diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/mmap64.c')
| -rw-r--r-- | sysdeps/unix/sysv/linux/mmap64.c | 57 |
1 files changed, 30 insertions, 27 deletions
diff --git a/sysdeps/unix/sysv/linux/mmap64.c b/sysdeps/unix/sysv/linux/mmap64.c index e823600a0d..d3ea279afe 100644 --- a/sysdeps/unix/sysv/linux/mmap64.c +++ b/sysdeps/unix/sysv/linux/mmap64.c @@ -1,4 +1,5 @@ -/* Copyright (C) 1999-2017 Free Software Foundation, Inc. +/* mmap - map files or devices into memory. Linux version. + Copyright (C) 1999-2017 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Jakub Jelinek <jakub@redhat.com>, 1999. @@ -19,39 +20,41 @@ #include <errno.h> #include <unistd.h> #include <sys/mman.h> -#include <string.h> - #include <sysdep.h> -#include <sys/syscall.h> +#include <mmap_internal.h> -/* This is always 12, even on architectures where PAGE_SHIFT != 12. */ -#ifndef MMAP2_PAGE_SHIFT -# define MMAP2_PAGE_SHIFT 12 -#endif -#if MMAP2_PAGE_SHIFT == -1 -static int page_shift; -#else -#define page_shift MMAP2_PAGE_SHIFT -#endif +/* To avoid silent truncation of offset when using mmap2, do not accept + offset larger than 1 << (page_shift + off_t bits). For archictures with + 32 bits off_t and page size of 4096 it would be 1^44. */ +#define MMAP_OFF_HIGH_MASK \ + ((-(MMAP2_PAGE_UNIT << 1) << (8 * sizeof (off_t) - 1))) +#define MMAP_OFF_MASK (MMAP_OFF_HIGH_MASK | MMAP_OFF_LOW_MASK) + +/* An architecture may override this. */ +#ifndef MMAP_PREPARE +# define MMAP_PREPARE(addr, len, prot, flags, fd, offset) +#endif void * __mmap64 (void *addr, size_t len, int prot, int flags, int fd, off64_t offset) { -#if MMAP2_PAGE_SHIFT == -1 - if (page_shift == 0) - { - int page_size = __getpagesize (); - page_shift = __ffs (page_size) - 1; - } -#endif - if (offset & ((1 << page_shift) - 1)) + MMAP_CHECK_PAGE_UNIT (); + + if (offset & MMAP_OFF_MASK) return (void *) INLINE_SYSCALL_ERROR_RETURN_VALUE (EINVAL); - void *result; - result = (void *) - INLINE_SYSCALL (mmap2, 6, addr, - len, prot, flags, fd, - (off_t) (offset >> page_shift)); - return result; + + MMAP_PREPARE (addr, len, prot, flags, fd, offset); +#ifdef __NR_mmap2 + return (void *) MMAP_CALL (mmap2, addr, len, prot, flags, fd, + (off_t) (offset / MMAP2_PAGE_UNIT)); +#else + return (void *) MMAP_CALL (mmap, addr, len, prot, flags, fd, offset); +#endif } weak_alias (__mmap64, mmap64) + +#ifdef __OFF_T_MATCHES_OFF64_T +weak_alias (__mmap64, mmap) +weak_alias (__mmap64, __mmap) +#endif |