From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf0-f53.google.com (mail-lf0-f53.google.com [209.85.215.53]) by kanga.kvack.org (Postfix) with ESMTP id 5EFDC6B0009 for ; Sat, 23 Jan 2016 15:52:36 -0500 (EST) Received: by mail-lf0-f53.google.com with SMTP id m198so65359352lfm.0 for ; Sat, 23 Jan 2016 12:52:36 -0800 (PST) Received: from mail-lf0-x244.google.com (mail-lf0-x244.google.com. [2a00:1450:4010:c07::244]) by mx.google.com with ESMTPS id p2si5905635lfb.55.2016.01.23.12.52.34 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 23 Jan 2016 12:52:34 -0800 (PST) Received: by mail-lf0-x244.google.com with SMTP id n70so5891778lfn.1 for ; Sat, 23 Jan 2016 12:52:34 -0800 (PST) Subject: [PATCH v3] mm: warn about VmData over RLIMIT_DATA From: Konstantin Khlebnikov Date: Sat, 23 Jan 2016 23:52:29 +0300 Message-ID: <145358234948.18573.2681359119037889087.stgit@zurg> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Cyrill Gorcunov , linux-mm@kvack.org, Linus Torvalds , Andrew Morton , linux-kernel@vger.kernel.org Cc: Vegard Nossum , Peter Zijlstra , Vladimir Davydov , Andy Lutomirski , Quentin Casasnovas , Kees Cook , Willy Tarreau , Pavel Emelyanov This patch fixes 84638335900f ("mm: rework virtual memory accounting") Before that commit RLIMIT_DATA have control only over size of the brk region. But that change have caused problems with all existing versions of valgrind, because it set RLIMIT_DATA to zero. This patch fixes rlimit check (limit actually in bytes, not pages) and by default turns it into warning which prints at first VmData misuse: "mmap: top (795): VmData 516096 exceed data ulimit 512000. Will be forbidden soon." Behavior is controlled by boot param ignore_rlimit_data=y/n and by sysfs /sys/module/kernel/parameters/ignore_rlimit_data. For now it set to "y". Signed-off-by: Konstantin Khlebnikov Link: http://lkml.kernel.org/r/20151228211015.GL2194@uranus Reported-by: Christian Borntraeger --- Documentation/kernel-parameters.txt | 5 +++++ mm/internal.h | 16 ++++++++++++++++ mm/mmap.c | 23 +++++++++++++++++------ 3 files changed, 38 insertions(+), 6 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index cfb2c0f1a4a8..e3507c2e14b0 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1461,6 +1461,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted. could change it dynamically, usually by /sys/module/printk/parameters/ignore_loglevel. + ignore_rlimit_data + Ignore RLIMIT_DATA setting for data mappings, + print warning at first misuse. Could be changed by + /sys/module/kernel/parameters/ignore_rlimit_data. + ihash_entries= [KNL] Set number of hash buckets for inode cache. diff --git a/mm/internal.h b/mm/internal.h index ed8b5ffcf9b1..6e976302ddd8 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -216,6 +216,22 @@ static inline bool is_cow_mapping(vm_flags_t flags) return (flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; } +static inline bool is_exec_mapping(vm_flags_t flags) +{ + return (flags & (VM_EXEC | VM_WRITE)) == VM_EXEC; +} + +static inline bool is_stack_mapping(vm_flags_t flags) +{ + return (flags & (VM_STACK_FLAGS & (VM_GROWSUP | VM_GROWSDOWN))) != 0; +} + +static inline bool is_data_mapping(vm_flags_t flags) +{ + return (flags & ((VM_STACK_FLAGS & (VM_GROWSUP | VM_GROWSDOWN)) | + VM_WRITE | VM_SHARED)) == VM_WRITE; +} + /* mm/util.c */ void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma, struct vm_area_struct *prev, struct rb_node *rb_parent); diff --git a/mm/mmap.c b/mm/mmap.c index 84b12624ceb0..cfc0cdca421e 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -42,6 +42,7 @@ #include #include #include +#include #include #include @@ -69,6 +70,8 @@ const int mmap_rnd_compat_bits_max = CONFIG_ARCH_MMAP_RND_COMPAT_BITS_MAX; int mmap_rnd_compat_bits __read_mostly = CONFIG_ARCH_MMAP_RND_COMPAT_BITS; #endif +static bool ignore_rlimit_data = true; +core_param(ignore_rlimit_data, ignore_rlimit_data, bool, 0644); static void unmap_region(struct mm_struct *mm, struct vm_area_struct *vma, struct vm_area_struct *prev, @@ -2982,9 +2985,17 @@ bool may_expand_vm(struct mm_struct *mm, vm_flags_t flags, unsigned long npages) if (mm->total_vm + npages > rlimit(RLIMIT_AS) >> PAGE_SHIFT) return false; - if ((flags & (VM_WRITE | VM_SHARED | (VM_STACK_FLAGS & - (VM_GROWSUP | VM_GROWSDOWN)))) == VM_WRITE) - return mm->data_vm + npages <= rlimit(RLIMIT_DATA); + if (is_data_mapping(flags) && + mm->data_vm + npages > rlimit(RLIMIT_DATA) >> PAGE_SHIFT) { + if (ignore_rlimit_data) + pr_warn_once("%s (%d): VmData %lu exceed data ulimit " + "%lu. Will be forbidden soon.\n", + current->comm, current->pid, + (mm->data_vm + npages) << PAGE_SHIFT, + rlimit(RLIMIT_DATA)); + else + return false; + } return true; } @@ -2993,11 +3004,11 @@ void vm_stat_account(struct mm_struct *mm, vm_flags_t flags, long npages) { mm->total_vm += npages; - if ((flags & (VM_EXEC | VM_WRITE)) == VM_EXEC) + if (is_exec_mapping(flags)) mm->exec_vm += npages; - else if (flags & (VM_STACK_FLAGS & (VM_GROWSUP | VM_GROWSDOWN))) + else if (is_stack_mapping(flags)) mm->stack_vm += npages; - else if ((flags & (VM_WRITE | VM_SHARED)) == VM_WRITE) + else if (is_data_mapping(flags)) mm->data_vm += npages; } -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org