From nobody Mon Feb 9 16:53:02 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass(p=quarantine dis=none) header.from=crudebyte.com ARC-Seal: i=1; a=rsa-sha256; t=1646401423; cv=none; d=zohomail.com; s=zohoarc; b=cLhnwNcLm7dbB/b0FDcZYBvJ3kqrhqFxv8YWItyOQvt17xMehvEhcz+ykZJTyJShXsTDeGxz374iLQNkFIGEqjsQp74ApXPHaaeHNPpISpTasanpRmYYSHfx5Bw7lxpkZIng1J3ZA6Hp0Kbj3yHzA624k5F/WQsr29yn0TwJtLM= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1646401423; h=Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:Message-ID:References:Sender:Subject:To; bh=ZLhjctf3DaE6G5VPiaCQu0lAdUS2EVV/reV2M8c9RTk=; b=OYRYI0qoEZ+2QZNzTUV794J7vjZ03+y/fweylLYr/0vEynKdF09d8JsoOe7/uCl/QEJU/Lx6EcEyliYponvA2arze9HPOKeTUNI1S10by/rgVS546BZTR/RbFX5TwIeKw8r0CyKBO//mpNJ3oKHYf87Jg4fDXf34NiTXT8BszlI= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass header.from= (p=quarantine dis=none) Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 164640142384138.94947096023145; Fri, 4 Mar 2022 05:43:43 -0800 (PST) Received: from localhost ([::1]:33628 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nQ8De-00063z-P5 for importer@patchew.org; Fri, 04 Mar 2022 08:43:42 -0500 Received: from eggs.gnu.org ([209.51.188.92]:52070) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from <24187e2b6419dbcb60f57ad204d3afdd0ac1b3a5@lizzy.crudebyte.com>) id 1nQ7uM-0008Lb-2k for qemu-devel@nongnu.org; Fri, 04 Mar 2022 08:23:51 -0500 Received: from lizzy.crudebyte.com ([91.194.90.13]:36137) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from <24187e2b6419dbcb60f57ad204d3afdd0ac1b3a5@lizzy.crudebyte.com>) id 1nQ7uK-00049e-7B for qemu-devel@nongnu.org; Fri, 04 Mar 2022 08:23:45 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=crudebyte.com; s=lizzy; h=Cc:To:Subject:Date:From:References:In-Reply-To: Message-Id:Content-Type:Content-Transfer-Encoding:MIME-Version:Content-ID: Content-Description; bh=ZLhjctf3DaE6G5VPiaCQu0lAdUS2EVV/reV2M8c9RTk=; b=BLTBx Mabp+8COVKTzHFaStU8lYTBvUqlOabsp5AY4C2ukN7IOoYrIdWFkK6zLfiTn6TD0jXRrQ8K6He4Sv uNbuTxWTfg2fGA89On7/FQDErjaoNMpSkfKIKZaFKBOAGdIJ5tLB+Fsj68OqcrBEzg/BuZTDC1S3D Unn9LltNYOKZq/kE69F6wPJrrIMZ4MQdbjsGsRNFvytdNxiyUeKNaV5qM8ex0J+/3fiuL13ZgWv/p hiAU3MAVAEtMAC/DuOnOr7OxL0mJRj9ZERgXaI2MGidZcmr6lwbPuZyvefpbUlhKw74VQSRXr14Lk PtDxQntDKft7t4aQRZrba0ZiREOLA==; Message-Id: <24187e2b6419dbcb60f57ad204d3afdd0ac1b3a5.1646396869.git.qemu_oss@crudebyte.com> In-Reply-To: References: From: Christian Schoenebeck Date: Fri, 04 Mar 2022 13:27:49 +0100 Subject: [PULL 09/19] 9p: darwin: Implement compatibility for mknodat To: qemu-devel@nongnu.org, Peter Maydell Cc: Greg Kurz Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: none client-ip=91.194.90.13; envelope-from=24187e2b6419dbcb60f57ad204d3afdd0ac1b3a5@lizzy.crudebyte.com; helo=lizzy.crudebyte.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_HELO_NONE=0.001, SPF_NONE=0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: pass (identity @crudebyte.com) X-ZM-MESSAGEID: 1646401425390100001 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: Keno Fischer Darwin does not support mknodat. However, to avoid race conditions with later setting the permissions, we must avoid using mknod on the full path instead. We could try to fchdir, but that would cause problems if multiple threads try to call mknodat at the same time. However, luckily there is a solution: Darwin includes a function that sets the cwd for the current thread only. This should suffice to use mknod safely. This function (pthread_fchdir_np) is protected by a check in meson in a patch later in this series. Signed-off-by: Keno Fischer Signed-off-by: Michael Roitzsch [Will Cohen: - Adjust coding style - Replace clang references with gcc - Note radar filed with Apple for missing syscall - Replace direct syscall with pthread_fchdir_np and adjust patch notes accordingly - Declare pthread_fchdir_np with - __attribute__((weak_import)) to allow checking for its presence before usage - Move declarations above cplusplus guard - Add CONFIG_PTHREAD_FCHDIR_NP to meson and check for presence in 9p-util - Rebase to apply cleanly on top of the 2022-02-10 changes to 9pfs - Fix line over 90 characters formatting error] Signed-off-by: Will Cohen Message-Id: <20220227223522.91937-10-wwcohen@gmail.com> Signed-off-by: Christian Schoenebeck Reviewed-by: Christian Schoenebeck --- hw/9pfs/9p-local.c | 4 ++-- hw/9pfs/9p-util-darwin.c | 33 +++++++++++++++++++++++++++++++++ hw/9pfs/9p-util-linux.c | 6 ++++++ hw/9pfs/9p-util.h | 11 +++++++++++ meson.build | 1 + 5 files changed, 53 insertions(+), 2 deletions(-) diff --git a/hw/9pfs/9p-local.c b/hw/9pfs/9p-local.c index a0d08e5216..d42ce6d8b8 100644 --- a/hw/9pfs/9p-local.c +++ b/hw/9pfs/9p-local.c @@ -682,7 +682,7 @@ static int local_mknod(FsContext *fs_ctx, V9fsPath *dir= _path, =20 if (fs_ctx->export_flags & V9FS_SM_MAPPED || fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) { - err =3D mknodat(dirfd, name, fs_ctx->fmode | S_IFREG, 0); + err =3D qemu_mknodat(dirfd, name, fs_ctx->fmode | S_IFREG, 0); if (err =3D=3D -1) { goto out; } @@ -697,7 +697,7 @@ static int local_mknod(FsContext *fs_ctx, V9fsPath *dir= _path, } } else if (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH || fs_ctx->export_flags & V9FS_SM_NONE) { - err =3D mknodat(dirfd, name, credp->fc_mode, credp->fc_rdev); + err =3D qemu_mknodat(dirfd, name, credp->fc_mode, credp->fc_rdev); if (err =3D=3D -1) { goto out; } diff --git a/hw/9pfs/9p-util-darwin.c b/hw/9pfs/9p-util-darwin.c index cdb4c9e24c..bec0253474 100644 --- a/hw/9pfs/9p-util-darwin.c +++ b/hw/9pfs/9p-util-darwin.c @@ -7,6 +7,8 @@ =20 #include "qemu/osdep.h" #include "qemu/xattr.h" +#include "qapi/error.h" +#include "qemu/error-report.h" #include "9p-util.h" =20 ssize_t fgetxattrat_nofollow(int dirfd, const char *filename, const char *= name, @@ -62,3 +64,34 @@ int fsetxattrat_nofollow(int dirfd, const char *filename= , const char *name, close_preserve_errno(fd); return ret; } + +/* + * As long as mknodat is not available on macOS, this workaround + * using pthread_fchdir_np is needed. + * + * Radar filed with Apple for implementing mknodat: + * rdar://FB9862426 (https://openradar.appspot.com/FB9862426) + */ +#if defined CONFIG_PTHREAD_FCHDIR_NP + +int qemu_mknodat(int dirfd, const char *filename, mode_t mode, dev_t dev) +{ + int preserved_errno, err; + if (!pthread_fchdir_np) { + error_report_once("pthread_fchdir_np() not available on this versi= on of macOS"); + return -ENOTSUP; + } + if (pthread_fchdir_np(dirfd) < 0) { + return -1; + } + err =3D mknod(filename, mode, dev); + preserved_errno =3D errno; + /* Stop using the thread-local cwd */ + pthread_fchdir_np(-1); + if (err < 0) { + errno =3D preserved_errno; + } + return err; +} + +#endif diff --git a/hw/9pfs/9p-util-linux.c b/hw/9pfs/9p-util-linux.c index 398614a5d0..db451b0784 100644 --- a/hw/9pfs/9p-util-linux.c +++ b/hw/9pfs/9p-util-linux.c @@ -61,4 +61,10 @@ int fsetxattrat_nofollow(int dirfd, const char *filename= , const char *name, ret =3D lsetxattr(proc_path, name, value, size, flags); g_free(proc_path); return ret; + +} + +int qemu_mknodat(int dirfd, const char *filename, mode_t mode, dev_t dev) +{ + return mknodat(dirfd, filename, mode, dev); } diff --git a/hw/9pfs/9p-util.h b/hw/9pfs/9p-util.h index 9abff79884..1f74d37558 100644 --- a/hw/9pfs/9p-util.h +++ b/hw/9pfs/9p-util.h @@ -112,5 +112,16 @@ static inline off_t qemu_dirent_off(struct dirent *den= t) #endif } =20 +/* + * As long as mknodat is not available on macOS, this workaround + * using pthread_fchdir_np is needed. qemu_mknodat is defined in + * os-posix.c. pthread_fchdir_np is weakly linked here as a guard + * in case it disappears in future macOS versions, because it is + * is a private API. + */ +#if defined CONFIG_DARWIN && defined CONFIG_PTHREAD_FCHDIR_NP +int pthread_fchdir_np(int fd) __attribute__((weak_import)); +#endif +int qemu_mknodat(int dirfd, const char *filename, mode_t mode, dev_t dev); =20 #endif diff --git a/meson.build b/meson.build index a5b63e62cd..6058ea3896 100644 --- a/meson.build +++ b/meson.build @@ -1622,6 +1622,7 @@ config_host_data.set('CONFIG_POSIX_FALLOCATE', cc.has= _function('posix_fallocate' config_host_data.set('CONFIG_POSIX_MEMALIGN', cc.has_function('posix_memal= ign')) config_host_data.set('CONFIG_PPOLL', cc.has_function('ppoll')) config_host_data.set('CONFIG_PREADV', cc.has_function('preadv', prefix: '#= include ')) +config_host_data.set('CONFIG_PTHREAD_FCHDIR_NP', cc.has_function('pthread_= fchdir_np')) config_host_data.set('CONFIG_SEM_TIMEDWAIT', cc.has_function('sem_timedwai= t', dependencies: threads)) config_host_data.set('CONFIG_SENDFILE', cc.has_function('sendfile')) config_host_data.set('CONFIG_SETNS', cc.has_function('setns') and cc.has_f= unction('unshare')) --=20 2.20.1