X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/1b1016c3ad9e396286bf2c692c92cf5fd567b1d3..ea74f5d95928a521a588737e81f1de94eef25d19:/src/xbt/mmalloc/mmorecore.c diff --git a/src/xbt/mmalloc/mmorecore.c b/src/xbt/mmalloc/mmorecore.c index 2182cc4add..828e2f505e 100644 --- a/src/xbt/mmalloc/mmorecore.c +++ b/src/xbt/mmalloc/mmorecore.c @@ -1,147 +1,100 @@ -/* Support for an sbrk-like function that uses mmap. - Copyright 1992, 2000 Free Software Foundation, Inc. +/* Support for an sbrk-like function that uses mmap. */ - Contributed by Fred Fish at Cygnus Support. fnf@cygnus.com */ - -/* Copyright (c) 2010-2014. The SimGrid Team. +/* Copyright (c) 2010-2022. The SimGrid Team. * All rights reserved. */ /* This program is free software; you can redistribute it and/or modify it * under the terms of the license (GNU LGPL) which comes with this package. */ -#ifndef MAP_ANONYMOUS -#define MAP_ANONYMOUS MAP_ANON -#endif +/* Copyright 1992, 2000 Free Software Foundation, Inc. -#ifdef HAVE_UNISTD_H -#include /* Prototypes for lseek */ -#endif + Contributed by Fred Fish at Cygnus Support. fnf@cygnus.com */ + +#include "src/internal_config.h" #include #include #include +#include +#include #include "mmprivate.h" +#ifndef MAP_ANONYMOUS +#define MAP_ANONYMOUS MAP_ANON +#endif + #define PAGE_ALIGN(addr) (void*) (((long)(addr) + xbt_pagesize - 1) & \ ~((long)xbt_pagesize - 1)) -/* Return MAP_PRIVATE if MDP represents /dev/zero. Otherwise, return - MAP_SHARED. */ -#define MAP_PRIVATE_OR_SHARED(MDP) (( MDP -> flags & MMALLOC_ANONYMOUS) \ - ? MAP_PRIVATE \ - : MAP_SHARED) - -/* Return MAP_ANONYMOUS if MDP uses anonymous mapping. Otherwise, return 0 */ -#define MAP_IS_ANONYMOUS(MDP) (((MDP) -> flags & MMALLOC_ANONYMOUS) \ - ? MAP_ANONYMOUS \ - : 0) - -/* Return -1 if MDP uses anonymous mapping. Otherwise, return MDP->FD */ -#define MAP_ANON_OR_FD(MDP) (((MDP) -> flags & MMALLOC_ANONYMOUS) \ - ? -1 \ - : (MDP) -> fd) - -/* Get core for the memory region specified by MDP, using SIZE as the - amount to either add to or subtract from the existing region. Works - like sbrk(), but using mmap(). - - It never returns NULL. Instead, it dies verbosely on errors. */ - +/** @brief Add memory to this heap + * + * Get core for the memory region specified by MDP, using SIZE as the + * amount to either add to or subtract from the existing region. Works + * like sbrk(), but using mmap(). + * + * It never returns NULL. Instead, it dies verbosely on errors. + * + * @param mdp The heap + * @param size Bytes to allocate for this heap (or <0 to free memory from this heap) + */ void *mmorecore(struct mdesc *mdp, ssize_t size) { - ssize_t test = 0; - void *result; // please keep it uninitialized to track issues - off_t foffset; /* File offset at which new mapping will start */ + void* result; // please keep it uninitialized to track issues size_t mapbytes; /* Number of bytes to map */ - void *moveto; /* Address where we wish to move "break value" to */ - void *mapto; /* Address we actually mapped to */ - char buf = 0; /* Single byte to write to extend mapped file */ - -// fprintf(stderr,"increase %p by %u\n",mdp,size); + void* moveto; /* Address where we wish to move "break value" to */ + void* mapto; /* Address we actually mapped to */ if (size == 0) { /* Just return the current "break" value. */ - result = mdp->breakval; + return mdp->breakval; + } - } else if (size < 0) { - /* We are deallocating memory. If the amount requested would cause - us to try to deallocate back past the base of the mmap'd region - then die verbosely. Otherwise, deallocate the memory and return - the old break value. */ - if (((char *) mdp->breakval) + size >= (char *) mdp->base) { - result = (void *) mdp->breakval; - mdp->breakval = (char *) mdp->breakval + size; + if (size < 0) { + /* We are deallocating memory. If the amount requested would cause us to try to deallocate back past the base of + * the mmap'd region then die verbosely. Otherwise, deallocate the memory and return the old break value. */ + if (((char*)mdp->breakval) + size >= (char*)mdp->base) { + result = mdp->breakval; + mdp->breakval = (char*)mdp->breakval + size; moveto = PAGE_ALIGN(mdp->breakval); - munmap(moveto, - (size_t) (((char *) mdp->top) - ((char *) moveto)) - 1); + munmap(moveto, (size_t)(((char*)mdp->top) - ((char*)moveto)) - 1); mdp->top = moveto; } else { fprintf(stderr,"Internal error: mmap was asked to deallocate more memory than it previously allocated. Bailling out now!\n"); abort(); } - } else { - /* We are allocating memory. Make sure we have an open file - descriptor if not working with anonymous memory. */ - if (!(mdp->flags & MMALLOC_ANONYMOUS) && mdp->fd < 0) { - fprintf(stderr,"Internal error: mmap file descriptor <0 (%d), without MMALLOC_ANONYMOUS being in the flags.\n",mdp->fd); + } else if ((char*)mdp->breakval + size > (char*)mdp->top) { + /* The request would move us past the end of the currently mapped memory, so map in enough more memory to satisfy + the request. This means we also have to grow the mapped-to file by an appropriate amount, since mmap cannot + be used to extend a file. */ + moveto = PAGE_ALIGN((char*)mdp->breakval + size); + mapbytes = (char*)moveto - (char*)mdp->top; + + /* Let's call mmap. Note that it is possible that mdp->top is 0. In this case mmap will choose the address for us. + This call might very well overwrite an already existing memory mapping (leading to weird bugs). + */ + mapto = mmap(mdp->top, mapbytes, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0); + + if (mapto == MAP_FAILED) { + char buff[1024]; + fprintf(stderr, "Internal error: mmap returned MAP_FAILED! error: %s\n", strerror(errno)); + snprintf(buff, 1024, "cat /proc/%d/maps", getpid()); + int status = system(buff); + if (status == -1 || !(WIFEXITED(status) && WEXITSTATUS(status) == 0)) + fprintf(stderr, "Something went wrong when trying to %s\n", buff); + sleep(1); abort(); - } else if ((char *) mdp->breakval + size > (char *) mdp->top) { - /* The request would move us past the end of the currently - mapped memory, so map in enough more memory to satisfy - the request. This means we also have to grow the mapped-to - file by an appropriate amount, since mmap cannot be used - to extend a file. */ - moveto = PAGE_ALIGN((char *) mdp->breakval + size); - mapbytes = (char *) moveto - (char *) mdp->top; - foffset = (char *) mdp->top - (char *) mdp->base; - - if (mdp->fd > 0) { - /* FIXME: Test results of lseek() */ - lseek(mdp->fd, foffset + mapbytes - 1, SEEK_SET); - test = write(mdp->fd, &buf, 1); - if (test == -1) { - fprintf(stderr,"Internal error: write to mmap'ed fd failed! error: %s", strerror(errno)); - abort(); - } - } - - /* Let's call mmap. Note that it is possible that mdp->top - is 0. In this case mmap will choose the address for us */ - mapto = mmap(mdp->top, mapbytes, PROT_READ | PROT_WRITE, - MAP_PRIVATE_OR_SHARED(mdp) | MAP_IS_ANONYMOUS(mdp) | - MAP_FIXED, MAP_ANON_OR_FD(mdp), foffset); - - if (mapto == (void *) -1/* That's MAP_FAILED */) { - char buff[1024]; - fprintf(stderr,"Internal error: mmap returned MAP_FAILED! error: %s\n",strerror(errno)); - sprintf(buff,"cat /proc/%d/maps",getpid()); - int status = system(buff); - if (status == -1 || !(WIFEXITED(status) && WEXITSTATUS(status) == 0)) - fprintf(stderr, "Something went wrong when trying to %s\n", buff); - sleep(1); - abort(); - } - - if (mdp->top == 0) - mdp->base = mdp->breakval = mapto; - - mdp->top = PAGE_ALIGN((char *) mdp->breakval + size); - result = (void *) mdp->breakval; - mdp->breakval = (char *) mdp->breakval + size; - } else { - result = (void *) mdp->breakval; - mdp->breakval = (char *) mdp->breakval + size; } - } - return (result); -} -void *__mmalloc_remap_core(xbt_mheap_t mdp) -{ - /* FIXME: Quick hack, needs error checking and other attention. */ + if (mdp->top == 0) + mdp->base = mdp->breakval = mapto; - return mmap(mdp->base, (char*) mdp->top - (char*) mdp->base, - PROT_READ | PROT_WRITE | PROT_EXEC, - MAP_PRIVATE_OR_SHARED(mdp) | MAP_FIXED, mdp->fd, 0); + mdp->top = PAGE_ALIGN((char*)mdp->breakval + size); + result = mdp->breakval; + mdp->breakval = (char*)mdp->breakval + size; + } else { + /* Memory is already mapped, we only need to increase the breakval: */ + result = mdp->breakval; + mdp->breakval = (char*)mdp->breakval + size; + } + return result; } -