arch/x86/vdso/vdso2c.c

   1 #include <inttypes.h>
   2 #include <stdint.h>
   3 #include <unistd.h>
   4 #include <stdarg.h>
   5 #include <stdlib.h>
   6 #include <stdio.h>
   7 #include <string.h>
   8 #include <fcntl.h>
   9 #include <err.h>
  10
  11 #include <sys/mman.h>
  12 #include <sys/types.h>
  13
  14 #include <linux/elf.h>
  15 #include <linux/types.h>
  16
  17 /* Symbols that we need in vdso2c. */
  18 char const * const required_syms[] = {
  19         "VDSO32_NOTE_MASK",
  20         "VDSO32_SYSENTER_RETURN",
  21         "__kernel_vsyscall",
  22         "__kernel_sigreturn",
  23         "__kernel_rt_sigreturn",
  24 };
  25
  26 __attribute__((format(printf, 1, 2))) __attribute__((noreturn))
  27 static void fail(const char *format, ...)
  28 {
  29         va_list ap;
  30         va_start(ap, format);
  31         fprintf(stderr, "Error: ");
  32         vfprintf(stderr, format, ap);
  33         exit(1);
  34         va_end(ap);
  35 }
  36
  37 #define NSYMS (sizeof(required_syms) / sizeof(required_syms[0]))
  38
  39 #define BITS 64
  40 #define GOFUNC go64
  41 #define Elf_Ehdr Elf64_Ehdr
  42 #define Elf_Shdr Elf64_Shdr
  43 #define Elf_Phdr Elf64_Phdr
  44 #define Elf_Sym Elf64_Sym
  45 #define Elf_Dyn Elf64_Dyn
  46 #include "vdso2c.h"
  47 #undef BITS
  48 #undef GOFUNC
  49 #undef Elf_Ehdr
  50 #undef Elf_Shdr
  51 #undef Elf_Phdr
  52 #undef Elf_Sym
  53 #undef Elf_Dyn
  54
  55 #define BITS 32
  56 #define GOFUNC go32
  57 #define Elf_Ehdr Elf32_Ehdr
  58 #define Elf_Shdr Elf32_Shdr
  59 #define Elf_Phdr Elf32_Phdr
  60 #define Elf_Sym Elf32_Sym
  61 #define Elf_Dyn Elf32_Dyn
  62 #include "vdso2c.h"
  63 #undef BITS
  64 #undef GOFUNC
  65 #undef Elf_Ehdr
  66 #undef Elf_Shdr
  67 #undef Elf_Phdr
  68 #undef Elf_Sym
  69 #undef Elf_Dyn
  70
  71 static int go(void *addr, size_t len, FILE *outfile, const char *name)
  72 {
  73         Elf64_Ehdr *hdr = (Elf64_Ehdr *)addr;
  74
  75         if (hdr->e_ident[EI_CLASS] == ELFCLASS64) {
  76                 return go64(addr, len, outfile, name);
  77         } else if (hdr->e_ident[EI_CLASS] == ELFCLASS32) {
  78                 return go32(addr, len, outfile, name);
  79         } else {
  80                 fprintf(stderr, "Error: unknown ELF class\n");
  81                 return 1;
  82         }
  83 }
  84
  85 int main(int argc, char **argv)
  86 {
  87         int fd;
  88         off_t len;
  89         void *addr;
  90         FILE *outfile;
  91         int ret;
  92         char *name, *tmp;
  93         int namelen;
  94
  95         if (argc != 3) {
  96                 printf("Usage: vdso2c INPUT OUTPUT\n");
  97                 return 1;
  98         }
  99
 100         /*
 101          * Figure out the struct name.  If we're writing to a .so file,
 102          * generate raw output insted.
 103          */
 104         name = strdup(argv[2]);
 105         namelen = strlen(name);
 106         if (namelen >= 3 && !strcmp(name + namelen - 3, ".so")) {
 107                 name = NULL;
 108         } else {
 109                 tmp = strrchr(name, '/');
 110                 if (tmp)
 111                         name = tmp + 1;
 112                 tmp = strchr(name, '.');
 113                 if (tmp)
 114                         *tmp = '\0';
 115                 for (tmp = name; *tmp; tmp++)
 116                         if (*tmp == '-')
 117                                 *tmp = '_';
 118         }
 119
 120         fd = open(argv[1], O_RDONLY);
 121         if (fd == -1)
 122                 err(1, "%s", argv[1]);
 123
 124         len = lseek(fd, 0, SEEK_END);
 125         if (len == (off_t)-1)
 126                 err(1, "lseek");
 127
 128         addr = mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
 129         if (addr == MAP_FAILED)
 130                 err(1, "mmap");
 131
 132         outfile = fopen(argv[2], "w");
 133         if (!outfile)
 134                 err(1, "%s", argv[2]);
 135
 136         ret = go(addr, (size_t)len, outfile, name);
 137
 138         munmap(addr, len);
 139         fclose(outfile);
 140
 141         return ret;
 142 }