From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F121D1E909B; Wed, 6 Nov 2024 12:43:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730897014; cv=none; b=UMYe7gJw10Zv2G/VFgg3+plkfhiko1V95s07k6tz8ogZ2oSI65ugCrifK+dlLCk2PYD6bfIksITR72y/LDC+RXqqSHTazmo4TLDzfX3oxKkYXZG20jeTM8V2WKjbvw1uHucfVAf21dMzTYEKumlfpXXvlsh1pymHa/lHx4sEbaY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730897014; c=relaxed/simple; bh=VxIUSFcd+iEZBrjcSYFDjSRpLwGEkhRMgnFTfT4CwXw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Wi3v3WQiJATuaTKNvES969RmVB1ZPLR+LX6kgHfFtYxJJ1V7Ivc/6hbGB/7sBhANGrlXzxgUft2mZ1WASf2Sp04Agx1XvKVWBwH3pDjnaAGRFvHEBvz9yyGnmn1MoVf++qxqS8+vr+AvFesfk28qxeEJUqX0088bHCjtBNJBj3M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Dw6PCFUx; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Dw6PCFUx" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 34904C4CED3; Wed, 6 Nov 2024 12:43:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1730897013; bh=VxIUSFcd+iEZBrjcSYFDjSRpLwGEkhRMgnFTfT4CwXw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Dw6PCFUx0mSQiPLEaRlkoRhzlG5vAMOBUkmuNr8AiorbhC+O9KrKqWEcrYYolA1wU NTxp8ETJ0m7oovaFH8wMAmEeYDc4SFuTcerD23KpkJQ1/Sb8VA89cO9f7E/HOenzPM rFuVlcWH5am40+q0Zn0WA1AjavartO9YjrGKjys8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Alexander Gordeev , Heiko Carstens , Vasily Gorbik , Andrew Morton , Sasha Levin Subject: [PATCH 6.1 008/126] fs/proc/kcore.c: allow translation of physical memory addresses Date: Wed, 6 Nov 2024 13:03:29 +0100 Message-ID: <20241106120306.292454731@linuxfoundation.org> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241106120306.038154857@linuxfoundation.org> References: <20241106120306.038154857@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alexander Gordeev [ Upstream commit 3d5854d75e3187147613130561b58f0b06166172 ] When /proc/kcore is read an attempt to read the first two pages results in HW-specific page swap on s390 and another (so called prefix) pages are accessed instead. That leads to a wrong read. Allow architecture-specific translation of memory addresses using kc_xlate_dev_mem_ptr() and kc_unxlate_dev_mem_ptr() callbacks similarily to /dev/mem xlate_dev_mem_ptr() and unxlate_dev_mem_ptr() callbacks. That way an architecture can deal with specific physical memory ranges. Re-use the existing /dev/mem callback implementation on s390, which handles the described prefix pages swapping correctly. For other architectures the default callback is basically NOP. It is expected the condition (vaddr == __va(__pa(vaddr))) always holds true for KCORE_RAM memory type. Link: https://lkml.kernel.org/r/20240930122119.1651546-1-agordeev@linux.ibm.com Signed-off-by: Alexander Gordeev Suggested-by: Heiko Carstens Cc: Vasily Gorbik Cc: Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin --- arch/s390/include/asm/io.h | 2 ++ fs/proc/kcore.c | 36 ++++++++++++++++++++++++++++++++++-- 2 files changed, 36 insertions(+), 2 deletions(-) diff --git a/arch/s390/include/asm/io.h b/arch/s390/include/asm/io.h index e3882b012bfa4..70e679d87984b 100644 --- a/arch/s390/include/asm/io.h +++ b/arch/s390/include/asm/io.h @@ -16,8 +16,10 @@ #include #define xlate_dev_mem_ptr xlate_dev_mem_ptr +#define kc_xlate_dev_mem_ptr xlate_dev_mem_ptr void *xlate_dev_mem_ptr(phys_addr_t phys); #define unxlate_dev_mem_ptr unxlate_dev_mem_ptr +#define kc_unxlate_dev_mem_ptr unxlate_dev_mem_ptr void unxlate_dev_mem_ptr(phys_addr_t phys, void *addr); #define IO_SPACE_LIMIT 0 diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c index 87a46f2d84195..a2d430549012f 100644 --- a/fs/proc/kcore.c +++ b/fs/proc/kcore.c @@ -51,6 +51,20 @@ static struct proc_dir_entry *proc_root_kcore; #define kc_offset_to_vaddr(o) ((o) + PAGE_OFFSET) #endif +#ifndef kc_xlate_dev_mem_ptr +#define kc_xlate_dev_mem_ptr kc_xlate_dev_mem_ptr +static inline void *kc_xlate_dev_mem_ptr(phys_addr_t phys) +{ + return __va(phys); +} +#endif +#ifndef kc_unxlate_dev_mem_ptr +#define kc_unxlate_dev_mem_ptr kc_unxlate_dev_mem_ptr +static inline void kc_unxlate_dev_mem_ptr(phys_addr_t phys, void *virt) +{ +} +#endif + static LIST_HEAD(kclist_head); static DECLARE_RWSEM(kclist_lock); static int kcore_need_update = 1; @@ -474,6 +488,8 @@ read_kcore_iter(struct kiocb *iocb, struct iov_iter *iter) while (buflen) { struct page *page; unsigned long pfn; + phys_addr_t phys; + void *__start; /* * If this is the first iteration or the address is not within @@ -523,7 +539,8 @@ read_kcore_iter(struct kiocb *iocb, struct iov_iter *iter) } break; case KCORE_RAM: - pfn = __pa(start) >> PAGE_SHIFT; + phys = __pa(start); + pfn = phys >> PAGE_SHIFT; page = pfn_to_online_page(pfn); /* @@ -542,13 +559,28 @@ read_kcore_iter(struct kiocb *iocb, struct iov_iter *iter) fallthrough; case KCORE_VMEMMAP: case KCORE_TEXT: + if (m->type == KCORE_RAM) { + __start = kc_xlate_dev_mem_ptr(phys); + if (!__start) { + ret = -ENOMEM; + if (iov_iter_zero(tsz, iter) != tsz) + ret = -EFAULT; + goto out; + } + } else { + __start = (void *)start; + } + /* * Sadly we must use a bounce buffer here to be able to * make use of copy_from_kernel_nofault(), as these * memory regions might not always be mapped on all * architectures. */ - if (copy_from_kernel_nofault(buf, (void *)start, tsz)) { + ret = copy_from_kernel_nofault(buf, __start, tsz); + if (m->type == KCORE_RAM) + kc_unxlate_dev_mem_ptr(phys, __start); + if (ret) { if (iov_iter_zero(tsz, iter) != tsz) { ret = -EFAULT; goto out; -- 2.43.0