On Sun, Jan 21, 2018 at 11:50:24AM +0100, Otto Moerbeek wrote:
> Hi,
>
> chunk pages do not need to be junked, all allocated chunks are already
> junked on free. Same hold for a few error paths.
>
> Also, for freezero(), only clear the size as reqeusted instead of the
> whole allocation.
>
> Please review/test,
No feedback at all....
Anyone? Otherwise this goes to "test by commit" mode. Still it would
be a shame if I made a mistake in the freezero part and bytes that
should be won't be cleared anymore.
-Otto
>
> Index: malloc.c
> ===================================================================
> RCS file: /cvs/src/lib/libc/stdlib/malloc.c,v
> retrieving revision 1.241
> diff -u -p -r1.241 malloc.c
> --- malloc.c 18 Jan 2018 20:06:16 -0000 1.241
> +++ malloc.c 20 Jan 2018 20:46:57 -0000
> @@ -633,7 +633,7 @@ delete(struct dir_info *d, struct region
> * cache are in MALLOC_PAGESIZE units.
> */
> static void
> -unmap(struct dir_info *d, void *p, size_t sz, int clear)
> +unmap(struct dir_info *d, void *p, size_t sz, size_t clear, int junk)
> {
> size_t psz = sz >> MALLOC_PAGESHIFT;
> size_t rsz;
> @@ -650,7 +650,7 @@ unmap(struct dir_info *d, void *p, size_
> * to unmap is larger than the cache size or we're clearing and the
> * cache is full, just munmap
> */
> - if (psz > mopts.malloc_cache || (clear && rsz == 0)) {
> + if (psz > mopts.malloc_cache || (clear > 0 && rsz == 0)) {
> i = munmap(p, sz);
> if (i)
> wrterror(d, "munmap %p", p);
> @@ -686,11 +686,10 @@ unmap(struct dir_info *d, void *p, size_
> for (i = 0; ; i++) {
> r = &d->free_regions[(i + offset) & mask];
> if (r->p == NULL) {
> - if (clear)
> - memset(p, 0, sz - mopts.malloc_guard);
> - if (mopts.malloc_junk && !mopts.malloc_freeunmap) {
> - size_t amt = mopts.malloc_junk == 1 ?
> - MALLOC_MAXCHUNK : sz;
> + if (clear > 0)
> + memset(p, 0, clear);
> + if (junk && !mopts.malloc_freeunmap) {
> + size_t amt = junk == 1 ? MALLOC_MAXCHUNK : sz;
> memset(p, SOME_FREEJUNK, amt);
> }
> if (mopts.malloc_freeunmap)
> @@ -888,7 +887,7 @@ omalloc_make_chunks(struct dir_info *d,
> return bp;
>
> err:
> - unmap(d, pp, MALLOC_PAGESIZE, 0);
> + unmap(d, pp, MALLOC_PAGESIZE, 0, mopts.malloc_junk);
> return NULL;
> }
>
> @@ -1087,7 +1086,7 @@ free_bytes(struct dir_info *d, struct re
>
> if (info->size == 0 && !mopts.malloc_freeunmap)
> mprotect(info->page, MALLOC_PAGESIZE, PROT_READ | PROT_WRITE);
> - unmap(d, info->page, MALLOC_PAGESIZE, 0);
> + unmap(d, info->page, MALLOC_PAGESIZE, 0, 0);
>
> delete(d, r);
> if (info->size != 0)
> @@ -1118,7 +1117,7 @@ omalloc(struct dir_info *pool, size_t sz
> return NULL;
> }
> if (insert(pool, p, sz, f)) {
> - unmap(pool, p, psz, 0);
> + unmap(pool, p, psz, 0, 0);
> errno = ENOMEM;
> return NULL;
> }
> @@ -1309,8 +1308,7 @@ ofree(struct dir_info *argpool, void *p,
> uint32_t chunknum =
> find_chunknum(pool, info, p, 0);
>
> - if (info->bits[info->offset + chunknum] <
> - argsz)
> + if (info->bits[info->offset + chunknum] < argsz)
> wrterror(pool, "recorded size %hu"
> " < %zu",
> info->bits[info->offset + chunknum],
> @@ -1350,7 +1348,8 @@ ofree(struct dir_info *argpool, void *p,
> }
> STATS_SUB(pool->malloc_guarded, mopts.malloc_guard);
> }
> - unmap(pool, p, PAGEROUND(sz), clear);
> + unmap(pool, p, PAGEROUND(sz), clear ? argsz : 0,
> + mopts.malloc_junk);
> delete(pool, r);
> } else {
> /* Validate and optionally canary check */
> @@ -1376,8 +1375,8 @@ ofree(struct dir_info *argpool, void *p,
> pool->delayed_chunks[i] = tmp;
> if (mopts.malloc_junk)
> validate_junk(pool, p);
> - } else if (sz > 0)
> - memset(p, 0, sz);
> + } else if (argsz > 0)
> + memset(p, 0, argsz);
> if (p != NULL) {
> r = find(pool, p);
> if (r == NULL)
> @@ -1575,7 +1574,8 @@ gotit:
> PROT_NONE))
> wrterror(pool, "mprotect");
> }
> - unmap(pool, (char *)r->p + rnewsz, roldsz - rnewsz, 0);
> + unmap(pool, (char *)r->p + rnewsz, roldsz - rnewsz, 0,
> + mopts.malloc_junk);
> r->size = gnewsz;
> if (MALLOC_MOVE_COND(gnewsz)) {
> void *pp = MALLOC_MOVE(r->p, gnewsz);
> @@ -1791,7 +1791,7 @@ orecallocarray(struct dir_info *argpool,
> } else
> memcpy(newptr, p, newsize);
>
> - ofree(pool, p, 1, 0, 0);
> + ofree(pool, p, 1, 0, oldsize);
>
> done:
> if (argpool != pool) {
> @@ -1984,7 +1984,7 @@ omemalign(struct dir_info *pool, size_t
> }
>
> if (insert(pool, p, sz, f)) {
> - unmap(pool, p, psz, 0);
> + unmap(pool, p, psz, 0, 0);
> errno = ENOMEM;
> return NULL;
> }
