The patch titled
Subject: update to "kasan: support backing vmalloc space with real shadow memory"
has been added to the -mm tree. Its filename is
kasan-support-backing-vmalloc-space-with-real-shadow-memory-update.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/kasan-support-backing-vmalloc-space-with-real-shadow-memory-update.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/kasan-support-backing-vmalloc-space-with-real-shadow-memory-update.patch
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------------------------------------------------------
From: Daniel Axtens <dja@xxxxxxxxxx>
Subject: update to "kasan: support backing vmalloc space with real shadow memory"
There are 2 changes:
- A fixup to the per-cpu allocator path to avoid allocating memory
under a spinlock, thanks Qian Cai.
- Insert flush_cache_vmap() between mapping shadow and poisoning
it. This is a no-op on x86 and arm64, but on powerpc it does a
ptesync instruction which prevents occasional page faults.
Link: http://lkml.kernel.org/r/20191120052719.7201-1-dja@xxxxxxxxxx
Signed-off-by: Daniel Axtens <dja@xxxxxxxxxx>
Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx> [shadow rework]
Co-developed-by: Mark Rutland <mark.rutland@xxxxxxx>
Acked-by: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Reviewed-by: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Cc: Alexander Potapenko <glider@xxxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Christophe Leroy <christophe.leroy@xxxxxx>
Cc: Qian Cai <cai@xxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/kasan/common.c | 2 ++
mm/vmalloc.c | 5 ++++-
2 files changed, 6 insertions(+), 1 deletion(-)
--- a/mm/kasan/common.c~kasan-support-backing-vmalloc-space-with-real-shadow-memory-update
+++ a/mm/kasan/common.c
@@ -794,6 +794,8 @@ int kasan_populate_vmalloc(unsigned long
if (ret)
return ret;
+ flush_cache_vmap(shadow_start, shadow_end);
+
kasan_unpoison_shadow(area->addr, requested_size);
area->flags |= VM_KASAN;
--- a/mm/vmalloc.c~kasan-support-backing-vmalloc-space-with-real-shadow-memory-update
+++ a/mm/vmalloc.c
@@ -3414,11 +3414,14 @@ retry:
setup_vmalloc_vm_locked(vms[area], vas[area], VM_ALLOC,
pcpu_get_vm_areas);
+ }
+ spin_unlock(&vmap_area_lock);
+ /* populate the shadow space outside of the lock */
+ for (area = 0; area < nr_vms; area++) {
/* assume success here */
kasan_populate_vmalloc(sizes[area], vms[area]);
}
- spin_unlock(&vmap_area_lock);
kfree(vas);
return vms;
_
Patches currently in -mm which might be from dja@xxxxxxxxxx are
kasan-support-backing-vmalloc-space-with-real-shadow-memory.patch
kasan-support-backing-vmalloc-space-with-real-shadow-memory-update.patch
kasan-add-test-for-vmalloc.patch
fork-support-vmap_stack-with-kasan_vmalloc.patch
x86-kasan-support-kasan_vmalloc.patch
