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

    rb32c604 red903174  
    6262#include "include/elf_core.h"
    64 static off_t align_foff_up(off_t foff, uintptr_t vaddr, size_t page_size);
     64static off64_t align_foff_up(off64_t foff, uintptr_t vaddr, size_t page_size);
    6565static int write_all(int fd, void *data, size_t len);
    6666static int write_mem_area(int fd, as_area_info_t *area, int phoneid);
    7979 *                      ENOMEM on out of memory, EIO on write error.
    8080 */
    81 int elf_core_save(const char *file_name, as_area_info_t *ainfo, int n, int phoneid)
     81int elf_core_save(const char *file_name, as_area_info_t *ainfo, unsigned int n, int phoneid)
    8383        elf_header_t elf_hdr;
    84         off_t foff;
     84        off64_t foff;
    8585        size_t n_ph;
    8686        elf_word flags;
    8989        int fd;
    9090        int rc;
    91         int i;
     91        unsigned int i;
    9393        n_ph = n;
    185185        for (i = 0; i < n_ph; ++i) {
    186                 if (lseek(fd, p_hdr[i].p_offset, SEEK_SET) == (off_t) -1) {
     186                if (lseek(fd, p_hdr[i].p_offset, SEEK_SET) == (off64_t) -1) {
    187187                        printf("Failed writing memory data.\n");
    188188                        free(p_hdr);
    203203/** Align file offset up to be congruent with vaddr modulo page size. */
    204 static off_t align_foff_up(off_t foff, uintptr_t vaddr, size_t page_size)
    205 {
    206         off_t rfo, rva;
    207         off_t advance;
    209         rva = vaddr % page_size;
    210         rfo = foff % page_size;
    212         advance = (rva >= rfo) ? rva - rfo : (page_size + rva - rfo);
    213         return foff + advance;
     204static off64_t align_foff_up(off64_t foff, uintptr_t vaddr, size_t page_size)
     206        off64_t rva = vaddr % page_size;
     207        off64_t rfo = foff % page_size;
     209        if (rva >= rfo)
     210                return (foff + (rva - rfo));
     212        return (foff + (page_size + (rva - rfo)));
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