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Use alignment macros, pagesize and powerof2.

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We are replacing all of the bespoke alignment code with
ALIGN_UP, ALIGN_DOWN, PTR_ALIGN_UP, and PTR_ALIGN_DOWN.
This cleans up malloc/malloc.c, malloc/arena.c, and
elf/dl-reloc.c. It also makes all the code consistently
use pagesize, and powerof2 as required.

Code size is reduced with the removal of precomputed
pagemask, and use of pagesize instead. No measurable
difference in performance.

No regressions on x86_64.
This commit is contained in:
Carlos O'Donell
2015-02-17 19:25:01 -05:00
parent 1a2325c06c
commit 8a35c3fe12
4 changed files with 57 additions and 37 deletions
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28
elf/dl-reloc.c
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@@ -26,6 +26,7 @@
#include <sys/types.h>
#include <_itoa.h>
#include "dynamic-link.h"
#include <libc-internal.h>
/* Statistics function. */
#ifdef SHARED
@@ -74,9 +75,9 @@ _dl_try_allocate_static_tls (struct link_map *map)
map->l_tls_offset = GL(dl_tls_static_used) = offset;
#elif TLS_DTV_AT_TP
/* dl_tls_static_used includes the TCB at the beginning. */
size_t offset = (((GL(dl_tls_static_used)
- map->l_tls_firstbyte_offset
+ map->l_tls_align - 1) & -map->l_tls_align)
size_t offset = (ALIGN_UP(GL(dl_tls_static_used)
- map->l_tls_firstbyte_offset,
map->l_tls_align)
+ map->l_tls_firstbyte_offset);
size_t used = offset + map->l_tls_blocksize;
@@ -201,11 +202,10 @@ _dl_relocate_object (struct link_map *l, struct r_scope_elem *scope[],
struct textrels *newp;
newp = (struct textrels *) alloca (sizeof (*newp));
newp->len = (((ph->p_vaddr + ph->p_memsz + GLRO(dl_pagesize) - 1)
& ~(GLRO(dl_pagesize) - 1))
- (ph->p_vaddr & ~(GLRO(dl_pagesize) - 1)));
newp->start = ((ph->p_vaddr & ~(GLRO(dl_pagesize) - 1))
+ (caddr_t) l->l_addr);
newp->len = ALIGN_UP (ph->p_vaddr + ph->p_memsz, GLRO(dl_pagesize))
- ALIGN_DOWN (ph->p_vaddr, GLRO(dl_pagesize));
newp->start = PTR_ALIGN_DOWN (ph->p_vaddr, GLRO(dl_pagesize))
+ (caddr_t) l->l_addr;
if (__mprotect (newp->start, newp->len, PROT_READ|PROT_WRITE) < 0)
{
@@ -324,11 +324,13 @@ _dl_relocate_object (struct link_map *l, struct r_scope_elem *scope[],
void internal_function
_dl_protect_relro (struct link_map *l)
{
ElfW(Addr) start = ((l->l_addr + l->l_relro_addr)
& ~(GLRO(dl_pagesize) - 1));
ElfW(Addr) end = ((l->l_addr + l->l_relro_addr + l->l_relro_size)
& ~(GLRO(dl_pagesize) - 1));
ElfW(Addr) start = ALIGN_DOWN((l->l_addr
+ l->l_relro_addr),
GLRO(dl_pagesize));
ElfW(Addr) end = ALIGN_DOWN((l->l_addr
+ l->l_relro_addr
+ l->l_relro_size),
GLRO(dl_pagesize));
if (start != end
&& __mprotect ((void *) start, end - start, PROT_READ) < 0)
{