diff options
| -rw-r--r-- | ChangeLog | 5 | ||||
| -rw-r--r-- | time/tzfile.c | 57 |
2 files changed, 32 insertions, 30 deletions
@@ -1,3 +1,8 @@ +2019-02-04 Florian Weimer <fweimer@redhat.com> + + * time/tzfile.c (__tzfile_read): Reorder suballocations to avoid + alignment gaps. + 2019-02-03 Florian Weimer <fweimer@redhat.com> * time/tzfile.c (__tzfile_read): Use struct alloc_buffer and its diff --git a/time/tzfile.c b/time/tzfile.c index e107b33..7229ed9 100644 --- a/time/tzfile.c +++ b/time/tzfile.c @@ -246,25 +246,32 @@ __tzfile_read (const char *file, size_t extra, char **extrap) the following arrays: __time64_t transitions[num_transitions]; + struct leap leaps[num_leaps]; struct ttinfo types[num_types]; unsigned char type_idxs[num_types]; char zone_names[chars]; - struct leap leaps[num_leaps]; - char extra_array[extra]; // Stored into *pextras if requested. char tzspec[tzspec_len]; + char extra_array[extra]; // Stored into *pextras if requested. The piece-wise allocations from buf below verify that no - overflow/wraparound occurred in these computations. */ + overflow/wraparound occurred in these computations. + + The order of the suballocations is important for alignment + purposes. __time64_t outside a struct may require more alignment + then inside a struct on some architectures, so it must come + first. */ + _Static_assert (__alignof (__time64_t) >= __alignof (struct leap), + "alignment of __time64_t"); + _Static_assert (__alignof (struct leap) >= __alignof (struct ttinfo), + "alignment of struct leap"); struct alloc_buffer buf; { - size_t total_size = num_transitions * (sizeof (__time64_t) + 1); - total_size = ((total_size + __alignof__ (struct ttinfo) - 1) - & ~(__alignof__ (struct ttinfo) - 1)); - total_size += num_types * sizeof (struct ttinfo) + chars; - total_size = ((total_size + __alignof__ (struct leap) - 1) - & ~(__alignof__ (struct leap) - 1)); - total_size += num_leaps * sizeof (struct leap) + tzspec_len + extra; - + size_t total_size = (num_transitions * sizeof (__time64_t) + + num_leaps * sizeof (struct leap) + + num_types * sizeof (struct ttinfo) + + num_transitions /* type_idxs */ + + chars /* zone_names */ + + tzspec_len + extra); transitions = malloc (total_size); if (transitions == NULL) goto lose; @@ -274,35 +281,25 @@ __tzfile_read (const char *file, size_t extra, char **extrap) /* The address of the first allocation is already stored in the pointer transitions. */ (void) alloc_buffer_alloc_array (&buf, __time64_t, num_transitions); - type_idxs = alloc_buffer_alloc_array (&buf, unsigned char, num_transitions); + leaps = alloc_buffer_alloc_array (&buf, struct leap, num_leaps); types = alloc_buffer_alloc_array (&buf, struct ttinfo, num_types); + type_idxs = alloc_buffer_alloc_array (&buf, unsigned char, num_transitions); zone_names = alloc_buffer_alloc_array (&buf, char, chars); - leaps = alloc_buffer_alloc_array (&buf, struct leap, num_leaps); - if (extra > 0) - *extrap = alloc_buffer_alloc_array (&buf, char, extra); if (trans_width == 8) tzspec = alloc_buffer_alloc_array (&buf, char, tzspec_len); else tzspec = NULL; + if (extra > 0) + *extrap = alloc_buffer_alloc_array (&buf, char, extra); if (alloc_buffer_has_failed (&buf)) goto lose; - if (__builtin_expect (trans_width == 8, 1)) - { - if (__builtin_expect (__fread_unlocked (transitions, trans_width + 1, - num_transitions, f) - != num_transitions, 0)) + if (__glibc_unlikely (__fread_unlocked (transitions, trans_width, + num_transitions, f) + != num_transitions) + || __glibc_unlikely (__fread_unlocked (type_idxs, 1, num_transitions, f) + != num_transitions)) goto lose; - } - else - { - if (__builtin_expect (__fread_unlocked (transitions, 4, - num_transitions, f) - != num_transitions, 0) - || __builtin_expect (__fread_unlocked (type_idxs, 1, num_transitions, - f) != num_transitions, 0)) - goto lose; - } /* Check for bogus indices in the data file, so we can hereafter safely use type_idxs[T] as indices into `types' and never crash. */ |