From: Oleg Nesterov <oleg@redhat.com>
To: Stas Sergeev <stsp2@yandex.ru>
Cc: linux-kernel@vger.kernel.org,
Alexander Viro <viro@zeniv.linux.org.uk>,
Christian Brauner <brauner@kernel.org>, Jan Kara <jack@suse.cz>,
Jens Axboe <axboe@kernel.dk>,
Andrew Morton <akpm@linux-foundation.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Florent Revest <revest@chromium.org>, Kees Cook <kees@kernel.org>,
Palmer Dabbelt <palmer@rivosinc.com>,
Charlie Jenkins <charlie@rivosinc.com>,
Benjamin Gray <bgray@linux.ibm.com>, Helge Deller <deller@gmx.de>,
Zev Weiss <zev@bewilderbeest.net>,
Samuel Holland <samuel.holland@sifive.com>,
linux-fsdevel@vger.kernel.org,
Eric Biederman <ebiederm@xmission.com>,
Andy Lutomirski <luto@kernel.org>,
Josh Triplett <josh@joshtriplett.org>
Subject: Re: [PATCH v3] add group restriction bitmap
Date: Tue, 1 Oct 2024 13:15:17 +0200 [thread overview]
Message-ID: <20241001111516.GA23907@redhat.com> (raw)
In-Reply-To: <20240930195958.389922-1-stsp2@yandex.ru>
I can't comment the intent, just some nits about implementation.
On 09/30, Stas Sergeev wrote:
>
> struct group_info {
> refcount_t usage;
> + unsigned int restrict_bitmap;
Why not unsigned long?
> int groups_search(const struct group_info *group_info, kgid_t grp)
> {
> unsigned int left, right;
> @@ -105,7 +108,7 @@ int groups_search(const struct group_info *group_info, kgid_t grp)
> else if (gid_lt(grp, group_info->gid[mid]))
> right = mid;
> else
> - return 1;
> + return mid + 1;
Suppose we change groups_search()
--- a/kernel/groups.c
+++ b/kernel/groups.c
@@ -104,8 +104,11 @@ int groups_search(const struct group_info *group_info, kgid_t grp)
left = mid + 1;
else if (gid_lt(grp, group_info->gid[mid]))
right = mid;
- else
- return 1;
+ else {
+ bool r = mid < BITS_PER_LONG &&
+ test_bit(mid, &group_info->restrict_bitmap);
+ return r ? -1 : 1;
+ }
}
return 0;
}
so that it returns, say, -1 if the found grp is restricted.
Then everything else can be greatly simplified, afaics...
Oleg.
next prev parent reply other threads:[~2024-10-01 11:15 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-09-30 19:59 [PATCH v3] add group restriction bitmap Stas Sergeev
2024-10-01 11:15 ` Oleg Nesterov [this message]
2024-10-01 11:37 ` stsp
2024-10-01 13:02 ` Oleg Nesterov
2024-10-01 13:29 ` stsp
2024-10-01 15:02 ` Oleg Nesterov
2024-10-01 15:28 ` stsp
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