// SPDX-License-Identifier: GPL-2.0
#include <sys/sysmacros.h>
#include <sys/types.h>
#include <errno.h>
#include <libgen.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <unistd.h>
#include <inttypes.h>
#include <byteswap.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <linux/stringify.h>
#include "build-id.h"
#include "event.h"
#include "debug.h"
#include "evlist.h"
#include "namespaces.h"
#include "symbol.h"
#include <elf.h>
#include "tsc.h"
#include "session.h"
#include "jit.h"
#include "jitdump.h"
#include "genelf.h"
#include "thread.h"
#include <linux/ctype.h>
#include <linux/zalloc.h>
struct jit_buf_desc {
struct perf_data *output;
struct perf_session *session;
struct machine *machine;
struct nsinfo *nsi;
union jr_entry *entry;
void *buf;
uint64_t sample_type;
size_t bufsize;
FILE *in;
bool needs_bswap; /* handles cross-endianness */
bool use_arch_timestamp;
void *debug_data;
void *unwinding_data;
uint64_t unwinding_size;
uint64_t unwinding_mapped_size;
uint64_t eh_frame_hdr_size;
size_t nr_debug_entries;
uint32_t code_load_count;
u64 bytes_written;
struct rb_root code_root;
char dir[PATH_MAX];
};
struct jit_tool {
struct perf_tool tool;
struct perf_data output;
struct perf_data input;
u64 bytes_written;
};
#define hmax(a, b) ((a) > (b) ? (a) : (b))
#define get_jit_tool(t) (container_of(tool, struct jit_tool, tool))
static int
jit_emit_elf(struct jit_buf_desc *jd,
char *filename,
const char *sym,
uint64_t code_addr,
const void *code,
int csize,
void *debug,
int nr_debug_entries,
void *unwinding,
uint32_t unwinding_header_size,
uint32_t unwinding_size)
{
int ret, fd, saved_errno;
struct nscookie nsc;
if (verbose > 0)
fprintf(stderr, "write ELF image %s\n", filename);
nsinfo__mountns_enter(jd->nsi, &nsc);
fd = open(filename, O_CREAT|O_TRUNC|O_WRONLY, 0644);
saved_errno = errno;
nsinfo__mountns_exit(&nsc);
if (fd == -1) {
pr_warning("cannot create jit ELF %s: %s\n", filename, strerror(saved_errno));
return -1;
}
ret = jit_write_elf(fd, code_addr, sym, (const void *)code, csize, debug, nr_debug_entries,
unwinding, unwinding_header_size, unwinding_size);
close(fd);
if (ret) {
nsinfo__mountns_enter(jd->nsi, &nsc);
unlink(filename);
nsinfo__mountns_exit(&nsc);
}
return ret;
}
static void
jit_close(struct jit_buf_desc *jd)
{
if (!(jd && jd->in))
return;
funlockfile(jd->in);
fclose(jd->in);
jd->in = NULL;
}
static int
jit_validate_events(struct perf_session *session)
{
struct evsel *evsel;
/*
* check that all events use CLOCK_MONOTONIC
*/
evlist__for_each_entry(session->evlist, evsel) {
if (evsel->core.attr.use_clockid == 0 || evsel->core.attr.clockid != CLOCK_MONOTONIC)
return -1;
}
return 0;
}
static int
jit_open(struct jit_buf_desc *jd, const char *name)
{
struct jitheader header;
struct nscookie nsc;
struct jr_prefix *prefix;
ssize_t bs, bsz = 0;
void *n, *buf = NULL;
int ret, retval = -1;
nsinfo__mountns_enter(jd->nsi, &nsc);
jd->in = fopen(name, "r");
nsinfo__mountns_exit(&nsc);
if (!jd->in)
return -1;
bsz = hmax(sizeof(header), sizeof(*prefix));
buf = malloc(bsz);
if (!buf)
goto error;
/*
* protect from writer modifying the file while we are reading it
*/
flockfile(jd->in);
ret = fread(buf, sizeof(header), 1, jd->in);
if (ret != 1)
goto error;
memcpy(&header, buf, sizeof(header));
if (header.magic != JITHEADER_MAGIC) {
if (header.magic != JITHEADER_MAGIC_SW)
goto error;
jd->needs_bswap = true;
}
if (jd->needs_bswap) {
header.version = bswap_32(header.version);
header.total_size = bswap_32(header.total_size);
header.pid = bswap_32(header.pid);
header.elf_mach = bswap_32(header.elf_mach);
header.timestamp = bswap_64(header.timestamp);
header.flags = bswap_64(header.flags);
}
jd->use_arch_timestamp = header.flags & JITDUMP_FLAGS_ARCH_TIMESTAMP;
if (verbose > 2)
pr_debug("version=%u\nhdr.size=%u\nts=0x%llx\npid=%d\nelf_mach=%d\nuse_arch_timestamp=%d\n",
header.version,
header.total_size,
(unsigned long long)header.timestamp,
header.pid,
header.elf_mach,
jd->use_arch_timestamp);
if (header.version > JITHEADER_VERSION) {
pr_err("wrong jitdump version %u, expected " __stringify(JITHEADER_VERSION),
header.version);
goto error;
}
if (header.flags & JITDUMP_FLAGS_RESERVED) {
pr_err("jitdump file contains invalid or unsupported flags 0x%llx\n",
(unsigned long long)header.flags & JITDUMP_FLAGS_RESERVED);
goto error;
}
if (jd->use_arch_timestamp && !jd->session->time_conv.time_mult) {
pr_err("jitdump file uses arch timestamps but there is no timestamp conversion\n");
goto error;
}
/*
* validate event is using the correct clockid
*/
if (!jd->use_arch_timestamp && jit_validate_events(jd->session)) {
pr_err("error, jitted code must be sampled with perf record -k 1\n");
goto error;
}
bs = header.total_size - sizeof(header);
if (bs > bsz) {
n = realloc(buf, bs);
if (!n)
goto error;
bsz = bs;
buf = n;
/* read extra we do not know about */
ret = fread(buf, bs - bsz, 1, jd->in);
if (ret != 1)
goto error;
}
/*
* keep dirname for generating files and mmap records
*/
strcpy(jd->dir, name);
dirname(jd->dir);
free(buf);
return 0;
error:
free(buf);
funlockfile(jd->in);
fclose(jd->in);
return retval;
}
static union jr_entry *
jit_get_next_entry(struct jit_buf_desc *jd)
{
struct jr_prefix *prefix;
union jr_entry *jr;
void *addr;
size_t bs, size;
int id, ret;
if (!(jd && jd->in))
return NULL;
if (jd->buf == NULL) {
size_t sz = getpagesize();
if (sz < sizeof(*prefix))
sz = sizeof(*prefix);
jd->buf = malloc(sz);
if (jd->buf == NULL)
return NULL;
jd->bufsize = sz;
}
prefix = jd->buf;
/*
* file is still locked at this point
*/
ret = fread(prefix, sizeof(*prefix), 1, jd->in);
if (ret != 1)
return NULL;
if (jd->needs_bswap) {
prefix->id = bswap_32(prefix->id);
prefix->total_size = bswap_32(prefix->total_size);
prefix->timestamp = bswap_64(prefix->timestamp);
}
id = prefix->id;
size = prefix->total_size;
bs = (size_t)size;
if (bs < sizeof(*prefix))
return NULL;
if (id >= JIT_CODE_MAX) {
pr_warning("next_entry: unknown record type %d, skipping\n", id);
}
if (bs > jd->bufsize) {
void *n;
n = realloc(jd->buf, bs);
if (!n)
return NULL;
jd->buf = n;
jd->bufsize = bs;
}
addr = ((void *)jd->buf) + sizeof(*prefix);
ret = fread(addr, bs - sizeof(*prefix), 1, jd->in);
if (ret != 1)
return NULL;
jr = (union jr_entry *)jd->buf;
switch(id) {
case JIT_CODE_DEBUG_INFO:
if (jd->needs_bswap) {
uint64_t n;
jr->info.code_addr = bswap_64(jr->info.code_addr);
jr->info.nr_entry = bswap_64(jr->info.nr_entry);
for (n = 0 ; n < jr->info.nr_entry; n++) {
jr->info.entries[n].addr = bswap_64(jr->info.entries[n].addr);
jr->info.entries[n].lineno = bswap_32(jr->info.entries[n].lineno);
jr->info.entries[n].discrim = bswap_32(jr->info.entries[n].discrim);
}
}
break;
case JIT_CODE_UNWINDING_INFO:
if (jd->needs_bswap) {
jr->unwinding.unwinding_size = bswap_64(jr->unwinding.unwinding_size);
jr->unwinding.eh_frame_hdr_size = bswap_64(jr->unwinding.eh_frame_hdr_size);
jr->unwinding.mapped_size = bswap_64(jr->unwinding.mapped_size);
}
break;
case JIT_CODE_CLOSE:
break;
case JIT_CODE_LOAD:
if (jd->needs_bswap) {
jr->load.pid = bswap_32(jr->load.pid);
jr->load.tid = bswap_32(jr->load.tid);
jr->load.vma = bswap_64(jr->load.vma);
jr->load.code_addr = bswap_64(jr->load.code_addr);
jr->load.code_size = bswap_64(jr->load.code_size);
jr->load.code_index= bswap_64(jr->load.code_index);
}
jd->code_load_count++;
break;
case JIT_CODE_MOVE:
if (jd->needs_bswap) {
jr->move.pid = bswap_32(jr->move.pid);
jr->move.tid = bswap_32(jr->move.tid);
jr->move.vma = bswap_64(jr->move.vma);
jr->move.old_code_addr = bswap_64(jr->move.old_code_addr);
jr->move.new_code_addr = bswap_64(jr->move.new_code_addr);
jr->move.code_size = bswap_64(jr->move.code_size);
jr->move.code_index = bswap_64(jr->move.code_index);
}
break;
case JIT_CODE_MAX:
default:
/* skip unknown record (we have read them) */
break;
}
return jr;
}
static int
jit_inject_event(struct jit_buf_desc *jd, union perf_event *event)
{
ssize_t size;
size = perf_data__write(jd->output, event, event->header.size);
if (size < 0)
return -1;
jd->bytes_written += size;
return 0;
}
static pid_t jr_entry_pid(struct jit_buf_desc *jd, union jr_entry *jr)
{
if (jd->nsi && nsinfo__in_pidns(jd->nsi))
return nsinfo__tgid(jd->nsi);
return jr->load.pid;
}
static pid_t jr_entry_tid(struct jit_buf_desc *jd, union jr_entry *jr)
{
if (jd->nsi && nsinfo__in_pidns(jd->nsi))
return nsinfo__pid(jd->nsi);
return jr->load.tid;
}
static uint64_t convert_timestamp(struct jit_buf_desc *jd, uint64_t timestamp)
{
struct perf_tsc_conversion tc = { .time_shift = 0, };
struct perf_record_time_conv *time_conv = &jd->session->time_conv;
if (!jd->use_arch_timestamp)
return timestamp;
tc.time_shift = time_conv->time_shift;
tc.time_mult = time_conv->time_mult;
tc.time_zero = time_conv->time_zero;
/*
* The event TIME_CONV was extended for the fields from "time_cycles"
* when supported cap_user_time_short, for backward compatibility,
* checks the event size and assigns these extended fields if these
* fields are contained in the event.
*/
if (event_contains(*time_conv, time_cycles)) {
tc.time_cycles = time_conv->time_cycles;
tc.time_mask = time_conv->time_mask;
tc.cap_user_time_zero = time_conv->cap_user_time_zero;
tc.cap_user_time_short = time_conv->cap_user_time_short;
if (!tc.cap_user_time_zero)
return 0;
}
return tsc_to_perf_time(timestamp, &tc);
}
static int jit_repipe_code_load(struct jit_buf_desc *jd, union jr_entry *jr)
{
struct perf_sample sample;
union perf_event *event;
const struct perf_tool *tool = jd->session->tool;
uint64_t code, addr;
uintptr_t uaddr;
char *filename;
struct stat st;
size_t size;
u16 idr_size;
const char *sym;
uint64_t count;
int ret, csize, usize;
pid_t nspid, pid, tid;
struct {
u32 pid, tid;
u64 time;
} *id;
nspid = jr->load.pid;
pid = jr_entry_pid(jd, jr);
tid = jr_entry_tid(jd, jr);
csize = jr->load.code_size;
usize = jd->unwinding_mapped_size;
addr = jr->load.code_addr;
sym = (void *)((unsigned long)jr + sizeof(jr->load));
code = (unsigned long)jr + jr->load.p.total_size - csize;
count = jr->load.code_index;
idr_size = jd->machine->id_hdr_size;
event = calloc(1, sizeof(*event) + idr_size);
if (!event)
return -1;
filename = event->mmap2.filename;
size = snprintf(filename, PATH_MAX, "%s/jitted-%d-%" PRIu64 ".so",
jd->dir,
nspid,
count);
size++; /* for \0 */
size = PERF_ALIGN(size, sizeof(u64));
uaddr = (uintptr_t)code;
ret = jit_emit_elf(jd, filename, sym, addr, (const void *)uaddr, csize, jd->debug_data, jd->nr_debug_entries,
jd->unwinding_data, jd->eh_frame_hdr_size, jd->unwinding_size);
if (jd->debug_data && jd->nr_debug_entries) {
zfree(&jd->debug_data);
jd->nr_debug_entries = 0;
}
if (jd->unwinding_data && jd->eh_frame_hdr_size) {
zfree(&jd->unwinding_data);
jd->eh_frame_hdr_size = 0;
jd->unwinding_mapped_size = 0;
jd->unwinding_size = 0;
}
if (ret) {
free(event);
return -1;
}
if (nsinfo__stat(filename, &st, jd->nsi))
memset(&st, 0, sizeof(st));
event->mmap2.header.type = PERF_RECORD_MMAP2;
event->mmap2.header.misc = PERF_RECORD_MISC_USER;
event->mmap2.header.size = (sizeof(event->mmap2) -
(sizeof(event->mmap2.filename) - size) + idr_size);
event->mmap2.pgoff = GEN_ELF_TEXT_OFFSET;
event->mmap2.start = addr;
event->mmap2.len = usize ? ALIGN_8(csize) + usize : csize;
event->mmap2.pid = pid;
event->mmap2.tid = tid;
event->mmap2.ino = st.st_ino;
event->mmap2.maj = major(st.st_dev);
event->mmap2.min = minor(st.st_dev);
event->mmap2.prot = st.st_mode;
event->mmap2.flags = MAP_SHARED;
event->mmap2.ino_generation = 1;
id = (void *)((unsigned long)event + event->mmap.header.size - idr_size);
if (jd->sample_type & PERF_SAMPLE_TID) {
id->pid = pid;
id->tid = tid;
}
if (jd->sample_type & PERF_SAMPLE_TIME)
id->time = convert_timestamp(jd, jr->load.p.timestamp);
/*
* create pseudo sample to induce dso hit increment
* use first address as sample address
*/
memset(&sample, 0, sizeof(sample));
sample.cpumode = PERF_RECORD_MISC_USER;
sample.pid = pid;
sample.tid = tid;
sample.time = id->time;
sample.ip = addr;
ret = perf_event__process_mmap2(tool, event, &sample, jd->machine);
if (ret)
goto out;
ret = jit_inject_event(jd, event);
/*
* mark dso as use to generate buildid in the header
*/
if (!ret)
build_id__mark_dso_hit(tool, event, &sample, NULL, jd->machine);
out:
free(event);
return ret;
}
static int jit_repipe_code_move(struct jit_buf_desc *jd, union jr_entry *jr)
{
struct perf_sample sample;
union perf_event *event;
const struct perf_tool *tool = jd->session->tool;
char *filename;
size_t size;
struct stat st;
int usize;
u16 idr_size;
int ret;
pid_t nspid, pid, tid;
struct {
u32 pid, tid;
u64 time;
} *id;
nspid = jr->load.pid;
pid = jr_entry_pid(jd, jr);
tid = jr_entry_tid(jd, jr);
usize = jd->unwinding_mapped_size;
idr_size = jd->machine->id_hdr_size;
/*
* +16 to account for sample_id_all (hack)
*/
event = calloc(1, sizeof(*event) + 16);
if (!event)
return -1;
filename = event->mmap2.filename;
size = snprintf(filename, PATH_MAX, "%s/jitted-%d-%" PRIu64 ".so",
jd->dir,
nspid,
jr->move.code_index);
size++; /* for \0 */
if (nsinfo__stat(filename, &st, jd->nsi))
memset(&st, 0, sizeof(st));
size = PERF_ALIGN(size, sizeof(u64));
event->mmap2.header.type = PERF_RECORD_MMAP2;
event->mmap2.header.misc = PERF_RECORD_MISC_USER;
event->mmap2.header.size = (sizeof(event->mmap2) -
(sizeof(event->mmap2.filename) - size) + idr_size);
event->mmap2.pgoff = GEN_ELF_TEXT_OFFSET;
event->mmap2.start = jr->move.new_code_addr;
event->mmap2.len = usize ? ALIGN_8(jr->move.code_size) + usize
: jr->move.code_size;
event->mmap2.pid = pid;
event->mmap2.tid = tid;
event->mmap2.ino = st.st_ino;
event->mmap2.maj = major(st.st_dev);
event->mmap2.min = minor(st.st_dev);
event->mmap2.prot = st.st_mode;
event->mmap2.flags = MAP_SHARED;
event->mmap2.ino_generation = 1;
id = (void *)((unsigned long)event + event->mmap.header.size - idr_size);
if (jd->sample_type & PERF_SAMPLE_TID) {
id->pid = pid;
id->tid = tid;
}
if (jd->sample_type & PERF_SAMPLE_TIME)
id->time = convert_timestamp(jd, jr->load.p.timestamp);
/*
* create pseudo sample to induce dso hit increment
* use first address as sample address
*/
memset(&sample, 0, sizeof(sample));
sample.cpumode = PERF_RECORD_MISC_USER;
sample.pid = pid;
sample.tid = tid;
sample.time = id->time;
sample.ip = jr->move.new_code_addr;
ret = perf_event__process_mmap2(tool, event, &sample, jd->machine);
if (ret)
return ret;
ret = jit_inject_event(jd, event);
if (!ret)
build_id__mark_dso_hit(tool, event, &sample, NULL, jd->machine);
return ret;
}
static int jit_repipe_debug_info(struct jit_buf_desc *jd, union jr_entry *jr)
{
void *data;
size_t sz;
if (!(jd && jr))
return -1;
sz = jr->prefix.total_size - sizeof(jr->info);
data = malloc(sz);
if (!data)
return -1;
memcpy(data, &jr->info.entries, sz);
jd->debug_data = data;
/*
* we must use nr_entry instead of size here because
* we cannot distinguish actual entry from padding otherwise
*/
jd->nr_debug_entries = jr->info.nr_entry;
return 0;
}
static int
jit_repipe_unwinding_info(struct jit_buf_desc *jd, union jr_entry *jr)
{
void *unwinding_data;
uint32_t unwinding_data_size;
if (!(jd && jr))
return -1;
unwinding_data_size = jr->prefix.total_size - sizeof(jr->unwinding);
unwinding_data = malloc(unwinding_data_size);
if (!unwinding_data)
return -1;
memcpy(unwinding_data, &jr->unwinding.unwinding_data,
unwinding_data_size);
jd->eh_frame_hdr_size = jr->unwinding.eh_frame_hdr_size;
jd->unwinding_size = jr->unwinding.unwinding_size;
jd->unwinding_mapped_size = jr->unwinding.mapped_size;
free(jd->unwinding_data);
jd->unwinding_data = unwinding_data;
return 0;
}
static int
jit_process_dump(struct jit_buf_desc *jd)
{
union jr_entry *jr;
int ret = 0;
while ((jr = jit_get_next_entry(jd))) {
switch(jr->prefix.id) {
case JIT_CODE_LOAD:
ret = jit_repipe_code_load(jd, jr);
break;
case JIT_CODE_MOVE:
ret = jit_repipe_code_move(jd, jr);
break;
case JIT_CODE_DEBUG_INFO:
ret = jit_repipe_debug_info(jd, jr);
break;
case JIT_CODE_UNWINDING_INFO:
ret = jit_repipe_unwinding_info(jd, jr);
break;
default:
ret = 0;
continue;
}
}
return ret;
}
static int
jit_inject(struct jit_buf_desc *jd, const char *path)
{
int ret;
if (verbose > 0)
fprintf(stderr, "injecting: %s\n", path);
ret = jit_open(jd, path);
if (ret)
return -1;
ret = jit_process_dump(jd);
jit_close(jd);
if (verbose > 0)
fprintf(stderr, "injected: %s (%d)\n", path, ret);
return 0;
}
/*
* File must be with pattern .../jit-XXXX.dump
* where XXXX is the PID of the process which did the mmap()
* as captured in the RECORD_MMAP record
*/
static int
jit_detect(const char *mmap_name, pid_t pid, struct nsinfo *nsi)
{
char *p;
char *end = NULL;
pid_t pid2;
if (verbose > 2)
fprintf(stderr, "jit marker trying : %s\n", mmap_name);
/*
* get file name
*/
p = strrchr(mmap_name, '/');
if (!p)
return -1;
/*
* match prefix
*/
if (strncmp(p, "/jit-", 5))
return -1;
/*
* skip prefix
*/
p += 5;
/*
* must be followed by a pid
*/
if (!isdigit(*p))
return -1;
pid2 = (int)strtol(p, &end, 10);
if (!end)
return -1;
/*
* pid does not match mmap pid
* pid==0 in system-wide mode (synthesized)
*/
if (pid && pid2 != nsinfo__nstgid(nsi))
return -1;
/*
* validate suffix
*/
if (strcmp(end, ".dump"))
return -1;
if (verbose > 0)
fprintf(stderr, "jit marker found: %s\n", mmap_name);
return 0;
}
static void jit_add_pid(struct machine *machine, pid_t pid)
{
struct thread *thread = machine__findnew_thread(machine, pid, pid);
if (!thread) {
pr_err("%s: thread %d not found or created\n", __func__, pid);
return;
}
thread__set_priv(thread, (void *)true);
thread__put(thread);
}
static bool jit_has_pid(struct machine *machine, pid_t pid)
{
struct thread *thread = machine__find_thread(machine, pid, pid);
void *priv;
if (!thread)
return false;
priv = thread__priv(thread);
thread__put(thread);
return (bool)priv;
}
int
jit_process(struct perf_session *session,
struct perf_data *output,
struct machine *machine,
const char *filename,
pid_t pid,
pid_t tid,
u64 *nbytes)
{
struct thread *thread;
struct nsinfo *nsi;
struct evsel *first;
struct jit_buf_desc jd;
int ret;
thread = machine__findnew_thread(machine, pid, tid);
if (thread == NULL) {
pr_err("problem processing JIT mmap event, skipping it.\n");
return 0;
}
nsi = nsinfo__get(thread__nsinfo(thread));
thread__put(thread);
/*
* first, detect marker mmap (i.e., the jitdump mmap)
*/
if (jit_detect(filename, pid, nsi)) {
nsinfo__put(nsi);
/*
* Strip //anon*, [anon:* and /memfd:* mmaps if we processed a jitdump for this pid
*/
if (jit_has_pid(machine, pid) &&
((strncmp(filename, "//anon", 6) == 0) ||
(strncmp(filename, "[anon:", 6) == 0) ||
(strncmp(filename, "/memfd:", 7) == 0)))
return 1;
return 0;
}
memset(&jd, 0, sizeof(jd));
jd.session = session;
jd.output = output;
jd.machine = machine;
jd.nsi = nsi;
/*
* track sample_type to compute id_all layout
* perf sets the same sample type to all events as of now
*/
first = evlist__first(session->evlist);
jd.sample_type = first->core.attr.sample_type;
*nbytes = 0;
ret = jit_inject(&jd, filename);
if (!ret) {
jit_add_pid(machine, pid);
*nbytes = jd.bytes_written;
ret = 1;
}
nsinfo__put(jd.nsi);
free(jd.buf);
return ret;
}
Codebase Browser
linux