diff options
Diffstat (limited to 'elf/dl-minimal.c')
| -rw-r--r-- | elf/dl-minimal.c | 122 |
1 files changed, 7 insertions, 115 deletions
diff --git a/elf/dl-minimal.c b/elf/dl-minimal.c index 4e7f11a..152192d 100644 --- a/elf/dl-minimal.c +++ b/elf/dl-minimal.c @@ -16,23 +16,14 @@ License along with the GNU C Library; if not, see <https://www.gnu.org/licenses/>. */ -#include <errno.h> -#include <limits.h> -#include <stdio.h> -#include <string.h> -#include <tls.h> -#include <unistd.h> -#include <sys/mman.h> -#include <sys/param.h> -#include <sys/types.h> +#include <assert.h> #include <ldsodefs.h> #include <dl-irel.h> #include <dl-hash.h> #include <dl-sym-post.h> #include <_itoa.h> -#include <malloc/malloc-internal.h> +#include <dl-minimal-malloc.h> -#include <assert.h> /* The rtld startup code calls __rtld_malloc_init_stubs after the first self-relocation to adjust the pointers to the minimal @@ -44,19 +35,13 @@ __typeof (free) *__rtld_free attribute_relro; __typeof (malloc) *__rtld_malloc attribute_relro; __typeof (realloc) *__rtld_realloc attribute_relro; -/* Defined below. */ -static __typeof (calloc) rtld_calloc; -static __typeof (free) rtld_free; -static __typeof (malloc) rtld_malloc; -static __typeof (realloc) rtld_realloc; - void __rtld_malloc_init_stubs (void) { - __rtld_calloc = &rtld_calloc; - __rtld_free = &rtld_free; - __rtld_malloc = &rtld_malloc; - __rtld_realloc = &rtld_realloc; + __rtld_calloc = &__minimal_calloc; + __rtld_free = &__minimal_free; + __rtld_malloc = &__minimal_malloc; + __rtld_realloc = &__minimal_realloc; } bool @@ -64,7 +49,7 @@ __rtld_malloc_is_complete (void) { /* The caller assumes that there is an active malloc. */ assert (__rtld_malloc != NULL); - return __rtld_malloc != &rtld_malloc; + return __rtld_malloc != &__minimal_malloc; } /* Lookup NAME at VERSION in the scope of MATCH. */ @@ -115,99 +100,6 @@ __rtld_malloc_init_real (struct link_map *main_map) __rtld_realloc = new_realloc; } -/* Minimal malloc allocator for used during initial link. After the - initial link, a full malloc implementation is interposed, either - the one in libc, or a different one supplied by the user through - interposition. */ - -static void *alloc_ptr, *alloc_end, *alloc_last_block; - -/* Allocate an aligned memory block. */ -static void * -rtld_malloc (size_t n) -{ - if (alloc_end == 0) - { - /* Consume any unused space in the last page of our data segment. */ - extern int _end attribute_hidden; - alloc_ptr = &_end; - alloc_end = (void *) 0 + (((alloc_ptr - (void *) 0) - + GLRO(dl_pagesize) - 1) - & ~(GLRO(dl_pagesize) - 1)); - } - - /* Make sure the allocation pointer is ideally aligned. */ - alloc_ptr = (void *) 0 + (((alloc_ptr - (void *) 0) + MALLOC_ALIGNMENT - 1) - & ~(MALLOC_ALIGNMENT - 1)); - - if (alloc_ptr + n >= alloc_end || n >= -(uintptr_t) alloc_ptr) - { - /* Insufficient space left; allocate another page plus one extra - page to reduce number of mmap calls. */ - caddr_t page; - size_t nup = (n + GLRO(dl_pagesize) - 1) & ~(GLRO(dl_pagesize) - 1); - if (__glibc_unlikely (nup == 0 && n != 0)) - return NULL; - nup += GLRO(dl_pagesize); - page = __mmap (0, nup, PROT_READ|PROT_WRITE, - MAP_ANON|MAP_PRIVATE, -1, 0); - if (page == MAP_FAILED) - return NULL; - if (page != alloc_end) - alloc_ptr = page; - alloc_end = page + nup; - } - - alloc_last_block = (void *) alloc_ptr; - alloc_ptr += n; - return alloc_last_block; -} - -/* We use this function occasionally since the real implementation may - be optimized when it can assume the memory it returns already is - set to NUL. */ -static void * -rtld_calloc (size_t nmemb, size_t size) -{ - /* New memory from the trivial malloc above is always already cleared. - (We make sure that's true in the rare occasion it might not be, - by clearing memory in free, below.) */ - size_t bytes = nmemb * size; - -#define HALF_SIZE_T (((size_t) 1) << (8 * sizeof (size_t) / 2)) - if (__builtin_expect ((nmemb | size) >= HALF_SIZE_T, 0) - && size != 0 && bytes / size != nmemb) - return NULL; - - return malloc (bytes); -} - -/* This will rarely be called. */ -void -rtld_free (void *ptr) -{ - /* We can free only the last block allocated. */ - if (ptr == alloc_last_block) - { - /* Since this is rare, we clear the freed block here - so that calloc can presume malloc returns cleared memory. */ - memset (alloc_last_block, '\0', alloc_ptr - alloc_last_block); - alloc_ptr = alloc_last_block; - } -} - -/* This is only called with the most recent block returned by malloc. */ -void * -rtld_realloc (void *ptr, size_t n) -{ - if (ptr == NULL) - return malloc (n); - assert (ptr == alloc_last_block); - size_t old_size = alloc_ptr - alloc_last_block; - alloc_ptr = alloc_last_block; - void *new = malloc (n); - return new != ptr ? memcpy (new, ptr, old_size) : new; -} /* Avoid signal frobnication in setjmp/longjmp. Keeps things smaller. */ |