diff options
Diffstat (limited to 'kernel/trace/trace_output.c')
| -rw-r--r-- | kernel/trace/trace_output.c | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index 03d56f711ad1..4b721cd4f21d 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -12,8 +12,11 @@ #include <linux/sched/clock.h> #include <linux/sched/mm.h> #include <linux/idr.h> +#include <linux/btf.h> +#include <linux/bpf.h> #include "trace_output.h" +#include "trace_btf.h" /* must be a power of 2 */ #define EVENT_HASHSIZE 128 @@ -684,6 +687,88 @@ 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 |