From f2817865e06e33ac5a63dc6f58c4393d34d49550 Mon Sep 17 00:00:00 2001 From: Gerd Moellmann Date: Tue, 16 Apr 2002 07:37:37 +0000 Subject: [PATCH] (MMAP_ALLOCATED_P): New macro to be set from system configuration files. (mmap_enlarge): Enlarge mapped regions only if MMAP_ALLOCATED_P returns 0. --- src/ChangeLog | 7 +++++++ src/buffer.c | 19 ++++++++++++++----- 2 files changed, 21 insertions(+), 5 deletions(-) diff --git a/src/ChangeLog b/src/ChangeLog index 693272711d1..473dc18101d 100644 --- a/src/ChangeLog +++ b/src/ChangeLog @@ -1,3 +1,10 @@ +2002-04-16 Gerd Moellmann + + * buffer.c (MMAP_ALLOCATED_P): New macro to be set from system + configuration files. + (mmap_enlarge): Enlarge mapped regions only if MMAP_ALLOCATED_P + returns 0. + 2002-04-13 Eli Zaretskii * unexelf.c (unexec) [__sgi]: Undo the change from 2002-01-20. diff --git a/src/buffer.c b/src/buffer.c index 19c9682f5da..96b09ed4eee 100644 --- a/src/buffer.c +++ b/src/buffer.c @@ -1,5 +1,5 @@ /* Buffer manipulation primitives for GNU Emacs. - Copyright (C) 1985,86,87,88,89,93,94,95,97,98, 1999, 2000, 2001 + Copyright (C) 1985,86,87,88,89,93,94,95,97,98, 1999, 2000, 2001, 2002 Free Software Foundation, Inc. This file is part of GNU Emacs. @@ -4277,6 +4277,18 @@ static int mmap_initialized_p; #define MEM_ALIGN sizeof (double) +/* Predicate returning true if part of the address range [START .. + END[ is currently mapped. Used to prevent overwriting an existing + memory mapping. + + Default is to conservativly assume the address range is occupied by + something else. This can be overridden by system configuration + files if system-specific means to determine this exists. */ + +#ifndef MMAP_ALLOCATED_P +#define MMAP_ALLOCATED_P(start, end) 1 +#endif + /* Function prototypes. */ static int mmap_free_1 P_ ((struct mmap_region *)); @@ -4369,16 +4381,13 @@ mmap_enlarge (r, npages) } else if (npages > 0) { - struct mmap_region *r2; - nbytes = npages * mmap_page_size; /* Try to map additional pages at the end of the region. We cannot do this if the address range is already occupied by something else because mmap deletes any previous mapping. I'm not sure this is worth doing, let's see. */ - r2 = mmap_find (region_end, region_end + nbytes); - if (r2 == NULL) + if (!MMAP_ALLOCATED_P (region_end, region_end + nbytes)) { POINTER_TYPE *p; -- 2.39.2