Date: Sat, 11 Jul 2020 13:08:17 +0000 (UTC) From: Edward Tomasz Napierala <trasz@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r363093 - head/sys/compat/linux Message-ID: <202007111308.06BD8H4R048496@repo.freebsd.org>
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Author: trasz Date: Sat Jul 11 13:08:16 2020 New Revision: 363093 URL: https://svnweb.freebsd.org/changeset/base/363093 Log: Make linux stat(2) return the same st_dev for every devfs instance. The reason for this is to work around an idiosyncrasy of glibc getttynam(3) implementation: it checks whether st_dev returned for fd 0 is the same as st_dev returned for the target of /proc/self/fd/0 symlink, and with linux chroots having their own devfs instance, the check will fail if you chrooted into it. PR: kern/240767 Reviewed by: kib MFC after: 2 weeks Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D25559 Modified: head/sys/compat/linux/linux_stats.c Modified: head/sys/compat/linux/linux_stats.c ============================================================================== --- head/sys/compat/linux/linux_stats.c Sat Jul 11 09:43:16 2020 (r363092) +++ head/sys/compat/linux/linux_stats.c Sat Jul 11 13:08:16 2020 (r363093) @@ -70,6 +70,17 @@ translate_vnhook_major_minor(struct vnode *vp, struct sb->st_mode |= S_IFBLK; } + /* + * Return the same st_dev for every devfs instance. The reason + * for this is to work around an idiosyncrasy of glibc getttynam() + * implementation: it checks whether st_dev returned for fd 0 + * is the same as st_dev returned for the target of /proc/self/fd/0 + * symlink, and with linux chroots having their own devfs instance, + * the check will fail if you chroot into it. + */ + if (rootdevmp != NULL && vp->v_mount->mnt_vfc == rootdevmp->mnt_vfc) + sb->st_dev = rootdevmp->mnt_stat.f_fsid.val[0]; + if (vp->v_type == VCHR && vp->v_rdev != NULL && linux_driver_get_major_minor(devtoname(vp->v_rdev), &major, &minor) == 0) { @@ -110,6 +121,7 @@ translate_fd_major_minor(struct thread *td, int fd, st { struct file *fp; struct vnode *vp; + struct mount *mp; int major, minor; /* @@ -122,6 +134,12 @@ translate_fd_major_minor(struct thread *td, int fd, st if (vp != NULL && vn_isdisk(vp, NULL)) { buf->st_mode &= ~S_IFMT; buf->st_mode |= S_IFBLK; + } + if (vp != NULL && rootdevmp != NULL) { + mp = vp->v_mount; + __compiler_membar(); + if (mp != NULL && mp->mnt_vfc == rootdevmp->mnt_vfc) + buf->st_dev = rootdevmp->mnt_stat.f_fsid.val[0]; } if (vp != NULL && vp->v_rdev != NULL && linux_driver_get_major_minor(devtoname(vp->v_rdev),
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