diff options
| -rw-r--r-- | debug/pcprofiledump.c | 83 |
1 files changed, 47 insertions, 36 deletions
diff --git a/debug/pcprofiledump.c b/debug/pcprofiledump.c index 049a9c2744..94530f0cf9 100644 --- a/debug/pcprofiledump.c +++ b/debug/pcprofiledump.c @@ -75,6 +75,44 @@ static struct argp argp = options, parse_opt, args_doc, doc, NULL, more_help }; +/* Try to read SIZE bytes from FD and store them on BUF. Terminate + the process upon read error. Also terminate the process if less + than SIZE bytes are remaining in the file. If !IN_HEADER, do not + terminate the process if the end of the file is encountered + immediately, before any bytes are read. + + Returns true if SIZE bytes have been read, and false if no bytes + have been read due to an end-of-file condition. */ +static bool +read_exactly (int fd, void *buffer, size_t size, bool in_header) +{ + char *p = buffer; + char *end = p + size; + while (p < end) + { + ssize_t ret = TEMP_FAILURE_RETRY (read (fd, p, end - p)); + if (ret < 0) + { + if (in_header) + error (EXIT_FAILURE, errno, _("cannot read header")); + else + error (EXIT_FAILURE, errno, _("cannot read pointer pair")); + } + if (ret == 0) + { + if (p == buffer && !in_header) + /* Nothing has been read. */ + return false; + if (in_header) + error (EXIT_FAILURE, 0, _("unexpected end of file in header")); + else + error (EXIT_FAILURE, 0, + _("unexpected end of file in pointer pair")); + } + p += ret; + } + return true; +} int main (int argc, char *argv[]) @@ -110,8 +148,7 @@ main (int argc, char *argv[]) /* Read the first 4-byte word. It contains the information about the word size and the endianness. */ uint32_t word; - if (TEMP_FAILURE_RETRY (read (fd, &word, 4)) != 4) - error (EXIT_FAILURE, errno, _("cannot read header")); + read_exactly (fd, &word, sizeof (word), true); /* Check whether we have to swap the byte order. */ int must_swap = (word & 0x0fffffff) == bswap_32 (0xdeb00000); @@ -121,56 +158,30 @@ main (int argc, char *argv[]) /* We have two loops, one for 32 bit pointers, one for 64 bit pointers. */ if (word == 0xdeb00004) { - union - { - uint32_t ptrs[2]; - char bytes[8]; - } pair; + uint32_t ptrs[2]; while (1) { - size_t len = sizeof (pair); - size_t n; - - while (len > 0 - && (n = TEMP_FAILURE_RETRY (read (fd, &pair.bytes[8 - len], - len))) != 0) - len -= n; - - if (len != 0) - /* Nothing to read. */ + if (!read_exactly (fd, ptrs, sizeof (ptrs), false)) break; printf ("this = %#010" PRIx32 ", caller = %#010" PRIx32 "\n", - must_swap ? bswap_32 (pair.ptrs[0]) : pair.ptrs[0], - must_swap ? bswap_32 (pair.ptrs[1]) : pair.ptrs[1]); + must_swap ? bswap_32 (ptrs[0]) : ptrs[0], + must_swap ? bswap_32 (ptrs[1]) : ptrs[1]); } } else if (word == 0xdeb00008) { - union - { - uint64_t ptrs[2]; - char bytes[16]; - } pair; + uint64_t ptrs[2]; while (1) { - size_t len = sizeof (pair); - size_t n; - - while (len > 0 - && (n = TEMP_FAILURE_RETRY (read (fd, &pair.bytes[8 - len], - len))) != 0) - len -= n; - - if (len != 0) - /* Nothing to read. */ + if (!read_exactly (fd, ptrs, sizeof (ptrs), false)) break; printf ("this = %#018" PRIx64 ", caller = %#018" PRIx64 "\n", - must_swap ? bswap_64 (pair.ptrs[0]) : pair.ptrs[0], - must_swap ? bswap_64 (pair.ptrs[1]) : pair.ptrs[1]); + must_swap ? bswap_64 (ptrs[0]) : ptrs[0], + must_swap ? bswap_64 (ptrs[1]) : ptrs[1]); } } else |