From: Phillip Wood <phillip.wood123@gmail.com>
To: "Ævar Arnfjörð Bjarmason" <avarab@gmail.com>, git@vger.kernel.org
Cc: Junio C Hamano <gitster@pobox.com>, Jeff King <peff@peff.net>
Subject: Re: [PATCH 4/7] xdiff: use G[C]ALLOC_ARRAY(), not XDL_CALLOC_ARRAY()
Date: Mon, 11 Jul 2022 11:10:20 +0100 [thread overview]
Message-ID: <37667911-3049-4e78-e67d-9fcb7389dfc0@gmail.com> (raw)
In-Reply-To: <patch-4.7-19567077b84-20220708T140354Z-avarab@gmail.com>
Hi Ævar
On 08/07/2022 15:20, Ævar Arnfjörð Bjarmason wrote:
> Use the newly created GCALLOC_ARRAY() helpers rather than the recently
> introduced XDL_[C]ALLOC_ARRAY().
>
> As shown in this diff the calling convention differs, we cannot use
> GCALLOC_ARRAY() as an expression, but that's an advantage in not
> having to relay the "sizeof()" down via a wrapper function.
>
> This also:
>
> * Fixes long-standing potential overflow issues, as we're using
> st_mult() in the underlying G_[C]ALLOC(). Note that the
What issues is this fixing? XDL_ALLOC_ARRAY() already checks for overflow.
> * Slightly optimizes the "XDL_CALLOC_ARRAY", as we'll now use
> calloc() rather than malloc() + memset() (although smart compilers
> will probably do the same for both...).
That's addressed in V2 of my series, unfortunately I sent it just after
you'd sent this series.
> * Changes the "XDL_CALLOC_ARRAY" behavior where we'd shortcut if the
> size was already large enough, but this behavior was changed when
> XDL_ALLOC_ARRAY() was introduced, so this is safe.
I'm not sure what you mean here - how did we shortcut before?
>
> Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
> ---
> xdiff/xdiffi.c | 3 ++-
> xdiff/xhistogram.c | 9 ++++++---
> xdiff/xmacros.h | 12 ------------
> xdiff/xpatience.c | 6 ++++--
> xdiff/xprepare.c | 24 ++++++++++++++++--------
> 5 files changed, 28 insertions(+), 26 deletions(-)
>
> diff --git a/xdiff/xdiffi.c b/xdiff/xdiffi.c
> index 6fded43e87d..077cc456087 100644
> --- a/xdiff/xdiffi.c
> +++ b/xdiff/xdiffi.c
> @@ -333,7 +333,8 @@ int xdl_do_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
> * One is to store the forward path and one to store the backward path.
> */
> ndiags = xe->xdf1.nreff + xe->xdf2.nreff + 3;
> - if (!XDL_ALLOC_ARRAY(kvd, 2 * ndiags + 2))
> + GALLOC_ARRAY(kvd, 2 * ndiags + 2);
> + if (!kvd)
> return -1;
> kvdf = kvd;
> kvdb = kvdf + ndiags;
> diff --git a/xdiff/xhistogram.c b/xdiff/xhistogram.c
> index df909004c10..f20592bfbdd 100644
> --- a/xdiff/xhistogram.c
> +++ b/xdiff/xhistogram.c
> @@ -266,14 +266,17 @@ static int find_lcs(xpparam_t const *xpp, xdfenv_t *env,
>
> index.table_bits = xdl_hashbits(count1);
> index.records_size = 1 << index.table_bits;
> - if (!XDL_CALLOC_ARRAY(index.records, index.records_size))
> + GCALLOC_ARRAY(index.records, index.records_size);
> + if (!index.records)
I don't think that having GALLOC_ARRAY() as a statement is an
improvement here.
Best Wishes
Phillip
> goto cleanup;
>
> index.line_map_size = count1;
> - if (!XDL_CALLOC_ARRAY(index.line_map, index.line_map_size))
> + GCALLOC_ARRAY(index.line_map, index.line_map_size);
> + if (!index.line_map)
> goto cleanup;
>
> - if (!XDL_CALLOC_ARRAY(index.next_ptrs, index.line_map_size))
> + GCALLOC_ARRAY(index.next_ptrs, index.line_map_size);
> + if (!index.next_ptrs)
> goto cleanup;
>
> /* lines / 4 + 1 comes from xprepare.c:xdl_prepare_ctx() */
> diff --git a/xdiff/xmacros.h b/xdiff/xmacros.h
> index d13a6724629..75506bdf17e 100644
> --- a/xdiff/xmacros.h
> +++ b/xdiff/xmacros.h
> @@ -49,18 +49,6 @@ do { \
> ((unsigned long) __p[2]) << 16 | ((unsigned long) __p[3]) << 24; \
> } while (0)
>
> -/* Allocate an array of nr elements, returns NULL on failure */
> -#define XDL_ALLOC_ARRAY(p, nr) \
> - ((p) = SIZE_MAX / sizeof(*(p)) >= (size_t)(nr) \
> - ? xdl_malloc((nr) * sizeof(*(p))) \
> - : NULL)
> -
> -/* Allocate an array of nr zeroed out elements, returns NULL on failure */
> -#define XDL_CALLOC_ARRAY(p, nr) \
> - (XDL_ALLOC_ARRAY((p), (nr)) \
> - ? memset((p), 0, (nr) * sizeof(*(p))) \
> - : NULL)
> -
> /*
> * Ensure array p can accommodate at least nr elements, growing the
> * array and updating alloc (which is the number of allocated
> diff --git a/xdiff/xpatience.c b/xdiff/xpatience.c
> index fe39c2978cb..bb328d9f852 100644
> --- a/xdiff/xpatience.c
> +++ b/xdiff/xpatience.c
> @@ -151,7 +151,8 @@ static int fill_hashmap(mmfile_t *file1, mmfile_t *file2,
>
> /* We know exactly how large we want the hash map */
> result->alloc = count1 * 2;
> - if (!XDL_CALLOC_ARRAY(result->entries, result->alloc))
> + GCALLOC_ARRAY(result->entries, result->alloc);
> + if (!result->entries)
> return -1;
>
> /* First, fill with entries from the first file */
> @@ -208,7 +209,8 @@ static int find_longest_common_sequence(struct hashmap *map, struct entry **res)
> */
> int anchor_i = -1;
>
> - if (!XDL_ALLOC_ARRAY(sequence, map->nr))
> + GALLOC_ARRAY(sequence, map->nr);
> + if (!sequence)
> return -1;
>
> for (entry = map->first; entry; entry = entry->next) {
> diff --git a/xdiff/xprepare.c b/xdiff/xprepare.c
> index c84549f6c50..d6cbee32a2a 100644
> --- a/xdiff/xprepare.c
> +++ b/xdiff/xprepare.c
> @@ -78,15 +78,17 @@ static int xdl_init_classifier(xdlclassifier_t *cf, long size, long flags) {
>
> return -1;
> }
> - if (!XDL_CALLOC_ARRAY(cf->rchash, cf->hsize)) {
> + GCALLOC_ARRAY(cf->rchash, cf->hsize);
> + if (!cf->rchash) {
>
> xdl_cha_free(&cf->ncha);
> return -1;
> }
>
> cf->alloc = size;
> - if (!XDL_ALLOC_ARRAY(cf->rcrecs, cf->alloc)) {
>
> + GALLOC_ARRAY(cf->rcrecs, cf->alloc);
> + if (!cf->rcrecs) {
> xdl_free(cf->rchash);
> xdl_cha_free(&cf->ncha);
> return -1;
> @@ -170,12 +172,14 @@ static int xdl_prepare_ctx(unsigned int pass, mmfile_t *mf, long narec, xpparam_
>
> if (xdl_cha_init(&xdf->rcha, sizeof(xrecord_t), narec / 4 + 1) < 0)
> goto abort;
> - if (!XDL_ALLOC_ARRAY(recs, narec))
> + GALLOC_ARRAY(recs, narec);
> + if (!recs)
> goto abort;
>
> hbits = xdl_hashbits((unsigned int) narec);
> hsize = 1 << hbits;
> - if (!XDL_CALLOC_ARRAY(rhash, hsize))
> + GCALLOC_ARRAY(rhash, hsize);
> + if (!rhash)
> goto abort;
>
> nrec = 0;
> @@ -196,14 +200,17 @@ static int xdl_prepare_ctx(unsigned int pass, mmfile_t *mf, long narec, xpparam_
> }
> }
>
> - if (!XDL_CALLOC_ARRAY(rchg, nrec + 2))
> + GCALLOC_ARRAY(rchg, nrec + 2);
> + if (!rchg)
> goto abort;
>
> if ((XDF_DIFF_ALG(xpp->flags) != XDF_PATIENCE_DIFF) &&
> (XDF_DIFF_ALG(xpp->flags) != XDF_HISTOGRAM_DIFF)) {
> - if (!XDL_ALLOC_ARRAY(rindex, nrec + 1))
> + GALLOC_ARRAY(rindex, nrec + 1);
> + if (!rindex)
> goto abort;
> - if (!XDL_ALLOC_ARRAY(ha, nrec + 1))
> + GALLOC_ARRAY(ha, nrec + 1);
> + if (!ha)
> goto abort;
> }
>
> @@ -369,7 +376,8 @@ static int xdl_cleanup_records(xdlclassifier_t *cf, xdfile_t *xdf1, xdfile_t *xd
> xdlclass_t *rcrec;
> char *dis, *dis1, *dis2;
>
> - if (!XDL_CALLOC_ARRAY(dis, xdf1->nrec + xdf2->nrec + 2))
> + GCALLOC_ARRAY(dis, xdf1->nrec + xdf2->nrec + 2);
> + if (!dis)
> return -1;
> dis1 = dis;
> dis2 = dis1 + xdf1->nrec + 1;
next prev parent reply other threads:[~2022-07-11 11:03 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-29 15:25 [PATCH 0/3] xdiff: introduce memory allocation macros Phillip Wood via GitGitGadget
2022-06-29 15:25 ` [PATCH 1/3] xdiff: introduce XDL_ALLOC_ARRAY() Phillip Wood via GitGitGadget
2022-06-29 15:25 ` [PATCH 2/3] xdiff: introduce XDL_CALLOC_ARRAY() Phillip Wood via GitGitGadget
2022-06-30 18:17 ` Junio C Hamano
2022-07-06 13:17 ` Phillip Wood
2022-06-29 15:25 ` [PATCH 3/3] xdiff: introduce XDL_ALLOC_GROW() Phillip Wood via GitGitGadget
2022-06-30 10:54 ` Ævar Arnfjörð Bjarmason
2022-06-30 12:03 ` Phillip Wood
2022-06-30 12:38 ` Phillip Wood
2022-06-30 13:25 ` Ævar Arnfjörð Bjarmason
2022-07-06 13:23 ` Phillip Wood
2022-07-07 11:17 ` Ævar Arnfjörð Bjarmason
2022-07-08 9:35 ` Phillip Wood
2022-07-08 14:20 ` [PATCH 0/7] xdiff: use standard alloc macros, share them via git-shared-util.h Ævar Arnfjörð Bjarmason
2022-07-08 14:20 ` [PATCH 1/7] xdiff: simplify freeing patterns around xdl_free_env() Ævar Arnfjörð Bjarmason
2022-07-08 14:20 ` [PATCH 2/7] git-shared-util.h: move "shared" allocation utilities here Ævar Arnfjörð Bjarmason
2022-07-08 14:20 ` [PATCH 3/7] git-shared-util.h: add G*() versions of *ALLOC_*() Ævar Arnfjörð Bjarmason
2022-07-11 10:06 ` Phillip Wood
2022-07-08 14:20 ` [PATCH 4/7] xdiff: use G[C]ALLOC_ARRAY(), not XDL_CALLOC_ARRAY() Ævar Arnfjörð Bjarmason
2022-07-11 10:10 ` Phillip Wood [this message]
2022-07-08 14:20 ` [PATCH 5/7] xdiff: use GALLOC_GROW(), not XDL_ALLOC_GROW() Ævar Arnfjörð Bjarmason
2022-07-11 10:13 ` Phillip Wood
2022-07-11 10:48 ` Ævar Arnfjörð Bjarmason
2022-07-13 9:09 ` Phillip Wood
2022-07-13 10:48 ` Ævar Arnfjörð Bjarmason
2022-07-13 13:21 ` Phillip Wood
2022-07-08 14:20 ` [PATCH 6/7] xdiff: remove xdl_malloc() wrapper, use malloc(), not xmalloc() Ævar Arnfjörð Bjarmason
2022-07-08 17:42 ` Phillip Wood
2022-07-08 21:44 ` Ævar Arnfjörð Bjarmason
2022-07-08 19:35 ` Jeff King
2022-07-08 21:47 ` Ævar Arnfjörð Bjarmason
2022-07-11 9:33 ` Jeff King
2022-07-08 14:20 ` [PATCH 7/7] xdiff: remove xdl_free(), use free() instead Ævar Arnfjörð Bjarmason
2022-07-08 17:51 ` Phillip Wood
2022-07-08 21:26 ` Ævar Arnfjörð Bjarmason
2022-07-11 9:26 ` Phillip Wood
2022-07-11 9:54 ` Phillip Wood
2022-07-11 10:02 ` Ævar Arnfjörð Bjarmason
2022-07-13 13:00 ` Phillip Wood
2022-07-13 13:18 ` Ævar Arnfjörð Bjarmason
2022-06-30 18:32 ` [PATCH 3/3] xdiff: introduce XDL_ALLOC_GROW() Junio C Hamano
2022-07-06 13:14 ` Phillip Wood
2022-06-30 10:46 ` [PATCH 0/3] xdiff: introduce memory allocation macros Ævar Arnfjörð Bjarmason
2022-07-08 16:25 ` [PATCH v2 0/4] " Phillip Wood via GitGitGadget
2022-07-08 16:25 ` [PATCH v2 1/4] xdiff: introduce XDL_ALLOC_ARRAY() Phillip Wood via GitGitGadget
2022-07-08 16:25 ` [PATCH v2 2/4] xdiff: introduce xdl_calloc Phillip Wood via GitGitGadget
2022-07-08 16:25 ` [PATCH v2 3/4] xdiff: introduce XDL_CALLOC_ARRAY() Phillip Wood via GitGitGadget
2022-07-08 16:25 ` [PATCH v2 4/4] xdiff: introduce XDL_ALLOC_GROW() Phillip Wood via GitGitGadget
2022-07-08 22:17 ` Ævar Arnfjörð Bjarmason
2022-07-11 10:00 ` Phillip Wood
2022-07-12 7:19 ` Jeff King
2022-07-13 9:38 ` Phillip Wood
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