#define scribblecheck #define public #define rcheck #define NBUCKETS 30 #include #ifdef MALLOC_DEBUG #define register #endif MALLOC_DEBUG malloc_warning(s) char *s; { printf("Malloc warning: %s\n",s); } botch(s) char *s; { printf("Botch: <%s> dumping core...\n",s); fflush(stdout); fflush(stderr); abort(); } /* Copyright (C) 1985 Richard M. Stallman, based mostly on the public domain work of others. This program is distributed in the hope that it will be useful, but without any warranty. No author or distributor accepts responsibility to anyone for the consequences of using it or for whether it serves any particular purpose or works at all, unless he says so in writing. Permission is granted to anyone to distribute verbatim copies of this program's source code as received, in any medium, provided that the copyright notice, the nonwarraty notice above and this permission notice are preserved, and that the distributor grants the recipient all rights for further redistribution as permitted by this notice, and informs him of these rights. Permission is granted to distribute modified versions of this program's source code, or of portions of it, under the above conditions, plus the conditions that all changed files carry prominent notices stating who last changed them and that the derived material, including anything packaged together with it and conceptually functioning as a modification of it rather than an application of it, is in its entirety subject to a permission notice identical to this one. Permission is granted to distribute this program (verbatim or as modified) in compiled or executable form, provided verbatim redistribution is permitted as stated above for source code, and A. it is accompanied by the corresponding machine-readable source code, under the above conditions, or B. it is accompanied by a written offer, with no time limit, to distribute the corresponding machine-readable source code, under the above conditions, to any one, in return for reimbursement of the cost of distribution. Verbatim redistribution of the written offer must be permitted. Or, C. it is distributed by someone who received only the compiled or executable form, and is accompanied by a copy of the written offer of source code which he received along with it. Permission is granted to distribute this program (verbatim or as modified) in executable form as part of a larger system provided that the source code for this program, including any modifications used, is also distributed or offered as stated in the preceding paragraph. In other words, you are welcome to use, share and improve this program. You are forbidden to forbid anyone else to use, share and improve what you give them. Help stamp out software-hoarding! */ /**************************************************************** * * * Helpful historical comments * * * ****************************************************************/ /* * @(#)nmalloc.c 1 (Caltech) 2/21/82 * * U of M Modified: 20 Jun 1983 ACT: strange hacks for Emacs * * Nov 1983, Mike@BRL, Added support for 4.1C/4.2 BSD. * * This is a very fast storage allocator. It allocates blocks of a small * number of different sizes, and keeps free lists of each size. Blocks * that don't exactly fit are passed up to the next larger size. In this * implementation, the available sizes are (2^n)-4 (or -16) bytes long. * This is designed for use in a program that uses vast quantities of * memory, but bombs when it runs out. To make it a little better, it * warns the user when he starts to get near the end. * * June 84, ACT: modified rcheck code to check the range given to malloc, * rather than the range determined by the 2-power used. * * Jan 85, RMS: calls malloc_warning to issue warning on nearly full. * No longer Emacs-specific; can serve as all-purpose malloc for GNU. * You should call malloc_init to reinitialize after loading dumped Emacs. * Call malloc_stats to get info on memory stats if MSTATS turned on. * realloc knows how to return same block given, just changing its size, * if the power of 2 is correct. * * Jan 86, WDC: Removed Emacs specific stuff, and neatened a few comments. * * March 86 WDC: Added in code by Eichin for Scribble checking of blocks * Scribble check writes a known pattern into the free blocks, checks it * to see if it is still undamaged before allocating it. It writes a * different pattern into the space beyond the end of an allocated block, * and tests it for damage when expanding the block's bounds in realloc. * Note, this check takes *TIME* and should not be compiled in by default. * * Aug 18 1986, MWE: added 'public' stuff to allow makedecl to generate * a malloc.h file. * * Berkeley UNIX 4.3 has a storage allocator that shares a common * ancestor with this one. It handles realloc compatibly with the * archaic use of realloc on an already freed block to "compact" * storage. It uses a pagesize system call rather than assuming the * page size is 1024 bytes. Finally it guarantees that a freed block * is not munged by the allocator itself, incase someone wants to fiddle * with freed space after freeing it but before allocating more. * * This particular storage allocator would benefit from having a * non-hardwired pagesize. But because of the scribble check it would * not be useful to keep the free pointer in the header. SO: When you * free something allocated with this allocator, DONT TRY TO USE IT. * It is GUARANTEED to be damaged by the freeing process. * * For interfacing to systems that want to be able to ask the size of * the allocated block, rather than remembering it, the m_blocksize * function, rips open the block and tells you how big it is. The size * returned is nbytes, the number of bytes asked for, NOT the actual * amount of space in the block. * * This malloc also has a horrible but very useful hack which can be * enabled by defined MALLOC_DEBUG. This causes malloc to keep track * of who requested a particular block of memory to be malloc'ed or * free'ed. A dump function (which is usually called from a signal * handler) will then print out what all the blocks of memory and who * last malloc'ed or free'ed it. It accomplishes this feat by opening * the binary and groveling over the symbol table. Thus, this is not * guaranteed to work across all systems. It will work on BSD 4.[23] * systems, however. */ /**************************************************************** * * * Includes, declarations, and definitions * * * ****************************************************************/ #include "nmalloc.h" #ifndef public #define New(TYPE) ((TYPE *)malloc(sizeof(TYPE))) #endif public /* Determine which kind of system this is. */ #include #ifndef SIGTSTP #define USG #else /* SIGTSTP */ #ifdef SIGIO #define BSD42 #endif /* SIGIO */ #endif /* SIGTSTP */ #ifndef BSD42 #ifndef USG #include /* warn the user when near the end */ #endif #else /* if BSD42 */ #include #include #endif /* BSD42 */ #ifdef scribblecheck #define rcheck #endif /* we need to have range data to use block boundary checking */ #ifdef rcheck /* * To implement range checking, we write magic values in at the * beginning and end of each allocated block, and make sure they * are undisturbed whenever a free or a realloc occurs. */ /* Written in each of the 4 bytes following the block's real space */ #define MAGIC1 0x55 #define MAGICFREE 0x69 /* 0110 1001 Magic value for Free blocks */ /* Written in the 4 bytes before the block's real space */ #define MAGIC4 0x55555555 #define MAGICFREE4 0x69696969 #define ASSERT(p) if (!(p)) botch("p"); else #define EXTRA 4 /* 4 bytes extra for MAGIC1s */ #else #define ASSERT(p) #define EXTRA 0 #endif /* rcheck */ #define ISALLOC ((char) 0xf7) /* magic byte that implies allocation */ #define ISFREE ((char) 0x54) /* magic byte that implies free block */ /* this is for error checking only */ /* If range checking is not turned on, all we have is a flag * indicating whether memory is allocated, an index in nextf[], * and a field that tells how many bytes. * To realloc() memory we copy nbytes. * 16 bits of header space is unused. */ struct mhead { char mh_alloc; /* ISALLOC or ISFREE */ char mh_index; /* index in nextf[] */ unsigned short mh_extra;/* Currently wasted 16 bits */ /* Remainder are valid only when block is allocated */ unsigned mh_nbytes; /* number of bytes allocated */ #ifdef MALLOC_DEBUG char *mh_parent; /* set to caller of malloc/realloc */ struct mhead *mh_link; /* set to next block or NULL */ #endif MALLOC_DEBUG #ifdef rcheck int mh_magic4; /* should be == MAGIC4 */ #endif /* rcheck */ }; #ifdef MALLOC_DEBUG struct mhead *baselink=NULL; struct mhead *endlink=NULL; #endif MALLOC_DEBUG /* * Access free-list pointer of a block. * It is stored at block + 4. * This is not a field in the mhead structure because we want * sizeof (struct mhead) to describe the overhead for when the * block is in use, and we do not want the free-list pointer * to count in that. */ #define CHAIN(a) \ (*(struct mhead **) (sizeof (char *) + (char *) (a))) /**************************************************************** * * * Variable Creations * * * ****************************************************************/ extern char etext; extern char *start_of_data (); /* This seems necessary for USG */ /* These two are for user programs to look at, when they are interested. */ int malloc_sbrk_used; /* amount of data space used now */ int malloc_sbrk_unused; /* amount more we can have */ /* start of data space; can be changed by calling init_malloc */ static char *data_space_start = 0; #ifdef MSTATS /* * nmalloc[i] is the difference between the number of mallocs and frees * for a given block size. */ static int nmalloc[NBUCKETS]; static int nmal, nfre; #endif /* MSTATS */ /* * nextf[i] is the pointer to the next free block of size 2^(i+3). The * smallest allocatable block is 8 bytes. The overhead information will * go in the first int of the block, and the returned pointer will point * to the second. */ static struct mhead *nextf[NBUCKETS]; /* Number of bytes of writable memory we can expect to be able to get */ static int lim_data = 0; /* Level number of warnings already issued. * 0 -- no warnings issued. * 1 -- 75% warning already issued. * 2 -- 85% warning already issued. */ static int warnlevel = 0; /* nonzero once initial bunch of free blocks made */ static int gotpool; /**************************************************************** * * * Start of procedures * * * * malloc_init, m_blocksize * * * ****************************************************************/ /* * Cause reinitialization based on job parameters; * also declare where the end of pure storage is. */ public malloc_init (start) char *start; { data_space_start = start; lim_data = 0; warnlevel = 0; #ifdef MALLOC_DEBUG baselink = NULL; endlink = NULL; #endif MALLOC_DEBUG } public int m_blocksize(a_block) register char *a_block; { if (a_block == (char *)0) return 0; return(((struct mhead *)a_block-1)->mh_nbytes); } /**************************************************************** * * * morecore - Ask the system for more memory * * * ****************************************************************/ static morecore (nu) /* ask system for more memory */ register int nu; /* size index to get more of */ { char *sbrk (); register char *cp; register int nblks; register int siz; if (!data_space_start) { #if defined(USG) data_space_start = start_of_data (); #else /* not USG */ data_space_start = &etext; #endif /* not USG */ } if (lim_data == 0) get_lim_data (); /* On initial startup, get two blocks of each size up to 1k bytes */ if (!gotpool) getpool (), getpool (), gotpool = 1; /* Find current end of memory and issue warning if getting near max */ cp = sbrk (0); siz = cp - data_space_start; malloc_sbrk_used = siz; malloc_sbrk_unused = lim_data - siz; switch (warnlevel) { case 0: if (siz > (lim_data / 4) * 3) { warnlevel++; malloc_warning ("Warning: past 75% of memory limit"); } break; case 1: if (siz > (lim_data / 20) * 17) { warnlevel++; malloc_warning ("Warning: past 85% of memory limit"); } break; case 2: if (siz > (lim_data / 20) * 19) { warnlevel++; malloc_warning ("Warning: past 95% of memory limit"); } break; } if ((int) cp & 0x3ff) /* land on 1K boundaries */ sbrk (1024 - ((int) cp & 0x3ff)); /* Take at least 2k, and figure out how many blocks of the desired size we're about to get */ nblks = 1; if ((siz = nu) < 8) nblks = 1 << ((siz = 8) - nu); if ((cp = sbrk (1 << (siz + 3))) == (char *) -1) return; /* no more room! */ if ((int) cp & 7) { /* shouldn't happen, but just in case */ cp = (char *) (((int) cp + 8) & ~7); nblks--; } /* save new header and link the nblks blocks together */ nextf[nu] = (struct mhead *) cp; siz = 1 << (nu + 3); while (1) { ((struct mhead *) cp) -> mh_alloc = ISFREE; ((struct mhead *) cp) -> mh_index = nu; #ifdef MALLOC_DEBUG ((struct mhead *) cp) -> mh_parent = NULL; ((struct mhead *) cp) -> mh_link = NULL; #endif MALLOC_DEBUG #ifdef rcheck ((struct mhead *) cp) -> mh_magic4 = MAGICFREE4; #endif /* rcheck */ #ifdef scribblecheck { /* Check that upper stuff was still MAGIC1 */ register char *m = (char *)((struct mhead *)cp+1); register char *en = (8< mh_alloc = ISFREE; ((struct mhead *) cp) -> mh_index = 0; #ifdef MALLOC_DEBUG ((struct mhead *) cp) -> mh_parent = NULL; ((struct mhead *) cp) -> mh_link = NULL; #endif MALLOC_DEBUG #ifdef rcheck ((struct mhead *) cp) -> mh_magic4 = MAGICFREE4; #endif /* rcheck */ cp += 8; for (nu = 0; nu < 7; nu++) { CHAIN (cp) = nextf[nu]; nextf[nu] = (struct mhead *) cp; ((struct mhead *) cp) -> mh_alloc = ISFREE; ((struct mhead *) cp) -> mh_index = nu; #ifdef rcheck ((struct mhead *) cp) -> mh_magic4 = MAGICFREE4; #endif /* rcheck */ #ifdef scribblecheck { register char *m = (char *)((struct mhead *)cp+1); register char *en = (8<> 2; while (shiftr >>= 1) nunits++; } /* If there are no blocks of the appropriate size, go get some */ /* COULD SPLIT UP A LARGER BLOCK HERE ... ACT */ if (nextf[nunits] == 0) morecore (nunits); /* Get one block off the list, and set the new list head */ if ((p = nextf[nunits]) == 0) return 0; nextf[nunits] = CHAIN (p); /* Check for free block clobbered */ /* If not for this check, we would gobble a clobbered free chain ptr */ /* and bomb out on the NEXT allocate of this size block */ if (p -> mh_alloc != ISFREE || p -> mh_index != nunits) botch ("block on free list clobbered"); #ifdef rcheck if (p -> mh_magic4 != MAGICFREE4) botch ("Magic in block on free list clobbered"); #endif /* rcheck */ #ifdef scribblecheck /* Check for block filled with magic numbers, then change to zeros */ { register char *m = (char *) (p + 1); register char *en = (8<mh_index) + (char *) p; register int block_valid = 0; while(m mh_alloc = ISALLOC; p -> mh_nbytes = n; #ifdef MALLOC_DEBUG p -> mh_parent = PAPA; if(!baselink) { baselink = p; endlink = p; } else if (p -> mh_link == NULL && endlink != p) { endlink -> mh_link = p; endlink = p; } #endif MALLOC_DEBUG #ifdef rcheck p -> mh_magic4 = MAGIC4; { register char *m = (char *) (p + 1) + n; #ifdef scribblecheck register char *en = (8<mh_index)+(char *)p; /* point to end of block */ while (m mh_alloc == ISALLOC); #ifdef rcheck ASSERT (p -> mh_magic4 == MAGIC4); ap += p -> mh_nbytes; p->mh_magic4 = MAGICFREE4; ASSERT (*ap++ == MAGIC1); ASSERT (*ap++ == MAGIC1); ASSERT (*ap++ == MAGIC1); ASSERT (*ap == MAGIC1); #endif /* rcheck */ } { register int nunits = p -> mh_index; ASSERT (nunits < NBUCKETS); #ifdef scribblecheck { /* Check that upper stuff was still MAGIC1 */ register char *m = (char *) (p + 1) + p->mh_nbytes; register char *en = (8<mh_index) + (char *) p; register int block_valid = 0; while(m mh_alloc = ISFREE; CHAIN (p) = nextf[nunits]; nextf[nunits] = p; #ifdef MSTATS nmalloc[nunits]--; nfre++; #endif /* MSTATS */ } #ifdef MALLOC_DEBUG p -> mh_parent = PAPA; /* since it IS freed... */ #endif MALLOC_DEBUG } /**************************************************************** * * * realloc - resize a block, copy if necessary * * * ****************************************************************/ public char * realloc (mem, n) char *mem; register unsigned n; { register struct mhead *p; register unsigned int tocopy; register int nbytes; register int nunits; #ifdef MALLOC_DEBUG char *PAPA = *(char **)((&mem)-2); #endif MALLOC_DEBUG if ((p = (struct mhead *) mem) == 0) return malloc (n); /* well, shouldn't realloc(NULL) anyway... */ p--; #ifdef MALLOC_DEBUG p -> mh_parent = PAPA; #endif MALLOC_DEBUG nunits = p -> mh_index; ASSERT (p -> mh_alloc == ISALLOC); tocopy = p -> mh_nbytes; #ifdef rcheck ASSERT (p -> mh_magic4 == MAGIC4); { register char *m = mem + tocopy; #ifdef scribblecheck register char *en = (8<mh_index) + (char *)p; register int block_valid = 0; while(m (4 << nunits) && nbytes <= (8 << nunits)) { /* Here we check on realloc if we are grabbing unused space */ #ifdef rcheck register char *m = mem + tocopy; #ifdef scribblecheck register char *en = (8<mh_index) + (char *) p; while (m mh_nbytes = n; return mem; } if (n < tocopy) tocopy = n; { register char *new; if ((new = malloc (n)) == 0) return 0; (void) memcpy (new, mem, tocopy); free (mem); return new; } } /**************************************************************** * * * Memory Statistics stuff * * * ****************************************************************/ #ifdef MSTATS /* Return statistics describing allocation of blocks of size 2**n. */ #ifndef public struct mstats_value { int blocksize; int nfree; int nused; }; #endif public public struct mstats_value malloc_stats (size) int size; { struct mstats_value v; register int i; register struct mhead *p; v.nfree = 0; if (size < 0 || size >= NBUCKETS) { v.blocksize = 0; v.nused = 0; return v; } v.blocksize = 1 << (size + 3); v.nused = nmalloc[size]; for (p = nextf[size]; p; p = CHAIN (p)) v.nfree++; return v; } /* * showall - print out statistics about malloc * * Prints two lines of numbers, one showing the length of the free list * for each size category, the second showing the number of mallocs - * frees for each size category. */ showall(v) char **v; { register int i, j; register struct mhead *p; int totfree = 0, totused = 0; printf("tcsh memory allocation statistics\nfree:\t"); for (i = 0; i < NBUCKETS; i++) { j=0; for (p = nextf[i]; p; p = CHAIN(p)) j++; printf(" %4d", j); totfree += j * (1 << (i + 3)); } printf("\nused:\t"); for (i = 0; i < NBUCKETS; i++) { printf(" %4d", nmalloc[i]); totused += nmalloc[i] * (1 << (i + 3)); } printf("\n\tTotal in use: %d, total free: %d\n", totused, totfree); } #endif /**************************************************************** * * * Stuff having to do with determining memory limits * * * ****************************************************************/ /* * This function returns the total number of bytes that the process * will be allowed to allocate via the sbrk(2) system call. On * BSD systems this is the total space allocatable to stack and * data. On USG systems this is the data space only. */ #ifdef USG public get_lim_data () { extern long ulimit (); lim_data = ulimit (3, 0); lim_data -= (long) data_space_start; } #else /* not USG */ #ifndef BSD42 public get_lim_data () { lim_data = vlimit (LIM_DATA, -1); } #else /* BSD42 */ public get_lim_data () { struct rlimit XXrlimit; getrlimit (RLIMIT_DATA, &XXrlimit); lim_data = XXrlimit.rlim_cur; /* soft limit */ } #endif /* BSD42 */ #endif /* not USG */ #ifdef MALLOC_DEBUG /* Here we have the interesting dump routines to describe the inner state of malloc. */ #include #include #include /* * malloc_dump_all --- displays what routines malloced what and when. * * This is a gross kludge. However, it's wonderful for finding memory * leaks and other malloc problems. */ malloc_dump_all(file) char *file; { int fd; struct mhead *p; struct exec base; struct nlist *nls; int numsyms; char *strtab; int strtablen; int stat; printf("Dumping state:\n"); fd = open(file, O_RDONLY, 0777); /* open the binary */ if(fd<0) { perror("malloc_dump_all:open"); return; } stat = lseek(fd, 0L, L_SET); /* seek (redundant... for later) */ if(stat < 0) { perror("malloc_dump_all:initseek"); return; } stat = read(fd, &base, sizeof(base)); /* read in base block */ if(stat <= 0) { perror("malloc_dump_all:read"); return; } stat = lseek(fd, N_SYMOFF(base), L_SET); /* seek to symtab */ if(stat < 0) { perror("malloc_dump_all:symseek"); return; } nls = (struct nlist *)malloc(base.a_syms); numsyms = base.a_syms / sizeof(struct nlist); stat = read(fd, nls, base.a_syms); /* read in symtab */ if(stat <= 0) { perror("malloc_dump_all:symread"); return; } stat = lseek(fd, N_STROFF(base), L_SET); /* seek to string table */ if(stat < 0) { perror("malloc_dump_all:seekstrtab"); return; } stat = read(fd, &strtablen, sizeof(strtablen)); /* read stringtable len */ if(stat <= 0) { perror("malloc_dump_all:readstrtablen"); return; } strtab = malloc(strtablen); stat = read(fd, strtab, strtablen); /* read in stringtable */ if(stat <= 0) { perror("malloc_dump_all:readstrtab"); return; } for(p = baselink; p != endlink; p = p -> mh_link) { find_sym(nls, numsyms, strtab, p -> mh_parent); switch (p -> mh_alloc) { case ISALLOC: printf(" allocated %d bytes\n",p->mh_nbytes); break; case ISFREE: printf(" freed block\n"); break; default: printf(" invalid block (%d)\n", p-> mh_nbytes); break; } } flush(stdout); free(strtab); free(nls); printf("Done dumping state.\n"); } find_sym(nls, numsyms, strs, par) struct nlist *nls; int numsyms; char *strs; char *par; { int sym, stat; int last; int tfile=0, tf0=0; char *x; x = par; sym = -1; while(++sym < numsyms) { switch(nls[sym].n_type) { case N_TEXT: case N_SO: tf0 = tfile; tfile = nls[sym].n_un.n_strx; case N_SLINE: if(((char *)nls[sym].n_value) > x) { sym = numsyms; } else { last = nls[sym].n_desc; } break; default: break; } } printf("\"%s\", line %d: Address[0x%x]", strs+tf0-sizeof(int), last, x); } #endif MALLOC_DEBUG