ + struct kprobe_trace_entry field __attribute__((unused)); + int ret, i; + struct trace_probe *tp = (struct trace_probe *)call->data; + + SHOW_FIELD(unsigned long, ip, FIELD_STRING_IP); + SHOW_FIELD(int, nargs, FIELD_STRING_NARGS); + + /* Show fields */ + for (i = 0; i < tp->nr_args; i++) + SHOW_FIELD(unsigned long, args[i], tp->args[i].name); + trace_seq_puts(s, "\n"); + + return __probe_event_show_format(s, tp, "(%lx)", + "REC->" FIELD_STRING_IP); +} + +static int kretprobe_event_show_format(struct ftrace_event_call *call, + struct trace_seq *s) +{ + struct kretprobe_trace_entry field __attribute__((unused)); + int ret, i; + struct trace_probe *tp = (struct trace_probe *)call->data; + + SHOW_FIELD(unsigned long, func, FIELD_STRING_FUNC); + SHOW_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP); + SHOW_FIELD(int, nargs, FIELD_STRING_NARGS); + + /* Show fields */ + for (i = 0; i < tp->nr_args; i++) + SHOW_FIELD(unsigned long, args[i], tp->args[i].name); + trace_seq_puts(s, "\n"); + + return __probe_event_show_format(s, tp, "(%lx <- %lx)", + "REC->" FIELD_STRING_FUNC + ", REC->" FIELD_STRING_RETIP); +} + +#ifdef CONFIG_EVENT_PROFILE + +/* Kprobe profile handler */ +static __kprobes int kprobe_profile_func(struct kprobe *kp, + struct pt_regs *regs) +{ + struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp); + struct ftrace_event_call *call = &tp->call; + struct kprobe_trace_entry *entry; + struct trace_entry *ent; + int size, __size, i, pc, __cpu; + unsigned long irq_flags; + char *trace_buf; + char *raw_data; + int rctx; + + pc = preempt_count(); + __size = SIZEOF_KPROBE_TRACE_ENTRY(tp->nr_args); + size = ALIGN(__size + sizeof(u32), sizeof(u64)); + size -= sizeof(u32); + if (WARN_ONCE(size > FTRACE_MAX_PROFILE_SIZE, + "profile buffer not large enough")) + return 0; + + /* + * Protect the non nmi buffer + * This also protects the rcu read side + */ + local_irq_save(irq_flags); + + rctx = perf_swevent_get_recursion_context(); + if (rctx < 0) + goto end_recursion; + + __cpu = smp_processor_id(); + + if (in_nmi()) + trace_buf = rcu_dereference(perf_trace_buf_nmi); + else + trace_buf = rcu_dereference(perf_trace_buf); + + if (!trace_buf) + goto end; + + raw_data = per_cpu_ptr(trace_buf, __cpu); + + /* Zero dead bytes from alignment to avoid buffer leak to userspace */ + *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL; + entry = (struct kprobe_trace_entry *)raw_data; + ent = &entry->ent; + + tracing_generic_entry_update(ent, irq_flags, pc); + ent->type = call->id; + entry->nargs = tp->nr_args; + entry->ip = (unsigned long)kp->addr; + for (i = 0; i < tp->nr_args; i++) + entry->args[i] = call_fetch(&tp->args[i].fetch, regs); + perf_tp_event(call->id, entry->ip, 1, entry, size); + +end: + perf_swevent_put_recursion_context(rctx); +end_recursion: + local_irq_restore(irq_flags); + + return 0; +} + +/* Kretprobe profile handler */ +static __kprobes int kretprobe_profile_func(struct kretprobe_instance *ri, + struct pt_regs *regs) +{ + struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp); + struct ftrace_event_call *call = &tp->call; + struct kretprobe_trace_entry *entry; + struct trace_entry *ent; + int size, __size, i, pc, __cpu; + unsigned long irq_flags; + char *trace_buf; + char *raw_data; + int rctx; + + pc = preempt_count(); + __size = SIZEOF_KRETPROBE_TRACE_ENTRY(tp->nr_args); + size = ALIGN(__size + sizeof(u32), sizeof(u64)); + size -= sizeof(u32); + if (WARN_ONCE(size > FTRACE_MAX_PROFILE_SIZE, + "profile buffer not large enough")) + return 0; + + /* + * Protect the non nmi buffer + * This also protects the rcu read side + */ + local_irq_save(irq_flags); + + rctx = perf_swevent_get_recursion_context(); + if (rctx < 0) + goto end_recursion; + + __cpu = smp_processor_id(); + + if (in_nmi()) + trace_buf = rcu_dereference(perf_trace_buf_nmi); + else + trace_buf = rcu_dereference(perf_trace_buf); + + if (!trace_buf) + goto end; + + raw_data = per_cpu_ptr(trace_buf, __cpu); + + /* Zero dead bytes from alignment to avoid buffer leak to userspace */ + *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL; + entry = (struct kretprobe_trace_entry *)raw_data; + ent = &entry->ent; + + tracing_generic_entry_update(ent, irq_flags, pc); + ent->type = call->id; + entry->nargs = tp->nr_args; + entry->func = (unsigned long)tp->rp.kp.addr; + entry->ret_ip = (unsigned long)ri->ret_addr; + for (i = 0; i < tp->nr_args; i++) + entry->args[i] = call_fetch(&tp->args[i].fetch, regs); + perf_tp_event(call->id, entry->ret_ip, 1, entry, size); + +end: + perf_swevent_put_recursion_context(rctx); +end_recursion: + local_irq_restore(irq_flags); + + return 0; +} + +static int probe_profile_enable(struct ftrace_event_call *call) +{ + struct trace_probe *tp = (struct trace_probe *)call->data; + + tp->flags |= TP_FLAG_PROFILE; + + if (probe_is_return(tp)) + return enable_kretprobe(&tp->rp); + else + return enable_kprobe(&tp->rp.kp); +} + +static void probe_profile_disable(struct ftrace_event_call *call) +{ + struct trace_probe *tp = (struct trace_probe *)call->data; + + tp->flags &= ~TP_FLAG_PROFILE; + + if (!(tp->flags & TP_FLAG_TRACE)) { + if (probe_is_return(tp)) + disable_kretprobe(&tp->rp); + else + disable_kprobe(&tp->rp.kp); + } +} +#endif /* CONFIG_EVENT_PROFILE */ + + +static __kprobes +int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs) +{ + struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp); + + if (tp->flags & TP_FLAG_TRACE) + kprobe_trace_func(kp, regs); +#ifdef CONFIG_EVENT_PROFILE + if (tp->flags & TP_FLAG_PROFILE) + kprobe_profile_func(kp, regs); +#endif /* CONFIG_EVENT_PROFILE */ + return 0; /* We don't tweek kernel, so just return 0 */ +} + +static __kprobes +int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs) +{ + struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp); + + if (tp->flags & TP_FLAG_TRACE) + kretprobe_trace_func(ri, regs); +#ifdef CONFIG_EVENT_PROFILE + if (tp->flags & TP_FLAG_PROFILE) + kretprobe_profile_func(ri, regs); +#endif /* CONFIG_EVENT_PROFILE */ + return 0; /* We don't tweek kernel, so just return 0 */ +} + +static int register_probe_event(struct trace_probe *tp) +{ + struct ftrace_event_call *call = &tp->call; + int ret; + + /* Initialize ftrace_event_call */ + if (probe_is_return(tp)) { + tp->event.trace = print_kretprobe_event; + call->raw_init = probe_event_raw_init; + call->show_format = kretprobe_event_show_format; + call->define_fields = kretprobe_event_define_fields; + } else { + tp->event.trace = print_kprobe_event; + call->raw_init = probe_event_raw_init; + call->show_format = kprobe_event_show_format; + call->define_fields = kprobe_event_define_fields; + } + call->event = &tp->event; + call->id = register_ftrace_event(&tp->event); + if (!call->id) + return -ENODEV; + call->enabled = 0; + call->regfunc = probe_event_enable; + call->unregfunc = probe_event_disable; + +#ifdef CONFIG_EVENT_PROFILE + atomic_set(&call->profile_count, -1); + call->profile_enable = probe_profile_enable; + call->profile_disable = probe_profile_disable; +#endif + call->data = tp; + ret = trace_add_event_call(call); + if (ret) { + pr_info("Failed to register kprobe event: %s\n", call->name); + unregister_ftrace_event(&tp->event); + } + return ret; +} + +static void unregister_probe_event(struct trace_probe *tp) +{ + /* tp->event is unregistered in trace_remove_event_call() */ + trace_remove_event_call(&tp->call); +} + +/* Make a debugfs interface for controling probe points */ +static __init int init_kprobe_trace(void) +{ + struct dentry *d_tracer; + struct dentry *entry; + + d_tracer = tracing_init_dentry(); + if (!d_tracer) + return 0; + + entry = debugfs_create_file("kprobe_events", 0644, d_tracer, + NULL, &kprobe_events_ops); + + /* Event list interface */ + if (!entry) + pr_warning("Could not create debugfs " + "'kprobe_events' entry\n"); + + /* Profile interface */ + entry = debugfs_create_file("kprobe_profile", 0444, d_tracer, + NULL, &kprobe_profile_ops); + + if (!entry) + pr_warning("Could not create debugfs " + "'kprobe_profile' entry\n"); + return 0; +} +fs_initcall(init_kprobe_trace); + + +#ifdef CONFIG_FTRACE_STARTUP_TEST + +static int kprobe_trace_selftest_target(int a1, int a2, int a3, + int a4, int a5, int a6) +{ + return a1 + a2 + a3 + a4 + a5 + a6; +} + +static __init int kprobe_trace_self_tests_init(void) +{ + int ret; + int (*target)(int, int, int, int, int, int); + + target = kprobe_trace_selftest_target; + + pr_info("Testing kprobe tracing: "); + + ret = command_trace_probe("p:testprobe kprobe_trace_selftest_target " + "$arg1 $arg2 $arg3 $arg4 $stack $stack0"); + if (WARN_ON_ONCE(ret)) + pr_warning("error enabling function entry\n"); + + ret = command_trace_probe("r:testprobe2 kprobe_trace_selftest_target " + "$retval"); + if (WARN_ON_ONCE(ret)) + pr_warning("error enabling function return\n"); + + ret = target(1, 2, 3, 4, 5, 6); + + cleanup_all_probes(); + + pr_cont("OK\n"); + return 0; +} + +late_initcall(kprobe_trace_self_tests_init); + +#endif diff --git a/kernel/trace/trace_ksym.c b/kernel/trace/trace_ksym.c new file mode 100644 index 00000000000..ddfa0fd43bc --- /dev/null +++ b/kernel/trace/trace_ksym.c @@ -0,0 +1,550 @@ +/* + * trace_ksym.c - Kernel Symbol Tracer + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + * + * Copyright (C) IBM Corporation, 2009 + */ + +#include <linux/kallsyms.h> +#include <linux/uaccess.h> +#include <linux/debugfs.h> +#include <linux/ftrace.h> +#include <linux/module.h> +#include <linux/fs.h> + +#include "trace_output.h" +#include "trace_stat.h" +#include "trace.h" + +#include <linux/hw_breakpoint.h> +#include <asm/hw_breakpoint.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 perf_event **ksym_hbp; + struct perf_event_attr attr; +#ifdef CONFIG_PROFILE_KSYM_TRACER + unsigned long counter; +#endif + struct hlist_node ksym_hlist; +}; + +static struct trace_array *ksym_trace_array; + +static unsigned int ksym_filter_entry_count; +static unsigned int ksym_tracing_enabled; + +static HLIST_HEAD(ksym_filter_head); + +static DEFINE_MUTEX(ksym_tracer_mutex); + +#ifdef CONFIG_PROFILE_KSYM_TRACER + +#define MAX_UL_INT 0xffffffff + +void ksym_collect_stats(unsigned long hbp_hit_addr) +{ + struct hlist_node *node; + struct trace_ksym *entry; + + rcu_read_lock(); + hlist_for_each_entry_rcu(entry, node, &ksym_filter_head, ksym_hlist) { + if ((entry->attr.bp_addr == hbp_hit_addr) && + (entry->counter <= MAX_UL_INT)) { + entry->counter++; + break; + } + } + rcu_read_unlock(); +} +#endif /* CONFIG_PROFILE_KSYM_TRACER */ + +void ksym_hbp_handler(struct perf_event *hbp, void *data) +{ + struct ring_buffer_event *event; + struct ksym_trace_entry *entry; + struct pt_regs *regs = data; + struct ring_buffer *buffer; + int pc; + + if (!ksym_tracing_enabled) + return; + + buffer = ksym_trace_array->buffer; + + pc = preempt_count(); + + 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 = 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(hw_breakpoint_addr(hbp)); +#endif /* CONFIG_PROFILE_KSYM_TRACER */ + + trace_buffer_unlock_commit(buffer, event, 0, pc); +} + +/* Valid access types are represented as + * + * rw- : Set Read/Write Access Breakpoint + * -w- : Set Write Access Breakpoint + * --- : Clear Breakpoints + * --x : Set Execution Break points (Not available yet) + * + */ +static int ksym_trace_get_access_type(char *str) +{ + int access = 0; + + if (str[0] == 'r') + access |= HW_BREAKPOINT_R; + + if (str[1] == 'w') + access |= HW_BREAKPOINT_W; + + if (str[2] == 'x') + access |= HW_BREAKPOINT_X; + + switch (access) { + case HW_BREAKPOINT_R: + case HW_BREAKPOINT_W: + case HW_BREAKPOINT_W | HW_BREAKPOINT_R: + return access; + default: + return -EINVAL; + } +} + +/* + * There can be several possible malformed requests and we attempt to capture + * all of them. We enumerate some of the rules + * 1. We will not allow kernel symbols with ':' since it is used as a delimiter. + * i.e. multiple ':' symbols disallowed. Possible uses are of the form + * <module>:<ksym_name>:<op>. + * 2. No delimiter symbol ':' in the input string + * 3. Spurious operator symbols or symbols not in their respective positions + * 4. <ksym_name>:--- i.e. clear breakpoint request when ksym_name not in file + * 5. Kernel symbol not a part of /proc/kallsyms + * 6. Duplicate requests + */ +static int parse_ksym_trace_str(char *input_string, char **ksymname, + unsigned long *addr) +{ + int ret; + + *ksymname = strsep(&input_string, ":"); + *addr = kallsyms_lookup_name(*ksymname); + + /* Check for malformed request: (2), (1) and (5) */ + if ((!input_string) || + (strlen(input_string) != KSYM_TRACER_OP_LEN) || + (*addr == 0)) + return -EINVAL;; + + ret = ksym_trace_get_access_type(input_string); + + return ret; +} + +int process_new_ksym_entry(char *ksymname, int op, unsigned long addr) +{ + struct trace_ksym *entry; + int ret = -ENOMEM; + + if (ksym_filter_entry_count >= KSYM_TRACER_MAX) { + printk(KERN_ERR "ksym_tracer: Maximum limit:(%d) reached. No" + " new requests for tracing can be accepted now.\n", + KSYM_TRACER_MAX); + return -ENOSPC; + } + + entry = kzalloc(sizeof(struct trace_ksym), GFP_KERNEL); + if (!entry) + return -ENOMEM; + + hw_breakpoint_init(&entry->attr); + + entry->attr.bp_type = op; + entry->attr.bp_addr = addr; + entry->attr.bp_len = HW_BREAKPOINT_LEN_4; + + ret = -EAGAIN; + entry->ksym_hbp = register_wide_hw_breakpoint(&entry->attr, + ksym_hbp_handler); + + if (IS_ERR(entry->ksym_hbp)) { + ret = PTR_ERR(entry->ksym_hbp); + printk(KERN_INFO "ksym_tracer request failed. Try again" + " later!!\n"); + goto err; + } + + hlist_add_head_rcu(&(entry->ksym_hlist), &ksym_filter_head); + ksym_filter_entry_count++; + + return 0; + +err: + kfree(entry); + + return ret; +} + +static ssize_t ksym_trace_filter_read(struct file *filp, char __user *ubuf, + size_t count, loff_t *ppos) +{ + struct trace_ksym *entry; + struct hlist_node *node; + struct trace_seq *s; + ssize_t cnt = 0; + int ret; + + s = kmalloc(sizeof(*s), GFP_KERNEL); + if (!s) + return -ENOMEM; + trace_seq_init(s); + + mutex_lock(&ksym_tracer_mutex); + + hlist_for_each_entry(entry, node, &ksym_filter_head, ksym_hlist) { + ret = trace_seq_printf(s, "%pS:", (void *)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->attr.bp_type == (HW_BREAKPOINT_W | HW_BREAKPOINT_R)) + ret = trace_seq_puts(s, "rw-\n"); + WARN_ON_ONCE(!ret); + } + + cnt = simple_read_from_buffer(ubuf, count, ppos, s->buffer, s->len); + + mutex_unlock(&ksym_tracer_mutex); + + kfree(s); + + 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; + unsigned long ksym_addr = 0; + int ret, op, changed = 0; + + input_string = kzalloc(count + 1, GFP_KERNEL); + if (!input_string) + return -ENOMEM; + + if (copy_from_user(input_string, buffer, count)) { + kfree(input_string); + return -EFAULT; + } + input_string[count] = '\0'; + + strstrip(input_string); + + /* + * 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(); + kfree(input_string); + return count; + } + + ret = op = parse_ksym_trace_str(input_string, &ksymname, &ksym_addr); + if (ret < 0) { + kfree(input_string); + return ret; + } + + mutex_lock(&ksym_tracer_mutex); + + ret = -EINVAL; + hlist_for_each_entry(entry, node, &ksym_filter_head, ksym_hlist) { + if (entry->attr.bp_addr == ksym_addr) { + /* Check for malformed request: (6) */ + if (entry->attr.bp_type != op) + changed = 1; + else + goto out; + break; + } + } + if (changed) { + unregister_wide_hw_breakpoint(entry->ksym_hbp); + entry->attr.bp_type = op; + ret = 0; + if (op > 0) { + 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; + } + /* Error or "symbol:---" case: drop it */ + ksym_filter_entry_count--; + hlist_del_rcu(&(entry->ksym_hlist)); + synchronize_rcu(); + kfree(entry); + goto out; + } else { + /* Check for malformed request: (4) */ + if (op == 0) + goto out; + ret = process_new_ksym_entry(ksymname, op, ksym_addr); + } +out: + mutex_unlock(&ksym_tracer_mutex); + + kfree(input_string); + + if (!ret) + ret = count; + return ret; +} + +static const struct file_operations ksym_tracing_fops = { + .open = tracing_open_generic, + .read = ksym_trace_filter_read, + .write = ksym_trace_filter_write, +}; + +static void ksym_trace_reset(struct trace_array *tr) +{ + ksym_tracing_enabled = 0; + __ksym_trace_reset(); +} + +static int ksym_trace_init(struct trace_array *tr) +{ + int cpu, ret = 0; + + for_each_online_cpu(cpu) + tracing_reset(tr, cpu); + ksym_tracing_enabled = 1; + ksym_trace_array = tr; + + return ret; +} + +static void ksym_trace_print_header(struct seq_file *m) +{ + seq_puts(m, + "# TASK-PID CPU# Symbol " + "Type Function\n"); + seq_puts(m, + "# | | | " + " | |\n"); +} + +static enum print_line_t ksym_trace_output(struct trace_iterator *iter) +{ + struct trace_entry *entry = iter->ent; + struct trace_seq *s = &iter->seq; + struct ksym_trace_entry *field; + char str[KSYM_SYMBOL_LEN]; + int ret; + + if (entry->type != TRACE_KSYM) + return TRACE_TYPE_UNHANDLED; + + trace_assign_type(field, entry); + + 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_R: + ret = trace_seq_printf(s, " R "); + break; + case HW_BREAKPOINT_W: + ret = trace_seq_printf(s, " W "); + break; + case HW_BREAKPOINT_R | HW_BREAKPOINT_W: + ret = trace_seq_printf(s, " RW "); + break; + default: + return TRACE_TYPE_PARTIAL_LINE; + } + + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + + sprint_symbol(str, field->ip); + ret = trace_seq_printf(s, "%s\n", str); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + + return TRACE_TYPE_HANDLED; +} + +struct tracer ksym_tracer __read_mostly = +{ + .name = "ksym_tracer", + .init = ksym_trace_init, + .reset = ksym_trace_reset, +#ifdef CONFIG_FTRACE_SELFTEST + .selftest = trace_selftest_startup_ksym, +#endif + .print_header = ksym_trace_print_header, + .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_puts(m, " Access Type "); + seq_puts(m, " Symbol Counter\n"); + seq_puts(m, " ----------- "); + seq_puts(m, " ------ -------\n"); + return 0; +} + +static int ksym_tracer_stat_show(struct seq_file *m, void *v) +{ + struct hlist_node *stat = v; + struct trace_ksym *entry; + int access_type = 0; + char fn_name[KSYM_NAME_LEN]; + + entry = hlist_entry(stat, struct trace_ksym, ksym_hlist); + + 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->attr.bp_addr, fn_name) >= 0) + seq_printf(m, " %-36s", fn_name); + else + seq_printf(m, " %-36s", "<NA>"); + seq_printf(m, " %15lu\n", entry->counter); + + return 0; +} + +static void *ksym_tracer_stat_start(struct tracer_stat *trace) +{ + return ksym_filter_head.first; +} + +static void * +ksym_tracer_stat_next(void *v, int idx) +{ + struct hlist_node *stat = v; + + return stat->next; +} + +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 +}; + +__init static int ksym_tracer_stat_init(void) +{ + int ret; + + ret = register_stat_tracer(&ksym_tracer_stats); + if (ret) { + printk(KERN_WARNING "Warning: could not register " + "ksym tracer stats\n"); + return 1; + } + + return 0; +} +fs_initcall(ksym_tracer_stat_init); +#endif /* CONFIG_PROFILE_KSYM_TRACER */ diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index d2cdbabb4ea..dc98309e839 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -17,6 +17,7 @@ static inline int trace_valid_entry(struct trace_entry *entry) case TRACE_GRAPH_ENT: case TRACE_GRAPH_RET: case TRACE_HW_BRANCHES: + case TRACE_KSYM: return 1; } return 0; @@ -808,3 +809,57 @@ trace_selftest_startup_hw_branches(struct tracer *trace, return ret; } #endif /* CONFIG_HW_BRANCH_TRACER */ + +#ifdef CONFIG_KSYM_TRACER +static int ksym_selftest_dummy; + +int +trace_selftest_startup_ksym(struct tracer *trace, struct trace_array *tr) +{ + unsigned long count; + int ret; + + /* start the tracing */ + ret = tracer_init(trace, tr); + if (ret) { + warn_failed_init_tracer(trace, ret); + return ret; + } + + ksym_selftest_dummy = 0; + /* Register the read-write tracing request */ + + ret = process_new_ksym_entry("ksym_selftest_dummy", + HW_BREAKPOINT_R | HW_BREAKPOINT_W, + (unsigned long)(&ksym_selftest_dummy)); + + if (ret < 0) { + printk(KERN_CONT "ksym_trace read-write startup test failed\n"); + goto ret_path; + } + /* Perform a read and a write operation over the dummy variable to + * trigger the tracer + */ + if (ksym_selftest_dummy == 0) + ksym_selftest_dummy++; + + /* stop the tracing. */ + tracing_stop(); + /* check the trace buffer */ + ret = trace_test_buffer(tr, &count); + trace->reset(tr); + tracing_start(); + + /* read & write operations - one each is performed on the dummy variable + * triggering two entries in the trace buffer + */ + if (!ret && count != 2) { + printk(KERN_CONT "Ksym tracer startup test failed"); + ret = -1; + } + +ret_path: + return ret; +} +#endif /* CONFIG_KSYM_TRACER */ + diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c index ddee9c59373..57501d90096 100644 --- a/kernel/trace/trace_syscalls.c +++ b/kernel/trace/trace_syscalls.c @@ -51,32 +51,6 @@ static struct syscall_metadata *syscall_nr_to_meta(int nr) return syscalls_metadata[nr]; } -int syscall_name_to_nr(char *name) -{ - int i; - - if (!syscalls_metadata) - return -1; - - for (i = 0; i < NR_syscalls; i++) { - if (syscalls_metadata[i]) { - if (!strcmp(syscalls_metadata[i]->name, name)) - return i; - } - } - return -1; -} - -void set_syscall_enter_id(int num, int id) -{ - syscalls_metadata[num]->enter_id = id; -} - -void set_syscall_exit_id(int num, int id) -{ - syscalls_metadata[num]->exit_id = id; -} - enum print_line_t print_syscall_enter(struct trace_iterator *iter, int flags) { @@ -93,7 +67,7 @@ print_syscall_enter(struct trace_iterator *iter, int flags) if (!entry) goto end; - if (entry->enter_id != ent->type) { + if (entry->enter_event->id != ent->type) { WARN_ON_ONCE(1); goto end; } @@ -148,7 +122,7 @@ print_syscall_exit(struct trace_iterator *iter, int flags) return TRACE_TYPE_HANDLED; } - if (entry->exit_id != ent->type) { + if (entry->exit_event->id != ent->type) { WARN_ON_ONCE(1); return TRACE_TYPE_UNHANDLED; } @@ -166,24 +140,19 @@ extern char *__bad_type_size(void); #define SYSCALL_FIELD(type, name) \ sizeof(type) != sizeof(trace.name) ? \ __bad_type_size() : \ - #type, #name, offsetof(typeof(trace), name), sizeof(trace.name) + #type, #name, offsetof(typeof(trace), name), \ + sizeof(trace.name), is_signed_type(type) int syscall_enter_format(struct ftrace_event_call *call, struct trace_seq *s) { int i; - int nr; int ret; - struct syscall_metadata *entry; + struct syscall_metadata *entry = call->data; struct syscall_trace_enter trace; int offset = offsetof(struct syscall_trace_enter, args); - nr = syscall_name_to_nr(call->data); - entry = syscall_nr_to_meta(nr); - - if (!entry) - return 0; - - ret = trace_seq_printf(s, "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n", + ret = trace_seq_printf(s, "\tfield:%s %s;\toffset:%zu;\tsize:%zu;" + "\tsigned:%u;\n", SYSCALL_FIELD(int, nr)); if (!ret) return 0; @@ -193,8 +162,10 @@ int syscall_enter_format(struct ftrace_event_call *call, struct trace_seq *s) entry->args[i]); if (!ret) return 0; - ret = trace_seq_printf(s, "\toffset:%d;\tsize:%zu;\n", offset, - sizeof(unsigned long)); + ret = trace_seq_printf(s, "\toffset:%d;\tsize:%zu;" + "\tsigned:%u;\n", offset, + sizeof(unsigned long), + is_signed_type(unsigned long)); if (!ret) return 0; offset += sizeof(unsigned long); @@ -226,8 +197,10 @@ int syscall_exit_format(struct ftrace_event_call *call, struct trace_seq *s) struct syscall_trace_exit trace; ret = trace_seq_printf(s, - "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n" - "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n", + "\tfield:%s %s;\toffset:%zu;\tsize:%zu;" + "\tsigned:%u;\n" + "\tfield:%s %s;\toffset:%zu;\tsize:%zu;" + "\tsigned:%u;\n", SYSCALL_FIELD(int, nr), SYSCALL_FIELD(long, ret)); if (!ret) @@ -239,22 +212,19 @@ int syscall_exit_format(struct ftrace_event_call *call, struct trace_seq *s) int syscall_enter_define_fields(struct ftrace_event_call *call) { struct syscall_trace_enter trace; - struct syscall_metadata *meta; + struct syscall_metadata *meta = call->data; int ret; - int nr; int i; int offset = offsetof(typeof(trace), args); - nr = syscall_name_to_nr(call->data); - meta = syscall_nr_to_meta(nr); - - if (!meta) - return 0; - ret = trace_define_common_fields(call); if (ret) return ret; + ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER); + if (ret) + return ret; + for (i = 0; i < meta->nb_args; i++) { ret = trace_define_field(call, meta->types[i], meta->args[i], offset, @@ -275,7 +245,11 @@ int syscall_exit_define_fields(struct ftrace_event_call *call) if (ret) return ret; - ret = trace_define_field(call, SYSCALL_FIELD(long, ret), 0, + ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER); + if (ret) + return ret; + + ret = trace_define_field(call, SYSCALL_FIELD(long, ret), FILTER_OTHER); return ret; @@ -302,8 +276,8 @@ void ftrace_syscall_enter(struct pt_regs *regs, long id) size = sizeof(*entry) + sizeof(unsigned long) * sys_data->nb_args; - event = trace_current_buffer_lock_reserve(&buffer, sys_data->enter_id, - size, 0, 0); + event = trace_current_buffer_lock_reserve(&buffer, + sys_data->enter_event->id, size, 0, 0); if (!event) return; @@ -334,8 +308,8 @@ void ftrace_syscall_exit(struct pt_regs *regs, long ret) if (!sys_data) return; - event = trace_current_buffer_lock_reserve(&buffer, sys_data->exit_id, - sizeof(*entry), 0, 0); + event = trace_current_buffer_lock_reserve(&buffer, + sys_data->exit_event->id, sizeof(*entry), 0, 0); if (!event) return; @@ -348,14 +322,12 @@ void ftrace_syscall_exit(struct pt_regs *regs, long ret) trace_current_buffer_unlock_commit(buffer, event, 0, 0); } -int reg_event_syscall_enter(void *ptr) +int reg_event_syscall_enter(struct ftrace_event_call *call) { int ret = 0; int num; - char *name; - name = (char *)ptr; - num = syscall_name_to_nr(name); + num = ((struct syscall_metadata *)call->data)->syscall_nr; if (num < 0 || num >= NR_syscalls) return -ENOSYS; mutex_lock(&syscall_trace_lock); @@ -372,13 +344,11 @@ int reg_event_syscall_enter(void *ptr) return ret; } -void unreg_event_syscall_enter(void *ptr) +void unreg_event_syscall_enter(struct ftrace_event_call *call) { int num; - char *name; - name = (char *)ptr; - num = syscall_name_to_nr(name); + num = ((struct syscall_metadata *)call->data)->syscall_nr; if (num < 0 || num >= NR_syscalls) return; mutex_lock(&syscall_trace_lock); @@ -389,14 +359,12 @@ void unreg_event_syscall_enter(void *ptr) mutex_unlock(&syscall_trace_lock); } -int reg_event_syscall_exit(void *ptr) +int reg_event_syscall_exit(struct ftrace_event_call *call) { int ret = 0; int num; - char *name; - name = (char *)ptr; - num = syscall_name_to_nr(name); + num = ((struct syscall_metadata *)call->data)->syscall_nr; if (num < 0 || num >= NR_syscalls) return -ENOSYS; mutex_lock(&syscall_trace_lock); @@ -413,13 +381,11 @@ int reg_event_syscall_exit(void *ptr) return ret; } -void unreg_event_syscall_exit(void *ptr) +void unreg_event_syscall_exit(struct ftrace_event_call *call) { int num; - char *name; - name = (char *)ptr; - num = syscall_name_to_nr(name); + num = ((struct syscall_metadata *)call->data)->syscall_nr; if (num < 0 || num >= NR_syscalls) return; mutex_lock(&syscall_trace_lock); @@ -430,13 +396,17 @@ void unreg_event_syscall_exit(void *ptr) mutex_unlock(&syscall_trace_lock); } -struct trace_event event_syscall_enter = { - .trace = print_syscall_enter, -}; +int init_syscall_trace(struct ftrace_event_call *call) +{ + int id; -struct trace_event event_syscall_exit = { - .trace = print_syscall_exit, -}; + id = register_ftrace_event(call->event); + if (!id) + return -ENODEV; + call->id = id; + INIT_LIST_HEAD(&call->fields); + return 0; +} int __init init_ftrace_syscalls(void) { @@ -454,6 +424,10 @@ int __init init_ftrace_syscalls(void) for (i = 0; i < NR_syscalls; i++) { addr = arch_syscall_addr(i); meta = find_syscall_meta(addr); + if (!meta) + continue; + + meta->syscall_nr = i; syscalls_metadata[i] = meta; } @@ -473,8 +447,10 @@ static void prof_syscall_enter(struct pt_regs *regs, long id) struct syscall_metadata *sys_data; struct syscall_trace_enter *rec; unsigned long flags; + char *trace_buf; char *raw_data; int syscall_nr; + int rctx; int size; int cpu; @@ -498,41 +474,42 @@ static void prof_syscall_enter(struct pt_regs *regs, long id) /* Protect the per cpu buffer, begin the rcu read side */ local_irq_save(flags); + rctx = perf_swevent_get_recursion_context(); + if (rctx < 0) + goto end_recursion; + cpu = smp_processor_id(); - if (in_nmi()) - raw_data = rcu_dereference(trace_profile_buf_nmi); - else - raw_data = rcu_dereference(trace_profile_buf); + trace_buf = rcu_dereference(perf_trace_buf); - if (!raw_data) + if (!trace_buf) goto end; - raw_data = per_cpu_ptr(raw_data, cpu); + raw_data = per_cpu_ptr(trace_buf, cpu); /* zero the dead bytes from align to not leak stack to user */ *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL; rec = (struct syscall_trace_enter *) raw_data; tracing_generic_entry_update(&rec->ent, 0, 0); - rec->ent.type = sys_data->enter_id; + rec->ent.type = sys_data->enter_event->id; rec->nr = syscall_nr; syscall_get_arguments(current, regs, 0, sys_data->nb_args, (unsigned long *)&rec->args); - perf_tp_event(sys_data->enter_id, 0, 1, rec, size); + perf_tp_event(sys_data->enter_event->id, 0, 1, rec, size); end: + perf_swevent_put_recursion_context(rctx); +end_recursion: local_irq_restore(flags); } -int reg_prof_syscall_enter(char *name) +int prof_sysenter_enable(struct ftrace_event_call *call) { int ret = 0; int num; - num = syscall_name_to_nr(name); - if (num < 0 || num >= NR_syscalls) - return -ENOSYS; + num = ((struct syscall_metadata *)call->data)->syscall_nr; mutex_lock(&syscall_trace_lock); if (!sys_prof_refcount_enter) @@ -548,13 +525,11 @@ int reg_prof_syscall_enter(char *name) return ret; } -void unreg_prof_syscall_enter(char *name) +void prof_sysenter_disable(struct ftrace_event_call *call) { int num; - num = syscall_name_to_nr(name); - if (num < 0 || num >= NR_syscalls) - return; + num = ((struct syscall_metadata *)call->data)->syscall_nr; mutex_lock(&syscall_trace_lock); sys_prof_refcount_enter--; @@ -570,7 +545,9 @@ static void prof_syscall_exit(struct pt_regs *regs, long ret) struct syscall_trace_exit *rec; unsigned long flags; int syscall_nr; + char *trace_buf; char *raw_data; + int rctx; int size; int cpu; @@ -596,17 +573,19 @@ static void prof_syscall_exit(struct pt_regs *regs, long ret) /* Protect the per cpu buffer, begin the rcu read side */ local_irq_save(flags); + + rctx = perf_swevent_get_recursion_context(); + if (rctx < 0) + goto end_recursion; + cpu = smp_processor_id(); - if (in_nmi()) - raw_data = rcu_dereference(trace_profile_buf_nmi); - else - raw_data = rcu_dereference(trace_profile_buf); + trace_buf = rcu_dereference(perf_trace_buf); - if (!raw_data) + if (!trace_buf) goto end; - raw_data = per_cpu_ptr(raw_data, cpu); + raw_data = per_cpu_ptr(trace_buf, cpu); /* zero the dead bytes from align to not leak stack to user */ *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL; @@ -614,24 +593,24 @@ static void prof_syscall_exit(struct pt_regs *regs, long ret) rec = (struct syscall_trace_exit *)raw_data; tracing_generic_entry_update(&rec->ent, 0, 0); - rec->ent.type = sys_data->exit_id; + rec->ent.type = sys_data->exit_event->id; rec->nr = syscall_nr; rec->ret = syscall_get_return_value(current, regs); - perf_tp_event(sys_data->exit_id, 0, 1, rec, size); + perf_tp_event(sys_data->exit_event->id, 0, 1, rec, size); end: + perf_swevent_put_recursion_context(rctx); +end_recursion: local_irq_restore(flags); } -int reg_prof_syscall_exit(char *name) +int prof_sysexit_enable(struct ftrace_event_call *call) { int ret = 0; int num; - num = syscall_name_to_nr(name); - if (num < 0 || num >= NR_syscalls) - return -ENOSYS; + num = ((struct syscall_metadata *)call->data)->syscall_nr; mutex_lock(&syscall_trace_lock); if (!sys_prof_refcount_exit) @@ -647,13 +626,11 @@ int reg_prof_syscall_exit(char *name) return ret; } -void unreg_prof_syscall_exit(char *name) +void prof_sysexit_disable(struct ftrace_event_call *call) { int num; - num = syscall_name_to_nr(name); - if (num < 0 || num >= NR_syscalls) - return; + num = ((struct syscall_metadata *)call->data)->syscall_nr; mutex_lock(&syscall_trace_lock); sys_prof_refcount_exit--; |