diff options
Diffstat (limited to 'sysdeps/generic/pagecopy.h')
| -rw-r--r-- | sysdeps/generic/pagecopy.h | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/sysdeps/generic/pagecopy.h b/sysdeps/generic/pagecopy.h index 07202a3..66e1ac3 100644 --- a/sysdeps/generic/pagecopy.h +++ b/sysdeps/generic/pagecopy.h @@ -42,25 +42,26 @@ Cambridge, MA 02139, USA. */ #if PAGE_COPY_THRESHOLD +#include <assert.h> + #define PAGE_COPY_FWD_MAYBE(dstp, srcp, nbytes_left, nbytes) \ do \ { \ if ((nbytes) >= PAGE_COPY_THRESHOLD && \ - PAGE_OFFSET (dstp) == PAGE_OFFSET (srcp)) \ + PAGE_OFFSET ((dstp) - (srcp)) == 0) \ { \ /* The amount to copy is past the threshold for copying \ pages virtually with kernel VM operations, and the \ source and destination addresses have the same alignment. */ \ - size_t nbytes_before = PAGE_OFFSET (PAGE_SIZE - PAGE_OFFSET (dstp));\ + size_t nbytes_before = PAGE_OFFSET (-(dstp)); \ if (nbytes_before != 0) \ { \ /* First copy the words before the first page boundary. */ \ WORD_COPY_FWD (dstp, srcp, nbytes_left, nbytes_before); \ - nbytes_before -= nbytes_left; \ + assert (nbytes_left == 0); \ nbytes -= nbytes_before; \ } \ - if (nbytes_before == 0) \ - PAGE_COPY_FWD (dstp, srcp, nbytes_left, nbytes); \ + PAGE_COPY_FWD (dstp, srcp, nbytes_left, nbytes); \ } \ } while (0) |