diff options
Diffstat (limited to 'scripts/recordmcount.c')
-rw-r--r-- | scripts/recordmcount.c | 168 |
1 files changed, 114 insertions, 54 deletions
diff --git a/scripts/recordmcount.c b/scripts/recordmcount.c index f9f6f52db77..ee52cb8e17a 100644 --- a/scripts/recordmcount.c +++ b/scripts/recordmcount.c @@ -24,6 +24,7 @@ #include <sys/types.h> #include <sys/mman.h> #include <sys/stat.h> +#include <getopt.h> #include <elf.h> #include <fcntl.h> #include <setjmp.h> @@ -39,6 +40,7 @@ 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 */ static const char *altmcount; /* alternate mcount symbol name */ +static int warn_on_notrace_sect; /* warn when section has mcount not being recorded */ /* setjmp() return values */ enum { @@ -78,7 +80,7 @@ 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) { + if (w == (off_t)-1) { perror("lseek"); fail_file(); } @@ -111,13 +113,41 @@ static void * umalloc(size_t size) { void *const addr = malloc(size); - if (0 == addr) { + if (addr == 0) { fprintf(stderr, "malloc failed: %zu bytes\n", size); fail_file(); } return addr; } +static unsigned char ideal_nop5_x86_64[5] = { 0x0f, 0x1f, 0x44, 0x00, 0x00 }; +static unsigned char ideal_nop5_x86_32[5] = { 0x3e, 0x8d, 0x74, 0x26, 0x00 }; +static unsigned char *ideal_nop; + +static char rel_type_nop; + +static int (*make_nop)(void *map, size_t const offset); + +static int make_nop_x86(void *map, size_t const offset) +{ + uint32_t *ptr; + unsigned char *op; + + /* Confirm we have 0xe8 0x0 0x0 0x0 0x0 */ + ptr = map + offset; + if (*ptr != 0) + return -1; + + op = map + offset - 1; + if (*op != 0xe8) + return -1; + + /* convert to nop */ + ulseek(fd_map, offset - 1, SEEK_SET); + uwrite(fd_map, ideal_nop, 5); + return 0; +} + /* * Get the whole file as a programming convenience in order to avoid * malloc+lseek+read+free of many pieces. If successful, then mmap @@ -136,7 +166,7 @@ static void *mmap_file(char const *fname) void *addr; fd_map = open(fname, O_RDWR); - if (0 > fd_map || 0 > fstat(fd_map, &sb)) { + if (fd_map < 0 || fstat(fd_map, &sb) < 0) { perror(fname); fail_file(); } @@ -147,7 +177,7 @@ static void *mmap_file(char const *fname) addr = mmap(0, sb.st_size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd_map, 0); mmap_failed = 0; - if (MAP_FAILED == addr) { + if (addr == MAP_FAILED) { mmap_failed = 1; addr = umalloc(sb.st_size); uread(fd_map, addr, sb.st_size); @@ -206,12 +236,13 @@ static uint32_t (*w2)(uint16_t); static int is_mcounted_section_name(char const *const txtname) { - return 0 == strcmp(".text", txtname) || - 0 == strcmp(".ref.text", txtname) || - 0 == strcmp(".sched.text", txtname) || - 0 == strcmp(".spinlock.text", txtname) || - 0 == strcmp(".irqentry.text", txtname) || - 0 == strcmp(".text.unlikely", txtname); + return strcmp(".text", txtname) == 0 || + strcmp(".ref.text", txtname) == 0 || + strcmp(".sched.text", txtname) == 0 || + strcmp(".spinlock.text", txtname) == 0 || + strcmp(".irqentry.text", txtname) == 0 || + strcmp(".kprobes.text", txtname) == 0 || + strcmp(".text.unlikely", txtname) == 0; } /* 32 bit and 64 bit are very similar */ @@ -264,43 +295,48 @@ do_file(char const *const fname) w8 = w8nat; switch (ehdr->e_ident[EI_DATA]) { static unsigned int const endian = 1; - default: { + 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) { + break; + case ELFDATA2LSB: + if (*(unsigned char const *)&endian != 1) { /* main() is big endian, file.o is little endian. */ w = w4rev; w2 = w2rev; w8 = w8rev; } - } break; - case ELFDATA2MSB: { - if (0 != *(unsigned char const *)&endian) { + break; + case ELFDATA2MSB: + if (*(unsigned char const *)&endian != 0) { /* main() is little endian, file.o is big endian. */ w = w4rev; w2 = w2rev; w8 = w8rev; } - } break; + break; } /* end switch */ - if (0 != memcmp(ELFMAG, ehdr->e_ident, SELFMAG) - || ET_REL != w2(ehdr->e_type) - || EV_CURRENT != ehdr->e_ident[EI_VERSION]) { + if (memcmp(ELFMAG, ehdr->e_ident, SELFMAG) != 0 + || w2(ehdr->e_type) != ET_REL + || ehdr->e_ident[EI_VERSION] != EV_CURRENT) { fprintf(stderr, "unrecognized ET_REL file %s\n", fname); fail_file(); } gpfx = 0; switch (w2(ehdr->e_machine)) { - default: { + 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; + break; + case EM_386: + reltype = R_386_32; + make_nop = make_nop_x86; + ideal_nop = ideal_nop5_x86_32; + mcount_adjust_32 = -1; + break; case EM_ARM: reltype = R_ARM_ABS32; altmcount = "__gnu_mcount_nc"; break; @@ -311,67 +347,91 @@ do_file(char const *const fname) 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; + case EM_X86_64: + make_nop = make_nop_x86; + ideal_nop = ideal_nop5_x86_64; + reltype = R_X86_64_64; + mcount_adjust_64 = -1; + break; } /* end switch */ switch (ehdr->e_ident[EI_CLASS]) { - default: { + 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)) { + break; + case ELFCLASS32: + if (w2(ehdr->e_ehsize) != sizeof(Elf32_Ehdr) + || w2(ehdr->e_shentsize) != sizeof(Elf32_Shdr)) { fprintf(stderr, "unrecognized ET_REL file: %s\n", fname); fail_file(); } - if (EM_S390 == w2(ehdr->e_machine)) + if (w2(ehdr->e_machine) == EM_S390) { reltype = R_390_32; - if (EM_MIPS == w2(ehdr->e_machine)) { + mcount_adjust_32 = -4; + } + if (w2(ehdr->e_machine) == EM_MIPS) { reltype = R_MIPS_32; is_fake_mcount32 = MIPS32_is_fake_mcount; } do32(ehdr, fname, reltype); - } break; + 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)) { + if (w2(ghdr->e_ehsize) != sizeof(Elf64_Ehdr) + || w2(ghdr->e_shentsize) != sizeof(Elf64_Shdr)) { fprintf(stderr, "unrecognized ET_REL file: %s\n", fname); fail_file(); } - if (EM_S390 == w2(ghdr->e_machine)) + if (w2(ghdr->e_machine) == EM_S390) { reltype = R_390_64; - if (EM_MIPS == w2(ghdr->e_machine)) { + mcount_adjust_64 = -8; + } + if (w2(ghdr->e_machine) == EM_MIPS) { reltype = R_MIPS_64; Elf64_r_sym = MIPS64_r_sym; Elf64_r_info = MIPS64_r_info; is_fake_mcount64 = MIPS64_is_fake_mcount; } do64(ghdr, fname, reltype); - } break; + break; + } } /* end switch */ cleanup(); } int -main(int argc, char const *argv[]) +main(int argc, char *argv[]) { const char ftrace[] = "/ftrace.o"; int ftrace_size = sizeof(ftrace) - 1; int n_error = 0; /* gcc-4.3.0 false positive complaint */ + int c; + int i; + + while ((c = getopt(argc, argv, "w")) >= 0) { + switch (c) { + case 'w': + warn_on_notrace_sect = 1; + break; + default: + fprintf(stderr, "usage: recordmcount [-w] file.o...\n"); + return 0; + } + } - if (argc <= 1) { - fprintf(stderr, "usage: recordmcount file.o...\n"); + if ((argc - optind) < 1) { + fprintf(stderr, "usage: recordmcount [-w] file.o...\n"); return 0; } /* Process each file in turn, allowing deep failure. */ - for (--argc, ++argv; 0 < argc; --argc, ++argv) { + for (i = optind; i < argc; i++) { + char *file = argv[i]; int const sjval = setjmp(jmpenv); int len; @@ -380,29 +440,29 @@ main(int argc, char const *argv[]) * function but does not call it. Since ftrace.o should * not be traced anyway, we just skip it. */ - len = strlen(argv[0]); + len = strlen(file); if (len >= ftrace_size && - strcmp(argv[0] + (len - ftrace_size), ftrace) == 0) + strcmp(file + (len - ftrace_size), ftrace) == 0) continue; switch (sjval) { - default: { - fprintf(stderr, "internal error: %s\n", argv[0]); + default: + fprintf(stderr, "internal error: %s\n", file); exit(1); - } break; - case SJ_SETJMP: { /* normal sequence */ + 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 */ + do_file(file); + break; + case SJ_FAIL: /* error in do_file or below */ ++n_error; - } break; - case SJ_SUCCEED: { /* premature success */ + break; + case SJ_SUCCEED: /* premature success */ /* do nothing */ - } break; + break; } /* end switch */ } return !!n_error; |