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Changeset ed903174 in mainline for uspace/app/taskdump/symtab.c

2010-02-10T23:51:23Z (12 years ago)
Martin Decky <martin@…>
lfn, master

implement support for 64bit file offsets

  • the libc API is a small deviation from standard, but we have no reason to keep a strict backward compatibility with ancient code so far
    • the basic signed 64bit offset type is called off64_t
      • lseek() and fseek() take off64_t arguments (since the argument represents a relative offset)
      • ftell() returns off64_t values (since it is a wrapper of lseek())
      • vfs_seek() implementation supports negative offsets when SEEK_CUR and SEEK_END is used
    • aoff64_t is used for internal unsigned representation of sizes (in bytes, blocks, etc.) and absolute offsets
      • mmap() and ftruncate() take aoff64_t arguments (since the full range of the absolute file offset should be used here)
      • struct stat stores the file size as aoff64_t
    • in both cases the explicit range of the types shown in the names is helpful for proper filesystem and IPC interaction
    • note: size_t should be used only for representing in-memory sizes and offsets, not device and file-related information, and vice versa
      • the code base still needs a thorough revision with respect to this rule
    • PRIdOFF64 and PRIuOFF64 can be used for printing the offsets
  • VFS_OUT_LOOKUP returns the 64bit file size in two IPC arguments
    • since all 5 IPC arguments have already been taken, the fs_handle is returned as the return value (fs_handle has only 16 bits, thus the return value can be used for both indicating errors as negative values and returning positive handles)
  • VFS_OUT_READ and VFS_OUT_WRITE use aoff64_t absolute offsets split into two IPC arguments

replace bn_t with aoff64_t as a generic 64bit bytes/block counter type

note: filesystem drivers need to be revised with respect to make sure that all out-of-range checks are correct (especially w.r.t. file and block offsets)

1 edited


  • uspace/app/taskdump/symtab.c

    rb32c604 red903174  
    4949static int section_hdr_load(int fd, const elf_header_t *ehdr, int idx,
    5050    elf_section_header_t *shdr);
    51 static int chunk_load(int fd, off_t start, off_t size, void **ptr);
     51static int chunk_load(int fd, off64_t start, size_t size, void **ptr);
    5252static int read_all(int fd, void *buf, size_t len);
    6565        elf_header_t elf_hdr;
    6666        elf_section_header_t sec_hdr;
    67         off_t shstrt_start, shstrt_size;
     67        off64_t shstrt_start;
     68        size_t shstrt_size;
    6869        char *shstrt, *sec_name;
    6970        void *data;
    307308        rc = lseek(fd, elf_hdr->e_shoff + idx * sizeof(elf_section_header_t),
    308309            SEEK_SET);
    309         if (rc == (off_t) -1)
     310        if (rc == (off64_t) -1)
    310311                return EIO;
    328329 * @return              EOK on success or EIO on failure.
    329330 */
    330 static int chunk_load(int fd, off_t start, off_t size, void **ptr)
     331static int chunk_load(int fd, off64_t start, size_t size, void **ptr)
    332333        int rc;
    334335        rc = lseek(fd, start, SEEK_SET);
    335         if (rc == (off_t) -1) {
     336        if (rc == (off64_t) -1) {
    336337                printf("failed seeking chunk\n");
    337338                *ptr = NULL;
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