[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-Id: <20201109192128.960-1-rppt@kernel.org>
Date: Mon, 9 Nov 2020 21:21:24 +0200
From: Mike Rapoport <rppt@...nel.org>
To: Andrew Morton <akpm@...ux-foundation.org>
Cc: Albert Ou <aou@...s.berkeley.edu>,
Andy Lutomirski <luto@...nel.org>,
Benjamin Herrenschmidt <benh@...nel.crashing.org>,
Borislav Petkov <bp@...en8.de>,
Catalin Marinas <catalin.marinas@....com>,
Christian Borntraeger <borntraeger@...ibm.com>,
Christoph Lameter <cl@...ux.com>,
"David S. Miller" <davem@...emloft.net>,
Dave Hansen <dave.hansen@...ux.intel.com>,
David Hildenbrand <david@...hat.com>,
David Rientjes <rientjes@...gle.com>,
"Edgecombe, Rick P" <rick.p.edgecombe@...el.com>,
"H. Peter Anvin" <hpa@...or.com>,
Heiko Carstens <hca@...ux.ibm.com>,
Ingo Molnar <mingo@...hat.com>,
Joonsoo Kim <iamjoonsoo.kim@....com>,
"Kirill A . Shutemov" <kirill.shutemov@...ux.intel.com>,
"Kirill A. Shutemov" <kirill@...temov.name>,
Len Brown <len.brown@...el.com>,
Michael Ellerman <mpe@...erman.id.au>,
Mike Rapoport <rppt@...nel.org>,
Mike Rapoport <rppt@...ux.ibm.com>,
Palmer Dabbelt <palmer@...belt.com>,
Paul Mackerras <paulus@...ba.org>,
Paul Walmsley <paul.walmsley@...ive.com>,
Pavel Machek <pavel@....cz>, Pekka Enberg <penberg@...nel.org>,
Peter Zijlstra <peterz@...radead.org>,
"Rafael J. Wysocki" <rjw@...ysocki.net>,
Thomas Gleixner <tglx@...utronix.de>,
Vasily Gorbik <gor@...ux.ibm.com>,
Vlastimil Babka <vbabka@...e.cz>,
Will Deacon <will@...nel.org>,
linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
linux-mm@...ck.org, linux-pm@...r.kernel.org,
linux-riscv@...ts.infradead.org, linux-s390@...r.kernel.org,
linuxppc-dev@...ts.ozlabs.org, sparclinux@...r.kernel.org,
x86@...nel.org
Subject: [PATCH v7 0/4] arch, mm: improve robustness of direct map manipulation
From: Mike Rapoport <rppt@...ux.ibm.com>
Hi,
During recent discussion about KVM protected memory, David raised a concern
about usage of __kernel_map_pages() outside of DEBUG_PAGEALLOC scope [1].
Indeed, for architectures that define CONFIG_ARCH_HAS_SET_DIRECT_MAP it is
possible that __kernel_map_pages() would fail, but since this function is
void, the failure will go unnoticed.
Moreover, there's lack of consistency of __kernel_map_pages() semantics
across architectures as some guard this function with
#ifdef DEBUG_PAGEALLOC, some refuse to update the direct map if page
allocation debugging is disabled at run time and some allow modifying the
direct map regardless of DEBUG_PAGEALLOC settings.
This set straightens this out by restoring dependency of
__kernel_map_pages() on DEBUG_PAGEALLOC and updating the call sites
accordingly.
Since currently the only user of __kernel_map_pages() outside
DEBUG_PAGEALLOC is hibernation, it is updated to make direct map accesses
there more explicit.
[1] https://lore.kernel.org/lkml/2759b4bf-e1e3-d006-7d86-78a40348269d@redhat.com
v7 changes:
* fix a rebase error that sneaked into v6 after removal of slab changes
v6 changes:
* revert slab changes to avoid redundant check of static key
https://lore.kernel.org/lkml/20201109162415.13764-1-rppt@kernel.org
v5 changes:
* use pairs of _map()/_unmap() functions instead of _map(..., int enable) as
Vlastimil suggested
https://lore.kernel.org/lkml/20201108065758.1815-1-rppt@kernel.org
v4 changes:
* s/WARN_ON/pr_warn_once/ per David and Kirill
* rebase on v5.10-rc2
* add Acked/Reviewed tags
https://lore.kernel.org/lkml/20201103162057.22916-1-rppt@kernel.org
v3 changes:
* update arm64 changes to avoid regression, per Rick's comments
* fix bisectability
https://lore.kernel.org/lkml/20201101170815.9795-1-rppt@kernel.org
v2 changes:
* Rephrase patch 2 changelog to better describe the change intentions and
implications
* Move removal of kernel_map_pages() from patch 1 to patch 2, per David
https://lore.kernel.org/lkml/20201029161902.19272-1-rppt@kernel.org
v1:
https://lore.kernel.org/lkml/20201025101555.3057-1-rppt@kernel.org
Mike Rapoport (4):
mm: introduce debug_pagealloc_{map,unmap}_pages() helpers
PM: hibernate: make direct map manipulations more explicit
arch, mm: restore dependency of __kernel_map_pages() on DEBUG_PAGEALLOC
arch, mm: make kernel_page_present() always available
arch/Kconfig | 3 +++
arch/arm64/Kconfig | 4 +--
arch/arm64/include/asm/cacheflush.h | 1 +
arch/arm64/mm/pageattr.c | 6 +++--
arch/powerpc/Kconfig | 5 +---
arch/riscv/Kconfig | 4 +--
arch/riscv/include/asm/pgtable.h | 2 --
arch/riscv/include/asm/set_memory.h | 1 +
arch/riscv/mm/pageattr.c | 31 ++++++++++++++++++++++
arch/s390/Kconfig | 4 +--
arch/sparc/Kconfig | 4 +--
arch/x86/Kconfig | 4 +--
arch/x86/include/asm/set_memory.h | 1 +
arch/x86/mm/pat/set_memory.c | 4 +--
include/linux/mm.h | 40 ++++++++++++++---------------
include/linux/set_memory.h | 5 ++++
kernel/power/snapshot.c | 38 +++++++++++++++++++++++++--
mm/memory_hotplug.c | 3 +--
mm/page_alloc.c | 6 ++---
19 files changed, 113 insertions(+), 53 deletions(-)
--
2.28.0
*** BLURB HERE ***
Mike Rapoport (4):
mm: introduce debug_pagealloc_{map,unmap}_pages() helpers
PM: hibernate: make direct map manipulations more explicit
arch, mm: restore dependency of __kernel_map_pages() on
DEBUG_PAGEALLOC
arch, mm: make kernel_page_present() always available
arch/Kconfig | 3 +++
arch/arm64/Kconfig | 4 +--
arch/arm64/include/asm/cacheflush.h | 1 +
arch/arm64/mm/pageattr.c | 6 +++--
arch/powerpc/Kconfig | 5 +---
arch/riscv/Kconfig | 4 +--
arch/riscv/include/asm/pgtable.h | 2 --
arch/riscv/include/asm/set_memory.h | 1 +
arch/riscv/mm/pageattr.c | 31 ++++++++++++++++++++++
arch/s390/Kconfig | 4 +--
arch/sparc/Kconfig | 4 +--
arch/x86/Kconfig | 4 +--
arch/x86/include/asm/set_memory.h | 1 +
arch/x86/mm/pat/set_memory.c | 4 +--
include/linux/mm.h | 40 ++++++++++++++---------------
include/linux/set_memory.h | 5 ++++
kernel/power/snapshot.c | 38 +++++++++++++++++++++++++--
mm/memory_hotplug.c | 3 +--
mm/page_alloc.c | 6 ++---
mm/slab.c | 2 +-
20 files changed, 114 insertions(+), 54 deletions(-)
--
2.28.0
Powered by blists - more mailing lists