From mboxrd@z Thu Jan 1 00:00:00 1970 From: akpm@linux-foundation.org Subject: [merged] maccess-return-erange-when-copy_from_kernel_nofault_allowed-fails.patch removed from -mm tree Date: Tue, 09 Jun 2020 17:40:40 -0700 Message-ID: <20200610004040.4SZ6OqL65%akpm@linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Return-path: Received: from mail.kernel.org ([198.145.29.99]:42302 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726017AbgFJAkl (ORCPT ); Tue, 9 Jun 2020 20:40:41 -0400 Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: ast@kernel.org, daniel@iogearbox.net, hch@lst.de, hpa@zytor.com, mhiramat@kernel.org, mingo@elte.hu, mm-commits@vger.kernel.org, tglx@linutronix.de The patch titled Subject: maccess: return -ERANGE when probe_kernel_read() fails has been removed from the -mm tree. Its filename was maccess-return-erange-when-copy_from_kernel_nofault_allowed-fails.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Christoph Hellwig Subject: maccess: return -ERANGE when probe_kernel_read() fails Allow the callers to distinguish a real unmapped address vs a range that can't be probed. Link: http://lkml.kernel.org/r/20200521152301.2587579-24-hch@lst.de Signed-off-by: Christoph Hellwig Suggested-by: Masami Hiramatsu Reviewed-by: Masami Hiramatsu Cc: Alexei Starovoitov Cc: Daniel Borkmann Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Thomas Gleixner Signed-off-by: Andrew Morton --- mm/maccess.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) --- a/mm/maccess.c~maccess-return-erange-when-copy_from_kernel_nofault_allowed-fails +++ a/mm/maccess.c @@ -24,7 +24,7 @@ bool __weak probe_kernel_read_allowed(co long probe_kernel_read(void *dst, const void *src, size_t size) { if (!probe_kernel_read_allowed(src, size)) - return -EFAULT; + return -ERANGE; pagefault_disable(); probe_kernel_read_loop(dst, src, size, u64, Efault); @@ -68,7 +68,7 @@ long strncpy_from_kernel_nofault(char *d if (unlikely(count <= 0)) return 0; if (!probe_kernel_read_allowed(unsafe_addr, count)) - return -EFAULT; + return -ERANGE; pagefault_disable(); do { @@ -93,7 +93,8 @@ Efault: * @size: size of the data chunk * * Safely read from kernel address @src to the buffer at @dst. If a kernel - * fault happens, handle that and return -EFAULT. + * fault happens, handle that and return -EFAULT. If @src is not a valid kernel + * address, return -ERANGE. * * We ensure that the copy_from_user is executed in atomic context so that * do_page_fault() doesn't attempt to take mmap_lock. This makes @@ -106,7 +107,7 @@ long probe_kernel_read(void *dst, const mm_segment_t old_fs = get_fs(); if (!probe_kernel_read_allowed(src, size)) - return -EFAULT; + return -ERANGE; set_fs(KERNEL_DS); pagefault_disable(); @@ -158,8 +159,9 @@ long probe_kernel_write(void *dst, const * * On success, returns the length of the string INCLUDING the trailing NUL. * - * If access fails, returns -EFAULT (some data may have been copied - * and the trailing NUL added). + * If access fails, returns -EFAULT (some data may have been copied and the + * trailing NUL added). If @unsafe_addr is not a valid kernel address, return + * -ERANGE. * * If @count is smaller than the length of the string, copies @count-1 bytes, * sets the last byte of @dst buffer to NUL and returns @count. @@ -173,7 +175,7 @@ long strncpy_from_kernel_nofault(char *d if (unlikely(count <= 0)) return 0; if (!probe_kernel_read_allowed(unsafe_addr, count)) - return -EFAULT; + return -ERANGE; set_fs(KERNEL_DS); pagefault_disable(); _ Patches currently in -mm which might be from hch@lst.de are amdgpu-a-null-mm-does-not-mean-a-thread-is-a-kthread.patch kernel-move-use_mm-unuse_mm-to-kthreadc.patch kernel-move-use_mm-unuse_mm-to-kthreadc-v2.patch kernel-better-document-the-use_mm-unuse_mm-api-contract.patch kernel-better-document-the-use_mm-unuse_mm-api-contract-v2.patch kernel-set-user_ds-in-kthread_use_mm.patch