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 E7E0D21A1C; Fri, 4 Oct 2024 02:26:17 +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=1728008778; cv=none; b=uC6VmhJbmxvKgVSlb9n0+A75SdCuyqoQTBRvDVc0CT0Cs0W+BacM/93x15EVJSKsXIJlGv9sOn+EoMfNZr9tyQEOiG74WS+wg6oY7InhZldYEknf0+1tDlcTePF381bUwDmxgmJ4pfaQA9UEdcjhUQGes2DEuwyy4ZwoQSQPjYc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728008778; c=relaxed/simple; bh=g02fdDsNR33eWNgHvfG1kZf5xmlE+HGU4pUmMwVneV0=; h=Date:To:From:Subject:Message-Id; b=acbFr1pHuJso0sjiKtoievUwuDKZfcWvk+MewMlsDIlTVMBwF1OOYwU0NDZXUE1ruRqI0XXJdZi/+mxGp425llkYWbUGfRlmhHxLINfi9t/FLdZcVOcBnZsHdsXwLrnWapZnYnLzUwgebVBKRl9ijw1xfAsU0aKI1eJq0pgXC/w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=Eri9gN7g; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="Eri9gN7g" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A4CFBC4CEC5; Fri, 4 Oct 2024 02:26:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1728008777; bh=g02fdDsNR33eWNgHvfG1kZf5xmlE+HGU4pUmMwVneV0=; h=Date:To:From:Subject:From; b=Eri9gN7gk+UUSdvPa8Uj0ojxf2KmyA7mKr3o+mUl9Ss7HHvmtm1hjxtlQ4AC1P+qI rSe3c/BPgHs9rPpxeFE1dK4iSFcSa58qVZ6Tcw9kyBSG4x34g75ZXPmkpmizqor31M BpoxY6uU9DtCuJK41PGY6uu2DoIYMiW/6LEoYcms= Date: Thu, 03 Oct 2024 19:26:17 -0700 To: mm-commits@vger.kernel.org,stable@vger.kernel.org,hca@linux.ibm.com,gor@linux.ibm.com,agordeev@linux.ibm.com,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-hotfixes-stable] fs-proc-kcorec-allow-translation-of-physical-memory-addresses.patch removed from -mm tree Message-Id: <20241004022617.A4CFBC4CEC5@smtp.kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: fs/proc/kcore.c: allow translation of physical memory addresses has been removed from the -mm tree. Its filename was fs-proc-kcorec-allow-translation-of-physical-memory-addresses.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Alexander Gordeev Subject: fs/proc/kcore.c: allow translation of physical memory addresses Date: Mon, 30 Sep 2024 14:21:19 +0200 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 --- arch/s390/include/asm/io.h | 2 + fs/proc/kcore.c | 36 +++++++++++++++++++++++++++++++++-- 2 files changed, 36 insertions(+), 2 deletions(-) --- a/arch/s390/include/asm/io.h~fs-proc-kcorec-allow-translation-of-physical-memory-addresses +++ a/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 --- a/fs/proc/kcore.c~fs-proc-kcorec-allow-translation-of-physical-memory-addresses +++ a/fs/proc/kcore.c @@ -50,6 +50,20 @@ static struct proc_dir_entry *proc_root_ #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; @@ -471,6 +485,8 @@ static ssize_t read_kcore_iter(struct ki 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 @@ -537,7 +553,8 @@ static ssize_t read_kcore_iter(struct ki } break; case KCORE_RAM: - pfn = __pa(start) >> PAGE_SHIFT; + phys = __pa(start); + pfn = phys >> PAGE_SHIFT; page = pfn_to_online_page(pfn); /* @@ -557,13 +574,28 @@ static ssize_t read_kcore_iter(struct ki 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; _ Patches currently in -mm which might be from agordeev@linux.ibm.com are