From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-it0-f69.google.com (mail-it0-f69.google.com [209.85.214.69]) by kanga.kvack.org (Postfix) with ESMTP id 70BBC8E0005 for ; Wed, 12 Sep 2018 16:25:05 -0400 (EDT) Received: by mail-it0-f69.google.com with SMTP id e62-v6so5429744itb.3 for ; Wed, 12 Sep 2018 13:25:05 -0700 (PDT) Received: from aserp2120.oracle.com (aserp2120.oracle.com. [141.146.126.78]) by mx.google.com with ESMTPS id b62-v6si1616292iti.112.2018.09.12.13.25.04 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 12 Sep 2018 13:25:04 -0700 (PDT) From: Prakash Sangappa Subject: [PATCH V2 4/6] Add support to lseek /proc//numa_vamaps file Date: Wed, 12 Sep 2018 13:24:02 -0700 Message-Id: <1536783844-4145-5-git-send-email-prakash.sangappa@oracle.com> In-Reply-To: <1536783844-4145-1-git-send-email-prakash.sangappa@oracle.com> References: <1536783844-4145-1-git-send-email-prakash.sangappa@oracle.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: dave.hansen@intel.com, mhocko@suse.com, nao.horiguchi@gmail.com, akpm@linux-foundation.org, kirill.shutemov@linux.intel.com, khandual@linux.vnet.ibm.com, steven.sistare@oracle.com, prakash.sangappa@oracle.com Allow lseeking to a process virtual address(VA), starting from where the address range to numa node information can be read. The lseek offset will be the process virtual address. Signed-off-by: Prakash Sangappa Reviewed-by: Steve Sistare --- fs/proc/task_mmu.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 1371e379..93dce46 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -1866,6 +1866,27 @@ static int gather_hole_info_vamap(unsigned long start, unsigned long end, return 0; } +static loff_t numa_vamaps_llseek(struct file *file, loff_t offset, int orig) +{ + struct numa_vamaps_private *nvm = file->private_data; + + if (orig == SEEK_CUR && offset < 0 && nvm->vm_start < -offset) + return -EINVAL; + + switch (orig) { + case SEEK_SET: + nvm->vm_start = offset & PAGE_MASK; + break; + case SEEK_CUR: + nvm->vm_start += offset; + nvm->vm_start = nvm->vm_start & PAGE_MASK; + break; + default: + return -EINVAL; + } + return nvm->vm_start; +} + static int vamap_vprintf(struct numa_vamaps_private *nvm, const char *f, ...) { va_list args; @@ -2052,7 +2073,7 @@ const struct file_operations proc_pid_numa_maps_operations = { const struct file_operations proc_numa_vamaps_operations = { .open = numa_vamaps_open, .read = numa_vamaps_read, - .llseek = noop_llseek, + .llseek = numa_vamaps_llseek, .release = numa_vamaps_release, }; #endif /* CONFIG_NUMA */ -- 2.7.4