Merge branch 'tip/perf/recordmcount-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/core
This commit is contained in:
Ingo Molnar
commit
0fdf13606b
6
Makefile
6
Makefile
|
|
@ -568,6 +568,12 @@ endif
|
|||
|
||||
ifdef CONFIG_FUNCTION_TRACER
|
||||
KBUILD_CFLAGS += -pg
|
||||
ifdef CONFIG_DYNAMIC_FTRACE
|
||||
ifdef CONFIG_HAVE_C_RECORDMCOUNT
|
||||
BUILD_C_RECORDMCOUNT := y
|
||||
export BUILD_C_RECORDMCOUNT
|
||||
endif
|
||||
endif
|
||||
endif
|
||||
|
||||
# We trigger additional mismatches with less inlining
|
||||
|
|
|
|||
|
|
@ -33,6 +33,7 @@ config X86
|
|||
select HAVE_KRETPROBES
|
||||
select HAVE_OPTPROBES
|
||||
select HAVE_FTRACE_MCOUNT_RECORD
|
||||
select HAVE_C_RECORDMCOUNT
|
||||
select HAVE_DYNAMIC_FTRACE
|
||||
select HAVE_FUNCTION_TRACER
|
||||
select HAVE_FUNCTION_GRAPH_TRACER
|
||||
|
|
|
|||
|
|
@ -49,6 +49,11 @@ config HAVE_SYSCALL_TRACEPOINTS
|
|||
help
|
||||
See Documentation/trace/ftrace-design.txt
|
||||
|
||||
config HAVE_C_RECORDMCOUNT
|
||||
bool
|
||||
help
|
||||
C version of recordmcount available?
|
||||
|
||||
config TRACER_MAX_TRACE
|
||||
bool
|
||||
|
||||
|
|
|
|||
|
|
@ -11,6 +11,7 @@ hostprogs-$(CONFIG_KALLSYMS) += kallsyms
|
|||
hostprogs-$(CONFIG_LOGO) += pnmtologo
|
||||
hostprogs-$(CONFIG_VT) += conmakehash
|
||||
hostprogs-$(CONFIG_IKCONFIG) += bin2c
|
||||
hostprogs-$(BUILD_C_RECORDMCOUNT) += recordmcount
|
||||
|
||||
always := $(hostprogs-y) $(hostprogs-m)
|
||||
|
||||
|
|
|
|||
|
|
@ -209,12 +209,16 @@ cmd_modversions = \
|
|||
endif
|
||||
|
||||
ifdef CONFIG_FTRACE_MCOUNT_RECORD
|
||||
ifdef BUILD_C_RECORDMCOUNT
|
||||
cmd_record_mcount = $(srctree)/scripts/recordmcount "$(@)";
|
||||
else
|
||||
cmd_record_mcount = set -e ; perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
|
||||
"$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
|
||||
"$(if $(CONFIG_64BIT),64,32)" \
|
||||
"$(OBJDUMP)" "$(OBJCOPY)" "$(CC)" "$(LD)" "$(NM)" "$(RM)" "$(MV)" \
|
||||
"$(if $(part-of-module),1,0)" "$(@)";
|
||||
endif
|
||||
endif
|
||||
|
||||
define rule_cc_o_c
|
||||
$(call echo-cmd,checksrc) $(cmd_checksrc) \
|
||||
|
|
|
|||
|
|
@ -0,0 +1,345 @@
|
|||
/*
|
||||
* recordmcount.c: construct a table of the locations of calls to 'mcount'
|
||||
* so that ftrace can find them quickly.
|
||||
* Copyright 2009 John F. Reiser <jreiser@BitWagon.com>. All rights reserved.
|
||||
* Licensed under the GNU General Public License, version 2 (GPLv2).
|
||||
*
|
||||
* Restructured to fit Linux format, as well as other updates:
|
||||
* Copyright 2010 Steven Rostedt <srostedt@redhat.com>, Red Hat Inc.
|
||||
*/
|
||||
|
||||
/*
|
||||
* Strategy: alter the .o file in-place.
|
||||
*
|
||||
* Append a new STRTAB that has the new section names, followed by a new array
|
||||
* ElfXX_Shdr[] that has the new section headers, followed by the section
|
||||
* contents for __mcount_loc and its relocations. The old shstrtab strings,
|
||||
* and the old ElfXX_Shdr[] array, remain as "garbage" (commonly, a couple
|
||||
* kilobytes.) Subsequent processing by /bin/ld (or the kernel module loader)
|
||||
* will ignore the garbage regions, because they are not designated by the
|
||||
* new .e_shoff nor the new ElfXX_Shdr[]. [In order to remove the garbage,
|
||||
* then use "ld -r" to create a new file that omits the garbage.]
|
||||
*/
|
||||
|
||||
#include <sys/types.h>
|
||||
#include <sys/mman.h>
|
||||
#include <sys/stat.h>
|
||||
#include <elf.h>
|
||||
#include <fcntl.h>
|
||||
#include <setjmp.h>
|
||||
#include <stdio.h>
|
||||
#include <stdlib.h>
|
||||
#include <string.h>
|
||||
#include <unistd.h>
|
||||
|
||||
static int fd_map; /* File descriptor for file being modified. */
|
||||
static int mmap_failed; /* Boolean flag. */
|
||||
static void *ehdr_curr; /* current ElfXX_Ehdr * for resource cleanup */
|
||||
static char gpfx; /* prefix for global symbol name (sometimes '_') */
|
||||
static struct stat sb; /* Remember .st_size, etc. */
|
||||
static jmp_buf jmpenv; /* setjmp/longjmp per-file error escape */
|
||||
|
||||
/* setjmp() return values */
|
||||
enum {
|
||||
SJ_SETJMP = 0, /* hardwired first return */
|
||||
SJ_FAIL,
|
||||
SJ_SUCCEED
|
||||
};
|
||||
|
||||
/* Per-file resource cleanup when multiple files. */
|
||||
static void
|
||||
cleanup(void)
|
||||
{
|
||||
if (!mmap_failed)
|
||||
munmap(ehdr_curr, sb.st_size);
|
||||
else
|
||||
free(ehdr_curr);
|
||||
close(fd_map);
|
||||
}
|
||||
|
||||
static void __attribute__((noreturn))
|
||||
fail_file(void)
|
||||
{
|
||||
cleanup();
|
||||
longjmp(jmpenv, SJ_FAIL);
|
||||
}
|
||||
|
||||
static void __attribute__((noreturn))
|
||||
succeed_file(void)
|
||||
{
|
||||
cleanup();
|
||||
longjmp(jmpenv, SJ_SUCCEED);
|
||||
}
|
||||
|
||||
/* ulseek, uread, ...: Check return value for errors. */
|
||||
|
||||
static off_t
|
||||
ulseek(int const fd, off_t const offset, int const whence)
|
||||
{
|
||||
off_t const w = lseek(fd, offset, whence);
|
||||
if ((off_t)-1 == w) {
|
||||
perror("lseek");
|
||||
fail_file();
|
||||
}
|
||||
return w;
|
||||
}
|
||||
|
||||
static size_t
|
||||
uread(int const fd, void *const buf, size_t const count)
|
||||
{
|
||||
size_t const n = read(fd, buf, count);
|
||||
if (n != count) {
|
||||
perror("read");
|
||||
fail_file();
|
||||
}
|
||||
return n;
|
||||
}
|
||||
|
||||
static size_t
|
||||
uwrite(int const fd, void const *const buf, size_t const count)
|
||||
{
|
||||
size_t const n = write(fd, buf, count);
|
||||
if (n != count) {
|
||||
perror("write");
|
||||
fail_file();
|
||||
}
|
||||
return n;
|
||||
}
|
||||
|
||||
static void *
|
||||
umalloc(size_t size)
|
||||
{
|
||||
void *const addr = malloc(size);
|
||||
if (0 == addr) {
|
||||
fprintf(stderr, "malloc failed: %zu bytes\n", size);
|
||||
fail_file();
|
||||
}
|
||||
return addr;
|
||||
}
|
||||
|
||||
/*
|
||||
* Get the whole file as a programming convenience in order to avoid
|
||||
* malloc+lseek+read+free of many pieces. If successful, then mmap
|
||||
* avoids copying unused pieces; else just read the whole file.
|
||||
* Open for both read and write; new info will be appended to the file.
|
||||
* Use MAP_PRIVATE so that a few changes to the in-memory ElfXX_Ehdr
|
||||
* do not propagate to the file until an explicit overwrite at the last.
|
||||
* This preserves most aspects of consistency (all except .st_size)
|
||||
* for simultaneous readers of the file while we are appending to it.
|
||||
* However, multiple writers still are bad. We choose not to use
|
||||
* locking because it is expensive and the use case of kernel build
|
||||
* makes multiple writers unlikely.
|
||||
*/
|
||||
static void *mmap_file(char const *fname)
|
||||
{
|
||||
void *addr;
|
||||
|
||||
fd_map = open(fname, O_RDWR);
|
||||
if (0 > fd_map || 0 > fstat(fd_map, &sb)) {
|
||||
perror(fname);
|
||||
fail_file();
|
||||
}
|
||||
if (!S_ISREG(sb.st_mode)) {
|
||||
fprintf(stderr, "not a regular file: %s\n", fname);
|
||||
fail_file();
|
||||
}
|
||||
addr = mmap(0, sb.st_size, PROT_READ|PROT_WRITE, MAP_PRIVATE,
|
||||
fd_map, 0);
|
||||
mmap_failed = 0;
|
||||
if (MAP_FAILED == addr) {
|
||||
mmap_failed = 1;
|
||||
addr = umalloc(sb.st_size);
|
||||
uread(fd_map, addr, sb.st_size);
|
||||
}
|
||||
return addr;
|
||||
}
|
||||
|
||||
/* w8rev, w8nat, ...: Handle endianness. */
|
||||
|
||||
static uint64_t w8rev(uint64_t const x)
|
||||
{
|
||||
return ((0xff & (x >> (0 * 8))) << (7 * 8))
|
||||
| ((0xff & (x >> (1 * 8))) << (6 * 8))
|
||||
| ((0xff & (x >> (2 * 8))) << (5 * 8))
|
||||
| ((0xff & (x >> (3 * 8))) << (4 * 8))
|
||||
| ((0xff & (x >> (4 * 8))) << (3 * 8))
|
||||
| ((0xff & (x >> (5 * 8))) << (2 * 8))
|
||||
| ((0xff & (x >> (6 * 8))) << (1 * 8))
|
||||
| ((0xff & (x >> (7 * 8))) << (0 * 8));
|
||||
}
|
||||
|
||||
static uint32_t w4rev(uint32_t const x)
|
||||
{
|
||||
return ((0xff & (x >> (0 * 8))) << (3 * 8))
|
||||
| ((0xff & (x >> (1 * 8))) << (2 * 8))
|
||||
| ((0xff & (x >> (2 * 8))) << (1 * 8))
|
||||
| ((0xff & (x >> (3 * 8))) << (0 * 8));
|
||||
}
|
||||
|
||||
static uint32_t w2rev(uint16_t const x)
|
||||
{
|
||||
return ((0xff & (x >> (0 * 8))) << (1 * 8))
|
||||
| ((0xff & (x >> (1 * 8))) << (0 * 8));
|
||||
}
|
||||
|
||||
static uint64_t w8nat(uint64_t const x)
|
||||
{
|
||||
return x;
|
||||
}
|
||||
|
||||
static uint32_t w4nat(uint32_t const x)
|
||||
{
|
||||
return x;
|
||||
}
|
||||
|
||||
static uint32_t w2nat(uint16_t const x)
|
||||
{
|
||||
return x;
|
||||
}
|
||||
|
||||
static uint64_t (*w8)(uint64_t);
|
||||
static uint32_t (*w)(uint32_t);
|
||||
static uint32_t (*w2)(uint16_t);
|
||||
|
||||
/* Names of the sections that could contain calls to mcount. */
|
||||
static int
|
||||
is_mcounted_section_name(char const *const txtname)
|
||||
{
|
||||
return 0 == strcmp(".text", txtname) ||
|
||||
0 == strcmp(".sched.text", txtname) ||
|
||||
0 == strcmp(".spinlock.text", txtname) ||
|
||||
0 == strcmp(".irqentry.text", txtname) ||
|
||||
0 == strcmp(".text.unlikely", txtname);
|
||||
}
|
||||
|
||||
/* 32 bit and 64 bit are very similar */
|
||||
#include "recordmcount.h"
|
||||
#define RECORD_MCOUNT_64
|
||||
#include "recordmcount.h"
|
||||
|
||||
static void
|
||||
do_file(char const *const fname)
|
||||
{
|
||||
Elf32_Ehdr *const ehdr = mmap_file(fname);
|
||||
unsigned int reltype = 0;
|
||||
|
||||
ehdr_curr = ehdr;
|
||||
w = w4nat;
|
||||
w2 = w2nat;
|
||||
w8 = w8nat;
|
||||
switch (ehdr->e_ident[EI_DATA]) {
|
||||
static unsigned int const endian = 1;
|
||||
default: {
|
||||
fprintf(stderr, "unrecognized ELF data encoding %d: %s\n",
|
||||
ehdr->e_ident[EI_DATA], fname);
|
||||
fail_file();
|
||||
} break;
|
||||
case ELFDATA2LSB: {
|
||||
if (1 != *(unsigned char const *)&endian) {
|
||||
/* main() is big endian, file.o is little endian. */
|
||||
w = w4rev;
|
||||
w2 = w2rev;
|
||||
w8 = w8rev;
|
||||
}
|
||||
} break;
|
||||
case ELFDATA2MSB: {
|
||||
if (0 != *(unsigned char const *)&endian) {
|
||||
/* main() is little endian, file.o is big endian. */
|
||||
w = w4rev;
|
||||
w2 = w2rev;
|
||||
w8 = w8rev;
|
||||
}
|
||||
} break;
|
||||
} /* end switch */
|
||||
if (0 != memcmp(ELFMAG, ehdr->e_ident, SELFMAG)
|
||||
|| ET_REL != w2(ehdr->e_type)
|
||||
|| EV_CURRENT != ehdr->e_ident[EI_VERSION]) {
|
||||
fprintf(stderr, "unrecognized ET_REL file %s\n", fname);
|
||||
fail_file();
|
||||
}
|
||||
|
||||
gpfx = 0;
|
||||
switch (w2(ehdr->e_machine)) {
|
||||
default: {
|
||||
fprintf(stderr, "unrecognized e_machine %d %s\n",
|
||||
w2(ehdr->e_machine), fname);
|
||||
fail_file();
|
||||
} break;
|
||||
case EM_386: reltype = R_386_32; break;
|
||||
case EM_ARM: reltype = R_ARM_ABS32; break;
|
||||
case EM_IA_64: reltype = R_IA64_IMM64; gpfx = '_'; break;
|
||||
case EM_PPC: reltype = R_PPC_ADDR32; gpfx = '_'; break;
|
||||
case EM_PPC64: reltype = R_PPC64_ADDR64; gpfx = '_'; break;
|
||||
case EM_S390: /* reltype: e_class */ gpfx = '_'; break;
|
||||
case EM_SH: reltype = R_SH_DIR32; break;
|
||||
case EM_SPARCV9: reltype = R_SPARC_64; gpfx = '_'; break;
|
||||
case EM_X86_64: reltype = R_X86_64_64; break;
|
||||
} /* end switch */
|
||||
|
||||
switch (ehdr->e_ident[EI_CLASS]) {
|
||||
default: {
|
||||
fprintf(stderr, "unrecognized ELF class %d %s\n",
|
||||
ehdr->e_ident[EI_CLASS], fname);
|
||||
fail_file();
|
||||
} break;
|
||||
case ELFCLASS32: {
|
||||
if (sizeof(Elf32_Ehdr) != w2(ehdr->e_ehsize)
|
||||
|| sizeof(Elf32_Shdr) != w2(ehdr->e_shentsize)) {
|
||||
fprintf(stderr,
|
||||
"unrecognized ET_REL file: %s\n", fname);
|
||||
fail_file();
|
||||
}
|
||||
if (EM_S390 == w2(ehdr->e_machine))
|
||||
reltype = R_390_32;
|
||||
do32(ehdr, fname, reltype);
|
||||
} break;
|
||||
case ELFCLASS64: {
|
||||
Elf64_Ehdr *const ghdr = (Elf64_Ehdr *)ehdr;
|
||||
if (sizeof(Elf64_Ehdr) != w2(ghdr->e_ehsize)
|
||||
|| sizeof(Elf64_Shdr) != w2(ghdr->e_shentsize)) {
|
||||
fprintf(stderr,
|
||||
"unrecognized ET_REL file: %s\n", fname);
|
||||
fail_file();
|
||||
}
|
||||
if (EM_S390 == w2(ghdr->e_machine))
|
||||
reltype = R_390_64;
|
||||
do64(ghdr, fname, reltype);
|
||||
} break;
|
||||
} /* end switch */
|
||||
|
||||
cleanup();
|
||||
}
|
||||
|
||||
int
|
||||
main(int argc, char const *argv[])
|
||||
{
|
||||
int n_error = 0; /* gcc-4.3.0 false positive complaint */
|
||||
if (argc <= 1)
|
||||
fprintf(stderr, "usage: recordmcount file.o...\n");
|
||||
else /* Process each file in turn, allowing deep failure. */
|
||||
for (--argc, ++argv; 0 < argc; --argc, ++argv) {
|
||||
int const sjval = setjmp(jmpenv);
|
||||
switch (sjval) {
|
||||
default: {
|
||||
fprintf(stderr, "internal error: %s\n", argv[0]);
|
||||
exit(1);
|
||||
} break;
|
||||
case SJ_SETJMP: { /* normal sequence */
|
||||
/* Avoid problems if early cleanup() */
|
||||
fd_map = -1;
|
||||
ehdr_curr = NULL;
|
||||
mmap_failed = 1;
|
||||
do_file(argv[0]);
|
||||
} break;
|
||||
case SJ_FAIL: { /* error in do_file or below */
|
||||
++n_error;
|
||||
} break;
|
||||
case SJ_SUCCEED: { /* premature success */
|
||||
/* do nothing */
|
||||
} break;
|
||||
} /* end switch */
|
||||
}
|
||||
return !!n_error;
|
||||
}
|
||||
|
||||
|
||||
|
|
@ -0,0 +1,366 @@
|
|||
/*
|
||||
* recordmcount.h
|
||||
*
|
||||
* This code was taken out of recordmcount.c written by
|
||||
* Copyright 2009 John F. Reiser <jreiser@BitWagon.com>. All rights reserved.
|
||||
*
|
||||
* The original code had the same algorithms for both 32bit
|
||||
* and 64bit ELF files, but the code was duplicated to support
|
||||
* the difference in structures that were used. This
|
||||
* file creates a macro of everything that is different between
|
||||
* the 64 and 32 bit code, such that by including this header
|
||||
* twice we can create both sets of functions by including this
|
||||
* header once with RECORD_MCOUNT_64 undefined, and again with
|
||||
* it defined.
|
||||
*
|
||||
* This conversion to macros was done by:
|
||||
* Copyright 2010 Steven Rostedt <srostedt@redhat.com>, Red Hat Inc.
|
||||
*
|
||||
* Licensed under the GNU General Public License, version 2 (GPLv2).
|
||||
*/
|
||||
#undef append_func
|
||||
#undef sift_rel_mcount
|
||||
#undef find_secsym_ndx
|
||||
#undef __has_rel_mcount
|
||||
#undef has_rel_mcount
|
||||
#undef tot_relsize
|
||||
#undef do_func
|
||||
#undef Elf_Ehdr
|
||||
#undef Elf_Shdr
|
||||
#undef Elf_Rel
|
||||
#undef Elf_Rela
|
||||
#undef Elf_Sym
|
||||
#undef ELF_R_SYM
|
||||
#undef ELF_R_INFO
|
||||
#undef ELF_ST_BIND
|
||||
#undef uint_t
|
||||
#undef _w
|
||||
#undef _align
|
||||
#undef _size
|
||||
|
||||
#ifdef RECORD_MCOUNT_64
|
||||
# define append_func append64
|
||||
# define sift_rel_mcount sift64_rel_mcount
|
||||
# define find_secsym_ndx find64_secsym_ndx
|
||||
# define __has_rel_mcount __has64_rel_mcount
|
||||
# define has_rel_mcount has64_rel_mcount
|
||||
# define tot_relsize tot64_relsize
|
||||
# define do_func do64
|
||||
# define Elf_Ehdr Elf64_Ehdr
|
||||
# define Elf_Shdr Elf64_Shdr
|
||||
# define Elf_Rel Elf64_Rel
|
||||
# define Elf_Rela Elf64_Rela
|
||||
# define Elf_Sym Elf64_Sym
|
||||
# define ELF_R_SYM ELF64_R_SYM
|
||||
# define ELF_R_INFO ELF64_R_INFO
|
||||
# define ELF_ST_BIND ELF64_ST_BIND
|
||||
# define uint_t uint64_t
|
||||
# define _w w8
|
||||
# define _align 7u
|
||||
# define _size 8
|
||||
#else
|
||||
# define append_func append32
|
||||
# define sift_rel_mcount sift32_rel_mcount
|
||||
# define find_secsym_ndx find32_secsym_ndx
|
||||
# define __has_rel_mcount __has32_rel_mcount
|
||||
# define has_rel_mcount has32_rel_mcount
|
||||
# define tot_relsize tot32_relsize
|
||||
# define do_func do32
|
||||
# define Elf_Ehdr Elf32_Ehdr
|
||||
# define Elf_Shdr Elf32_Shdr
|
||||
# define Elf_Rel Elf32_Rel
|
||||
# define Elf_Rela Elf32_Rela
|
||||
# define Elf_Sym Elf32_Sym
|
||||
# define ELF_R_SYM ELF32_R_SYM
|
||||
# define ELF_R_INFO ELF32_R_INFO
|
||||
# define ELF_ST_BIND ELF32_ST_BIND
|
||||
# define uint_t uint32_t
|
||||
# define _w w
|
||||
# define _align 3u
|
||||
# define _size 4
|
||||
#endif
|
||||
|
||||
/* Append the new shstrtab, Elf_Shdr[], __mcount_loc and its relocations. */
|
||||
static void append_func(Elf_Ehdr *const ehdr,
|
||||
Elf_Shdr *const shstr,
|
||||
uint_t const *const mloc0,
|
||||
uint_t const *const mlocp,
|
||||
Elf_Rel const *const mrel0,
|
||||
Elf_Rel const *const mrelp,
|
||||
unsigned int const rel_entsize,
|
||||
unsigned int const symsec_sh_link)
|
||||
{
|
||||
/* Begin constructing output file */
|
||||
Elf_Shdr mcsec;
|
||||
char const *mc_name = (sizeof(Elf_Rela) == rel_entsize)
|
||||
? ".rela__mcount_loc"
|
||||
: ".rel__mcount_loc";
|
||||
unsigned const old_shnum = w2(ehdr->e_shnum);
|
||||
uint_t const old_shoff = _w(ehdr->e_shoff);
|
||||
uint_t const old_shstr_sh_size = _w(shstr->sh_size);
|
||||
uint_t const old_shstr_sh_offset = _w(shstr->sh_offset);
|
||||
uint_t t = 1 + strlen(mc_name) + _w(shstr->sh_size);
|
||||
uint_t new_e_shoff;
|
||||
|
||||
shstr->sh_size = _w(t);
|
||||
shstr->sh_offset = _w(sb.st_size);
|
||||
t += sb.st_size;
|
||||
t += (_align & -t); /* word-byte align */
|
||||
new_e_shoff = t;
|
||||
|
||||
/* body for new shstrtab */
|
||||
ulseek(fd_map, sb.st_size, SEEK_SET);
|
||||
uwrite(fd_map, old_shstr_sh_offset + (void *)ehdr, old_shstr_sh_size);
|
||||
uwrite(fd_map, mc_name, 1 + strlen(mc_name));
|
||||
|
||||
/* old(modified) Elf_Shdr table, word-byte aligned */
|
||||
ulseek(fd_map, t, SEEK_SET);
|
||||
t += sizeof(Elf_Shdr) * old_shnum;
|
||||
uwrite(fd_map, old_shoff + (void *)ehdr,
|
||||
sizeof(Elf_Shdr) * old_shnum);
|
||||
|
||||
/* new sections __mcount_loc and .rel__mcount_loc */
|
||||
t += 2*sizeof(mcsec);
|
||||
mcsec.sh_name = w((sizeof(Elf_Rela) == rel_entsize) + strlen(".rel")
|
||||
+ old_shstr_sh_size);
|
||||
mcsec.sh_type = w(SHT_PROGBITS);
|
||||
mcsec.sh_flags = _w(SHF_ALLOC);
|
||||
mcsec.sh_addr = 0;
|
||||
mcsec.sh_offset = _w(t);
|
||||
mcsec.sh_size = _w((void *)mlocp - (void *)mloc0);
|
||||
mcsec.sh_link = 0;
|
||||
mcsec.sh_info = 0;
|
||||
mcsec.sh_addralign = _w(_size);
|
||||
mcsec.sh_entsize = _w(_size);
|
||||
uwrite(fd_map, &mcsec, sizeof(mcsec));
|
||||
|
||||
mcsec.sh_name = w(old_shstr_sh_size);
|
||||
mcsec.sh_type = (sizeof(Elf_Rela) == rel_entsize)
|
||||
? w(SHT_RELA)
|
||||
: w(SHT_REL);
|
||||
mcsec.sh_flags = 0;
|
||||
mcsec.sh_addr = 0;
|
||||
mcsec.sh_offset = _w((void *)mlocp - (void *)mloc0 + t);
|
||||
mcsec.sh_size = _w((void *)mrelp - (void *)mrel0);
|
||||
mcsec.sh_link = w(symsec_sh_link);
|
||||
mcsec.sh_info = w(old_shnum);
|
||||
mcsec.sh_addralign = _w(_size);
|
||||
mcsec.sh_entsize = _w(rel_entsize);
|
||||
uwrite(fd_map, &mcsec, sizeof(mcsec));
|
||||
|
||||
uwrite(fd_map, mloc0, (void *)mlocp - (void *)mloc0);
|
||||
uwrite(fd_map, mrel0, (void *)mrelp - (void *)mrel0);
|
||||
|
||||
ehdr->e_shoff = _w(new_e_shoff);
|
||||
ehdr->e_shnum = w2(2 + w2(ehdr->e_shnum)); /* {.rel,}__mcount_loc */
|
||||
ulseek(fd_map, 0, SEEK_SET);
|
||||
uwrite(fd_map, ehdr, sizeof(*ehdr));
|
||||
}
|
||||
|
||||
|
||||
/*
|
||||
* Look at the relocations in order to find the calls to mcount.
|
||||
* Accumulate the section offsets that are found, and their relocation info,
|
||||
* onto the end of the existing arrays.
|
||||
*/
|
||||
static uint_t *sift_rel_mcount(uint_t *mlocp,
|
||||
unsigned const offbase,
|
||||
Elf_Rel **const mrelpp,
|
||||
Elf_Shdr const *const relhdr,
|
||||
Elf_Ehdr const *const ehdr,
|
||||
unsigned const recsym,
|
||||
uint_t const recval,
|
||||
unsigned const reltype)
|
||||
{
|
||||
uint_t *const mloc0 = mlocp;
|
||||
Elf_Rel *mrelp = *mrelpp;
|
||||
Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff)
|
||||
+ (void *)ehdr);
|
||||
unsigned const symsec_sh_link = w(relhdr->sh_link);
|
||||
Elf_Shdr const *const symsec = &shdr0[symsec_sh_link];
|
||||
Elf_Sym const *const sym0 = (Elf_Sym const *)(_w(symsec->sh_offset)
|
||||
+ (void *)ehdr);
|
||||
|
||||
Elf_Shdr const *const strsec = &shdr0[w(symsec->sh_link)];
|
||||
char const *const str0 = (char const *)(_w(strsec->sh_offset)
|
||||
+ (void *)ehdr);
|
||||
|
||||
Elf_Rel const *const rel0 = (Elf_Rel const *)(_w(relhdr->sh_offset)
|
||||
+ (void *)ehdr);
|
||||
unsigned rel_entsize = _w(relhdr->sh_entsize);
|
||||
unsigned const nrel = _w(relhdr->sh_size) / rel_entsize;
|
||||
Elf_Rel const *relp = rel0;
|
||||
|
||||
unsigned mcountsym = 0;
|
||||
unsigned t;
|
||||
|
||||
for (t = nrel; t; --t) {
|
||||
if (!mcountsym) {
|
||||
Elf_Sym const *const symp =
|
||||
&sym0[ELF_R_SYM(_w(relp->r_info))];
|
||||
char const *symname = &str0[w(symp->st_name)];
|
||||
|
||||
if ('.' == symname[0])
|
||||
++symname; /* ppc64 hack */
|
||||
if (0 == strcmp((('_' == gpfx) ? "_mcount" : "mcount"),
|
||||
symname))
|
||||
mcountsym = ELF_R_SYM(_w(relp->r_info));
|
||||
}
|
||||
|
||||
if (mcountsym == ELF_R_SYM(_w(relp->r_info))) {
|
||||
uint_t const addend = _w(_w(relp->r_offset) - recval);
|
||||
|
||||
mrelp->r_offset = _w(offbase
|
||||
+ ((void *)mlocp - (void *)mloc0));
|
||||
mrelp->r_info = _w(ELF_R_INFO(recsym, reltype));
|
||||
if (sizeof(Elf_Rela) == rel_entsize) {
|
||||
((Elf_Rela *)mrelp)->r_addend = addend;
|
||||
*mlocp++ = 0;
|
||||
} else
|
||||
*mlocp++ = addend;
|
||||
|
||||
mrelp = (Elf_Rel *)(rel_entsize + (void *)mrelp);
|
||||
}
|
||||
relp = (Elf_Rel const *)(rel_entsize + (void *)relp);
|
||||
}
|
||||
*mrelpp = mrelp;
|
||||
return mlocp;
|
||||
}
|
||||
|
||||
|
||||
/*
|
||||
* Find a symbol in the given section, to be used as the base for relocating
|
||||
* the table of offsets of calls to mcount. A local or global symbol suffices,
|
||||
* but avoid a Weak symbol because it may be overridden; the change in value
|
||||
* would invalidate the relocations of the offsets of the calls to mcount.
|
||||
* Often the found symbol will be the unnamed local symbol generated by
|
||||
* GNU 'as' for the start of each section. For example:
|
||||
* Num: Value Size Type Bind Vis Ndx Name
|
||||
* 2: 00000000 0 SECTION LOCAL DEFAULT 1
|
||||
*/
|
||||
static unsigned find_secsym_ndx(unsigned const txtndx,
|
||||
char const *const txtname,
|
||||
uint_t *const recvalp,
|
||||
Elf_Shdr const *const symhdr,
|
||||
Elf_Ehdr const *const ehdr)
|
||||
{
|
||||
Elf_Sym const *const sym0 = (Elf_Sym const *)(_w(symhdr->sh_offset)
|
||||
+ (void *)ehdr);
|
||||
unsigned const nsym = _w(symhdr->sh_size) / _w(symhdr->sh_entsize);
|
||||
Elf_Sym const *symp;
|
||||
unsigned t;
|
||||
|
||||
for (symp = sym0, t = nsym; t; --t, ++symp) {
|
||||
unsigned int const st_bind = ELF_ST_BIND(symp->st_info);
|
||||
|
||||
if (txtndx == w2(symp->st_shndx)
|
||||
/* avoid STB_WEAK */
|
||||
&& (STB_LOCAL == st_bind || STB_GLOBAL == st_bind)) {
|
||||
*recvalp = _w(symp->st_value);
|
||||
return symp - sym0;
|
||||
}
|
||||
}
|
||||
fprintf(stderr, "Cannot find symbol for section %d: %s.\n",
|
||||
txtndx, txtname);
|
||||
fail_file();
|
||||
}
|
||||
|
||||
|
||||
/* Evade ISO C restriction: no declaration after statement in has_rel_mcount. */
|
||||
static char const *
|
||||
__has_rel_mcount(Elf_Shdr const *const relhdr, /* is SHT_REL or SHT_RELA */
|
||||
Elf_Shdr const *const shdr0,
|
||||
char const *const shstrtab,
|
||||
char const *const fname)
|
||||
{
|
||||
/* .sh_info depends on .sh_type == SHT_REL[,A] */
|
||||
Elf_Shdr const *const txthdr = &shdr0[w(relhdr->sh_info)];
|
||||
char const *const txtname = &shstrtab[w(txthdr->sh_name)];
|
||||
|
||||
if (0 == strcmp("__mcount_loc", txtname)) {
|
||||
fprintf(stderr, "warning: __mcount_loc already exists: %s\n",
|
||||
fname);
|
||||
succeed_file();
|
||||
}
|
||||
if (SHT_PROGBITS != w(txthdr->sh_type) ||
|
||||
!is_mcounted_section_name(txtname))
|
||||
return NULL;
|
||||
return txtname;
|
||||
}
|
||||
|
||||
static char const *has_rel_mcount(Elf_Shdr const *const relhdr,
|
||||
Elf_Shdr const *const shdr0,
|
||||
char const *const shstrtab,
|
||||
char const *const fname)
|
||||
{
|
||||
if (SHT_REL != w(relhdr->sh_type) && SHT_RELA != w(relhdr->sh_type))
|
||||
return NULL;
|
||||
return __has_rel_mcount(relhdr, shdr0, shstrtab, fname);
|
||||
}
|
||||
|
||||
|
||||
static unsigned tot_relsize(Elf_Shdr const *const shdr0,
|
||||
unsigned nhdr,
|
||||
const char *const shstrtab,
|
||||
const char *const fname)
|
||||
{
|
||||
unsigned totrelsz = 0;
|
||||
Elf_Shdr const *shdrp = shdr0;
|
||||
|
||||
for (; nhdr; --nhdr, ++shdrp) {
|
||||
if (has_rel_mcount(shdrp, shdr0, shstrtab, fname))
|
||||
totrelsz += _w(shdrp->sh_size);
|
||||
}
|
||||
return totrelsz;
|
||||
}
|
||||
|
||||
|
||||
/* Overall supervision for Elf32 ET_REL file. */
|
||||
static void
|
||||
do_func(Elf_Ehdr *const ehdr, char const *const fname, unsigned const reltype)
|
||||
{
|
||||
Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff)
|
||||
+ (void *)ehdr);
|
||||
unsigned const nhdr = w2(ehdr->e_shnum);
|
||||
Elf_Shdr *const shstr = &shdr0[w2(ehdr->e_shstrndx)];
|
||||
char const *const shstrtab = (char const *)(_w(shstr->sh_offset)
|
||||
+ (void *)ehdr);
|
||||
|
||||
Elf_Shdr const *relhdr;
|
||||
unsigned k;
|
||||
|
||||
/* Upper bound on space: assume all relevant relocs are for mcount. */
|
||||
unsigned const totrelsz = tot_relsize(shdr0, nhdr, shstrtab, fname);
|
||||
Elf_Rel *const mrel0 = umalloc(totrelsz);
|
||||
Elf_Rel * mrelp = mrel0;
|
||||
|
||||
/* 2*sizeof(address) <= sizeof(Elf_Rel) */
|
||||
uint_t *const mloc0 = umalloc(totrelsz>>1);
|
||||
uint_t * mlocp = mloc0;
|
||||
|
||||
unsigned rel_entsize = 0;
|
||||
unsigned symsec_sh_link = 0;
|
||||
|
||||
for (relhdr = shdr0, k = nhdr; k; --k, ++relhdr) {
|
||||
char const *const txtname = has_rel_mcount(relhdr, shdr0,
|
||||
shstrtab, fname);
|
||||
if (txtname) {
|
||||
uint_t recval = 0;
|
||||
unsigned const recsym = find_secsym_ndx(
|
||||
w(relhdr->sh_info), txtname, &recval,
|
||||
&shdr0[symsec_sh_link = w(relhdr->sh_link)],
|
||||
ehdr);
|
||||
|
||||
rel_entsize = _w(relhdr->sh_entsize);
|
||||
mlocp = sift_rel_mcount(mlocp,
|
||||
(void *)mlocp - (void *)mloc0, &mrelp,
|
||||
relhdr, ehdr, recsym, recval, reltype);
|
||||
}
|
||||
}
|
||||
if (mloc0 != mlocp) {
|
||||
append_func(ehdr, shstr, mloc0, mlocp, mrel0, mrelp,
|
||||
rel_entsize, symsec_sh_link);
|
||||
}
|
||||
free(mrel0);
|
||||
free(mloc0);
|
||||
}
|
||||
Loading…
Reference in New Issue