From 84638335900f1995495838fe1bd4870c43ec1f67 Mon Sep 17 00:00:00 2001 From: Konstantin Khlebnikov Date: Thu, 14 Jan 2016 15:22:07 -0800 Subject: mm: rework virtual memory accounting When inspecting a vague code inside prctl(PR_SET_MM_MEM) call (which testing the RLIMIT_DATA value to figure out if we're allowed to assign new @start_brk, @brk, @start_data, @end_data from mm_struct) it's been commited that RLIMIT_DATA in a form it's implemented now doesn't do anything useful because most of user-space libraries use mmap() syscall for dynamic memory allocations. Linus suggested to convert RLIMIT_DATA rlimit into something suitable for anonymous memory accounting. But in this patch we go further, and the changes are bundled together as: * keep vma counting if CONFIG_PROC_FS=n, will be used for limits * replace mm->shared_vm with better defined mm->data_vm * account anonymous executable areas as executable * account file-backed growsdown/up areas as stack * drop struct file* argument from vm_stat_account * enforce RLIMIT_DATA for size of data areas This way code looks cleaner: now code/stack/data classification depends only on vm_flags state: VM_EXEC & ~VM_WRITE -> code (VmExe + VmLib in proc) VM_GROWSUP | VM_GROWSDOWN -> stack (VmStk) VM_WRITE & ~VM_SHARED & !stack -> data (VmData) The rest (VmSize - VmData - VmStk - VmExe - VmLib) could be called "shared", but that might be strange beast like readonly-private or VM_IO area. - RLIMIT_AS limits whole address space "VmSize" - RLIMIT_STACK limits stack "VmStk" (but each vma individually) - RLIMIT_DATA now limits "VmData" Signed-off-by: Konstantin Khlebnikov Signed-off-by: Cyrill Gorcunov Cc: Quentin Casasnovas Cc: Vegard Nossum Acked-by: Linus Torvalds Cc: Willy Tarreau Cc: Andy Lutomirski Cc: Kees Cook Cc: Vladimir Davydov Cc: Pavel Emelyanov Cc: Peter Zijlstra Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/proc/task_mmu.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) (limited to 'fs/proc') diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 46d9619..a353b4c 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -23,7 +23,7 @@ void task_mem(struct seq_file *m, struct mm_struct *mm) { - unsigned long data, text, lib, swap, ptes, pmds, anon, file, shmem; + unsigned long text, lib, swap, ptes, pmds, anon, file, shmem; unsigned long hiwater_vm, total_vm, hiwater_rss, total_rss; anon = get_mm_counter(mm, MM_ANONPAGES); @@ -44,7 +44,6 @@ void task_mem(struct seq_file *m, struct mm_struct *mm) if (hiwater_rss < mm->hiwater_rss) hiwater_rss = mm->hiwater_rss; - data = mm->total_vm - mm->shared_vm - mm->stack_vm; text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK)) >> 10; lib = (mm->exec_vm << (PAGE_SHIFT-10)) - text; swap = get_mm_counter(mm, MM_SWAPENTS); @@ -76,7 +75,7 @@ void task_mem(struct seq_file *m, struct mm_struct *mm) anon << (PAGE_SHIFT-10), file << (PAGE_SHIFT-10), shmem << (PAGE_SHIFT-10), - data << (PAGE_SHIFT-10), + mm->data_vm << (PAGE_SHIFT-10), mm->stack_vm << (PAGE_SHIFT-10), text, lib, ptes >> 10, pmds >> 10, @@ -97,7 +96,7 @@ unsigned long task_statm(struct mm_struct *mm, get_mm_counter(mm, MM_SHMEMPAGES); *text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK)) >> PAGE_SHIFT; - *data = mm->total_vm - mm->shared_vm; + *data = mm->data_vm + mm->stack_vm; *resident = *shared + get_mm_counter(mm, MM_ANONPAGES); return mm->total_vm; } -- cgit v1.1