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perf tools: Add support for PERF_RECORD_TEXT_POKE

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Add processing for PERF_RECORD_TEXT_POKE events. When a text poke event
is processed, then the kernel dso data cache is updated with the poked
bytes.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: x86@kernel.org
Link: http://lore.kernel.org/lkml/20200512121922.8997-12-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Adrian Hunter 2020-05-12 15:19:18 +03:00 committed by Arnaldo Carvalho de Melo
parent b39730a663
commit 246eba8e90
14 changed files with 216 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
tools/include/uapi/linux/perf_event.h
View File

@ -383,7 +383,8 @@ struct perf_event_attr {
bpf_event : 1, /* include bpf events */
aux_output : 1, /* generate AUX records instead of events */
cgroup : 1, /* include cgroup events */
__reserved_1 : 31;
text_poke : 1, /* include text poke events */
__reserved_1 : 30;
union {
__u32 wakeup_events; /* wakeup every n events */
@ -1024,6 +1025,24 @@ enum perf_event_type {
*/
PERF_RECORD_CGROUP = 19,
/*
* Records changes to kernel text i.e. self-modified code. 'old_len' is
* the number of old bytes, 'new_len' is the number of new bytes. Either
* 'old_len' or 'new_len' may be zero to indicate, for example, the
* addition or removal of a trampoline. 'bytes' contains the old bytes
* followed immediately by the new bytes.
*
* struct {
* struct perf_event_header header;
* u64 addr;
* u16 old_len;
* u16 new_len;
* u8 bytes[];
* struct sample_id sample_id;
* };
*/
PERF_RECORD_TEXT_POKE = 20,
PERF_RECORD_MAX, /* non-ABI */
};

9
tools/lib/perf/include/perf/event.h
View File

@ -111,6 +111,14 @@ struct perf_record_cgroup {
char path[PATH_MAX];
};
struct perf_record_text_poke_event {
struct perf_event_header header;
__u64 addr;
__u16 old_len;
__u16 new_len;
__u8 bytes[];
};
struct perf_record_sample {
struct perf_event_header header;
__u64 array[];
@ -367,6 +375,7 @@ union perf_event {
struct perf_record_sample sample;
struct perf_record_bpf_event bpf;
struct perf_record_ksymbol ksymbol;
struct perf_record_text_poke_event text_poke;
struct perf_record_header_attr attr;
struct perf_record_event_update event_update;
struct perf_record_header_event_type event_type;

45
tools/perf/builtin-record.c
View File

@ -765,6 +765,43 @@ static int record__auxtrace_init(struct record *rec __maybe_unused)
#endif
static int record__config_text_poke(struct evlist *evlist)
{
struct evsel *evsel;
int err;
/* Nothing to do if text poke is already configured */
evlist__for_each_entry(evlist, evsel) {
if (evsel->core.attr.text_poke)
return 0;
}
err = parse_events(evlist, "dummy:u", NULL);
if (err)
return err;
evsel = evlist__last(evlist);
evsel->core.attr.freq = 0;
evsel->core.attr.sample_period = 1;
evsel->core.attr.text_poke = 1;
evsel->core.attr.ksymbol = 1;
evsel->core.system_wide = true;
evsel->no_aux_samples = true;
evsel->immediate = true;
/* Text poke must be collected on all CPUs */
perf_cpu_map__put(evsel->core.own_cpus);
evsel->core.own_cpus = perf_cpu_map__new(NULL);
perf_cpu_map__put(evsel->core.cpus);
evsel->core.cpus = perf_cpu_map__get(evsel->core.own_cpus);
evsel__set_sample_bit(evsel, TIME);
return 0;
}
static bool record__kcore_readable(struct machine *machine)
{
char kcore[PATH_MAX];
@ -2766,6 +2803,14 @@ int cmd_record(int argc, const char **argv)
if (rec->opts.full_auxtrace)
rec->buildid_all = true;
if (rec->opts.text_poke) {
err = record__config_text_poke(rec->evlist);
if (err) {
pr_err("record__config_text_poke failed, error %d\n", err);
goto out;
}
}
if (record_opts__config(&rec->opts)) {
err = -EINVAL;
goto out;

47
tools/perf/util/event.c
View File

@ -31,6 +31,7 @@
#include "stat.h"
#include "session.h"
#include "bpf-event.h"
#include "print_binary.h"
#include "tool.h"
#include "../perf.h"
@ -55,6 +56,7 @@ static const char *perf_event__names[] = {
[PERF_RECORD_KSYMBOL] = "KSYMBOL",
[PERF_RECORD_BPF_EVENT] = "BPF_EVENT",
[PERF_RECORD_CGROUP] = "CGROUP",
[PERF_RECORD_TEXT_POKE] = "TEXT_POKE",
[PERF_RECORD_HEADER_ATTR] = "ATTR",
[PERF_RECORD_HEADER_EVENT_TYPE] = "EVENT_TYPE",
[PERF_RECORD_HEADER_TRACING_DATA] = "TRACING_DATA",
@ -267,6 +269,14 @@ int perf_event__process_bpf(struct perf_tool *tool __maybe_unused,
return machine__process_bpf(machine, event, sample);
}
int perf_event__process_text_poke(struct perf_tool *tool __maybe_unused,
union perf_event *event,
struct perf_sample *sample,
struct machine *machine)
{
return machine__process_text_poke(machine, event, sample);
}
size_t perf_event__fprintf_mmap(union perf_event *event, FILE *fp)
{
return fprintf(fp, " %d/%d: [%#" PRI_lx64 "(%#" PRI_lx64 ") @ %#" PRI_lx64 "]: %c %s\n",
@ -413,6 +423,40 @@ size_t perf_event__fprintf_bpf(union perf_event *event, FILE *fp)
event->bpf.type, event->bpf.flags, event->bpf.id);
}
static int text_poke_printer(enum binary_printer_ops op, unsigned int val,
void *extra, FILE *fp)
{
bool old = *(bool *)extra;
switch ((int)op) {
case BINARY_PRINT_LINE_BEGIN:
return fprintf(fp, " %s bytes:", old ? "Old" : "New");
case BINARY_PRINT_NUM_DATA:
return fprintf(fp, " %02x", val);
case BINARY_PRINT_LINE_END:
return fprintf(fp, "\n");
default:
return 0;
}
}
size_t perf_event__fprintf_text_poke(union perf_event *event, FILE *fp)
{
struct perf_record_text_poke_event *tp = &event->text_poke;
size_t ret;
bool old;
ret = fprintf(fp, " %" PRI_lx64 " old len %u new len %u\n",
tp->addr, tp->old_len, tp->new_len);
old = true;
ret += binary__fprintf(tp->bytes, tp->old_len, 16, text_poke_printer,
&old, fp);
old = false;
ret += binary__fprintf(tp->bytes + tp->old_len, tp->new_len, 16,
text_poke_printer, &old, fp);
return ret;
}
size_t perf_event__fprintf(union perf_event *event, FILE *fp)
{
size_t ret = fprintf(fp, "PERF_RECORD_%s",
@ -457,6 +501,9 @@ size_t perf_event__fprintf(union perf_event *event, FILE *fp)
case PERF_RECORD_BPF_EVENT:
ret += perf_event__fprintf_bpf(event, fp);
break;
case PERF_RECORD_TEXT_POKE:
ret += perf_event__fprintf_text_poke(event, fp);
break;
default:
ret += fprintf(fp, "\n");
}

5
tools/perf/util/event.h
View File

@ -351,6 +351,10 @@ int perf_event__process_bpf(struct perf_tool *tool,
union perf_event *event,
struct perf_sample *sample,
struct machine *machine);
int perf_event__process_text_poke(struct perf_tool *tool,
union perf_event *event,
struct perf_sample *sample,
struct machine *machine);
int perf_event__process(struct perf_tool *tool,
union perf_event *event,
struct perf_sample *sample,
@ -385,6 +389,7 @@ size_t perf_event__fprintf_namespaces(union perf_event *event, FILE *fp);
size_t perf_event__fprintf_cgroup(union perf_event *event, FILE *fp);
size_t perf_event__fprintf_ksymbol(union perf_event *event, FILE *fp);
size_t perf_event__fprintf_bpf(union perf_event *event, FILE *fp);
size_t perf_event__fprintf_text_poke(union perf_event *event, FILE *fp);
size_t perf_event__fprintf(union perf_event *event, FILE *fp);
int kallsyms__get_function_start(const char *kallsyms_filename,

7
tools/perf/util/evsel.c
View File

@ -1064,7 +1064,12 @@ void evsel__config(struct evsel *evsel, struct record_opts *opts,
attr->mmap = track;
attr->mmap2 = track && !perf_missing_features.mmap2;
attr->comm = track;
attr->ksymbol = track && !perf_missing_features.ksymbol;
/*
* ksymbol is tracked separately with text poke because it needs to be
* system wide and enabled immediately.
*/
if (!opts->text_poke)
attr->ksymbol = track && !perf_missing_features.ksymbol;
attr->bpf_event = track && !opts->no_bpf_event && !perf_missing_features.bpf;
if (opts->record_namespaces)

43
tools/perf/util/machine.c
View File

@ -808,6 +808,47 @@ int machine__process_ksymbol(struct machine *machine __maybe_unused,
return machine__process_ksymbol_register(machine, event, sample);
}
int machine__process_text_poke(struct machine *machine, union perf_event *event,
struct perf_sample *sample __maybe_unused)
{
struct map *map = maps__find(&machine->kmaps, event->text_poke.addr);
u8 cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
if (dump_trace)
perf_event__fprintf_text_poke(event, stdout);
if (!event->text_poke.new_len)
return 0;
if (cpumode != PERF_RECORD_MISC_KERNEL) {
pr_debug("%s: unsupported cpumode - ignoring\n", __func__);
return 0;
}
if (map && map->dso) {
u8 *new_bytes = event->text_poke.bytes + event->text_poke.old_len;
int ret;
/*
* Kernel maps might be changed when loading symbols so loading
* must be done prior to using kernel maps.
*/
map__load(map);
ret = dso__data_write_cache_addr(map->dso, map, machine,
event->text_poke.addr,
new_bytes,
event->text_poke.new_len);
if (ret != event->text_poke.new_len)
pr_debug("Failed to write kernel text poke at %#" PRI_lx64 "\n",
event->text_poke.addr);
} else {
pr_debug("Failed to find kernel text poke address map for %#" PRI_lx64 "\n",
event->text_poke.addr);
}
return 0;
}
static struct map *machine__addnew_module_map(struct machine *machine, u64 start,
const char *filename)
{
@ -1930,6 +1971,8 @@ int machine__process_event(struct machine *machine, union perf_event *event,
ret = machine__process_ksymbol(machine, event, sample); break;
case PERF_RECORD_BPF_EVENT:
ret = machine__process_bpf(machine, event, sample); break;
case PERF_RECORD_TEXT_POKE:
ret = machine__process_text_poke(machine, event, sample); break;
default:
ret = -1;
break;

3
tools/perf/util/machine.h
View File

@ -138,6 +138,9 @@ int machine__process_mmap2_event(struct machine *machine, union perf_event *even
int machine__process_ksymbol(struct machine *machine,
union perf_event *event,
struct perf_sample *sample);
int machine__process_text_poke(struct machine *machine,
union perf_event *event,
struct perf_sample *sample);
int machine__process_event(struct machine *machine, union perf_event *event,
struct perf_sample *sample);

10
tools/perf/util/perf_api_probe.c
View File

@ -93,6 +93,11 @@ static void perf_probe_context_switch(struct evsel *evsel)
evsel->core.attr.context_switch = 1;
}
static void perf_probe_text_poke(struct evsel *evsel)
{
evsel->core.attr.text_poke = 1;
}
bool perf_can_sample_identifier(void)
{
return perf_probe_api(perf_probe_sample_identifier);
@ -108,6 +113,11 @@ bool perf_can_record_switch_events(void)
return perf_probe_api(perf_probe_context_switch);
}
bool perf_can_record_text_poke_events(void)
{
return perf_probe_api(perf_probe_text_poke);
}
bool perf_can_record_cpu_wide(void)
{
struct perf_event_attr attr = {

1
tools/perf/util/perf_api_probe.h
View File

@ -9,6 +9,7 @@ bool perf_can_aux_sample(void);
bool perf_can_comm_exec(void);
bool perf_can_record_cpu_wide(void);
bool perf_can_record_switch_events(void);
bool perf_can_record_text_poke_events(void);
bool perf_can_sample_identifier(void);
#endif // __PERF_API_PROBE_H

1
tools/perf/util/perf_event_attr_fprintf.c
View File

@ -147,6 +147,7 @@ int perf_event_attr__fprintf(FILE *fp, struct perf_event_attr *attr,
PRINT_ATTRf(aux_watermark, p_unsigned);
PRINT_ATTRf(sample_max_stack, p_unsigned);
PRINT_ATTRf(aux_sample_size, p_unsigned);
PRINT_ATTRf(text_poke, p_unsigned);
return ret;
}

1
tools/perf/util/record.h
View File

@ -48,6 +48,7 @@ struct record_opts {
bool sample_id;
bool no_bpf_event;
bool kcore;
bool text_poke;
unsigned int freq;
unsigned int mmap_pages;
unsigned int auxtrace_mmap_pages;

23
tools/perf/util/session.c
View File

@ -490,6 +490,8 @@ void perf_tool__fill_defaults(struct perf_tool *tool)
tool->ksymbol = perf_event__process_ksymbol;
if (tool->bpf == NULL)
tool->bpf = perf_event__process_bpf;
if (tool->text_poke == NULL)
tool->text_poke = perf_event__process_text_poke;
if (tool->read == NULL)
tool->read = process_event_sample_stub;
if (tool->throttle == NULL)
@ -659,6 +661,24 @@ static void perf_event__switch_swap(union perf_event *event, bool sample_id_all)
swap_sample_id_all(event, &event->context_switch + 1);
}
static void perf_event__text_poke_swap(union perf_event *event, bool sample_id_all)
{
event->text_poke.addr = bswap_64(event->text_poke.addr);
event->text_poke.old_len = bswap_16(event->text_poke.old_len);
event->text_poke.new_len = bswap_16(event->text_poke.new_len);
if (sample_id_all) {
size_t len = sizeof(event->text_poke.old_len) +
sizeof(event->text_poke.new_len) +
event->text_poke.old_len +
event->text_poke.new_len;
void *data = &event->text_poke.old_len;
data += PERF_ALIGN(len, sizeof(u64));
swap_sample_id_all(event, data);
}
}
static void perf_event__throttle_swap(union perf_event *event,
bool sample_id_all)
{
@ -932,6 +952,7 @@ static perf_event__swap_op perf_event__swap_ops[] = {
[PERF_RECORD_SWITCH] = perf_event__switch_swap,
[PERF_RECORD_SWITCH_CPU_WIDE] = perf_event__switch_swap,
[PERF_RECORD_NAMESPACES] = perf_event__namespaces_swap,
[PERF_RECORD_TEXT_POKE] = perf_event__text_poke_swap,
[PERF_RECORD_HEADER_ATTR] = perf_event__hdr_attr_swap,
[PERF_RECORD_HEADER_EVENT_TYPE] = perf_event__event_type_swap,
[PERF_RECORD_HEADER_TRACING_DATA] = perf_event__tracing_data_swap,
@ -1474,6 +1495,8 @@ static int machines__deliver_event(struct machines *machines,
return tool->ksymbol(tool, event, sample, machine);
case PERF_RECORD_BPF_EVENT:
return tool->bpf(tool, event, sample, machine);
case PERF_RECORD_TEXT_POKE:
return tool->text_poke(tool, event, sample, machine);
default:
++evlist->stats.nr_unknown_events;
return -1;

3
tools/perf/util/tool.h
View File

@ -57,7 +57,8 @@ struct perf_tool {
throttle,
unthrottle,
ksymbol,
bpf;
bpf,
text_poke;
event_attr_op attr;
event_attr_op event_update;