Date: Tue, 26 Dec 2023 12:09:47 +0800 From: Zhenlei Huang <zlei@FreeBSD.org> To: Konstantin Belousov <kostikbel@gmail.com> Cc: "src-committers@freebsd.org" <src-committers@freebsd.org>, "dev-commits-src-all@freebsd.org" <dev-commits-src-all@freebsd.org>, "dev-commits-src-main@freebsd.org" <dev-commits-src-main@freebsd.org> Subject: Re: git: 2a1d50fc12f6 - main - vfs_domount_update(): correct fsidcmp() usage Message-ID: <640284C5-ACE1-4D31-9BBB-AF181C0C7632@FreeBSD.org> In-Reply-To: <ZYpPQoNvAIc81wOu@kib.kiev.ua> References: <202312260136.3BQ1aOxq051977@gitrepo.freebsd.org> <72190C27-0D45-4300-BB78-719F5EB510E9@FreeBSD.org> <78061056-76D8-457C-A522-8CE62B481317@FreeBSD.org> <ZYpPQoNvAIc81wOu@kib.kiev.ua>
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> On Dec 26, 2023, at 11:57 AM, Konstantin Belousov = <kostikbel@gmail.com> wrote: >=20 > On Tue, Dec 26, 2023 at 11:31:38AM +0800, Zhenlei Huang wrote: >>=20 >>=20 >>> On Dec 26, 2023, at 11:29 AM, Zhenlei Huang <zlei@FreeBSD.org> = wrote: >>>=20 >>>=20 >>>=20 >>>> On Dec 26, 2023, at 9:36 AM, Konstantin Belousov <kib@FreeBSD.org = <mailto:kib@FreeBSD.org>> wrote: >>>>=20 >>>> The branch main has been updated by kib: >>>>=20 >>>> URL: = https://cgit.FreeBSD.org/src/commit/?id=3D2a1d50fc12f6e604da834fbaea961d41= 2aae6e85 = <https://cgit.freebsd.org/src/commit/?id=3D2a1d50fc12f6e604da834fbaea961d4= 12aae6e85> >>>>=20 >>>> commit 2a1d50fc12f6e604da834fbaea961d412aae6e85 >>>> Author: Andrew Gierth <andrew@tao146.riddles.org.uk = <mailto:andrew@tao146.riddles.org.uk>> >>>> AuthorDate: 2023-12-24 12:04:21 +0000 >>>> Commit: Konstantin Belousov <kib@FreeBSD.org = <mailto:kib@FreeBSD.org>> >>>> CommitDate: 2023-12-26 01:35:46 +0000 >>>>=20 >>>> vfs_domount_update(): correct fsidcmp() usage >>>>=20 >>>> MFC after: 3 days >>>> --- >>>> sys/kern/vfs_mount.c | 2 +- >>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>>=20 >>>> diff --git a/sys/kern/vfs_mount.c b/sys/kern/vfs_mount.c >>>> index 8e54c832e9f1..331e4887c200 100644 >>>> --- a/sys/kern/vfs_mount.c >>>> +++ b/sys/kern/vfs_mount.c >>>> @@ -1388,7 +1388,7 @@ vfs_domount_update( >>>> error =3D EINVAL; >>>> goto end; >>>> } >>>> - if (fsidcmp(&fsid_up, &mp->mnt_stat.f_fsid) !=3D 0) { >>>> + if (fsidcmp(fsid_up, &mp->mnt_stat.f_fsid) !=3D 0) { >>>> error =3D ENOENT; >>>> goto end; >>>> } >>>=20 >>>=20 >>=20 >> The fsidcmp is currently defined as >> ``` >> #define fsidcmp(a, b) memcmp((a), (b), sizeof(fsid_t)) >> ``` > Yes, and the issue should be fixed by making it (inline) function, = which > automatically would type-check it args. An inline function sound much better (than macro). It is also simple ;) >=20 >>=20 >>>=20 >>> I guess we want to ensure ` typeof(a) =3D=3D typeof(b) =3D=3D fsid_t = `, to prevent such kind of error in future. >>>=20 >>> I see both gcc [1] and clang [2] have __builtin_types_compatible_p , = so probably a good definition of fsidcmp should be >>>=20 >>> ``` >>> #define TYPEASSERT(v, t) \ >>> _Static_assert(__builtin_types_compatible_p(typeof(v), t), = "Requires type '" #t "'") >>>=20 >>> #define fsidcmp(a, b) ({ \ >>> TYPEASSERT((a), fsid_t *); \ >>> TYPEASSERT((b), fsid_t *); \ >>> memcmp((a), (b), sizeof(fsid_t)); \ >>> }) >>> ``` >>>=20 >>> 1. https://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html = <https://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html>; >>> 2. https://clang.llvm.org/docs/LanguageExtensions.html = <https://clang.llvm.org/docs/LanguageExtensions.html>; >>> Best regards, >>> Zhenlei >>>=20 >>=20 >>=20
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