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Diffstat (limited to 'mmalloc/attach.c')
| -rw-r--r-- | mmalloc/attach.c | 221 |
1 files changed, 0 insertions, 221 deletions
diff --git a/mmalloc/attach.c b/mmalloc/attach.c deleted file mode 100644 index 2bd70bfdf05..00000000000 --- a/mmalloc/attach.c +++ /dev/null @@ -1,221 +0,0 @@ -/* Initialization for access to a mmap'd malloc managed region. - Copyright 1992, 2000 Free Software Foundation, Inc. - - Contributed by Fred Fish at Cygnus Support. fnf@cygnus.com - -This file is part of the GNU C Library. - -The GNU C Library is free software; you can redistribute it and/or -modify it under the terms of the GNU Library General Public License as -published by the Free Software Foundation; either version 2 of the -License, or (at your option) any later version. - -The GNU C Library is distributed in the hope that it will be useful, -but WITHOUT ANY WARRANTY; without even the implied warranty of -MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU -Library General Public License for more details. - -You should have received a copy of the GNU Library General Public -License along with the GNU C Library; see the file COPYING.LIB. If -not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, -Boston, MA 02111-1307, USA. */ - -#include <sys/types.h> -#include <fcntl.h> /* After sys/types.h, at least for dpx/2. */ -#include <sys/stat.h> -#include <string.h> -#ifdef HAVE_UNISTD_H -#include <unistd.h> /* Prototypes for lseek */ -#endif -#include "mmprivate.h" - -#ifndef SEEK_SET -#define SEEK_SET 0 -#endif - - -#if defined(HAVE_MMAP) - -/* Forward declarations/prototypes for local functions */ - -static struct mdesc *reuse PARAMS ((int)); - -/* Initialize access to a mmalloc managed region. - - If FD is a valid file descriptor for an open file then data for the - mmalloc managed region is mapped to that file, otherwise "/dev/zero" - is used and the data will not exist in any filesystem object. - - If the open file corresponding to FD is from a previous use of - mmalloc and passes some basic sanity checks to ensure that it is - compatible with the current mmalloc package, then it's data is - mapped in and is immediately accessible at the same addresses in - the current process as the process that created the file. - - If BASEADDR is not NULL, the mapping is established starting at the - specified address in the process address space. If BASEADDR is NULL, - the mmalloc package chooses a suitable address at which to start the - mapped region, which will be the value of the previous mapping if - opening an existing file which was previously built by mmalloc, or - for new files will be a value chosen by mmap. - - Specifying BASEADDR provides more control over where the regions - start and how big they can be before bumping into existing mapped - regions or future mapped regions. - - On success, returns a "malloc descriptor" which is used in subsequent - calls to other mmalloc package functions. It is explicitly "void *" - ("char *" for systems that don't fully support void) so that users - of the package don't have to worry about the actual implementation - details. - - On failure returns NULL. */ - -PTR -mmalloc_attach (fd, baseaddr) - int fd; - PTR baseaddr; -{ - struct mdesc mtemp; - struct mdesc *mdp; - PTR mbase; - struct stat sbuf; - - /* First check to see if FD is a valid file descriptor, and if so, see - if the file has any current contents (size > 0). If it does, then - attempt to reuse the file. If we can't reuse the file, either - because it isn't a valid mmalloc produced file, was produced by an - obsolete version, or any other reason, then we fail to attach to - this file. */ - - if (fd >= 0) - { - if (fstat (fd, &sbuf) < 0) - { - return (NULL); - } - else if (sbuf.st_size > 0) - { - return ((PTR) reuse (fd)); - } - } - - /* We start off with the malloc descriptor allocated on the stack, until - we build it up enough to call _mmalloc_mmap_morecore() to allocate the - first page of the region and copy it there. Ensure that it is zero'd and - then initialize the fields that we know values for. */ - - mdp = &mtemp; - memset ((char *) mdp, 0, sizeof (mtemp)); - strncpy (mdp -> magic, MMALLOC_MAGIC, MMALLOC_MAGIC_SIZE); - mdp -> headersize = sizeof (mtemp); - mdp -> version = MMALLOC_VERSION; - mdp -> morecore = __mmalloc_mmap_morecore; - mdp -> fd = fd; - mdp -> base = mdp -> breakval = mdp -> top = baseaddr; - - /* If we have not been passed a valid open file descriptor for the file - to map to, then open /dev/zero and use that to map to. */ - - if (mdp -> fd < 0) - { - if ((mdp -> fd = open ("/dev/zero", O_RDWR)) < 0) - { - return (NULL); - } - else - { - mdp -> flags |= MMALLOC_DEVZERO; - } - } - - /* Now try to map in the first page, copy the malloc descriptor structure - there, and arrange to return a pointer to this new copy. If the mapping - fails, then close the file descriptor if it was opened by us, and arrange - to return a NULL. */ - - if ((mbase = mdp -> morecore (mdp, sizeof (mtemp))) != NULL) - { - memcpy (mbase, mdp, sizeof (mtemp)); - mdp = (struct mdesc *) mbase; - } - else - { - if (mdp -> flags & MMALLOC_DEVZERO) - { - close (mdp -> fd); - } - mdp = NULL; - } - - return ((PTR) mdp); -} - -/* Given an valid file descriptor on an open file, test to see if that file - is a valid mmalloc produced file, and if so, attempt to remap it into the - current process at the same address to which it was previously mapped. - - Note that we have to update the file descriptor number in the malloc- - descriptor read from the file to match the current valid one, before - trying to map the file in, and again after a successful mapping and - after we've switched over to using the mapped in malloc descriptor - rather than the temporary one on the stack. - - Once we've switched over to using the mapped in malloc descriptor, we - have to update the pointer to the morecore function, since it almost - certainly will be at a different address if the process reusing the - mapped region is from a different executable. - - Also note that if the heap being remapped previously used the mmcheckf() - routines, we need to update the hooks since their target functions - will have certainly moved if the executable has changed in any way. - We do this by calling mmcheckf() internally. - - Returns a pointer to the malloc descriptor if successful, or NULL if - unsuccessful for some reason. */ - -static struct mdesc * -reuse (fd) - int fd; -{ - struct mdesc mtemp; - struct mdesc *mdp = NULL; - - if ((lseek (fd, 0L, SEEK_SET) == 0) && - (read (fd, (char *) &mtemp, sizeof (mtemp)) == sizeof (mtemp)) && - (mtemp.headersize == sizeof (mtemp)) && - (strcmp (mtemp.magic, MMALLOC_MAGIC) == 0) && - (mtemp.version <= MMALLOC_VERSION)) - { - mtemp.fd = fd; - if (__mmalloc_remap_core (&mtemp) == mtemp.base) - { - mdp = (struct mdesc *) mtemp.base; - mdp -> fd = fd; - mdp -> morecore = __mmalloc_mmap_morecore; - if (mdp -> mfree_hook != NULL) - { - mmcheckf ((PTR) mdp, (void (*) PARAMS ((void))) NULL, 1); - } - } - } - return (mdp); -} - -#else /* !defined (HAVE_MMAP) */ - -/* For systems without mmap, the library still supplies an entry point - to link to, but trying to initialize access to an mmap'd managed region - always fails. */ - -/* ARGSUSED */ -PTR -mmalloc_attach (fd, baseaddr) - int fd; - PTR baseaddr; -{ - return (NULL); -} - -#endif /* defined (HAVE_MMAP) */ - |