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      1 /*-
      2  * Copyright (c) 2009, 2010, 2011, 2013, 2014, 2016
      3  *	mirabilos <m (at) mirbsd.org>
      4  *
      5  * Provided that these terms and disclaimer and all copyright notices
      6  * are retained or reproduced in an accompanying document, permission
      7  * is granted to deal in this work without restriction, including un-
      8  * limited rights to use, publicly perform, distribute, sell, modify,
      9  * merge, give away, or sublicence.
     10  *
     11  * This work is provided "AS IS" and WITHOUT WARRANTY of any kind, to
     12  * the utmost extent permitted by applicable law, neither express nor
     13  * implied; without malicious intent or gross negligence. In no event
     14  * may a licensor, author or contributor be held liable for indirect,
     15  * direct, other damage, loss, or other issues arising in any way out
     16  * of dealing in the work, even if advised of the possibility of such
     17  * damage or existence of a defect, except proven that it results out
     18  * of said person's immediate fault when using the work as intended.
     19  */
     20 
     21 #include "sh.h"
     22 #ifdef MKSH_ALLOC_CATCH_UNDERRUNS
     23 #include <err.h>
     24 #endif
     25 
     26 __RCSID("$MirOS: src/bin/mksh/lalloc.c,v 1.26 2016/02/26 21:53:36 tg Exp $");
     27 
     28 /* build with CPPFLAGS+= -DUSE_REALLOC_MALLOC=0 on ancient systems */
     29 #if defined(USE_REALLOC_MALLOC) && (USE_REALLOC_MALLOC == 0)
     30 #define remalloc(p,n)	((p) == NULL ? malloc_osi(n) : realloc_osi((p), (n)))
     31 #else
     32 #define remalloc(p,n)	realloc_osi((p), (n))
     33 #endif
     34 
     35 
     36 static struct lalloc_common *findptr(struct lalloc_common **, char *, Area *);
     37 
     38 #ifndef MKSH_ALLOC_CATCH_UNDERRUNS
     39 #define ALLOC_ISUNALIGNED(p) (((size_t)(p)) % sizeof(struct lalloc_common))
     40 #else
     41 #define ALLOC_ISUNALIGNED(p) (((size_t)(p)) & 4095)
     42 #undef remalloc
     43 #undef free_osimalloc
     44 
     45 static void
     46 free_osimalloc(void *ptr)
     47 {
     48 	struct lalloc_item *lp = ptr;
     49 
     50 	if (munmap(lp, lp->len))
     51 		err(1, "free_osimalloc");
     52 }
     53 
     54 static void *
     55 remalloc(void *ptr, size_t size)
     56 {
     57 	struct lalloc_item *lp, *lold = ptr;
     58 
     59 	size = (size + 4095) & ~(size_t)4095;
     60 
     61 	if (lold && lold->len >= size)
     62 		return (ptr);
     63 
     64 	if ((lp = mmap(NULL, size, PROT_READ | PROT_WRITE,
     65 	    MAP_ANON | MAP_PRIVATE, -1, (off_t)0)) == MAP_FAILED)
     66 		err(1, "remalloc: mmap(%zu)", size);
     67 	if (ALLOC_ISUNALIGNED(lp))
     68 		errx(1, "remalloc: unaligned(%p)", lp);
     69 	if (mprotect(((char *)lp) + 4096, 4096, PROT_NONE))
     70 		err(1, "remalloc: mprotect");
     71 	lp->len = size;
     72 
     73 	if (lold) {
     74 		memcpy(((char *)lp) + 8192, ((char *)lold) + 8192,
     75 		    lold->len - 8192);
     76 		if (munmap(lold, lold->len))
     77 			err(1, "remalloc: munmap");
     78 	}
     79 
     80 	return (lp);
     81 }
     82 #endif
     83 
     84 void
     85 ainit(Area *ap)
     86 {
     87 #ifdef MKSH_ALLOC_CATCH_UNDERRUNS
     88 	if (sysconf(_SC_PAGESIZE) != 4096) {
     89 		fprintf(stderr, "mksh: fatal: pagesize %lu not 4096!\n",
     90 		    sysconf(_SC_PAGESIZE));
     91 		fflush(stderr);
     92 		abort();
     93 	}
     94 #endif
     95 	/* area pointer and items share struct lalloc_common */
     96 	ap->next = NULL;
     97 }
     98 
     99 static struct lalloc_common *
    100 findptr(struct lalloc_common **lpp, char *ptr, Area *ap)
    101 {
    102 	void *lp;
    103 
    104 #ifndef MKSH_SMALL
    105 	if (ALLOC_ISUNALIGNED(ptr))
    106 		goto fail;
    107 #endif
    108 	/* get address of ALLOC_ITEM from user item */
    109 	/*
    110 	 * note: the alignment of "ptr" to ALLOC_ITEM is checked
    111 	 * above; the "void *" gets us rid of a gcc 2.95 warning
    112 	 */
    113 	*lpp = (lp = ptr - sizeof(ALLOC_ITEM));
    114 	/* search for allocation item in group list */
    115 	while (ap->next != lp)
    116 		if ((ap = ap->next) == NULL) {
    117 #ifndef MKSH_SMALL
    118  fail:
    119 #endif
    120 #ifdef DEBUG
    121 			internal_warningf("rogue pointer %zX in ap %zX",
    122 			    (size_t)ptr, (size_t)ap);
    123 			/* try to get a coredump */
    124 			abort();
    125 #else
    126 			internal_errorf("rogue pointer %zX", (size_t)ptr);
    127 #endif
    128 		}
    129 	return (ap);
    130 }
    131 
    132 void *
    133 aresize2(void *ptr, size_t fac1, size_t fac2, Area *ap)
    134 {
    135 	if (notoktomul(fac1, fac2))
    136 		internal_errorf(Tintovfl, fac1, '*', fac2);
    137 	return (aresize(ptr, fac1 * fac2, ap));
    138 }
    139 
    140 void *
    141 aresize(void *ptr, size_t numb, Area *ap)
    142 {
    143 	struct lalloc_common *lp = NULL;
    144 
    145 	/* resizing (true) or newly allocating? */
    146 	if (ptr != NULL) {
    147 		struct lalloc_common *pp;
    148 
    149 		pp = findptr(&lp, ptr, ap);
    150 		pp->next = lp->next;
    151 	}
    152 
    153 	if (notoktoadd(numb, sizeof(ALLOC_ITEM)) ||
    154 	    (lp = remalloc(lp, numb + sizeof(ALLOC_ITEM))) == NULL
    155 #ifndef MKSH_SMALL
    156 	    || ALLOC_ISUNALIGNED(lp)
    157 #endif
    158 	    )
    159 		internal_errorf(Toomem, numb);
    160 	/* area pointer and items share struct lalloc_common */
    161 	lp->next = ap->next;
    162 	ap->next = lp;
    163 	/* return user item address */
    164 	return ((char *)lp + sizeof(ALLOC_ITEM));
    165 }
    166 
    167 void
    168 afree(void *ptr, Area *ap)
    169 {
    170 	if (ptr != NULL) {
    171 		struct lalloc_common *lp, *pp;
    172 
    173 		pp = findptr(&lp, ptr, ap);
    174 		/* unhook */
    175 		pp->next = lp->next;
    176 		/* now free ALLOC_ITEM */
    177 		free_osimalloc(lp);
    178 	}
    179 }
    180 
    181 void
    182 afreeall(Area *ap)
    183 {
    184 	struct lalloc_common *lp;
    185 
    186 	/* traverse group (linked list) */
    187 	while ((lp = ap->next) != NULL) {
    188 		/* make next ALLOC_ITEM head of list */
    189 		ap->next = lp->next;
    190 		/* free old head */
    191 		free_osimalloc(lp);
    192 	}
    193 }
    194