From: Masami Hiramatsu (Google) <[email protected]> Since the relative offset stacktrace requires a special module loading events to decode binary, it should be an optional for normal use case. User can enable this feature via `options/relative-stacktrace`.
Signed-off-by: Masami Hiramatsu (Google) <[email protected]> --- kernel/trace/trace.c | 13 ++++++++----- kernel/trace/trace.h | 2 ++ kernel/trace/trace_entries.h | 22 ++++++++++++++++++++++ kernel/trace/trace_output.c | 37 ++++++++++++++++++++++++++++++++----- 4 files changed, 64 insertions(+), 10 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 8e86a43b368c..b4da5e29957f 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2926,6 +2926,7 @@ static void __ftrace_trace_stack(struct trace_array *tr, struct ftrace_stack *fstack; struct stack_entry *entry; int stackidx; + int type; /* * Add one, for this function and the call to save_stack_trace() @@ -2937,6 +2938,7 @@ static void __ftrace_trace_stack(struct trace_array *tr, #endif preempt_disable_notrace(); + type = (tr->trace_flags & TRACE_ITER_REL_STACK_BIT) ? TRACE_REL_STACK : TRACE_STACK; stackidx = __this_cpu_inc_return(ftrace_stack_reserve) - 1; @@ -2973,17 +2975,18 @@ static void __ftrace_trace_stack(struct trace_array *tr, for (int i = 0; i < nr_entries; i++) { if (calls[i] >= tramp_start && calls[i] < tramp_end) calls[i] = FTRACE_TRAMPOLINE_MARKER; - else + else if (type == TRACE_REL_STACK) calls[i] -= (unsigned long)_stext; } } #else - /* Adjsut entries as the offset from _stext, instead of raw address. */ - for (int i = 0; i < nr_entries; i++) - fstack->calls[i] -= (unsigned long)_stext; + if (type == TRACE_REL_STACK) + /* Adjsut entries as the offset from _stext, instead of raw address. */ + for (int i = 0; i < nr_entries; i++) + fstack->calls[i] -= (unsigned long)_stext; #endif - event = __trace_buffer_lock_reserve(buffer, TRACE_STACK, + event = __trace_buffer_lock_reserve(buffer, type, struct_size(entry, caller, nr_entries), trace_ctx); if (!event) diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 9c21ba45b7af..602aea0ec69a 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -55,6 +55,7 @@ enum trace_type { TRACE_TIMERLAT, TRACE_RAW_DATA, TRACE_FUNC_REPEATS, + TRACE_REL_STACK, __TRACE_LAST_TYPE, }; @@ -1350,6 +1351,7 @@ extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf, C(TRACE_PRINTK, "trace_printk_dest"), \ C(PAUSE_ON_TRACE, "pause-on-trace"), \ C(HASH_PTR, "hash-ptr"), /* Print hashed pointer */ \ + C(REL_STACK, "relative-stacktrace"), \ FUNCTION_FLAGS \ FGRAPH_FLAGS \ STACK_FLAGS \ diff --git a/kernel/trace/trace_entries.h b/kernel/trace/trace_entries.h index fbfb396905a6..7769f95b70fe 100644 --- a/kernel/trace/trace_entries.h +++ b/kernel/trace/trace_entries.h @@ -229,6 +229,28 @@ FTRACE_ENTRY(kernel_stack, stack_entry, (void *)__entry->caller[6], (void *)__entry->caller[7]) ); +FTRACE_ENTRY_DUP(kernel_rel_stack, stack_entry, + + TRACE_REL_STACK, + + F_STRUCT( + __field( int, size ) + __stack_array( unsigned long, caller, FTRACE_STACK_ENTRIES, size) + ), + + F_printk("\t=> %ps\n\t=> %ps\n\t=> %ps\n" + "\t=> %ps\n\t=> %ps\n\t=> %ps\n" + "\t=> %ps\n\t=> %ps\n", + (void *)__entry->caller[0] + (unsigned long)_stext, + (void *)__entry->caller[1] + (unsigned long)_stext, + (void *)__entry->caller[2] + (unsigned long)_stext, + (void *)__entry->caller[3] + (unsigned long)_stext, + (void *)__entry->caller[4] + (unsigned long)_stext, + (void *)__entry->caller[5] + (unsigned long)_stext, + (void *)__entry->caller[6] + (unsigned long)_stext, + (void *)__entry->caller[7] + (unsigned long)_stext) +); + FTRACE_ENTRY(user_stack, userstack_entry, TRACE_USER_STACK, diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index 497872df48f6..47e4ab549e81 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -1239,16 +1239,17 @@ static struct trace_event trace_wake_event = { .funcs = &trace_wake_funcs, }; -/* TRACE_STACK */ - -static enum print_line_t trace_stack_print(struct trace_iterator *iter, - int flags, struct trace_event *event) +static enum print_line_t trace_kernel_stack_print(struct trace_iterator *iter, + int flags, struct trace_event *event, bool relative) { struct stack_entry *field; struct trace_seq *s = &iter->seq; unsigned long *p; unsigned long *end; - long delta = (unsigned long)_stext + iter->tr->text_delta; + long delta = iter->tr->text_delta; + + if (relative) + delta += (unsigned long)_stext; trace_assign_type(field, iter->ent); end = (unsigned long *)((long)iter->ent + iter->ent_size); @@ -1272,6 +1273,14 @@ static enum print_line_t trace_stack_print(struct trace_iterator *iter, return trace_handle_return(s); } +/* TRACE_STACK */ + +static enum print_line_t trace_stack_print(struct trace_iterator *iter, + int flags, struct trace_event *event) +{ + return trace_kernel_stack_print(iter, flags, event, false); +} + static struct trace_event_functions trace_stack_funcs = { .trace = trace_stack_print, }; @@ -1281,6 +1290,23 @@ static struct trace_event trace_stack_event = { .funcs = &trace_stack_funcs, }; +/* TRACE_REL_STACK */ + +static enum print_line_t trace_rel_stack_print(struct trace_iterator *iter, + int flags, struct trace_event *event) +{ + return trace_kernel_stack_print(iter, flags, event, true); +} + +static struct trace_event_functions trace_rel_stack_funcs = { + .trace = trace_rel_stack_print, +}; + +static struct trace_event trace_rel_stack_event = { + .type = TRACE_REL_STACK, + .funcs = &trace_rel_stack_funcs, +}; + /* TRACE_USER_STACK */ static enum print_line_t trace_user_stack_print(struct trace_iterator *iter, int flags, struct trace_event *event) @@ -1724,6 +1750,7 @@ static struct trace_event *events[] __initdata = { &trace_ctx_event, &trace_wake_event, &trace_stack_event, + &trace_rel_stack_event, &trace_user_stack_event, &trace_bputs_event, &trace_bprint_event,
