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* nscd/nscd_helper.c (get_mapping): Avoid the pread call, just go

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ahead and map the file.  This should always be correct and we can
	catch problems later.
This commit is contained in:
Ulrich Drepper
2007-08-29 05:16:12 +00:00
parent 3586b2b60b
commit 0adfcc0526
2 changed files with 35 additions and 30 deletions
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6
ChangeLog
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@@ -1,3 +1,9 @@
2007-08-28 Ulrich Drepper <drepper@redhat.com>
* nscd/nscd_helper.c (get_mapping): Avoid the pread call, just go
ahead and map the file. This should always be correct and we can
catch problems later.
2007-08-28 Jakub Jelinek <jakub@redhat.com> 2007-08-28 Jakub Jelinek <jakub@redhat.com>
* libio/bits/stdio2.h (__fread_chk, __fread_unlocked_chk): New * libio/bits/stdio2.h (__fread_chk, __fread_unlocked_chk): New

59
nscd/nscd_helper.c
View File

@@ -286,45 +286,44 @@ get_mapping (request_type type, const char *key,
|| __builtin_expect (st.st_size < sizeof (struct database_pers_head), 0)) || __builtin_expect (st.st_size < sizeof (struct database_pers_head), 0))
goto out_close; goto out_close;
struct database_pers_head head;
if (__builtin_expect (TEMP_FAILURE_RETRY (__pread (mapfd, &head,
sizeof (head), 0))
!= sizeof (head), 0))
goto out_close;
if (__builtin_expect (head.version != DB_VERSION, 0)
|| __builtin_expect (head.header_size != sizeof (head), 0)
/* This really should not happen but who knows, maybe the update
thread got stuck. */
|| __builtin_expect (! head.nscd_certainly_running
&& head.timestamp + MAPPING_TIMEOUT < time (NULL),
0))
goto out_close;
size_t size = (sizeof (head) + roundup (head.module * sizeof (ref_t), ALIGN)
+ head.data_size);
if (__builtin_expect (st.st_size < size, 0))
goto out_close;
/* The file is large enough, map it now. */ /* The file is large enough, map it now. */
void *mapping = __mmap (NULL, size, PROT_READ, MAP_SHARED, mapfd, 0); void *mapping = __mmap (NULL, st.st_size, PROT_READ, MAP_SHARED, mapfd, 0);
if (__builtin_expect (mapping != MAP_FAILED, 1)) if (__builtin_expect (mapping != MAP_FAILED, 1))
{ {
/* Allocate a record for the mapping. */ /* Check whether the database is correct and up-to-date. */
struct mapped_database *newp = malloc (sizeof (*newp)); struct database_pers_head *head = mapping;
if (newp == NULL)
if (__builtin_expect (head->version != DB_VERSION, 0)
|| __builtin_expect (head->header_size != sizeof (*head), 0)
/* This really should not happen but who knows, maybe the update
thread got stuck. */
|| __builtin_expect (! head->nscd_certainly_running
&& (head->timestamp + MAPPING_TIMEOUT
< time (NULL)), 0))
{ {
/* Ugh, after all we went through the memory allocation failed. */ out_unmap:
__munmap (mapping, size); __munmap (mapping, st.st_size);
goto out_close; goto out_close;
} }
size_t size = (sizeof (*head) + roundup (head->module * sizeof (ref_t),
ALIGN)
+ head->data_size);
if (__builtin_expect (st.st_size < size, 0))
goto out_unmap;
/* Allocate a record for the mapping. */
struct mapped_database *newp = malloc (sizeof (*newp));
if (newp == NULL)
/* Ugh, after all we went through the memory allocation failed. */
goto out_unmap;
newp->head = mapping; newp->head = mapping;
newp->data = ((char *) mapping + head.header_size newp->data = ((char *) mapping + head->header_size
+ roundup (head.module * sizeof (ref_t), ALIGN)); + roundup (head->module * sizeof (ref_t), ALIGN));
newp->mapsize = size; newp->mapsize = size;
newp->datasize = head.data_size; newp->datasize = head->data_size;
/* Set counter to 1 to show it is usable. */ /* Set counter to 1 to show it is usable. */
newp->counter = 1; newp->counter = 1;