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. This is safe because task anyway can increase rlim_cur up to rlim_max. Size of brk is still checked against rlim_cur, so this part is completely compatible - zero rlim_cur forbids brk() but allows private mmap(). v2: tweak line breaking and keep warn-once warning Signed-off-by: Konstantin Khlebnikov <[email protected]> Link: http://lkml.kernel.org/r/[email protected] --- mm/mmap.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index bd2e1a533bc1..dae8283b749d 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; core_param(ignore_rlimit_data, ignore_rlimit_data, bool, 0644); static void unmap_region(struct mm_struct *mm, @@ -2891,13 +2891,17 @@ 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", + /* Workaround for Valgrind */ + if (rlimit(RLIMIT_DATA) == 0 && + mm->data_vm + npages <= rlimit_max(RLIMIT_DATA) >> PAGE_SHIFT) + return true; + if (!ignore_rlimit_data) { + pr_warn_once("%s (%d): VmData %lu exceed data ulimit %lu. Update limits or use boot option ignore_rlimit_data.\n", current->comm, current->pid, (mm->data_vm + npages) << PAGE_SHIFT, rlimit(RLIMIT_DATA)); - else return false; + } } return true;
