diff options
Diffstat (limited to 'malloc/malloc.c')
| -rw-r--r-- | malloc/malloc.c | 74 |
1 files changed, 50 insertions, 24 deletions
diff --git a/malloc/malloc.c b/malloc/malloc.c index 4db4051..824b6cc 100644 --- a/malloc/malloc.c +++ b/malloc/malloc.c @@ -283,6 +283,9 @@ extern "C" { /* For va_arg, va_start, va_end. */ #include <stdarg.h> +/* For writev and struct iovec. */ +#include <sys/uio.h> + /* Debugging: @@ -1501,7 +1504,7 @@ static size_t mUSABLe(Void_t*); static void mSTATs(void); static int mALLOPt(int, int); static struct mallinfo mALLINFo(mstate); -static void malloc_printf_nc(int action, const char *template, ...); +static void malloc_printerr(int action, const char *str, void *ptr); static Void_t* internal_function mem2mem_check(Void_t *p, size_t sz); static int internal_function top_check(void); @@ -1971,10 +1974,11 @@ typedef struct malloc_chunk* mbinptr; FD = P->fd; \ BK = P->bk; \ if (__builtin_expect (FD->bk != P || BK->fd != P, 0)) \ - malloc_printf_nc (check_action, \ - "corrupted double-linked list at %p!\n", P); \ - FD->bk = BK; \ - BK->fd = FD; \ + malloc_printerr (check_action, "corrupted double-linked list", P); \ + else { \ + FD->bk = BK; \ + BK->fd = FD; \ + } \ } /* @@ -4177,7 +4181,7 @@ _int_free(mstate av, Void_t* mem) here by accident or by "design" from some intruder. */ if (__builtin_expect ((uintptr_t) p > (uintptr_t) -size, 0)) { - malloc_printf_nc (check_action, "free(): invalid pointer %p!\n", mem); + malloc_printerr (check_action, "free(): invalid pointer", mem); return; } @@ -4205,7 +4209,8 @@ _int_free(mstate av, Void_t* mem) record we are going to add (i.e., double free). */ if (__builtin_expect (*fb == p, 0)) { - malloc_printf_nc (check_action, "double free(%p)!\n", mem); + double_free: + malloc_printerr (check_action, "double free or corruption", mem); return; } p->fd = *fb; @@ -4218,6 +4223,19 @@ _int_free(mstate av, Void_t* mem) else if (!chunk_is_mmapped(p)) { nextchunk = chunk_at_offset(p, size); + + /* Lightweight tests: check whether the block is already the + top block. */ + if (__builtin_expect (p == av->top, 0)) + goto double_free; + /* Or whether the next chunk is beyond the boundaries of the arena. */ + if (__builtin_expect ((char *) nextchunk >= ((char *) av->top + + chunksize(av->top)), 0)) + goto double_free; + /* Or whether the block is actually not marked used. */ + if (__builtin_expect (!prev_inuse(nextchunk), 0)) + goto double_free; + nextsize = chunksize(nextchunk); assert(nextsize > 0); @@ -5413,27 +5431,35 @@ int mALLOPt(param_number, value) int param_number; int value; /* Helper code. */ static void -malloc_printf_nc(int action, const char *template, ...) +malloc_printerr(int action, const char *str, void *ptr) { if (action & 1) { -#ifdef _LIBC - _IO_flockfile (stderr); - int old_flags2 = ((_IO_FILE *) stderr)->_flags2; - ((_IO_FILE *) stderr)->_flags2 |= _IO_FLAGS2_NOTCANCEL; -#endif - - va_list ap; - va_start (ap, template); - - vfprintf (stderr, template, ap); - - va_end (ap); + /* output string will be ": ADDR ***\n" */ + static const char suffix[] = " ***\n"; + static const char prefix[] = ": 0x"; + char buf[sizeof (prefix) - 1 + sizeof (void *) * 2 + sizeof (suffix)]; + char *cp; + if (action & 4) + cp = memcpy (&buf[sizeof (buf) - 2], "\n", 2); + else + { + cp = memcpy (&buf[sizeof (buf) - sizeof (suffix)], suffix, + sizeof (suffix)); + cp = _itoa_word ((unsigned long int) ptr, cp, 16, 0); + while (cp > &buf[sizeof (prefix) - 1]) + *--cp = '0'; + cp = memcpy (buf, prefix, sizeof (prefix) - 1); + } -#ifdef _LIBC - ((_IO_FILE *) stderr)->_flags2 |= old_flags2; - _IO_funlockfile (stderr); -#endif + struct iovec iov[3]; + iov[0].iov_base = (char *) "*** glibc detected *** "; + iov[0].iov_len = strlen (iov[0].iov_base); + iov[1].iov_base = (char *) str; + iov[1].iov_len = strlen (str); + iov[2].iov_base = cp; + iov[2].iov_len = &buf[sizeof (buf) - 1] - cp; + TEMP_FAILURE_RETRY (__writev (STDERR_FILENO, iov, 3)); } if (action & 2) abort (); |