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From: Junio C Hamano <gitster@pobox.com>
To: Jeff King <peff@peff.net>
Cc: Toon Claes <toon@iotcl.com>,
	 git@vger.kernel.org,  Karthik Nayak <karthik.188@gmail.com>,
	 Anders Kaseorg <andersk@mit.edu>
Subject: Re: [PATCH] last-modified: fix bug caused by inproper initialized memory
Date: Tue, 09 Dec 2025 07:42:56 +0900	[thread overview]
Message-ID: <xmqq5xaglhn3.fsf@gitster.g> (raw)
In-Reply-To: <20251208201501.GA216526@coredump.intra.peff.net> (Jeff King's message of "Mon, 8 Dec 2025 15:15:01 -0500")

Jeff King <peff@peff.net> writes:

>   git grep 'memset(.*0,.*\* \?sizeof'
>
> that's looking for memsets of "0" that also multiply by sizeof. Looks
> like there are a few:
>
>   add-patch.c:    memset(hunk + 1, 0, (splittable_into - 1) * sizeof(*hunk));
>   builtin/last-modified.c:        memset(lm->scratch->words, 0x0, lm->scratch->word_alloc * sizeof(eword_t));
>   compat/simple-ipc/ipc-win32.c:  memset(ea, 0, NR_EA * sizeof(EXPLICIT_ACCESS));
>   diff-delta.c:   memset(hash, 0, hsize * sizeof(*hash));
>   hashmap.c:      memset(map->table, 0, map->tablesize * sizeof(struct hashmap_entry *));
>   pack-revindex.c:                memset(pos, 0, BUCKETS * sizeof(*pos));
>
> The first one is an oddball, but the other five could use it. So if we
> were to do a patch adding MEMZERO_ARRAY(), it would probably make sense
> to convert those spots. I'd be OK either way.

Thanks for making an excellent suggestion while I was away from the
keyboard ;-)

Between MEMZERO_ARRAY() and CLEAR_ARRAY(), I am on the fence.

  reply	other threads:[~2025-12-08 22:42 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-11-28 16:37 [PATCH] last-modified: fix bug caused by inproper initialized memory Toon Claes
2025-11-28 20:55 ` Jeff King
2025-11-28 22:20   ` Anders Kaseorg
2025-11-29 10:50     ` Jeff King
2025-12-08 11:47   ` Toon Claes
2025-12-08 20:15     ` Jeff King
2025-12-08 22:42       ` Junio C Hamano [this message]
2025-11-29  2:01 ` Junio C Hamano
2025-11-29  2:11   ` Junio C Hamano
2025-11-29  9:38     ` Toon Claes
2025-12-08 11:46 ` [PATCH v2] last-modified: fix use of uninitialized memory Toon Claes
2025-12-08 13:26   ` Junio C Hamano
2025-12-09  8:43     ` Toon Claes
2025-12-09 12:18       ` Junio C Hamano

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