linux/tools/perf/util/genelf.c

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perf inject: Add jitdump mmap injection support This patch adds a --jit/-j option to perf inject. This options injects MMAP records into the perf.data file to cover the jitted code mmaps. It also emits ELF images for each function in the jidump file. Those images are created where the jitdump file is. The MMAP records point to that location as well. Typical flow: $ perf record -k mono -- java -agentpath:libpjvmti.so java_class $ perf inject --jit -i perf.data -o perf.data.jitted $ perf report -i perf.data.jitted Note that jitdump.h support is not limited to Java, it works with any jitted environment modified to emit the jitdump file format, include those where code can be jitted multiple times and moved around. The jitdump.h format is adapted from the Oprofile project. The genelf.c (ELF binary generation) depends on MD5 hash encoding for the buildid. To enable this, libssl-dev must be installed. If not, then genelf.c defaults to using urandom to generate the buildid, which is not ideal. The Makefile auto-detects the presence on libssl-dev. This version mmaps the jitdump file to create a marker MMAP record in the perf.data file. The marker is used to detect jitdump and cause perf inject to inject the jitted mmaps and generate ELF images for jitted functions. In V8, the following fixes and changes were made among other things: - the jidump header format include a new flags field to be used to carry information about the configuration of the runtime agent. Contributed by: Adrian Hunter <adrian.hunter@intel.com> - Fix mmap pgoff: MMAP event pgoff must be the offset within the ELF file at which the code resides. Contributed by: Adrian Hunter <adrian.hunter@intel.com> - Fix ELF virtual addresses: perf tools expect the ELF virtual addresses of dynamic objects to match the file offset. Contributed by: Adrian Hunter <adrian.hunter@intel.com> - JIT MMAP injection does not obey finished_round semantics. JIT MMAP injection injects all MMAP events in one go, so it does not obey finished_round semantics, so drop the finished_round events from the output perf.data file. Contributed by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Stephane Eranian <eranian@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Carl Love <cel@us.ibm.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: John McCutchan <johnmccutchan@google.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Pawel Moll <pawel.moll@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sonny Rao <sonnyrao@chromium.org> Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/1448874143-7269-3-git-send-email-eranian@google.com [ Moved inject.build_ids ordering bits to a separate patch, fixed the NO_LIBELF=1 build ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-11-30 09:02:21 +00:00
/*
* genelf.c
* Copyright (C) 2014, Google, Inc
*
* Contributed by:
* Stephane Eranian <eranian@gmail.com>
*
* Released under the GPL v2. (and only v2, not any later version)
*/
#include <sys/types.h>
#include <stdio.h>
#include <getopt.h>
#include <stddef.h>
#include <libelf.h>
#include <string.h>
#include <stdlib.h>
#include <inttypes.h>
#include <limits.h>
#include <fcntl.h>
#include <err.h>
#include <dwarf.h>
#include "perf.h"
#include "genelf.h"
#include "../util/jitdump.h"
#define JVMTI
#define BUILD_ID_URANDOM /* different uuid for each run */
#ifdef HAVE_LIBCRYPTO
#define BUILD_ID_MD5
#undef BUILD_ID_SHA /* does not seem to work well when linked with Java */
#undef BUILD_ID_URANDOM /* different uuid for each run */
#ifdef BUILD_ID_SHA
#include <openssl/sha.h>
#endif
#ifdef BUILD_ID_MD5
#include <openssl/md5.h>
#endif
#endif
typedef struct {
unsigned int namesz; /* Size of entry's owner string */
unsigned int descsz; /* Size of the note descriptor */
unsigned int type; /* Interpretation of the descriptor */
char name[0]; /* Start of the name+desc data */
} Elf_Note;
struct options {
char *output;
int fd;
};
static char shd_string_table[] = {
0,
'.', 't', 'e', 'x', 't', 0, /* 1 */
'.', 's', 'h', 's', 't', 'r', 't', 'a', 'b', 0, /* 7 */
'.', 's', 'y', 'm', 't', 'a', 'b', 0, /* 17 */
'.', 's', 't', 'r', 't', 'a', 'b', 0, /* 25 */
'.', 'n', 'o', 't', 'e', '.', 'g', 'n', 'u', '.', 'b', 'u', 'i', 'l', 'd', '-', 'i', 'd', 0, /* 33 */
'.', 'd', 'e', 'b', 'u', 'g', '_', 'l', 'i', 'n', 'e', 0, /* 52 */
'.', 'd', 'e', 'b', 'u', 'g', '_', 'i', 'n', 'f', 'o', 0, /* 64 */
'.', 'd', 'e', 'b', 'u', 'g', '_', 'a', 'b', 'b', 'r', 'e', 'v', 0, /* 76 */
};
static struct buildid_note {
Elf_Note desc; /* descsz: size of build-id, must be multiple of 4 */
char name[4]; /* GNU\0 */
char build_id[20];
} bnote;
static Elf_Sym symtab[]={
/* symbol 0 MUST be the undefined symbol */
{ .st_name = 0, /* index in sym_string table */
.st_info = ELF_ST_TYPE(STT_NOTYPE),
.st_shndx = 0, /* for now */
.st_value = 0x0,
.st_other = ELF_ST_VIS(STV_DEFAULT),
.st_size = 0,
},
{ .st_name = 1, /* index in sym_string table */
.st_info = ELF_ST_BIND(STB_LOCAL) | ELF_ST_TYPE(STT_FUNC),
.st_shndx = 1,
.st_value = 0, /* for now */
.st_other = ELF_ST_VIS(STV_DEFAULT),
.st_size = 0, /* for now */
}
};
#ifdef BUILD_ID_URANDOM
static void
gen_build_id(struct buildid_note *note,
unsigned long load_addr __maybe_unused,
const void *code __maybe_unused,
size_t csize __maybe_unused)
{
int fd;
size_t sz = sizeof(note->build_id);
ssize_t sret;
fd = open("/dev/urandom", O_RDONLY);
if (fd == -1)
err(1, "cannot access /dev/urandom for builid");
sret = read(fd, note->build_id, sz);
close(fd);
if (sret != (ssize_t)sz)
memset(note->build_id, 0, sz);
}
#endif
#ifdef BUILD_ID_SHA
static void
gen_build_id(struct buildid_note *note,
unsigned long load_addr __maybe_unused,
const void *code,
size_t csize)
{
if (sizeof(note->build_id) < SHA_DIGEST_LENGTH)
errx(1, "build_id too small for SHA1");
SHA1(code, csize, (unsigned char *)note->build_id);
}
#endif
#ifdef BUILD_ID_MD5
static void
gen_build_id(struct buildid_note *note, unsigned long load_addr, const void *code, size_t csize)
{
MD5_CTX context;
if (sizeof(note->build_id) < 16)
errx(1, "build_id too small for MD5");
MD5_Init(&context);
MD5_Update(&context, &load_addr, sizeof(load_addr));
MD5_Update(&context, code, csize);
MD5_Final((unsigned char *)note->build_id, &context);
}
#endif
/*
* fd: file descriptor open for writing for the output file
* load_addr: code load address (could be zero, just used for buildid)
* sym: function name (for native code - used as the symbol)
* code: the native code
* csize: the code size in bytes
*/
int
jit_write_elf(int fd, uint64_t load_addr, const char *sym,
const void *code, int csize,
void *debug, int nr_debug_entries)
perf inject: Add jitdump mmap injection support This patch adds a --jit/-j option to perf inject. This options injects MMAP records into the perf.data file to cover the jitted code mmaps. It also emits ELF images for each function in the jidump file. Those images are created where the jitdump file is. The MMAP records point to that location as well. Typical flow: $ perf record -k mono -- java -agentpath:libpjvmti.so java_class $ perf inject --jit -i perf.data -o perf.data.jitted $ perf report -i perf.data.jitted Note that jitdump.h support is not limited to Java, it works with any jitted environment modified to emit the jitdump file format, include those where code can be jitted multiple times and moved around. The jitdump.h format is adapted from the Oprofile project. The genelf.c (ELF binary generation) depends on MD5 hash encoding for the buildid. To enable this, libssl-dev must be installed. If not, then genelf.c defaults to using urandom to generate the buildid, which is not ideal. The Makefile auto-detects the presence on libssl-dev. This version mmaps the jitdump file to create a marker MMAP record in the perf.data file. The marker is used to detect jitdump and cause perf inject to inject the jitted mmaps and generate ELF images for jitted functions. In V8, the following fixes and changes were made among other things: - the jidump header format include a new flags field to be used to carry information about the configuration of the runtime agent. Contributed by: Adrian Hunter <adrian.hunter@intel.com> - Fix mmap pgoff: MMAP event pgoff must be the offset within the ELF file at which the code resides. Contributed by: Adrian Hunter <adrian.hunter@intel.com> - Fix ELF virtual addresses: perf tools expect the ELF virtual addresses of dynamic objects to match the file offset. Contributed by: Adrian Hunter <adrian.hunter@intel.com> - JIT MMAP injection does not obey finished_round semantics. JIT MMAP injection injects all MMAP events in one go, so it does not obey finished_round semantics, so drop the finished_round events from the output perf.data file. Contributed by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Stephane Eranian <eranian@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Carl Love <cel@us.ibm.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: John McCutchan <johnmccutchan@google.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Pawel Moll <pawel.moll@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sonny Rao <sonnyrao@chromium.org> Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/1448874143-7269-3-git-send-email-eranian@google.com [ Moved inject.build_ids ordering bits to a separate patch, fixed the NO_LIBELF=1 build ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-11-30 09:02:21 +00:00
{
Elf *e;
Elf_Data *d;
Elf_Scn *scn;
Elf_Ehdr *ehdr;
Elf_Shdr *shdr;
char *strsym = NULL;
int symlen;
int retval = -1;
if (elf_version(EV_CURRENT) == EV_NONE) {
warnx("ELF initialization failed");
return -1;
}
e = elf_begin(fd, ELF_C_WRITE, NULL);
if (!e) {
warnx("elf_begin failed");
goto error;
}
/*
* setup ELF header
*/
ehdr = elf_newehdr(e);
if (!ehdr) {
warnx("cannot get ehdr");
goto error;
}
ehdr->e_ident[EI_DATA] = GEN_ELF_ENDIAN;
ehdr->e_ident[EI_CLASS] = GEN_ELF_CLASS;
ehdr->e_machine = GEN_ELF_ARCH;
ehdr->e_type = ET_DYN;
ehdr->e_entry = GEN_ELF_TEXT_OFFSET;
ehdr->e_version = EV_CURRENT;
ehdr->e_shstrndx= 2; /* shdr index for section name */
/*
* setup text section
*/
scn = elf_newscn(e);
if (!scn) {
warnx("cannot create section");
goto error;
}
d = elf_newdata(scn);
if (!d) {
warnx("cannot get new data");
goto error;
}
d->d_align = 16;
d->d_off = 0LL;
d->d_buf = (void *)code;
d->d_type = ELF_T_BYTE;
d->d_size = csize;
d->d_version = EV_CURRENT;
shdr = elf_getshdr(scn);
if (!shdr) {
warnx("cannot get section header");
goto error;
}
shdr->sh_name = 1;
shdr->sh_type = SHT_PROGBITS;
shdr->sh_addr = GEN_ELF_TEXT_OFFSET;
shdr->sh_flags = SHF_EXECINSTR | SHF_ALLOC;
shdr->sh_entsize = 0;
/*
* setup section headers string table
*/
scn = elf_newscn(e);
if (!scn) {
warnx("cannot create section");
goto error;
}
d = elf_newdata(scn);
if (!d) {
warnx("cannot get new data");
goto error;
}
d->d_align = 1;
d->d_off = 0LL;
d->d_buf = shd_string_table;
d->d_type = ELF_T_BYTE;
d->d_size = sizeof(shd_string_table);
d->d_version = EV_CURRENT;
shdr = elf_getshdr(scn);
if (!shdr) {
warnx("cannot get section header");
goto error;
}
shdr->sh_name = 7; /* offset of '.shstrtab' in shd_string_table */
shdr->sh_type = SHT_STRTAB;
shdr->sh_flags = 0;
shdr->sh_entsize = 0;
/*
* setup symtab section
*/
symtab[1].st_size = csize;
symtab[1].st_value = GEN_ELF_TEXT_OFFSET;
scn = elf_newscn(e);
if (!scn) {
warnx("cannot create section");
goto error;
}
d = elf_newdata(scn);
if (!d) {
warnx("cannot get new data");
goto error;
}
d->d_align = 8;
d->d_off = 0LL;
d->d_buf = symtab;
d->d_type = ELF_T_SYM;
d->d_size = sizeof(symtab);
d->d_version = EV_CURRENT;
shdr = elf_getshdr(scn);
if (!shdr) {
warnx("cannot get section header");
goto error;
}
shdr->sh_name = 17; /* offset of '.symtab' in shd_string_table */
shdr->sh_type = SHT_SYMTAB;
shdr->sh_flags = 0;
shdr->sh_entsize = sizeof(Elf_Sym);
shdr->sh_link = 4; /* index of .strtab section */
/*
* setup symbols string table
* 2 = 1 for 0 in 1st entry, 1 for the 0 at end of symbol for 2nd entry
*/
symlen = 2 + strlen(sym);
strsym = calloc(1, symlen);
if (!strsym) {
warnx("cannot allocate strsym");
goto error;
}
strcpy(strsym + 1, sym);
scn = elf_newscn(e);
if (!scn) {
warnx("cannot create section");
goto error;
}
d = elf_newdata(scn);
if (!d) {
warnx("cannot get new data");
goto error;
}
d->d_align = 1;
d->d_off = 0LL;
d->d_buf = strsym;
d->d_type = ELF_T_BYTE;
d->d_size = symlen;
d->d_version = EV_CURRENT;
shdr = elf_getshdr(scn);
if (!shdr) {
warnx("cannot get section header");
goto error;
}
shdr->sh_name = 25; /* offset in shd_string_table */
shdr->sh_type = SHT_STRTAB;
shdr->sh_flags = 0;
shdr->sh_entsize = 0;
/*
* setup build-id section
*/
scn = elf_newscn(e);
if (!scn) {
warnx("cannot create section");
goto error;
}
d = elf_newdata(scn);
if (!d) {
warnx("cannot get new data");
goto error;
}
/*
* build-id generation
*/
gen_build_id(&bnote, load_addr, code, csize);
bnote.desc.namesz = sizeof(bnote.name); /* must include 0 termination */
bnote.desc.descsz = sizeof(bnote.build_id);
bnote.desc.type = NT_GNU_BUILD_ID;
strcpy(bnote.name, "GNU");
d->d_align = 4;
d->d_off = 0LL;
d->d_buf = &bnote;
d->d_type = ELF_T_BYTE;
d->d_size = sizeof(bnote);
d->d_version = EV_CURRENT;
shdr = elf_getshdr(scn);
if (!shdr) {
warnx("cannot get section header");
goto error;
}
shdr->sh_name = 33; /* offset in shd_string_table */
shdr->sh_type = SHT_NOTE;
shdr->sh_addr = 0x0;
shdr->sh_flags = SHF_ALLOC;
shdr->sh_size = sizeof(bnote);
shdr->sh_entsize = 0;
if (debug && nr_debug_entries) {
retval = jit_add_debug_info(e, load_addr, debug, nr_debug_entries);
if (retval)
goto error;
} else {
if (elf_update(e, ELF_C_WRITE) < 0) {
warnx("elf_update 4 failed");
goto error;
}
perf inject: Add jitdump mmap injection support This patch adds a --jit/-j option to perf inject. This options injects MMAP records into the perf.data file to cover the jitted code mmaps. It also emits ELF images for each function in the jidump file. Those images are created where the jitdump file is. The MMAP records point to that location as well. Typical flow: $ perf record -k mono -- java -agentpath:libpjvmti.so java_class $ perf inject --jit -i perf.data -o perf.data.jitted $ perf report -i perf.data.jitted Note that jitdump.h support is not limited to Java, it works with any jitted environment modified to emit the jitdump file format, include those where code can be jitted multiple times and moved around. The jitdump.h format is adapted from the Oprofile project. The genelf.c (ELF binary generation) depends on MD5 hash encoding for the buildid. To enable this, libssl-dev must be installed. If not, then genelf.c defaults to using urandom to generate the buildid, which is not ideal. The Makefile auto-detects the presence on libssl-dev. This version mmaps the jitdump file to create a marker MMAP record in the perf.data file. The marker is used to detect jitdump and cause perf inject to inject the jitted mmaps and generate ELF images for jitted functions. In V8, the following fixes and changes were made among other things: - the jidump header format include a new flags field to be used to carry information about the configuration of the runtime agent. Contributed by: Adrian Hunter <adrian.hunter@intel.com> - Fix mmap pgoff: MMAP event pgoff must be the offset within the ELF file at which the code resides. Contributed by: Adrian Hunter <adrian.hunter@intel.com> - Fix ELF virtual addresses: perf tools expect the ELF virtual addresses of dynamic objects to match the file offset. Contributed by: Adrian Hunter <adrian.hunter@intel.com> - JIT MMAP injection does not obey finished_round semantics. JIT MMAP injection injects all MMAP events in one go, so it does not obey finished_round semantics, so drop the finished_round events from the output perf.data file. Contributed by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Stephane Eranian <eranian@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Carl Love <cel@us.ibm.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: John McCutchan <johnmccutchan@google.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Pawel Moll <pawel.moll@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sonny Rao <sonnyrao@chromium.org> Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/1448874143-7269-3-git-send-email-eranian@google.com [ Moved inject.build_ids ordering bits to a separate patch, fixed the NO_LIBELF=1 build ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-11-30 09:02:21 +00:00
}
retval = 0;
error:
(void)elf_end(e);
free(strsym);
return retval;
}
#ifndef JVMTI
static unsigned char x86_code[] = {
0xBB, 0x2A, 0x00, 0x00, 0x00, /* movl $42, %ebx */
0xB8, 0x01, 0x00, 0x00, 0x00, /* movl $1, %eax */
0xCD, 0x80 /* int $0x80 */
};
static struct options options;
int main(int argc, char **argv)
{
int c, fd, ret;
while ((c = getopt(argc, argv, "o:h")) != -1) {
switch (c) {
case 'o':
options.output = optarg;
break;
case 'h':
printf("Usage: genelf -o output_file [-h]\n");
return 0;
default:
errx(1, "unknown option");
}
}
fd = open(options.output, O_CREAT|O_TRUNC|O_RDWR, 0666);
if (fd == -1)
err(1, "cannot create file %s", options.output);
ret = jit_write_elf(fd, "main", x86_code, sizeof(x86_code));
close(fd);
if (ret != 0)
unlink(options.output);
return ret;
}
#endif