• Konstantin Khlebnikov's avatar
    mm: warn about VmData over RLIMIT_DATA · d977d56c
    Konstantin Khlebnikov authored
    This patch provides a way of working around a slight regression
    introduced by commit 84638335 ("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".
    
    [akpm@linux-foundation.org: tweak kernel-parameters.txt text[
    Signed-off-by: default avatarKonstantin Khlebnikov <koct9i@gmail.com>
    Link: http://lkml.kernel.org/r/20151228211015.GL2194@uranusReported-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
    Cc: Cyrill Gorcunov <gorcunov@gmail.com>
    Cc: Linus Torvalds <torvalds@linux-foundation.org>
    Cc: Vegard Nossum <vegard.nossum@oracle.com>
    Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
    Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
    Cc: Andy Lutomirski <luto@amacapital.net>
    Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
    Cc: Kees Cook <keescook@google.com>
    Cc: Willy Tarreau <w@1wt.eu>
    Cc: Pavel Emelyanov <xemul@virtuozzo.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    d977d56c
mmap.c 91.4 KB