Since commit 84638335900f ("mm: rework virtual memory accounting")
RLIMIT_DATA limits both brk() and private mmap() but this's disabled by
default because of incompatibility with older versions of valgrind.Valgrind always set limit to zero and fails if RLIMIT_DATA is enabled. Fortunately it changes only rlim_cur and keeps rlim_max for reverting limit back when needed. This patch checks current usage also against rlim_max if rlim_cur is zero. Size of brk is still checked against rlim_cur, so this part is completely compatible - zero rlim_cur forbids brk() but allows private mmap(). Signed-off-by: Konstantin Khlebnikov <koc...@gmail.com> Link: http://lkml.kernel.org/r/56a28613.5070...@de.ibm.com --- mm/mmap.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index bd2e1a533bc1..317e45409893 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -70,7 +70,7 @@ 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; +static bool ignore_rlimit_data = false; core_param(ignore_rlimit_data, ignore_rlimit_data, bool, 0644); static void unmap_region(struct mm_struct *mm, @@ -2891,13 +2891,11 @@ bool may_expand_vm(struct mm_struct *mm, vm_flags_t flags, unsigned long npages) 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; + /* Workaround for Valgrind */ + if (rlimit(RLIMIT_DATA) == 0 && mm->data_vm + npages <= + rlimit_max(RLIMIT_DATA) >> PAGE_SHIFT) + return true; + return ignore_rlimit_data; } return true;
