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| author | Chet Ramey <chet.ramey@case.edu> | 2020-12-06 15:51:17 -0500 |
|---|---|---|
| committer | Chet Ramey <chet.ramey@case.edu> | 2020-12-06 15:51:17 -0500 |
| commit | 8868edaf2250e09c4e9a1c75ffe3274f28f38581 (patch) | |
| tree | d9a7812ab6cd2f45c5021755c4c094b19dab1b51 /lib/malloc/malloc.c | |
| parent | 36f2c406ff27995392a9247dfa90672fdaf7dc43 (diff) | |
| download | bash-8868edaf2250e09c4e9a1c75ffe3274f28f38581.tar.gz | |
bash-5.1 distribution sources and documentationbash-5.1
Diffstat (limited to 'lib/malloc/malloc.c')
| -rw-r--r-- | lib/malloc/malloc.c | 111 |
1 files changed, 85 insertions, 26 deletions
diff --git a/lib/malloc/malloc.c b/lib/malloc/malloc.c index 5621adf..439f8ef 100644 --- a/lib/malloc/malloc.c +++ b/lib/malloc/malloc.c @@ -1,6 +1,6 @@ /* malloc.c - dynamic memory allocation for bash. */ -/* Copyright (C) 1985-2005 Free Software Foundation, Inc. +/* Copyright (C) 1985-2020 Free Software Foundation, Inc. This file is part of GNU Bash, the Bourne-Again SHell. @@ -25,6 +25,8 @@ * * Nov 1983, Mike@BRL, Added support for 4.1C/4.2 BSD. * + * [VERY] old explanation: + * * 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 @@ -84,6 +86,10 @@ #include <errno.h> #include <stdio.h> +#if !defined (botch) +#include <stdlib.h> +#endif + #if defined (HAVE_MMAP) #include <sys/mman.h> #endif @@ -134,22 +140,35 @@ enough room in the block for the new size. Range checking is always done. */ union mhead { +#if SIZEOF_CHAR_P == 8 + bits64_t mh_align[2]; /* 16 */ +#else bits64_t mh_align; /* 8 */ +#endif struct { char mi_alloc; /* ISALLOC or ISFREE */ /* 1 */ char mi_index; /* index in nextf[] */ /* 1 */ /* Remainder are valid only when block is allocated */ u_bits16_t mi_magic2; /* should be == MAGIC2 */ /* 2 */ u_bits32_t mi_nbytes; /* # of bytes allocated */ /* 4 */ +#if SIZEOF_CHAR_P == 8 + char mi_magic8[8]; /* MAGIC1 guard bytes */ /* 8 */ +#endif } minfo; }; #define mh_alloc minfo.mi_alloc #define mh_index minfo.mi_index #define mh_nbytes minfo.mi_nbytes #define mh_magic2 minfo.mi_magic2 +#define mh_magic8 minfo.mi_magic8 #define MOVERHEAD sizeof(union mhead) + +#if SIZEOF_CHAR_P == 8 +#define MALIGN_MASK 15 +#else #define MALIGN_MASK 7 /* one less than desired alignment */ +#endif typedef union _malloc_guard { char s[4]; @@ -163,6 +182,8 @@ typedef union _malloc_guard { to describe the overhead for when the block is in use, and we do not want the free-list pointer to count in that. */ +/* If SIZEOF_CHAR_P == 8, this goes into the mh_magic8 buffer at the end of + the rest of the struct. This may need adjusting. */ #define CHAIN(a) \ (*(union mhead **) (sizeof (char *) + (char *) (a))) @@ -170,13 +191,14 @@ typedef union _malloc_guard { and end of each allocated block, and make sure they are undisturbed whenever a free or a realloc occurs. */ -/* Written in the 2 bytes before the block's real space (-4 bytes) */ +/* Written in the bytes before the block's real space (-SIZEOF_CHAR_P bytes) */ +#define MAGIC1 0x55 #define MAGIC2 0x5555 #define MSLOP 4 /* 4 bytes extra for u_bits32_t size */ /* How many bytes are actually allocated for a request of size N -- - rounded up to nearest multiple of 8 after accounting for malloc - overhead. */ + rounded up to nearest multiple of 2*SIZEOF_CHAR_P after accounting for + malloc overhead. */ #define ALLOCATED_BYTES(n) \ (((n) + MOVERHEAD + MSLOP + MALIGN_MASK) & ~MALIGN_MASK) @@ -204,12 +226,12 @@ typedef union _malloc_guard { /* Should we use mmap for large allocations? */ #if defined (HAVE_MMAP) -# if !defined (MAP_ANON) && defined (MAP_ANONYMOUS) -# define MAP_ANON MAP_ANONYMOUS +# if defined (MAP_ANON) && !defined (MAP_ANONYMOUS) +# define MAP_ANONYMOUS MAP_ANON # endif #endif -#if defined (HAVE_MMAP) && defined (MAP_ANON) +#if defined (HAVE_MMAP) && defined (MAP_ANONYMOUS) # define USE_MMAP #endif @@ -273,32 +295,32 @@ extern int errno; #endif /* Declarations for internal functions */ -static PTR_T internal_malloc __P((size_t, const char *, int, int)); -static PTR_T internal_realloc __P((PTR_T, size_t, const char *, int, int)); -static void internal_free __P((PTR_T, const char *, int, int)); -static PTR_T internal_memalign __P((size_t, size_t, const char *, int, int)); +static PTR_T internal_malloc PARAMS((size_t, const char *, int, int)); +static PTR_T internal_realloc PARAMS((PTR_T, size_t, const char *, int, int)); +static void internal_free PARAMS((PTR_T, const char *, int, int)); +static PTR_T internal_memalign PARAMS((size_t, size_t, const char *, int, int)); #ifndef NO_CALLOC -static PTR_T internal_calloc __P((size_t, size_t, const char *, int, int)); -static void internal_cfree __P((PTR_T, const char *, int, int)); +static PTR_T internal_calloc PARAMS((size_t, size_t, const char *, int, int)); +static void internal_cfree PARAMS((PTR_T, const char *, int, int)); #endif #ifndef NO_VALLOC -static PTR_T internal_valloc __P((size_t, const char *, int, int)); +static PTR_T internal_valloc PARAMS((size_t, const char *, int, int)); #endif #if defined (botch) extern void botch (); #else -static void botch __P((const char *, const char *, int)); +static void botch PARAMS((const char *, const char *, int)); #endif -static void xbotch __P((PTR_T, int, const char *, const char *, int)); +static void xbotch PARAMS((PTR_T, int, const char *, const char *, int)); #if !HAVE_DECL_SBRK extern char *sbrk (); #endif /* !HAVE_DECL_SBRK */ #ifdef SHELL -extern int interrupt_immediately, running_trap; -extern int signal_is_trapped __P((int)); +extern int running_trap; +extern int signal_is_trapped PARAMS((int)); #endif #ifdef MALLOC_STATS @@ -317,8 +339,8 @@ int malloc_mmap_threshold = MMAP_THRESHOLD; char _malloc_trace_buckets[NBUCKETS]; /* These should really go into a header file. */ -extern void mtrace_alloc __P((const char *, PTR_T, size_t, const char *, int)); -extern void mtrace_free __P((PTR_T, int, const char *, int)); +extern void mtrace_alloc PARAMS((const char *, PTR_T, size_t, const char *, int)); +extern void mtrace_free PARAMS((PTR_T, int, const char *, int)); #endif #if !defined (botch) @@ -598,9 +620,9 @@ morecore (nu) blocked_sigs = 0; #ifdef SHELL # if defined (SIGCHLD) - if (interrupt_immediately || running_trap || signal_is_trapped (SIGINT) || signal_is_trapped (SIGCHLD)) + if (running_trap || signal_is_trapped (SIGINT) || signal_is_trapped (SIGCHLD)) # else - if (interrupt_immediately || running_trap || signal_is_trapped (SIGINT)) + if (running_trap || signal_is_trapped (SIGINT)) # endif #endif { @@ -689,7 +711,7 @@ morecore (nu) memtop += sbrk_amt; - /* shouldn't happen, but just in case -- require 8-byte alignment */ + /* shouldn't happen, but just in case -- require 8- or 16-byte alignment */ if ((long)mp & MALIGN_MASK) { mp = (union mhead *) (((long)mp + MALIGN_MASK) & ~MALIGN_MASK); @@ -719,8 +741,13 @@ malloc_debug_dummy () write (1, "malloc_debug_dummy\n", 19); } +#if SIZEOF_CHAR_P == 8 +#define PREPOP_BIN 3 +#define PREPOP_SIZE 64 +#else #define PREPOP_BIN 2 #define PREPOP_SIZE 32 +#endif static int pagealign () @@ -756,8 +783,8 @@ pagealign () memtop += sbrk_needed; /* Take the memory which would otherwise be wasted and populate the most - popular bin (2 == 32 bytes) with it. Add whatever we need to curbrk - to make things 32-byte aligned, compute how many 32-byte chunks we're + popular bin (3 == 64 bytes) with it. Add whatever we need to curbrk + to make things 64-byte aligned, compute how many 64-byte chunks we're going to get, and set up the bin. */ curbrk += sbrk_needed & (PREPOP_SIZE - 1); sbrk_needed -= sbrk_needed & (PREPOP_SIZE - 1); @@ -818,7 +845,7 @@ internal_malloc (n, file, line, flags) /* get a block */ if (nbytes <= binsize(nunits)) break; - /* Silently reject too-large requests. */ + /* Silently reject too-large requests. XXX - can increase this if HAVE_MMAP */ if (nunits >= NBUCKETS) return ((PTR_T) NULL); @@ -859,6 +886,11 @@ internal_malloc (n, file, line, flags) /* get a block */ p->mh_magic2 = MAGIC2; p->mh_nbytes = n; +#if SIZEOF_CHAR_P == 8 + /* Begin guard */ + MALLOC_MEMSET ((char *)p->mh_magic8, MAGIC1, 8); +#endif + /* End guard */ mg.i = n; z = mg.s; @@ -893,6 +925,14 @@ internal_malloc (n, file, line, flags) /* get a block */ _malloc_ckwatch (p + 1, file, line, W_ALLOC, n); #endif +#if defined (MALLOC_DEBUG) + z = (char *) (p + 1); + /* Check alignment of returned pointer */ + if ((unsigned long)z & MALIGN_MASK) + fprintf (stderr, "malloc: %s:%d: warning: request for %d bytes not aligned on %d byte boundary\r\n", + file ? file : _("unknown"), line, p->mh_nbytes, MALIGN_MASK+1); +#endif + return (PTR_T) (p + 1); } @@ -952,6 +992,15 @@ internal_free (mem, file, line, flags) if (IN_BUCKET(nbytes, nunits) == 0) xbotch (mem, ERR_UNDERFLOW, _("free: underflow detected; mh_nbytes out of range"), file, line); +#if SIZEOF_CHAR_P == 8 + { + int i; + for (i = 0, z = p->mh_magic8; i < 8; i++) + if (*z++ != MAGIC1) + xbotch (mem, ERR_UNDERFLOW, + _("free: underflow detected; magic8 corrupted"), file, line); + } +#endif ap += p->mh_nbytes; z = mg.s; @@ -1083,6 +1132,16 @@ internal_realloc (mem, n, file, line, flags) if (IN_BUCKET(nbytes, nunits) == 0) xbotch (mem, ERR_UNDERFLOW, _("realloc: underflow detected; mh_nbytes out of range"), file, line); +#if SIZEOF_CHAR_P == 8 + { + int i; + for (i = 0, z = p->mh_magic8; i < 8; i++) + if (*z++ != MAGIC1) + xbotch (mem, ERR_UNDERFLOW, + _("realloc: underflow detected; magic8 corrupted"), file, line); + + } +#endif m = (char *)mem + (tocopy = p->mh_nbytes); z = mg.s; |
