diff options
Diffstat (limited to 'dmake/dbug/malloc/mlc_chn.c')
| -rw-r--r-- | dmake/dbug/malloc/mlc_chn.c | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/dmake/dbug/malloc/mlc_chn.c b/dmake/dbug/malloc/mlc_chn.c new file mode 100644 index 000000000000..3f24333611f9 --- /dev/null +++ b/dmake/dbug/malloc/mlc_chn.c @@ -0,0 +1,188 @@ +/* + * (c) Copyright 1990 Conor P. Cahill (uunet!virtech!cpcahil). + * You may copy, distribute, and use this software as long as this + * copyright statement is not removed. + */ +#include <stdio.h> +#include <fcntl.h> +#include "malloc.h" + +/* + * Function: malloc_chain_check() + * + * Purpose: to verify malloc chain is intact + * + * Arguments: todo - 0 - just check and return status + * 1 - call malloc_warn if error detected + * + * Returns: 0 - malloc chain intact & no overflows + * other - problems detected in malloc chain + * + * Narrative: + * + * Notes: If todo is non-zero the malloc_warn function, when called + * may not return (i.e. it may exit) + * + */ +#ifndef lint +static +char rcs_hdr[] = "$Id: mlc_chn.c,v 1.1.1.1 2000-09-22 15:33:26 hr Exp $"; +#endif + + +int +malloc_chain_check(todo) + int todo; +{ + char * func = "malloc_chain_check"; + int i; + extern char * malloc_data_start; + extern char * malloc_data_end; + extern struct mlist * malloc_end; + extern int malloc_errno; + extern struct mlist malloc_start; + struct mlist * oldptr; + struct mlist * ptr; + int rtn = 0; + + oldptr = &malloc_start; + for(ptr = malloc_start.next; ; ptr = ptr->next) + { + /* + * Since the malloc chain is a forward only chain, any + * pointer that we get should always be positioned in + * memory following the previous pointer. If this is not + * so, we must have a corrupted chain. + */ + if( ptr ) + { + if(ptr < oldptr ) + { + malloc_errno = M_CODE_CHAIN_BROKE; + if( todo ) + { + malloc_fatal(func); + } + rtn++; + break; + } + oldptr = ptr; + } + else + { + if( oldptr != malloc_end ) + { + /* + * This should never happen. If it does, then + * we got a real problem. + */ + malloc_errno = M_CODE_NO_END; + if( todo ) + { + malloc_fatal(func); + } + rtn++; + } + break; + } + + /* + * verify that ptr is within the malloc region... + * since we started within the malloc chain this should never + * happen. + */ + + if( ((char *)ptr < malloc_data_start) || + ((char *)ptr > malloc_data_end) ) + { + malloc_errno = M_CODE_BAD_PTR; + if( todo ) + { + malloc_fatal(func); + } + rtn++; + break; + } + + /* + * verify magic flag is set + */ + + if( (ptr->flag&M_MAGIC) != M_MAGIC ) + { + malloc_errno = M_CODE_BAD_MAGIC; + if( todo ) + { + malloc_warning(func); + } + rtn++; + continue; + } + + /* + * verify segments are correctly linked together + */ + + if( (ptr->prev && (ptr->prev->next != ptr) ) || + (ptr->next && (ptr->next->prev != ptr) ) || + ((ptr->next == NULL) && (ptr->prev == NULL)) ) + { + malloc_errno = M_CODE_BAD_CONNECT; + if( todo ) + { + malloc_warning(func); + } + rtn++; + continue; + } + + /* + * If this segment is allocated + */ + + if( (ptr->flag & M_INUSE) != 0 ) + { + /* + * verify no overflow of data area + */ + + for(i=ptr->r_size; i < ptr->s.size; i++) + { + if( ptr->data[i] != M_FILL ) + { + malloc_errno = M_CODE_OVERRUN; + if( todo ) + { + malloc_warning(func); + } + rtn++; + break; + } + } + } + else /* it's not allocated so */ + { + /* + * verify no reuse of freed data blocks + */ + + for(i=0; i < ptr->s.size; i++) + { + if( ptr->data[i] != M_FREE_FILL ) + { + malloc_errno = M_CODE_REUSE; + if( todo ) + { + malloc_warning(func); + } + rtn++; + break; + } + } + } + + } /* for(... */ + + return(rtn); + +} /* malloc_chain_check(... */ |