diff options
| author | Andy Wingo <wingo@pobox.com> | 2017-03-08 22:39:29 +0100 |
|---|---|---|
| committer | Andy Wingo <wingo@pobox.com> | 2017-03-08 22:49:24 +0100 |
| commit | c62f0b025649eadc28cb1cb1afd1be183414b9b0 (patch) | |
| tree | d44e2a055a4bdcb2f1ba28c7e73dc765e34e22d0 /libguile | |
| parent | 8157c2a3acc61b561903957f69e7e83163d5a1b5 (diff) | |
64KB segment alignment
* module/system/vm/linker.scm (*lcm-page-size*): Rename
from *page-size*, change to 64 KB.
* libguile/loader.c (load_thunk_from_memory): Only require page size
alignment, knowing that although Guile might emit ELF with 64k
alignment, it only really needs page alignment.
Diffstat (limited to 'libguile')
| -rw-r--r-- | libguile/loader.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/libguile/loader.c b/libguile/loader.c index 558a722ea..7b1adc9c9 100644 --- a/libguile/loader.c +++ b/libguile/loader.c @@ -420,7 +420,18 @@ load_thunk_from_memory (char *data, size_t len, int is_read_only) if (dynamic_segment < 0) ABORT ("no PT_DYNAMIC segment"); - if (!IS_ALIGNED ((scm_t_uintptr) data, alignment)) + /* The ELF images that Guile currently emits have segments that are + aligned on 64 KB boundaries, which might be larger than the actual + page size (usually 4 KB). However Guile doesn't actually use the + absolute addresses at all. All Guile needs is for the loaded image + to be able to make the data section writable (for the mmap path), + and for that the segment just needs to be page-aligned, and a page + is always bigger than Guile's minimum alignment. Since we know + (for the mmap path) that the base _is_ page-aligned, we proceed + ahead even if the image alignment is greater than the page + size. */ + if (!IS_ALIGNED ((scm_t_uintptr) data, alignment) + && !IS_ALIGNED (alignment, page_size)) ABORT ("incorrectly aligned base"); /* Allow writes to writable pages. */ @@ -433,7 +444,7 @@ load_thunk_from_memory (char *data, size_t len, int is_read_only) continue; if (ph[i].p_flags == PF_R) continue; - if (ph[i].p_align != page_size) + if (ph[i].p_align < page_size) continue; if (mprotect (data + ph[i].p_vaddr, |