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authorLinus Torvalds <torvalds@linux-foundation.org>2016-10-08 06:38:00 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2016-10-08 06:38:00 +0200
commitb66484cd74706fa8681d051840fe4b18a3da40ff (patch)
treee8215e7c25661d25f84abc4b98140c2062d6d5de /mm/mlock.c
parentMerge tag 'armsoc-late' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/... (diff)
parentconsole: don't prefer first registered if DT specifies stdout-path (diff)
downloadlinux-b66484cd74706fa8681d051840fe4b18a3da40ff.tar.xz
linux-b66484cd74706fa8681d051840fe4b18a3da40ff.zip
Merge branch 'akpm' (patches from Andrew)
Merge updates from Andrew Morton: - fsnotify updates - ocfs2 updates - all of MM * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (127 commits) console: don't prefer first registered if DT specifies stdout-path cred: simpler, 1D supplementary groups CREDITS: update Pavel's information, add GPG key, remove snail mail address mailmap: add Johan Hovold .gitattributes: set git diff driver for C source code files uprobes: remove function declarations from arch/{mips,s390} spelling.txt: "modeled" is spelt correctly nmi_backtrace: generate one-line reports for idle cpus arch/tile: adopt the new nmi_backtrace framework nmi_backtrace: do a local dump_stack() instead of a self-NMI nmi_backtrace: add more trigger_*_cpu_backtrace() methods min/max: remove sparse warnings when they're nested Documentation/filesystems/proc.txt: add more description for maps/smaps mm, proc: fix region lost in /proc/self/smaps proc: fix timerslack_ns CAP_SYS_NICE check when adjusting self proc: add LSM hook checks to /proc/<tid>/timerslack_ns proc: relax /proc/<tid>/timerslack_ns capability requirements meminfo: break apart a very long seq_printf with #ifdefs seq/proc: modify seq_put_decimal_[u]ll to take a const char *, not char proc: faster /proc/*/status ...
Diffstat (limited to 'mm/mlock.c')
-rw-r--r--mm/mlock.c52
1 files changed, 52 insertions, 0 deletions
diff --git a/mm/mlock.c b/mm/mlock.c
index 14645be06e30..145a4258ddbc 100644
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -516,6 +516,7 @@ static int mlock_fixup(struct vm_area_struct *vma, struct vm_area_struct **prev,
int nr_pages;
int ret = 0;
int lock = !!(newflags & VM_LOCKED);
+ vm_flags_t old_flags = vma->vm_flags;
if (newflags == vma->vm_flags || (vma->vm_flags & VM_SPECIAL) ||
is_vm_hugetlb_page(vma) || vma == get_gate_vma(current->mm))
@@ -550,6 +551,8 @@ success:
nr_pages = (end - start) >> PAGE_SHIFT;
if (!lock)
nr_pages = -nr_pages;
+ else if (old_flags & VM_LOCKED)
+ nr_pages = 0;
mm->locked_vm += nr_pages;
/*
@@ -617,6 +620,45 @@ static int apply_vma_lock_flags(unsigned long start, size_t len,
return error;
}
+/*
+ * Go through vma areas and sum size of mlocked
+ * vma pages, as return value.
+ * Note deferred memory locking case(mlock2(,,MLOCK_ONFAULT)
+ * is also counted.
+ * Return value: previously mlocked page counts
+ */
+static int count_mm_mlocked_page_nr(struct mm_struct *mm,
+ unsigned long start, size_t len)
+{
+ struct vm_area_struct *vma;
+ int count = 0;
+
+ if (mm == NULL)
+ mm = current->mm;
+
+ vma = find_vma(mm, start);
+ if (vma == NULL)
+ vma = mm->mmap;
+
+ for (; vma ; vma = vma->vm_next) {
+ if (start >= vma->vm_end)
+ continue;
+ if (start + len <= vma->vm_start)
+ break;
+ if (vma->vm_flags & VM_LOCKED) {
+ if (start > vma->vm_start)
+ count -= (start - vma->vm_start);
+ if (start + len < vma->vm_end) {
+ count += start + len - vma->vm_start;
+ break;
+ }
+ count += vma->vm_end - vma->vm_start;
+ }
+ }
+
+ return count >> PAGE_SHIFT;
+}
+
static __must_check int do_mlock(unsigned long start, size_t len, vm_flags_t flags)
{
unsigned long locked;
@@ -639,6 +681,16 @@ static __must_check int do_mlock(unsigned long start, size_t len, vm_flags_t fla
return -EINTR;
locked += current->mm->locked_vm;
+ if ((locked > lock_limit) && (!capable(CAP_IPC_LOCK))) {
+ /*
+ * It is possible that the regions requested intersect with
+ * previously mlocked areas, that part area in "mm->locked_vm"
+ * should not be counted to new mlock increment count. So check
+ * and adjust locked count if necessary.
+ */
+ locked -= count_mm_mlocked_page_nr(current->mm,
+ start, len);
+ }
/* check against resource limits */
if ((locked <= lock_limit) || capable(CAP_IPC_LOCK))