From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 65F2DC4708A for ; Tue, 29 Nov 2022 19:20:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236709AbiK2TUA (ORCPT ); Tue, 29 Nov 2022 14:20:00 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57256 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236735AbiK2TTM (ORCPT ); Tue, 29 Nov 2022 14:19:12 -0500 Received: from mail-wm1-x32c.google.com (mail-wm1-x32c.google.com [IPv6:2a00:1450:4864:20::32c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0440B6D489 for ; Tue, 29 Nov 2022 11:18:47 -0800 (PST) Received: by mail-wm1-x32c.google.com with SMTP id c65-20020a1c3544000000b003cfffd00fc0so15214731wma.1 for ; Tue, 29 Nov 2022 11:18:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=Wxyzq5HoGGPjbm+gODa1txXf4Q/7Y+OG+18WipqPvk8=; b=C7udiI9DZ9yrtSSFqKTvirw8jYU7kLh3jL5ugkLtf55sgtnKUK0l08r9A82M6adAaq jTkhTdaFW4s9L3hAvLP31VYKygvX0PS4i6Y5wHGHZiJ6mGvrUNTDyJap8TXhjRn+NSL1 U+9EPwBIcrL3NQPRXWuFblADZSBovx+GAKF33BCQ2fRRzBBs/cgDcqoOafCoIa2Wr85K kubHmbkWTRBLi+hYf5HI1atoQ4K/NF7JmiE2jfD3fDjl9H43JvRLkg+tVjsrhDkHE7nq drpoU9/5nF+HjuFS365ASEDU8WYmWjX3j4EEczY+2qLP0uskgXo+eXNBHFz31FHXc5Te u7GQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=Wxyzq5HoGGPjbm+gODa1txXf4Q/7Y+OG+18WipqPvk8=; b=qbv/JrGGKs8QnnuKfCZpn6PeOl8VaDl6EKHYVqslfUCXMEqIuVAlZR2eQnwiEd/qEW yhH0AvUEZYVWNLtuZfHtfO9MOm82PTQgsoYvhZhklqQsCUfEwRpnXjVk/zaQQRNDlEYo bwQsIGd2ZXE91NGOAuactfo5vsVkhv/W8bfVWIAVr3kCeeR/dGnL9VuxEoyMVZNGwirL BFj/PDVWRV+MLPJ1Evdm0/BRcyr9TelCoY1Ban86azJzvco7z5qMoVbtIFwaVbeDBdus RHd1ixiwCTQpUd1S7OOB7/ZYioKFqaCtkd2Eucynz75UILT5ngbV1T9+og7zojlbid8b O6aA== X-Gm-Message-State: ANoB5pld+ZYTOfcVOJOo6dNQuyyXyf1gQtvesRL8UpQxW0I7bIPfBp97 B59UTIMp5h3bDeU95N2cRYaVRA== X-Google-Smtp-Source: AA0mqf7kLqxJPfRzdFeSuQaSd8KasAfw0mgXxSdu4sxBwny26+wgEuzYUj7kChJX2IE1etT3yt85lg== X-Received: by 2002:a05:600c:3110:b0:3cf:b07a:cd56 with SMTP id g16-20020a05600c311000b003cfb07acd56mr44367090wmo.143.1669749526203; Tue, 29 Nov 2022 11:18:46 -0800 (PST) Received: from localhost ([2a00:79e0:9d:4:5011:adcc:fddd:accf]) by smtp.gmail.com with ESMTPSA id p9-20020adfce09000000b0022dc6e76bbdsm14349862wrn.46.2022.11.29.11.18.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 29 Nov 2022 11:18:45 -0800 (PST) From: Jann Horn To: Thomas Gleixner Cc: Andrei Vagin , linux-kernel@vger.kernel.org Subject: [PATCH 1/2] time/namespace: Refactor copy-pasted helper into one copy Date: Tue, 29 Nov 2022 20:18:38 +0100 Message-Id: <20221129191839.2471308-1-jannh@google.com> X-Mailer: git-send-email 2.38.1.584.g0f3c55d4c2-goog MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org find_timens_vvar_page() is not arch-specific, as can be seen from how all five per-architecture versions of it are the same. (arm64, powerpc and riscv are exactly the same; x86 and s390 have two characters difference inside a comment, less blank lines, and mark the !CONFIG_TIME_NS version as inline.) Refactor the five copies into a central copy in kernel/time/namespace.c. Marked for stable backporting because it is a prerequisite for the following patch. Cc: stable@vger.kernel.org Signed-off-by: Jann Horn --- arch/arm64/kernel/vdso.c | 22 ---------------------- arch/powerpc/kernel/vdso.c | 22 ---------------------- arch/riscv/kernel/vdso.c | 22 ---------------------- arch/s390/kernel/vdso.c | 20 -------------------- arch/x86/entry/vdso/vma.c | 23 ----------------------- include/linux/time_namespace.h | 6 ++++++ kernel/time/namespace.c | 20 ++++++++++++++++++++ 7 files changed, 26 insertions(+), 109 deletions(-) diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c index 99ae81ab91a74..e59a32aa0c49d 100644 --- a/arch/arm64/kernel/vdso.c +++ b/arch/arm64/kernel/vdso.c @@ -151,28 +151,6 @@ int vdso_join_timens(struct task_struct *task, struct time_namespace *ns) mmap_read_unlock(mm); return 0; } - -static struct page *find_timens_vvar_page(struct vm_area_struct *vma) -{ - if (likely(vma->vm_mm == current->mm)) - return current->nsproxy->time_ns->vvar_page; - - /* - * VM_PFNMAP | VM_IO protect .fault() handler from being called - * through interfaces like /proc/$pid/mem or - * process_vm_{readv,writev}() as long as there's no .access() - * in special_mapping_vmops. - * For more details check_vma_flags() and __access_remote_vm() - */ - WARN(1, "vvar_page accessed remotely"); - - return NULL; -} -#else -static struct page *find_timens_vvar_page(struct vm_area_struct *vma) -{ - return NULL; -} #endif static vm_fault_t vvar_fault(const struct vm_special_mapping *sm, diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c index 4abc019497020..507f8228f983b 100644 --- a/arch/powerpc/kernel/vdso.c +++ b/arch/powerpc/kernel/vdso.c @@ -129,28 +129,6 @@ int vdso_join_timens(struct task_struct *task, struct time_namespace *ns) return 0; } - -static struct page *find_timens_vvar_page(struct vm_area_struct *vma) -{ - if (likely(vma->vm_mm == current->mm)) - return current->nsproxy->time_ns->vvar_page; - - /* - * VM_PFNMAP | VM_IO protect .fault() handler from being called - * through interfaces like /proc/$pid/mem or - * process_vm_{readv,writev}() as long as there's no .access() - * in special_mapping_vmops. - * For more details check_vma_flags() and __access_remote_vm() - */ - WARN(1, "vvar_page accessed remotely"); - - return NULL; -} -#else -static struct page *find_timens_vvar_page(struct vm_area_struct *vma) -{ - return NULL; -} #endif static vm_fault_t vvar_fault(const struct vm_special_mapping *sm, diff --git a/arch/riscv/kernel/vdso.c b/arch/riscv/kernel/vdso.c index 123d05255fcfa..e410275918ac4 100644 --- a/arch/riscv/kernel/vdso.c +++ b/arch/riscv/kernel/vdso.c @@ -137,28 +137,6 @@ int vdso_join_timens(struct task_struct *task, struct time_namespace *ns) mmap_read_unlock(mm); return 0; } - -static struct page *find_timens_vvar_page(struct vm_area_struct *vma) -{ - if (likely(vma->vm_mm == current->mm)) - return current->nsproxy->time_ns->vvar_page; - - /* - * VM_PFNMAP | VM_IO protect .fault() handler from being called - * through interfaces like /proc/$pid/mem or - * process_vm_{readv,writev}() as long as there's no .access() - * in special_mapping_vmops. - * For more details check_vma_flags() and __access_remote_vm() - */ - WARN(1, "vvar_page accessed remotely"); - - return NULL; -} -#else -static struct page *find_timens_vvar_page(struct vm_area_struct *vma) -{ - return NULL; -} #endif static vm_fault_t vvar_fault(const struct vm_special_mapping *sm, diff --git a/arch/s390/kernel/vdso.c b/arch/s390/kernel/vdso.c index 3105ca5bd4701..d6df7169c01f2 100644 --- a/arch/s390/kernel/vdso.c +++ b/arch/s390/kernel/vdso.c @@ -44,21 +44,6 @@ struct vdso_data *arch_get_vdso_data(void *vvar_page) return (struct vdso_data *)(vvar_page); } -static struct page *find_timens_vvar_page(struct vm_area_struct *vma) -{ - if (likely(vma->vm_mm == current->mm)) - return current->nsproxy->time_ns->vvar_page; - /* - * VM_PFNMAP | VM_IO protect .fault() handler from being called - * through interfaces like /proc/$pid/mem or - * process_vm_{readv,writev}() as long as there's no .access() - * in special_mapping_vmops(). - * For more details check_vma_flags() and __access_remote_vm() - */ - WARN(1, "vvar_page accessed remotely"); - return NULL; -} - /* * The VVAR page layout depends on whether a task belongs to the root or * non-root time namespace. Whenever a task changes its namespace, the VVAR @@ -84,11 +69,6 @@ int vdso_join_timens(struct task_struct *task, struct time_namespace *ns) mmap_read_unlock(mm); return 0; } -#else -static inline struct page *find_timens_vvar_page(struct vm_area_struct *vma) -{ - return NULL; -} #endif static vm_fault_t vvar_fault(const struct vm_special_mapping *sm, diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c index 311eae30e0894..6b36485054e8a 100644 --- a/arch/x86/entry/vdso/vma.c +++ b/arch/x86/entry/vdso/vma.c @@ -98,24 +98,6 @@ static int vdso_mremap(const struct vm_special_mapping *sm, } #ifdef CONFIG_TIME_NS -static struct page *find_timens_vvar_page(struct vm_area_struct *vma) -{ - if (likely(vma->vm_mm == current->mm)) - return current->nsproxy->time_ns->vvar_page; - - /* - * VM_PFNMAP | VM_IO protect .fault() handler from being called - * through interfaces like /proc/$pid/mem or - * process_vm_{readv,writev}() as long as there's no .access() - * in special_mapping_vmops(). - * For more details check_vma_flags() and __access_remote_vm() - */ - - WARN(1, "vvar_page accessed remotely"); - - return NULL; -} - /* * The vvar page layout depends on whether a task belongs to the root or * non-root time namespace. Whenever a task changes its namespace, the VVAR @@ -140,11 +122,6 @@ int vdso_join_timens(struct task_struct *task, struct time_namespace *ns) return 0; } -#else -static inline struct page *find_timens_vvar_page(struct vm_area_struct *vma) -{ - return NULL; -} #endif static vm_fault_t vvar_fault(const struct vm_special_mapping *sm, diff --git a/include/linux/time_namespace.h b/include/linux/time_namespace.h index 3146f1c056c98..bb9d3f5542f8e 100644 --- a/include/linux/time_namespace.h +++ b/include/linux/time_namespace.h @@ -45,6 +45,7 @@ struct time_namespace *copy_time_ns(unsigned long flags, void free_time_ns(struct time_namespace *ns); void timens_on_fork(struct nsproxy *nsproxy, struct task_struct *tsk); struct vdso_data *arch_get_vdso_data(void *vvar_page); +struct page *find_timens_vvar_page(struct vm_area_struct *vma); static inline void put_time_ns(struct time_namespace *ns) { @@ -141,6 +142,11 @@ static inline void timens_on_fork(struct nsproxy *nsproxy, return; } +static inline struct page *find_timens_vvar_page(struct vm_area_struct *vma) +{ + return NULL; +} + static inline void timens_add_monotonic(struct timespec64 *ts) { } static inline void timens_add_boottime(struct timespec64 *ts) { } diff --git a/kernel/time/namespace.c b/kernel/time/namespace.c index aec832801c26c..761c0ada5142a 100644 --- a/kernel/time/namespace.c +++ b/kernel/time/namespace.c @@ -192,6 +192,26 @@ static void timens_setup_vdso_data(struct vdso_data *vdata, offset[CLOCK_BOOTTIME_ALARM] = boottime; } +struct page *find_timens_vvar_page(struct vm_area_struct *vma) +{ + if (likely(vma->vm_mm == current->mm)) + return current->nsproxy->time_ns->vvar_page; + + /* + * VM_PFNMAP | VM_IO protect .fault() handler from being called + * through interfaces like /proc/$pid/mem or + * process_vm_{readv,writev}() as long as there's no .access() + * in special_mapping_vmops(). + * For more details check_vma_flags() and __access_remote_vm() + */ + + WARN(1, "vvar_page accessed remotely"); + + return NULL; +} + + + /* * Protects possibly multiple offsets writers racing each other * and tasks entering the namespace. base-commit: ca57f02295f188d6c65ec02202402979880fa6d8 -- 2.38.1.584.g0f3c55d4c2-goog