Date: Tue, 26 Dec 2023 11:29:50 +0800 From: Zhenlei Huang <zlei@FreeBSD.org> To: Konstantin Belousov <kib@FreeBSD.org> 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: <72190C27-0D45-4300-BB78-719F5EB510E9@FreeBSD.org> In-Reply-To: <202312260136.3BQ1aOxq051977@gitrepo.freebsd.org> References: <202312260136.3BQ1aOxq051977@gitrepo.freebsd.org>
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[-- Attachment #1 --] > On Dec 26, 2023, at 9:36 AM, Konstantin Belousov <kib@FreeBSD.org> wrote: > > The branch main has been updated by kib: > > URL: https://cgit.FreeBSD.org/src/commit/?id=2a1d50fc12f6e604da834fbaea961d412aae6e85 > > commit 2a1d50fc12f6e604da834fbaea961d412aae6e85 > Author: Andrew Gierth <andrew@tao146.riddles.org.uk> > AuthorDate: 2023-12-24 12:04:21 +0000 > Commit: Konstantin Belousov <kib@FreeBSD.org> > CommitDate: 2023-12-26 01:35:46 +0000 > > vfs_domount_update(): correct fsidcmp() usage > > MFC after: 3 days > --- > sys/kern/vfs_mount.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > 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 = EINVAL; > goto end; > } > - if (fsidcmp(&fsid_up, &mp->mnt_stat.f_fsid) != 0) { > + if (fsidcmp(fsid_up, &mp->mnt_stat.f_fsid) != 0) { > error = ENOENT; > goto end; > } I guess we want to ensure ` typeof(a) == typeof(b) == fsid_t `, to prevent such kind of error in future. I see both gcc [1] and clang [2] have __builtin_types_compatible_p , so probably a good definition of fsidcmp should be ``` #define TYPEASSERT(v, t) \ _Static_assert(__builtin_types_compatible_p(typeof(v), t), "Requires type '" #t "'") #define fsidcmp(a, b) ({ \ TYPEASSERT((a), fsid_t *); \ TYPEASSERT((b), fsid_t *); \ memcmp((a), (b), sizeof(fsid_t)); \ }) ``` 1. https://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html 2. https://clang.llvm.org/docs/LanguageExtensions.html Best regards, Zhenlei [-- Attachment #2 --] <html><head><meta http-equiv="Content-Type" content="text/html; charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><br class=""><div><br class=""><blockquote type="cite" class=""><div class="">On Dec 26, 2023, at 9:36 AM, Konstantin Belousov <<a href="mailto:kib@FreeBSD.org" class="">kib@FreeBSD.org</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div class="">The branch main has been updated by kib:<br class=""><br class="">URL: <a href="https://cgit.FreeBSD.org/src/commit/?id=2a1d50fc12f6e604da834fbaea961d412aae6e85" class="">https://cgit.FreeBSD.org/src/commit/?id=2a1d50fc12f6e604da834fbaea961d412aae6e85</a><br class=""><br class="">commit 2a1d50fc12f6e604da834fbaea961d412aae6e85<br class="">Author: Andrew Gierth <<a href="mailto:andrew@tao146.riddles.org.uk" class="">andrew@tao146.riddles.org.uk</a>><br class="">AuthorDate: 2023-12-24 12:04:21 +0000<br class="">Commit: Konstantin Belousov <<a href="mailto:kib@FreeBSD.org" class="">kib@FreeBSD.org</a>><br class="">CommitDate: 2023-12-26 01:35:46 +0000<br class=""><br class=""> vfs_domount_update(): correct fsidcmp() usage<br class=""><br class=""> MFC after: 3 days<br class="">---<br class=""> sys/kern/vfs_mount.c | 2 +-<br class=""> 1 file changed, 1 insertion(+), 1 deletion(-)<br class=""><br class="">diff --git a/sys/kern/vfs_mount.c b/sys/kern/vfs_mount.c<br class="">index 8e54c832e9f1..331e4887c200 100644<br class="">--- a/sys/kern/vfs_mount.c<br class="">+++ b/sys/kern/vfs_mount.c<br class="">@@ -1388,7 +1388,7 @@ vfs_domount_update(<br class=""> <span class="Apple-tab-span" style="white-space:pre"> </span><span class="Apple-tab-span" style="white-space:pre"> </span><span class="Apple-tab-span" style="white-space:pre"> </span>error = EINVAL;<br class=""> <span class="Apple-tab-span" style="white-space:pre"> </span><span class="Apple-tab-span" style="white-space:pre"> </span><span class="Apple-tab-span" style="white-space:pre"> </span>goto end;<br class=""> <span class="Apple-tab-span" style="white-space:pre"> </span><span class="Apple-tab-span" style="white-space:pre"> </span>}<br class="">-<span class="Apple-tab-span" style="white-space:pre"> </span><span class="Apple-tab-span" style="white-space:pre"> </span>if (fsidcmp(&fsid_up, &mp->mnt_stat.f_fsid) != 0) {<br class="">+<span class="Apple-tab-span" style="white-space:pre"> </span><span class="Apple-tab-span" style="white-space:pre"> </span>if (fsidcmp(fsid_up, &mp->mnt_stat.f_fsid) != 0) {</div></div></blockquote><blockquote type="cite" class=""><div class=""><div class=""> <span class="Apple-tab-span" style="white-space:pre"> </span><span class="Apple-tab-span" style="white-space:pre"> </span><span class="Apple-tab-span" style="white-space:pre"> </span>error = ENOENT;<br class=""> <span class="Apple-tab-span" style="white-space:pre"> </span><span class="Apple-tab-span" style="white-space:pre"> </span><span class="Apple-tab-span" style="white-space:pre"> </span>goto end;<br class=""> <span class="Apple-tab-span" style="white-space:pre"> </span><span class="Apple-tab-span" style="white-space:pre"> </span>}<br class=""></div></div></blockquote></div><div class=""><br class=""></div><div class=""><br class=""></div><div class="">I guess we want to ensure ` typeof(a) == typeof(b) == <span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class="">fsid_t `, to prevent such kind of error in future.</span></div><div class=""><br class=""></div><div class=""><font color="#000000" class=""><span style="caret-color: rgb(0, 0, 0);" class="">I see both gcc [1] and clang [2] have __builtin_types_compatible_p , so probably a good definition of </span></font><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class="">fsidcmp should be</span></div><div class=""><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class=""><br class=""></span></div><div class=""><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class="">```</span></div><div class=""><font color="#000000" class=""><span style="caret-color: rgb(0, 0, 0);" class="">#define TYPEASSERT(v, t) \</span></font></div><div class=""><font color="#000000" class=""><span style="caret-color: rgb(0, 0, 0);" class=""><span class="Apple-tab-span" style="white-space:pre"> </span>_Static_assert(__builtin_types_compatible_p(typeof(v), t), "Requires type '" #t "'")</span></font></div><div class=""><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class=""><br class=""></span></div><div class=""><font color="#000000" class=""><span style="caret-color: rgb(0, 0, 0);" class="">#define fsidcmp(a, b) ({ \</span></font></div><div class=""><font color="#000000" class=""><span style="caret-color: rgb(0, 0, 0);" class=""><span class="Apple-tab-span" style="white-space:pre"> </span></span></font><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class="">TYPEASSERT((a), </span><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class="">fsid_t *); \</span></div><div class=""><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class=""><span class="Apple-tab-span" style="white-space:pre"> </span>TYPEASSERT((b), </span><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class="">fsid_t *); \</span></div><div class=""><span class="Apple-tab-span" style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); white-space: pre;"> </span><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class="">memcmp((a), (b), sizeof(fsid_t)); \</span></div><div class=""><div class=""><font color="#000000" class=""><span style="caret-color: rgb(0, 0, 0);" class="">})</span></font></div><div class=""><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class="">```</span></div><div class=""><font color="#000000" class=""><span style="caret-color: rgb(0, 0, 0);" class=""><br class=""></span></font></div><div class=""><font color="#000000" class=""><span style="caret-color: rgb(0, 0, 0);" class=""><div class="">1. <a href="https://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html" class="">https://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html</a></div><div class="">2. <a href="https://clang.llvm.org/docs/LanguageExtensions.html" class="">https://clang.llvm.org/docs/LanguageExtensions.html</a></div></span></font></div><br class=""><div class=""> <div>Best regards,</div><div>Zhenlei</div> </div> <br class=""></div></body></html>
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