commit 6f07048c00fd100ed8cab66c225c157e0b6c0a50 upstream.
Under certain circumstances, we hit a warning in lockdep_register_key:
if (WARN_ON_ONCE(static_obj(key)))
return;
This occurs when the key falls into initmem that has since been freed
and can now be reused. This has been observed on boot, and under
memory pressure.
Define arch_is_kernel_initmem_freed(), which allows lockdep to
correctly identify this memory as dynamic.
This fixes a bug picked up by the powerpc64 syzkaller instance where
we hit the WARN via alloc_netdev_mqs.
Reported-by: Qian Cai <cai@lca.pw>
Reported-by: ppc syzbot c/o Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Daniel Axtens <dja@axtens.net>
Link: https://lore.kernel.org/r/87lfs4f7d6.fsf@dja-thinkpad.axtens.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 552263456215ada7ee8700ce022d12b0cffe4802 ]
clock_getres in the vDSO library has to preserve the same behaviour
of posix_get_hrtimer_res().
In particular, posix_get_hrtimer_res() does:
sec = 0;
ns = hrtimer_resolution;
and hrtimer_resolution depends on the enablement of the high
resolution timers that can happen either at compile or at run time.
Fix the powerpc vdso implementation of clock_getres keeping a copy of
hrtimer_resolution in vdso data and using that directly.
Fixes: a7f290dad32e ("[PATCH] powerpc: Merge vdso's and add vdso support to 32 bits kernel")
Cc: stable@vger.kernel.org
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
[chleroy: changed CLOCK_REALTIME_RES to CLOCK_HRTIMER_RES]
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/a55eca3a5e85233838c2349783bcb5164dae1d09.1575273217.git.christophe.leroy@c-s.fr
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit af2e8c68b9c5403f77096969c516f742f5bb29e0 upstream. On some systems that are vulnerable to Spectre v2, it is up to software to flush the link stack (return address stack), in order to protect against Spectre-RSB. When exiting from a guest we do some house keeping and then potentially exit to C code which is several stack frames deep in the host kernel. We will then execute a series of returns without preceeding calls, opening up the possiblity that the guest could have poisoned the link stack, and direct speculative execution of the host to a gadget of some sort. To prevent this we add a flush of the link stack on exit from a guest. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 39e72bf96f5847ba87cc5bd7a3ce0fed813dc9ad upstream.
In commit ee13cb249fab ("powerpc/64s: Add support for software count
cache flush"), I added support for software to flush the count
cache (indirect branch cache) on context switch if firmware told us
that was the required mitigation for Spectre v2.
As part of that code we also added a software flush of the link
stack (return address stack), which protects against Spectre-RSB
between user processes.
That is all correct for CPUs that activate that mitigation, which is
currently Power9 Nimbus DD2.3.
What I got wrong is that on older CPUs, where firmware has disabled
the count cache, we also need to flush the link stack on context
switch.
To fix it we create a new feature bit which is not set by firmware,
which tells us we need to flush the link stack. We set that when
firmware tells us that either of the existing Spectre v2 mitigations
are enabled.
Then we adjust the patching code so that if we see that feature bit we
enable the link stack flush. If we're also told to flush the count
cache in software then we fall through and do that also.
On the older CPUs we don't need to do do the software count cache
flush, firmware has disabled it, so in that case we patch in an early
return after the link stack flush.
The naming of some of the functions is awkward after this patch,
because they're called "count cache" but they also do link stack. But
we'll fix that up in a later commit to ease backporting.
This is the fix for CVE-2019-18660.
Reported-by: Anthony Steinhauser <asteinhauser@google.com>
Fixes: ee13cb249fab ("powerpc/64s: Add support for software count cache flush")
Cc: stable@vger.kernel.org # v4.4+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The ultravisor will do an integrity check of the kernel image but we
relocated it so the check will fail. Restore the original image by
relocating it back to the kernel virtual base address.
This works because during build vmlinux is linked with an expected
virtual runtime address of KERNELBASE.
Fixes: 6a9c930bd775 ("powerpc/prom_init: Add the ESM call to prom_init")
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Tested-by: Michael Anderson <andmike@linux.ibm.com>
[mpe: Add IS_ENABLED() to fix the CONFIG_RELOCATABLE=n build]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190911163433.12822-1-bauerman@linux.ibm.com
Make sure starting addr is aligned to segment boundary so that when
incrementing the segment, the starting address of the new segment is
below the end address. Otherwise the last segment might get missed.
Fixes: a68c31fc01ef ("powerpc/32s: Implement Kernel Userspace Access Protection")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/067a1b09f15f421d40797c2d04c22d4049a1cee8.1571071875.git.christophe.leroy@c-s.fr
After merging the powerpc tree, today's linux-next build (powerpc64
allnoconfig) failed like this:
arch/powerpc/mm/book3s64/pgtable.c:216:3:
error: implicit declaration of function 'radix__flush_all_lpid_guest'
radix__flush_all_lpid_guest() is only declared for
CONFIG_PPC_RADIX_MMU which is not set for this build.
Fix it by adding an empty version for the RADIX_MMU=n case, which
should never be called.
Fixes: 99161de3a283 ("powerpc/64s/radix: tidy up TLB flushing code")
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
[mpe: Munge change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190930101342.36c1afa0@canb.auug.org.au
More libnvdimm updates from Dan Williams: - Complete the reworks to interoperate with powerpc dynamic huge page sizes - Fix a crash due to missed accounting for the powerpc 'struct page'-memmap mapping granularity - Fix badblock initialization for volatile (DRAM emulated) pmem ranges - Stop triggering request_key() notifications to userspace when NVDIMM-security is disabled / not present - Miscellaneous small fixups * tag 'libnvdimm-fixes-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: libnvdimm/region: Enable MAP_SYNC for volatile regions libnvdimm: prevent nvdimm from requesting key when security is disabled libnvdimm/region: Initialize bad block for volatile namespaces libnvdimm/nfit_test: Fix acpi_handle redefinition libnvdimm/altmap: Track namespace boundaries in altmap libnvdimm: Fix endian conversion issues libnvdimm/dax: Pick the right alignment default when creating dax devices powerpc/book3s64: Export has_transparent_hugepage() related functions.
Pull powerpc fixes from Michael Ellerman:
"An assortment of fixes that were either missed by me, or didn't arrive
quite in time for the first v5.4 pull.
- Most notable is a fix for an issue with tlbie (broadcast TLB
invalidation) on Power9, when using the Radix MMU. The tlbie can
race with an mtpid (move to PID register, essentially MMU context
switch) on another thread of the core, which can cause stores to
continue to go to a page after it's unmapped.
- A fix in our KVM code to add a missing barrier, the lack of which
has been observed to cause missed IPIs and subsequently stuck CPUs
in the host.
- A change to the way we initialise PCR (Processor Compatibility
Register) to make it forward compatible with future CPUs.
- On some older PowerVM systems our H_BLOCK_REMOVE support could
oops, fix it to detect such systems and fallback to the old
invalidation method.
- A fix for an oops seen on some machines when using KASAN on 32-bit.
- A handful of other minor fixes, and two new selftests.
Thanks to: Alistair Popple, Aneesh Kumar K.V, Christophe Leroy,
Gustavo Romero, Joel Stanley, Jordan Niethe, Laurent Dufour, Michael
Roth, Oliver O'Halloran"
* tag 'powerpc-5.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/eeh: Fix eeh eeh_debugfs_break_device() with SRIOV devices
powerpc/nvdimm: use H_SCM_QUERY hcall on H_OVERLAP error
powerpc/nvdimm: Use HCALL error as the return value
selftests/powerpc: Add test case for tlbie vs mtpidr ordering issue
powerpc/mm: Fixup tlbie vs mtpidr/mtlpidr ordering issue on POWER9
powerpc/book3s64/radix: Rename CPU_FTR_P9_TLBIE_BUG feature flag
powerpc/book3s64/mm: Don't do tlbie fixup for some hardware revisions
powerpc/pseries: Call H_BLOCK_REMOVE when supported
powerpc/pseries: Read TLB Block Invalidate Characteristics
KVM: PPC: Book3S HV: use smp_mb() when setting/clearing host_ipi flag
powerpc/mm: Fix an Oops in kasan_mmu_init()
powerpc/mm: Add a helper to select PAGE_KERNEL_RO or PAGE_READONLY
powerpc/64s: Set reserved PCR bits
powerpc: Fix definition of PCR bits to work with old binutils
powerpc/book3s64/radix: Remove WARN_ON in destroy_context()
powerpc/tm: Add tm-poison test
Merge updates from Andrew Morton: - a few hot fixes - ocfs2 updates - almost all of -mm (slab-generic, slab, slub, kmemleak, kasan, cleanups, debug, pagecache, memcg, gup, pagemap, memory-hotplug, sparsemem, vmalloc, initialization, z3fold, compaction, mempolicy, oom-kill, hugetlb, migration, thp, mmap, madvise, shmem, zswap, zsmalloc) * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (132 commits) mm/zsmalloc.c: fix a -Wunused-function warning zswap: do not map same object twice zswap: use movable memory if zpool support allocate movable memory zpool: add malloc_support_movable to zpool_driver shmem: fix obsolete comment in shmem_getpage_gfp() mm/madvise: reduce code duplication in error handling paths mm: mmap: increase sockets maximum memory size pgoff for 32bits mm/mmap.c: refine find_vma_prev() with rb_last() riscv: make mmap allocation top-down by default mips: use generic mmap top-down layout and brk randomization mips: replace arch specific way to determine 32bit task with generic version mips: adjust brk randomization offset to fit generic version mips: use STACK_TOP when computing mmap base address mips: properly account for stack randomization and stack guard gap arm: use generic mmap top-down layout and brk randomization arm: use STACK_TOP when computing mmap base address arm: properly account for stack randomization and stack guard gap arm64, mm: make randomization selected by generic topdown mmap layout arm64, mm: move generic mmap layout functions to mm arm64: consider stack randomization for mmap base only when necessary ...