diff options
Diffstat (limited to 'kernel/trace/trace_output.c')
| -rw-r--r-- | kernel/trace/trace_output.c | 122 |
1 files changed, 107 insertions, 15 deletions
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index 03d56f711ad1..72b699f909e8 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -12,15 +12,19 @@ #include <linux/sched/clock.h> #include <linux/sched/mm.h> #include <linux/idr.h> +#include <linux/btf.h> +#include <linux/bpf.h> +#include <linux/hashtable.h> #include "trace_output.h" +#include "trace_btf.h" -/* must be a power of 2 */ -#define EVENT_HASHSIZE 128 +/* 2^7 = 128 */ +#define EVENT_HASH_BITS 7 DECLARE_RWSEM(trace_event_sem); -static struct hlist_head event_hash[EVENT_HASHSIZE] __read_mostly; +static DEFINE_HASHTABLE(event_hash, EVENT_HASH_BITS); enum print_line_t trace_print_bputs_msg_only(struct trace_iterator *iter) { @@ -684,6 +688,88 @@ int trace_print_lat_context(struct trace_iterator *iter) return !trace_seq_has_overflowed(s); } +#ifdef CONFIG_FUNCTION_TRACE_ARGS +void print_function_args(struct trace_seq *s, unsigned long *args, + unsigned long func) +{ + const struct btf_param *param; + const struct btf_type *t; + const char *param_name; + char name[KSYM_NAME_LEN]; + unsigned long arg; + struct btf *btf; + s32 tid, nr = 0; + int a, p, x; + + trace_seq_printf(s, "("); + + if (!args) + goto out; + if (lookup_symbol_name(func, name)) + goto out; + + /* TODO: Pass module name here too */ + t = btf_find_func_proto(name, &btf); + if (IS_ERR_OR_NULL(t)) + goto out; + + param = btf_get_func_param(t, &nr); + if (!param) + goto out_put; + + for (a = 0, p = 0; p < nr; a++, p++) { + if (p) + trace_seq_puts(s, ", "); + + /* This only prints what the arch allows (6 args by default) */ + if (a == FTRACE_REGS_MAX_ARGS) { + trace_seq_puts(s, "..."); + break; + } + + arg = args[a]; + + param_name = btf_name_by_offset(btf, param[p].name_off); + if (param_name) + trace_seq_printf(s, "%s=", param_name); + t = btf_type_skip_modifiers(btf, param[p].type, &tid); + + switch (t ? BTF_INFO_KIND(t->info) : BTF_KIND_UNKN) { + case BTF_KIND_UNKN: + trace_seq_putc(s, '?'); + /* Still print unknown type values */ + fallthrough; + case BTF_KIND_PTR: + trace_seq_printf(s, "0x%lx", arg); + break; + case BTF_KIND_INT: + trace_seq_printf(s, "%ld", arg); + break; + case BTF_KIND_ENUM: + trace_seq_printf(s, "%ld", arg); + break; + default: + /* This does not handle complex arguments */ + trace_seq_printf(s, "(%s)[0x%lx", btf_type_str(t), arg); + for (x = sizeof(long); x < t->size; x += sizeof(long)) { + trace_seq_putc(s, ':'); + if (++a == FTRACE_REGS_MAX_ARGS) { + trace_seq_puts(s, "...]"); + goto out_put; + } + trace_seq_printf(s, "0x%lx", args[a]); + } + trace_seq_putc(s, ']'); + break; + } + } +out_put: + btf_put(btf); +out: + trace_seq_printf(s, ")"); +} +#endif + /** * ftrace_find_event - find a registered event * @type: the type of event to look for @@ -694,11 +780,8 @@ int trace_print_lat_context(struct trace_iterator *iter) struct trace_event *ftrace_find_event(int type) { struct trace_event *event; - unsigned key; - - key = type & (EVENT_HASHSIZE - 1); - hlist_for_each_entry(event, &event_hash[key], node) { + hash_for_each_possible(event_hash, event, node, type) { if (event->type == type) return event; } @@ -753,7 +836,6 @@ void trace_event_read_unlock(void) */ int register_trace_event(struct trace_event *event) { - unsigned key; int ret = 0; down_write(&trace_event_sem); @@ -786,9 +868,7 @@ int register_trace_event(struct trace_event *event) if (event->funcs->binary == NULL) event->funcs->binary = trace_nop_print; - key = event->type & (EVENT_HASHSIZE - 1); - - hlist_add_head(&event->node, &event_hash[key]); + hash_add(event_hash, &event->node, event->type); ret = event->type; out: @@ -803,7 +883,7 @@ EXPORT_SYMBOL_GPL(register_trace_event); */ int __unregister_trace_event(struct trace_event *event) { - hlist_del(&event->node); + hash_del(&event->node); free_trace_event_type(event->type); return 0; } @@ -1005,12 +1085,15 @@ enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags, } static void print_fn_trace(struct trace_seq *s, unsigned long ip, - unsigned long parent_ip, long delta, int flags) + unsigned long parent_ip, long delta, + unsigned long *args, int flags) { ip += delta; parent_ip += delta; seq_print_ip_sym(s, ip, flags); + if (args) + print_function_args(s, args, ip); if ((flags & TRACE_ITER_PRINT_PARENT) && parent_ip) { trace_seq_puts(s, " <-"); @@ -1024,10 +1107,19 @@ static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags, { struct ftrace_entry *field; struct trace_seq *s = &iter->seq; + unsigned long *args; + int args_size; trace_assign_type(field, iter->ent); - print_fn_trace(s, field->ip, field->parent_ip, iter->tr->text_delta, flags); + args_size = iter->ent_size - offsetof(struct ftrace_entry, args); + if (args_size >= FTRACE_REGS_MAX_ARGS * sizeof(long)) + args = field->args; + else + args = NULL; + + print_fn_trace(s, field->ip, field->parent_ip, iter->tr->text_delta, + args, flags); trace_seq_putc(s, '\n'); return trace_handle_return(s); @@ -1700,7 +1792,7 @@ trace_func_repeats_print(struct trace_iterator *iter, int flags, trace_assign_type(field, iter->ent); - print_fn_trace(s, field->ip, field->parent_ip, iter->tr->text_delta, flags); + print_fn_trace(s, field->ip, field->parent_ip, iter->tr->text_delta, NULL, flags); trace_seq_printf(s, " (repeats: %u, last_ts:", field->count); trace_print_time(s, iter, iter->ts - FUNC_REPEATS_GET_DELTA_TS(field)); |