From: Steven Rostedt <rostedt@goodmis.org>
To: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Mike Rapoport <rppt@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
LKML <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@kernel.org>, Linux-MM <linux-mm@kvack.org>,
Vlastimil Babka <vbabka@suse.cz>
Subject: Re: [PATCH v3 3/3] bootconfig: Free xbc_data in xbc_destroy_all()
Date: Wed, 15 Sep 2021 10:23:54 -0400 [thread overview]
Message-ID: <20210915102354.2841798d@oasis.local.home> (raw)
In-Reply-To: <163171199244.590070.6356174550728998874.stgit@devnote2>
On Wed, 15 Sep 2021 22:19:52 +0900
Masami Hiramatsu <mhiramat@kernel.org> wrote:
> @@ -810,6 +811,8 @@ void __init xbc_destroy_all(void)
> * In error cases, @emsg will be updated with an error message and
> * @epos will be updated with the error position which is the byte offset
> * of @buf. If the error is not a parser error, @epos will be -1.
> + * Note that the @buf ownership is transferred, so it will be freed
> + * in xbc_destroy_all().
> */
> int __init xbc_init(char *buf, const char **emsg, int *epos)
> {
I hate this "ownership transfer". Looking at the use case here:
init/main.c:
copy = memblock_alloc(size + 1, SMP_CACHE_BYTES);
if (!copy) {
pr_err("Failed to allocate memory for bootconfig\n");
return;
}
memcpy(copy, data, size);
copy[size] = '\0';
ret = xbc_init(copy, &msg, &pos);
if (ret < 0) {
Instead of having xbc_init() return the node count on success, how about
having it allocate the buffer to use and then return it?
That is, move the:
copy = memblock_alloc(size + 1, SMP_CACHE_BYTES);
if (!copy) {
pr_err("Failed to allocate memory for bootconfig\n");
return;
}
memcpy(copy, data, size);
copy[size] = '\0';
into xbc_init(), and have data, and size be passed to it.
Then, have it return the pointer of "copy" or NULL on error?
This will keep the semantics of xbc_* owning the buffer that gets
freed by the destroy.
The xbc_init() could also do the pr_info() that prints the bytes and
node count. There's no other reason to pass that node count to the
caller, is there?
-- Steve
next prev parent reply other threads:[~2021-09-15 14:24 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-15 13:19 [PATCH v3 0/3] bootconfig: Fixes to bootconfig memory management Masami Hiramatsu
2021-09-15 13:19 ` [PATCH v3 1/3] bootconfig: init: Fix memblock leak in xbc_make_cmdline() Masami Hiramatsu
2021-09-15 13:19 ` [PATCH v3 2/3] bootconfig: init: Fix memblock leak in setup_boot_config() Masami Hiramatsu
2021-09-15 13:19 ` [PATCH v3 3/3] bootconfig: Free xbc_data in xbc_destroy_all() Masami Hiramatsu
2021-09-15 14:23 ` Steven Rostedt [this message]
2021-09-16 0:05 ` Masami Hiramatsu
2021-09-16 0:17 ` Steven Rostedt
2021-09-15 16:47 ` [PATCH v3 0/3] bootconfig: Fixes to bootconfig memory management Linus Torvalds
2021-09-15 16:51 ` Linus Torvalds
2021-09-16 0:07 ` Masami Hiramatsu
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