/* Malloc implementation for multiple threads without lock contention. Copyright (C) 2001, 2002, 2003 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Wolfram Gloger , 2001. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details. You should have received a copy of the GNU Lesser 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. */ /* $Id: hooks.c,v 1.12 2003/09/12 22:28:01 drepper Exp $ */ #ifndef DEFAULT_CHECK_ACTION #define DEFAULT_CHECK_ACTION 1 #endif /* What to do if the standard debugging hooks are in place and a corrupt pointer is detected: do nothing (0), print an error message (1), or call abort() (2). */ /* Hooks for debugging versions. The initial hooks just call the initialization routine, then do the normal work. */ static Void_t* #if __STD_C malloc_hook_ini(size_t sz, const __malloc_ptr_t caller) #else malloc_hook_ini(sz, caller) size_t sz; const __malloc_ptr_t caller; #endif { __malloc_hook = NULL; ptmalloc_init(); return public_mALLOc(sz); } static Void_t* #if __STD_C realloc_hook_ini(Void_t* ptr, size_t sz, const __malloc_ptr_t caller) #else realloc_hook_ini(ptr, sz, caller) Void_t* ptr; size_t sz; const __malloc_ptr_t caller; #endif { __malloc_hook = NULL; __realloc_hook = NULL; ptmalloc_init(); return public_rEALLOc(ptr, sz); } static Void_t* #if __STD_C memalign_hook_ini(size_t alignment, size_t sz, const __malloc_ptr_t caller) #else memalign_hook_ini(alignment, sz, caller) size_t alignment; size_t sz; const __malloc_ptr_t caller; #endif { __memalign_hook = NULL; ptmalloc_init(); return public_mEMALIGn(alignment, sz); } static int check_action = DEFAULT_CHECK_ACTION; /* Whether we are using malloc checking. */ static int using_malloc_checking; /* A flag that is set by malloc_set_state, to signal that malloc checking must not be enabled on the request from the user (via the MALLOC_CHECK_ environment variable). It is reset by __malloc_check_init to tell malloc_set_state that the user has requested malloc checking. The purpose of this flag is to make sure that malloc checking is not enabled when the heap to be restored was constructed without malloc checking, and thus does not contain the required magic bytes. Otherwise the heap would be corrupted by calls to free and realloc. If it turns out that the heap was created with malloc checking and the user has requested it malloc_set_state just calls __malloc_check_init again to enable it. On the other hand, reusing such a heap without further malloc checking is safe. */ static int disallow_malloc_check; /* Activate a standard set of debugging hooks. */ void __malloc_check_init() { if (disallow_malloc_check) { disallow_malloc_check = 0; return; } using_malloc_checking = 1; __malloc_hook = malloc_check; __free_hook = free_check; __realloc_hook = realloc_check; __memalign_hook = memalign_check; if(check_action & 1) { #ifdef _LIBC _IO_flockfile (stderr); int old_flags2 = ((_IO_FILE *) stderr)->_flags2; ((_IO_FILE *) stderr)->_flags2 |= _IO_FLAGS2_NOTCANCEL; #endif fprintf(stderr, "malloc: using debugging hooks\n"); #ifdef _LIBC ((_IO_FILE *) stderr)->_flags2 |= old_flags2; _IO_funlockfile (stderr); #endif } } /* A simple, standard set of debugging hooks. Overhead is `only' one byte per chunk; still this will catch most cases of double frees or overruns. The goal here is to avoid obscure crashes due to invalid usage, unlike in the MALLOC_DEBUG code. */ #define MAGICBYTE(p) ( ( ((size_t)p >> 3) ^ ((size_t)p >> 11)) & 0xFF ) /* Instrument a chunk with overrun detector byte(s) and convert it into a user pointer with requested size sz. */ static Void_t* internal_function #if __STD_C mem2mem_check(Void_t *ptr, size_t sz) #else mem2mem_check(ptr, sz) Void_t *ptr; size_t sz; #endif { mchunkptr p; unsigned char* m_ptr = (unsigned char*)BOUNDED_N(ptr, sz); size_t i; if (!ptr) return ptr; p = mem2chunk(ptr); for(i = chunksize(p) - (chunk_is_mmapped(p) ? 2*SIZE_SZ+1 : SIZE_SZ+1); i > sz; i -= 0xFF) { if(i-sz < 0x100) { m_ptr[i] = (unsigned char)(i-sz); break; } m_ptr[i] = 0xFF; } m_ptr[sz] = MAGICBYTE(p); return (Void_t*)m_ptr; } /* Convert a pointer to be free()d or realloc()ed to a valid chunk pointer. If the provided pointer is not valid, return NULL. */ static mchunkptr internal_function #if __STD_C mem2chunk_check(Void_t* mem) #else mem2chunk_check(mem) Void_t* mem; #endif { mchunkptr p; INTERNAL_SIZE_T sz, c; unsigned char magic; if(!aligned_OK(mem)) return NULL; p = mem2chunk(mem); if( (char*)p>=mp_.sbrk_base && (char*)p<(mp_.sbrk_base+main_arena.system_mem) ) { /* Must be a chunk in conventional heap memory. */ if(chunk_is_mmapped(p) || ( (sz = chunksize(p)), ((char*)p + sz)>=(mp_.sbrk_base+main_arena.system_mem) ) || szprev_size&MALLOC_ALIGN_MASK || (long)prev_chunk(p)<(long)mp_.sbrk_base || next_chunk(prev_chunk(p))!=p) )) return NULL; magic = MAGICBYTE(p); for(sz += SIZE_SZ-1; (c = ((unsigned char*)p)[sz]) != magic; sz -= c) { if(c<=0 || sz<(c+2*SIZE_SZ)) return NULL; } ((unsigned char*)p)[sz] ^= 0xFF; } else { unsigned long offset, page_mask = malloc_getpagesize-1; /* mmap()ed chunks have MALLOC_ALIGNMENT or higher power-of-two alignment relative to the beginning of a page. Check this first. */ offset = (unsigned long)mem & page_mask; if((offset!=MALLOC_ALIGNMENT && offset!=0 && offset!=0x10 && offset!=0x20 && offset!=0x40 && offset!=0x80 && offset!=0x100 && offset!=0x200 && offset!=0x400 && offset!=0x800 && offset!=0x1000 && offset<0x2000) || !chunk_is_mmapped(p) || (p->size & PREV_INUSE) || ( (((unsigned long)p - p->prev_size) & page_mask) != 0 ) || ( (sz = chunksize(p)), ((p->prev_size + sz) & page_mask) != 0 ) ) return NULL; magic = MAGICBYTE(p); for(sz -= 1; (c = ((unsigned char*)p)[sz]) != magic; sz -= c) { if(c<=0 || sz<(c+2*SIZE_SZ)) return NULL; } ((unsigned char*)p)[sz] ^= 0xFF; } return p; } /* Check for corruption of the top chunk, and try to recover if necessary. */ static int internal_function #if __STD_C top_check(void) #else top_check() #endif { mchunkptr t = top(&main_arena); char* brk, * new_brk; INTERNAL_SIZE_T front_misalign, sbrk_size; unsigned long pagesz = malloc_getpagesize; if((char*)t + chunksize(t) == mp_.sbrk_base + main_arena.system_mem || t == initial_top(&main_arena)) return 0; if(check_action & 1) { #ifdef _LIBC _IO_flockfile (stderr); int old_flags2 = ((_IO_FILE *) stderr)->_flags2; ((_IO_FILE *) stderr)->_flags2 |= _IO_FLAGS2_NOTCANCEL; #endif fprintf(stderr, "malloc: top chunk is corrupt\n"); #ifdef _LIBC ((_IO_FILE *) stderr)->_flags2 |= old_flags2; _IO_funlockfile (stderr); #endif } if(check_action & 2) abort(); /* Try to set up a new top chunk. */ brk = MORECORE(0); front_misalign = (unsigned long)chunk2mem(brk) & MALLOC_ALIGN_MASK; if (front_misalign > 0) front_misalign = MALLOC_ALIGNMENT - front_misalign; sbrk_size = front_misalign + mp_.top_pad + MINSIZE; sbrk_size += pagesz - ((unsigned long)(brk + sbrk_size) & (pagesz - 1)); new_brk = (char*)(MORECORE (sbrk_size)); if (new_brk == (char*)(MORECORE_FAILURE)) return -1; /* Call the `morecore' hook if necessary. */ if (__after_morecore_hook) (*__after_morecore_hook) (); main_arena.system_mem = (new_brk - mp_.sbrk_base) + sbrk_size; top(&main_arena) = (mchunkptr)(brk + front_misalign); set_head(top(&main_arena), (sbrk_size - front_misalign) | PREV_INUSE); return 0; } static Void_t* #if __STD_C malloc_check(size_t sz, const Void_t *caller) #else malloc_check(sz, caller) size_t sz; const Void_t *caller; #endif { Void_t *victim; (void)mutex_lock(&main_arena.mutex); victim = (top_check() >= 0) ? _int_malloc(&main_arena, sz+1) : NULL; (void)mutex_unlock(&main_arena.mutex); return mem2mem_check(victim, sz); } static void #if __STD_C free_check(Void_t* mem, const Void_t *caller) #else free_check(mem, caller) Void_t* mem; const Void_t *caller; #endif { mchunkptr p; if(!mem) return; (void)mutex_lock(&main_arena.mutex); p = mem2chunk_check(mem); if(!p) { (void)mutex_unlock(&main_arena.mutex); if(check_action & 1) { #ifdef _LIBC _IO_flockfile (stderr); int old_flags2 = ((_IO_FILE *) stderr)->_flags2; ((_IO_FILE *) stderr)->_flags2 |= _IO_FLAGS2_NOTCANCEL; #endif fprintf(stderr, "free(): invalid pointer %p!\n", mem); #ifdef _LIBC ((_IO_FILE *) stderr)->_flags2 |= old_flags2; _IO_funlockfile (stderr); #endif } if(check_action & 2) abort(); return; } #if HAVE_MMAP if (chunk_is_mmapped(p)) { (void)mutex_unlock(&main_arena.mutex); munmap_chunk(p); return; } #endif #if 0 /* Erase freed memory. */ memset(mem, 0, chunksize(p) - (SIZE_SZ+1)); #endif _int_free(&main_arena, mem); (void)mutex_unlock(&main_arena.mutex); } static Void_t* #if __STD_C realloc_check(Void_t* oldmem, size_t bytes, const Void_t *caller) #else realloc_check(oldmem, bytes, caller) Void_t* oldmem; size_t bytes; const Void_t *caller; #endif { mchunkptr oldp; INTERNAL_SIZE_T nb, oldsize; Void_t* newmem = 0; if (oldmem == 0) return malloc_check(bytes, NULL); (void)mutex_lock(&main_arena.mutex); oldp = mem2chunk_check(oldmem); (void)mutex_unlock(&main_arena.mutex); if(!oldp) { if(check_action & 1) { #ifdef _LIBC _IO_flockfile (stderr); int old_flags2 = ((_IO_FILE *) stderr)->_flags2; ((_IO_FILE *) stderr)->_flags2 |= _IO_FLAGS2_NOTCANCEL; #endif fprintf(stderr, "realloc(): invalid pointer %p!\n", oldmem); #ifdef _LIBC ((_IO_FILE *) stderr)->_flags2 |= old_flags2; _IO_funlockfile (stderr); #endif } if(check_action & 2) abort(); return malloc_check(bytes, NULL); } oldsize = chunksize(oldp); checked_request2size(bytes+1, nb); (void)mutex_lock(&main_arena.mutex); #if HAVE_MMAP if (chunk_is_mmapped(oldp)) { #if HAVE_MREMAP mchunkptr newp = mremap_chunk(oldp, nb); if(newp) newmem = chunk2mem(newp); else #endif { /* Note the extra SIZE_SZ overhead. */ if(oldsize - SIZE_SZ >= nb) newmem = oldmem; /* do nothing */ else { /* Must alloc, copy, free. */ if (top_check() >= 0) newmem = _int_malloc(&main_arena, bytes+1); if (newmem) { MALLOC_COPY(BOUNDED_N(newmem, bytes+1), oldmem, oldsize - 2*SIZE_SZ); munmap_chunk(oldp); } } } } else { #endif /* HAVE_MMAP */ if (top_check() >= 0) newmem = _int_realloc(&main_arena, oldmem, bytes+1); #if 0 /* Erase freed memory. */ if(newmem) newp = mem2chunk(newmem); nb = chunksize(newp); if(oldp=chunk_at_offset(newp, nb)) { memset((char*)oldmem + 2*sizeof(mbinptr), 0, oldsize - (2*sizeof(mbinptr)+2*SIZE_SZ+1)); } else if(nb > oldsize+SIZE_SZ) { memset((char*)BOUNDED_N(chunk2mem(newp), bytes) + oldsize, 0, nb - (oldsize+SIZE_SZ)); } #endif #if HAVE_MMAP } #endif (void)mutex_unlock(&main_arena.mutex); return mem2mem_check(newmem, bytes); } static Void_t* #if __STD_C memalign_check(size_t alignment, size_t bytes, const Void_t *caller) #else memalign_check(alignment, bytes, caller) size_t alignment; size_t bytes; const Void_t *caller; #endif { INTERNAL_SIZE_T nb; Void_t* mem; if (alignment <= MALLOC_ALIGNMENT) return malloc_check(bytes, NULL); if (alignment < MINSIZE) alignment = MINSIZE; checked_request2size(bytes+1, nb); (void)mutex_lock(&main_arena.mutex); mem = (top_check() >= 0) ? _int_memalign(&main_arena, alignment, bytes+1) : NULL; (void)mutex_unlock(&main_arena.mutex); return mem2mem_check(mem, bytes); } #ifndef NO_THREADS # ifdef _LIBC # if USE___THREAD || (defined USE_TLS && !defined SHARED) /* These routines are never needed in this configuration. */ # define NO_STARTER # endif # endif # ifdef NO_STARTER # undef NO_STARTER # else /* The following hooks are used when the global initialization in ptmalloc_init() hasn't completed yet. */ static Void_t* #if __STD_C malloc_starter(size_t sz, const Void_t *caller) #else malloc_starter(sz, caller) size_t sz; const Void_t *caller; #endif { Void_t* victim; victim = _int_malloc(&main_arena, sz); return victim ? BOUNDED_N(victim, sz) : 0; } static Void_t* #if __STD_C memalign_starter(size_t align, size_t sz, const Void_t *caller) #else memalign_starter(align, sz, caller) size_t align, sz; const Void_t *caller; #endif { Void_t* victim; victim = _int_memalign(&main_arena, align, sz); return victim ? BOUNDED_N(victim, sz) : 0; } static void #if __STD_C free_starter(Void_t* mem, const Void_t *caller) #else free_starter(mem, caller) Void_t* mem; const Void_t *caller; #endif { mchunkptr p; if(!mem) return; p = mem2chunk(mem); #if HAVE_MMAP if (chunk_is_mmapped(p)) { munmap_chunk(p); return; } #endif _int_free(&main_arena, mem); } # endif /* !defiend NO_STARTER */ #endif /* NO_THREADS */ /* Get/set state: malloc_get_state() records the current state of all malloc variables (_except_ for the actual heap contents and `hook' function pointers) in a system dependent, opaque data structure. This data structure is dynamically allocated and can be free()d after use. malloc_set_state() restores the state of all malloc variables to the previously obtained state. This is especially useful when using this malloc as part of a shared library, and when the heap contents are saved/restored via some other method. The primary example for this is GNU Emacs with its `dumping' procedure. `Hook' function pointers are never saved or restored by these functions, with two exceptions: If malloc checking was in use when malloc_get_state() was called, then malloc_set_state() calls __malloc_check_init() if possible; if malloc checking was not in use in the recorded state but the user requested malloc checking, then the hooks are reset to 0. */ #define MALLOC_STATE_MAGIC 0x444c4541l #define MALLOC_STATE_VERSION (0*0x100l + 2l) /* major*0x100 + minor */ struct malloc_save_state { long magic; long version; mbinptr av[NBINS * 2 + 2]; char* sbrk_base; int sbrked_mem_bytes; unsigned long trim_threshold; unsigned long top_pad; unsigned int n_mmaps_max; unsigned long mmap_threshold; int check_action; unsigned long max_sbrked_mem; unsigned long max_total_mem; unsigned int n_mmaps; unsigned int max_n_mmaps; unsigned long mmapped_mem; unsigned long max_mmapped_mem; int using_malloc_checking; }; Void_t* public_gET_STATe(void) { struct malloc_save_state* ms; int i; mbinptr b; ms = (struct malloc_save_state*)public_mALLOc(sizeof(*ms)); if (!ms) return 0; (void)mutex_lock(&main_arena.mutex); malloc_consolidate(&main_arena); ms->magic = MALLOC_STATE_MAGIC; ms->version = MALLOC_STATE_VERSION; ms->av[0] = 0; ms->av[1] = 0; /* used to be binblocks, now no longer used */ ms->av[2] = top(&main_arena); ms->av[3] = 0; /* used to be undefined */ for(i=1; iav[2*i+2] = ms->av[2*i+3] = 0; /* empty bin */ else { ms->av[2*i+2] = first(b); ms->av[2*i+3] = last(b); } } ms->sbrk_base = mp_.sbrk_base; ms->sbrked_mem_bytes = main_arena.system_mem; ms->trim_threshold = mp_.trim_threshold; ms->top_pad = mp_.top_pad; ms->n_mmaps_max = mp_.n_mmaps_max; ms->mmap_threshold = mp_.mmap_threshold; ms->check_action = check_action; ms->max_sbrked_mem = main_arena.max_system_mem; #ifdef NO_THREADS ms->max_total_mem = mp_.max_total_mem; #else ms->max_total_mem = 0; #endif ms->n_mmaps = mp_.n_mmaps; ms->max_n_mmaps = mp_.max_n_mmaps; ms->mmapped_mem = mp_.mmapped_mem; ms->max_mmapped_mem = mp_.max_mmapped_mem; ms->using_malloc_checking = using_malloc_checking; (void)mutex_unlock(&main_arena.mutex); return (Void_t*)ms; } int public_sET_STATe(Void_t* msptr) { struct malloc_save_state* ms = (struct malloc_save_state*)msptr; size_t i; mbinptr b; disallow_malloc_check = 1; ptmalloc_init(); if(ms->magic != MALLOC_STATE_MAGIC) return -1; /* Must fail if the major version is too high. */ if((ms->version & ~0xffl) > (MALLOC_STATE_VERSION & ~0xffl)) return -2; (void)mutex_lock(&main_arena.mutex); /* There are no fastchunks. */ clear_fastchunks(&main_arena); set_max_fast(&main_arena, DEFAULT_MXFAST); for (i=0; iav[2]; main_arena.last_remainder = 0; for(i=1; iav[2*i+2] == 0) { assert(ms->av[2*i+3] == 0); first(b) = last(b) = b; } else { if(iav[2*i+2]))==i && largebin_index(chunksize(ms->av[2*i+3]))==i)) { first(b) = ms->av[2*i+2]; last(b) = ms->av[2*i+3]; /* Make sure the links to the bins within the heap are correct. */ first(b)->bk = b; last(b)->fd = b; /* Set bit in binblocks. */ mark_bin(&main_arena, i); } else { /* Oops, index computation from chunksize must have changed. Link the whole list into unsorted_chunks. */ first(b) = last(b) = b; b = unsorted_chunks(&main_arena); ms->av[2*i+2]->bk = b; ms->av[2*i+3]->fd = b->fd; b->fd->bk = ms->av[2*i+3]; b->fd = ms->av[2*i+2]; } } } mp_.sbrk_base = ms->sbrk_base; main_arena.system_mem = ms->sbrked_mem_bytes; mp_.trim_threshold = ms->trim_threshold; mp_.top_pad = ms->top_pad; mp_.n_mmaps_max = ms->n_mmaps_max; mp_.mmap_threshold = ms->mmap_threshold; check_action = ms->check_action; main_arena.max_system_mem = ms->max_sbrked_mem; #ifdef NO_THREADS mp_.max_total_mem = ms->max_total_mem; #endif mp_.n_mmaps = ms->n_mmaps; mp_.max_n_mmaps = ms->max_n_mmaps; mp_.mmapped_mem = ms->mmapped_mem; mp_.max_mmapped_mem = ms->max_mmapped_mem; /* add version-dependent code here */ if (ms->version >= 1) { /* Check whether it is safe to enable malloc checking, or whether it is necessary to disable it. */ if (ms->using_malloc_checking && !using_malloc_checking && !disallow_malloc_check) __malloc_check_init (); else if (!ms->using_malloc_checking && using_malloc_checking) { __malloc_hook = 0; __free_hook = 0; __realloc_hook = 0; __memalign_hook = 0; using_malloc_checking = 0; } } check_malloc_state(&main_arena); (void)mutex_unlock(&main_arena.mutex); return 0; } /* * Local variables: * c-basic-offset: 2 * End: */