Some early boot code runs before the virtual placement of the kernel is
finalized, and we used to go back to the very start and recreate the ID
map along with the page tables describing the virtual kernel mapping,
and this involved setting some global variables with the caches off.
In order to ensure that global state created by the KASLR code is not
corrupted by the cache invalidation that occurs in that case, we needed
to clean those global variables to the PoC explicitly.
This is no longer needed now that the ID map is created only once (and
the associated global variable updates are no longer repeated). So drop
the cache maintenance that is no longer necessary.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/20220624150651.1358849-9-ardb@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Split off the creation of the ID map page tables, so that we can avoid
running it again unnecessarily when KASLR is in effect (which only
randomizes the virtual placement). This will permit us to drop some
explicit cache maintenance to the PoC which was necessary because the
cache invalidation being performed on some global variables might
otherwise clobber unrelated variables that happen to share a cacheline.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20220624150651.1358849-8-ardb@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
In a future patch, we will start using an ID map that covers the entire
image, rather than a single page. This means that we need to deal with
the pathological case of an extended ID map where the kernel image does
not fit neatly inside a single entry at the root level, which means we
will need to create additional table entries and map additional pages
for page tables.
The existing map_memory macro already takes care of most of that, so
let's just extend it to deal with this case as well. While at it, drop
the conditional branch on the value of T0SZ: we don't set the variable
anymore in the entry code, and so we can just let the map_memory macro
deal with the case where the output address exceeds VA_BITS.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20220624150651.1358849-7-ardb@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Simplify the macros in head.S that are used to set up the early page
tables, by switching to immediates for the number of bits that are
interpreted as the table index at each level. This makes it much
easier to infer from the instruction stream what is going on, and
reduces the number of instructions emitted substantially.
Note that the extended ID map for cases where no additional level needs
to be configured now uses a compile time size as well, which means that
we interpret up to 10 bits as the table index at the root level (for
52-bit physical addressing), without taking into account whether or not
this is supported on the current system. However, those bits can only
be set if we are executing the image from an address that exceeds the
48-bit PA range, and are guaranteed to be cleared otherwise, and given
that we are dealing with a mapping in the lower TTBR0 range of the
address space, the result is therefore the same as if we'd mask off only
6 bits.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20220624150651.1358849-6-ardb@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
The assignment of idmap_ptrs_per_pgd lacks any cache invalidation, even
though it is updated with the MMU and caches disabled. However, we never
bother to read the value again except in the very next instruction, and
so we can just drop the variable entirely.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/20220624150651.1358849-5-ardb@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Setting idmap_t0sz involves fiddling with the caches if done with the
MMU off. Since we will be creating an initial ID map with the MMU and
caches off, and the permanent ID map with the MMU and caches on, let's
move this assignment of idmap_t0sz out of the startup code, and replace
it with a macro that simply issues the three instructions needed to
calculate the value wherever it is needed before the MMU is turned on.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20220624150651.1358849-4-ardb@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Currently, we only support 52-bit virtual addressing on 64k pages
configurations, and in all other cases, vabits_actual is guaranteed to
equal VA_BITS (== VA_BITS_MIN). So get rid of the variable entirely in
that case.
While at it, move the assignment out of the asm entry code - it has no
need to be there.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20220624150651.1358849-3-ardb@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Get rid of some clunky open coded arithmetic on section addresses, by
emitting the trampoline data variables into a separate, dedicated r/o
data section, and putting it at the next page boundary. This way, we can
access the literals via single LDR instruction.
While at it, get rid of other, implicit literals, and use ADRP/ADD or
MOVZ/MOVK sequences, as appropriate. Note that the latter are only
supported for CONFIG_RELOCATABLE=n (which is usually the case if
CONFIG_RANDOMIZE_BASE=n), so update the CPP conditionals to reflect
this.
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20220622161010.3845775-1-ardb@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Instead of defaulting to patching NOP opcodes at init time, and leaving
it to the architectures to override this if this is not needed, switch
to a model where doing nothing is the default. This is the common case
by far, as only MIPS requires NOP patching at init time. On all other
architectures, the correct encodings are emitted by the compiler and so
no initial patching is needed.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220615154142.1574619-4-ardb@kernel.org
The Arm v8.8 extension adds a new control FEAT_TIDCP1 that allows the
kernel to disable all implementation-defined system registers and
instructions in userspace. This can improve robustness against covert
channels between processes, for example in cases where the firmware or
hardware didn't disable that functionality by default.
The kernel does not currently support any implementation-defined
features, as there are no hwcaps for any such features, so disable all
imp-def features unconditionally. Any use of imp-def instructions will
result in a SIGILL being delivered to the process (same as for undefined
instructions).
Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>
Link: https://lore.kernel.org/r/20220622115424.683520-1-kristina.martsenko@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Commit b20d1ba3cf ("arm64: cpufeature: allow for version discrepancy in
PMU implementations") made it possible to run Linux on a machine with PMUs
with different versions without tainting the kernel. The patch relaxed the
restriction only for the ID_AA64DFR0_EL1.PMUVer field, and missed doing the
same for ID_DFR0_EL1.PerfMon , which also reports the PMU version, but for
the AArch32 state.
For example, with Linux running on two clusters with different PMU
versions, the kernel is tainted when bringing up secondaries with the
following message:
[ 0.097027] smp: Bringing up secondary CPUs ...
[..]
[ 0.142805] Detected PIPT I-cache on CPU4
[ 0.142805] CPU features: SANITY CHECK: Unexpected variation in SYS_ID_DFR0_EL1. Boot CPU: 0x00000004011088, CPU4: 0x00000005011088
[ 0.143555] CPU features: Unsupported CPU feature variation detected.
[ 0.143702] GICv3: CPU4: found redistributor 10000 region 0:0x000000002f180000
[ 0.143702] GICv3: CPU4: using allocated LPI pending table @0x00000008800d0000
[ 0.144888] CPU4: Booted secondary processor 0x0000010000 [0x410fd0f0]
The boot CPU implements FEAT_PMUv3p1 (ID_DFR0_EL1.PerfMon, bits 27:24, is
0b0100), but CPU4, part of the other cluster, implements FEAT_PMUv3p4
(ID_DFR0_EL1.PerfMon = 0b0101).
Treat the PerfMon field as FTR_NONSTRICT and FTR_EXACT to pass the sanity
check and to match how PMUVer is treated for the 64bit ID register.
Fixes: b20d1ba3cf ("arm64: cpufeature: allow for version discrepancy in PMU implementations")
Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Link: https://lore.kernel.org/r/20220617111332.203061-1-alexandru.elisei@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
In cases where we unmap the kernel while running in user space, we rely
on ASIDs to distinguish the minimal trampoline from the full kernel
mapping, and this means we must use non-global attributes for those
mappings, to ensure they are scoped by ASID and will not hit in the TLB
inadvertently.
We only do this when needed, as this is generally more costly in terms
of TLB pressure, and so we boot without these non-global attributes, and
apply them to all existing kernel mappings once all CPUs are up and we
know whether or not the non-global attributes are needed. At this point,
we cannot simply unmap and remap the entire address space, so we have to
update all existing block and page descriptors in place.
Currently, we go through a lot of trouble to perform these updates with
the MMU and caches off, to avoid violating break before make (BBM) rules
imposed by the architecture. Since we make changes to page tables that
are not covered by the ID map, we gain access to those descriptors by
disabling translations altogether. This means that the stores to memory
are issued with device attributes, and require extra care in terms of
coherency, which is costly. We also rely on the ID map to access a
shared flag, which requires the ID map to be executable and writable at
the same time, which is another thing we'd prefer to avoid.
So let's switch to an approach where we replace the kernel mapping with
a minimal mapping of a few pages that can be used for a minimal, ad-hoc
fixmap that we can use to map each page table in turn as we traverse the
hierarchy.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20220609174320.4035379-3-ardb@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
We currently expose MIDR and REVID to userspace through sysfs to enable it
to make decisions based on the specific implementation. Since SME supports
implementations where streaming mode is provided by a separate hardware
unit called a SMCU it provides a similar ID register SMIDR. Expose it to
userspace via sysfs when the system supports SME along with the other ID
registers.
Since we disable the SME priority mapping feature if it is supported by
hardware we currently mask out the SMPS bit which reports that it is
supported.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220607132857.1358361-1-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Pull arm64 fixes from Catalin Marinas:
- Revert the moving of the jump labels initialisation before
setup_machine_fdt(). The bug was fixed in drivers/char/random.c.
- Ftrace fixes: branch range check and consistent handling of PLTs.
- Clean rather than invalidate FROM_DEVICE buffers at start of DMA
transfer (safer if such buffer is mapped in user space). A cache
invalidation is done already at the end of the transfer.
- A couple of clean-ups (unexport symbol, remove unused label).
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64: mm: Don't invalidate FROM_DEVICE buffers at start of DMA transfer
arm64/cpufeature: Unexport set_cpu_feature()
arm64: ftrace: remove redundant label
arm64: ftrace: consistently handle PLTs.
arm64: ftrace: fix branch range checks
Revert "arm64: Initialize jump labels before setup_machine_fdt()"
We currently export set_cpu_feature() to modules but there are no in tree
users that can be built as modules and it is hard to see cases where it
would make sense for there to be any such users. Remove the export to avoid
anyone else having to worry about why it is there and ensure that any users
that do get added get a bit more visiblity.
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20220615191504.626604-1-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Sometimes it is necessary to use a PLT entry to call an ftrace
trampoline. This is handled by ftrace_make_call() and ftrace_make_nop(),
with each having *almost* identical logic, but this is not handled by
ftrace_modify_call() since its introduction in commit:
3b23e4991f ("arm64: implement ftrace with regs")
Due to this, if we ever were to call ftrace_modify_call() for a callsite
which requires a PLT entry for a trampoline, then either:
a) If the old addr requires a trampoline, ftrace_modify_call() will use
an out-of-range address to generate the 'old' branch instruction.
This will result in warnings from aarch64_insn_gen_branch_imm() and
ftrace_modify_code(), and no instructions will be modified. As
ftrace_modify_call() will return an error, this will result in
subsequent internal ftrace errors.
b) If the old addr does not require a trampoline, but the new addr does,
ftrace_modify_call() will use an out-of-range address to generate the
'new' branch instruction. This will result in warnings from
aarch64_insn_gen_branch_imm(), and ftrace_modify_code() will replace
the 'old' branch with a BRK. This will result in a kernel panic when
this BRK is later executed.
Practically speaking, case (a) is vastly more likely than case (b), and
typically this will result in internal ftrace errors that don't
necessarily affect the rest of the system. This can be demonstrated with
an out-of-tree test module which triggers ftrace_modify_call(), e.g.
| # insmod test_ftrace.ko
| test_ftrace: Function test_function raw=0xffffb3749399201c, callsite=0xffffb37493992024
| branch_imm_common: offset out of range
| branch_imm_common: offset out of range
| ------------[ ftrace bug ]------------
| ftrace failed to modify
| [<ffffb37493992024>] test_function+0x8/0x38 [test_ftrace]
| actual: 1d:00:00:94
| Updating ftrace call site to call a different ftrace function
| ftrace record flags: e0000002
| (2) R
| expected tramp: ffffb374ae42ed54
| ------------[ cut here ]------------
| WARNING: CPU: 0 PID: 165 at kernel/trace/ftrace.c:2085 ftrace_bug+0x280/0x2b0
| Modules linked in: test_ftrace(+)
| CPU: 0 PID: 165 Comm: insmod Not tainted 5.19.0-rc2-00002-g4d9ead8b45ce #13
| Hardware name: linux,dummy-virt (DT)
| pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
| pc : ftrace_bug+0x280/0x2b0
| lr : ftrace_bug+0x280/0x2b0
| sp : ffff80000839ba00
| x29: ffff80000839ba00 x28: 0000000000000000 x27: ffff80000839bcf0
| x26: ffffb37493994180 x25: ffffb374b0991c28 x24: ffffb374b0d70000
| x23: 00000000ffffffea x22: ffffb374afcc33b0 x21: ffffb374b08f9cc8
| x20: ffff572b8462c000 x19: ffffb374b08f9000 x18: ffffffffffffffff
| x17: 6c6c6163202c6331 x16: ffffb374ae5ad110 x15: ffffb374b0d51ee4
| x14: 0000000000000000 x13: 3435646532346561 x12: 3437336266666666
| x11: 203a706d61727420 x10: 6465746365707865 x9 : ffffb374ae5149e8
| x8 : 336266666666203a x7 : 706d617274206465 x6 : 00000000fffff167
| x5 : ffff572bffbc4a08 x4 : 00000000fffff167 x3 : 0000000000000000
| x2 : 0000000000000000 x1 : ffff572b84461e00 x0 : 0000000000000022
| Call trace:
| ftrace_bug+0x280/0x2b0
| ftrace_replace_code+0x98/0xa0
| ftrace_modify_all_code+0xe0/0x144
| arch_ftrace_update_code+0x14/0x20
| ftrace_startup+0xf8/0x1b0
| register_ftrace_function+0x38/0x90
| test_ftrace_init+0xd0/0x1000 [test_ftrace]
| do_one_initcall+0x50/0x2b0
| do_init_module+0x50/0x1f0
| load_module+0x17c8/0x1d64
| __do_sys_finit_module+0xa8/0x100
| __arm64_sys_finit_module+0x2c/0x3c
| invoke_syscall+0x50/0x120
| el0_svc_common.constprop.0+0xdc/0x100
| do_el0_svc+0x3c/0xd0
| el0_svc+0x34/0xb0
| el0t_64_sync_handler+0xbc/0x140
| el0t_64_sync+0x18c/0x190
| ---[ end trace 0000000000000000 ]---
We can solve this by consistently determining whether to use a PLT entry
for an address.
Note that since (the earlier) commit:
f1a54ae9af ("arm64: module/ftrace: intialize PLT at load time")
... we can consistently determine the PLT address that a given callsite
will use, and therefore ftrace_make_nop() does not need to skip
validation when a PLT is in use.
This patch factors the existing logic out of ftrace_make_call() and
ftrace_make_nop() into a common ftrace_find_callable_addr() helper
function, which is used by ftrace_make_call(), ftrace_make_nop(), and
ftrace_modify_call(). In ftrace_make_nop() the patching is consistently
validated by ftrace_modify_code() as we can always determine what the
old instruction should have been.
Fixes: 3b23e4991f ("arm64: implement ftrace with regs")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Will Deacon <will@kernel.org>
Tested-by: "Ivan T. Ivanov" <iivanov@suse.de>
Reviewed-by: Chengming Zhou <zhouchengming@bytedance.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20220614080944.1349146-3-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The branch range checks in ftrace_make_call() and ftrace_make_nop() are
incorrect, erroneously permitting a forwards branch of 128M and
erroneously rejecting a backwards branch of 128M.
This is because both functions calculate the offset backwards,
calculating the offset *from* the target *to* the branch, rather than
the other way around as the later comparisons expect.
If an out-of-range branch were erroeously permitted, this would later be
rejected by aarch64_insn_gen_branch_imm() as branch_imm_common() checks
the bounds correctly, resulting in warnings and the placement of a BRK
instruction. Note that this can only happen for a forwards branch of
exactly 128M, and so the caller would need to be exactly 128M bytes
below the relevant ftrace trampoline.
If an in-range branch were erroeously rejected, then:
* For modules when CONFIG_ARM64_MODULE_PLTS=y, this would result in the
use of a PLT entry, which is benign.
Note that this is the common case, as this is selected by
CONFIG_RANDOMIZE_BASE (and therefore RANDOMIZE_MODULE_REGION_FULL),
which distributions typically seelct. This is also selected by
CONFIG_ARM64_ERRATUM_843419.
* For modules when CONFIG_ARM64_MODULE_PLTS=n, this would result in
internal ftrace failures.
* For core kernel text, this would result in internal ftrace failues.
Note that for this to happen, the kernel text would need to be at
least 128M bytes in size, and typical configurations are smaller tha
this.
Fix this by calculating the offset *from* the branch *to* the target in
both functions.
Fixes: f8af0b364e ("arm64: ftrace: don't validate branch via PLT in ftrace_make_nop()")
Fixes: e71a4e1beb ("arm64: ftrace: add support for far branches to dynamic ftrace")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Will Deacon <will@kernel.org>
Tested-by: "Ivan T. Ivanov" <iivanov@suse.de>
Reviewed-by: Chengming Zhou <zhouchengming@bytedance.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20220614080944.1349146-2-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This reverts commit 73e2d827a5.
The reverted patch was needed as a fix after commit f5bda35fba
("random: use static branch for crng_ready()"). However, this was
already fixed by 60e5b2886b ("random: do not use jump labels before
they are initialized") and hence no longer necessary to initialise jump
labels before setup_machine_fdt().
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Pull kvm fixes from Paolo Bonzini:
"While last week's pull request contained miscellaneous fixes for x86,
this one covers other architectures, selftests changes, and a bigger
series for APIC virtualization bugs that were discovered during 5.20
development. The idea is to base 5.20 development for KVM on top of
this tag.
ARM64:
- Properly reset the SVE/SME flags on vcpu load
- Fix a vgic-v2 regression regarding accessing the pending state of a
HW interrupt from userspace (and make the code common with vgic-v3)
- Fix access to the idreg range for protected guests
- Ignore 'kvm-arm.mode=protected' when using VHE
- Return an error from kvm_arch_init_vm() on allocation failure
- A bunch of small cleanups (comments, annotations, indentation)
RISC-V:
- Typo fix in arch/riscv/kvm/vmid.c
- Remove broken reference pattern from MAINTAINERS entry
x86-64:
- Fix error in page tables with MKTME enabled
- Dirty page tracking performance test extended to running a nested
guest
- Disable APICv/AVIC in cases that it cannot implement correctly"
[ This merge also fixes a misplaced end parenthesis bug introduced in
commit 3743c2f025 ("KVM: x86: inhibit APICv/AVIC on changes to APIC
ID or APIC base") pointed out by Sean Christopherson ]
Link: https://lore.kernel.org/all/20220610191813.371682-1-seanjc@google.com/
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (34 commits)
KVM: selftests: Restrict test region to 48-bit physical addresses when using nested
KVM: selftests: Add option to run dirty_log_perf_test vCPUs in L2
KVM: selftests: Clean up LIBKVM files in Makefile
KVM: selftests: Link selftests directly with lib object files
KVM: selftests: Drop unnecessary rule for STATIC_LIBS
KVM: selftests: Add a helper to check EPT/VPID capabilities
KVM: selftests: Move VMX_EPT_VPID_CAP_AD_BITS to vmx.h
KVM: selftests: Refactor nested_map() to specify target level
KVM: selftests: Drop stale function parameter comment for nested_map()
KVM: selftests: Add option to create 2M and 1G EPT mappings
KVM: selftests: Replace x86_page_size with PG_LEVEL_XX
KVM: x86: SVM: fix nested PAUSE filtering when L0 intercepts PAUSE
KVM: x86: SVM: drop preempt-safe wrappers for avic_vcpu_load/put
KVM: x86: disable preemption around the call to kvm_arch_vcpu_{un|}blocking
KVM: x86: disable preemption while updating apicv inhibition
KVM: x86: SVM: fix avic_kick_target_vcpus_fast
KVM: x86: SVM: remove avic's broken code that updated APIC ID
KVM: x86: inhibit APICv/AVIC on changes to APIC ID or APIC base
KVM: x86: document AVIC/APICv inhibit reasons
KVM: x86/mmu: Set memory encryption "value", not "mask", in shadow PDPTRs
...
This function is only called from assembly, no need for a prototype
declaration in a header file. In addition, add #ifdef around the
function since it is only used when CONFIG_KASAN_HW_TAGS.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: kernel test robot <lkp@intel.com>
The EFI save/restore code is confused. When saving the check for saving
FFR is inverted due to confusion with the streaming mode check, and when
restoring we check if we need to restore FFR by checking the percpu
efi_sm_state without the required wrapper rather than based on the
combination of FA64 support and streaming mode.
Fixes: e0838f6373 ("arm64/sme: Save and restore streaming mode over EFI runtime calls")
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220602124132.3528951-1-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Pull kthread updates from Eric Biederman:
"This updates init and user mode helper tasks to be ordinary user mode
tasks.
Commit 40966e316f ("kthread: Ensure struct kthread is present for
all kthreads") caused init and the user mode helper threads that call
kernel_execve to have struct kthread allocated for them. This struct
kthread going away during execve in turned made a use after free of
struct kthread possible.
Here, commit 343f4c49f2 ("kthread: Don't allocate kthread_struct for
init and umh") is enough to fix the use after free and is simple
enough to be backportable.
The rest of the changes pass struct kernel_clone_args to clean things
up and cause the code to make sense.
In making init and the user mode helpers tasks purely user mode tasks
I ran into two complications. The function task_tick_numa was
detecting tasks without an mm by testing for the presence of
PF_KTHREAD. The initramfs code in populate_initrd_image was using
flush_delayed_fput to ensuere the closing of all it's file descriptors
was complete, and flush_delayed_fput does not work in a userspace
thread.
I have looked and looked and more complications and in my code review
I have not found any, and neither has anyone else with the code
sitting in linux-next"
* tag 'kthread-cleanups-for-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
sched: Update task_tick_numa to ignore tasks without an mm
fork: Stop allowing kthreads to call execve
fork: Explicitly set PF_KTHREAD
init: Deal with the init process being a user mode process
fork: Generalize PF_IO_WORKER handling
fork: Explicity test for idle tasks in copy_thread
fork: Pass struct kernel_clone_args into copy_thread
kthread: Don't allocate kthread_struct for init and umh
Pull arm64 fixes from Catalin Marinas:
"Most of issues addressed were introduced during this merging window.
- Initialise jump labels before setup_machine_fdt(), needed by commit
f5bda35fba ("random: use static branch for crng_ready()").
- Sparse warnings: missing prototype, incorrect __user annotation.
- Skip SVE kselftest if not sufficient vector lengths supported"
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
kselftest/arm64: signal: Skip SVE signal test if not enough VLs supported
arm64: Initialize jump labels before setup_machine_fdt()
arm64: hibernate: Fix syntax errors in comments
arm64: Remove the __user annotation for the restore_za_context() argument
ftrace/fgraph: fix increased missing-prototypes warnings
Pull more power management updates from Rafael Wysocki:
"These update the ARM cpufreq drivers and fix up the CPPC cpufreq
driver after recent changes, update the OPP code and PM documentation
and add power sequences support to the system reboot and power off
code.
Specifics:
- Add Tegra234 cpufreq support (Sumit Gupta)
- Clean up and enhance the Mediatek cpufreq driver (Wan Jiabing,
Rex-BC Chen, and Jia-Wei Chang)
- Fix up the CPPC cpufreq driver after recent changes (Zheng Bin,
Pierre Gondois)
- Minor update to dt-binding for Qcom's opp-v2-kryo-cpu (Yassine
Oudjana)
- Use list iterator only inside the list_for_each_entry loop
(Xiaomeng Tong, and Jakob Koschel)
- New APIs related to finding OPP based on interconnect bandwidth
(Krzysztof Kozlowski)
- Fix the missing of_node_put() in _bandwidth_supported() (Dan
Carpenter)
- Cleanups (Krzysztof Kozlowski, and Viresh Kumar)
- Add Out of Band mode description to the intel-speed-select utility
documentation (Srinivas Pandruvada)
- Add power sequences support to the system reboot and power off code
and make related platform-specific changes for multiple platforms
(Dmitry Osipenko, Geert Uytterhoeven)"
* tag 'pm-5.19-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (60 commits)
cpufreq: CPPC: Fix unused-function warning
cpufreq: CPPC: Fix build error without CONFIG_ACPI_CPPC_CPUFREQ_FIE
Documentation: admin-guide: PM: Add Out of Band mode
kernel/reboot: Change registration order of legacy power-off handler
m68k: virt: Switch to new sys-off handler API
kernel/reboot: Add devm_register_restart_handler()
kernel/reboot: Add devm_register_power_off_handler()
soc/tegra: pmc: Use sys-off handler API to power off Nexus 7 properly
reboot: Remove pm_power_off_prepare()
regulator: pfuze100: Use devm_register_sys_off_handler()
ACPI: power: Switch to sys-off handler API
memory: emif: Use kernel_can_power_off()
mips: Use do_kernel_power_off()
ia64: Use do_kernel_power_off()
x86: Use do_kernel_power_off()
sh: Use do_kernel_power_off()
m68k: Switch to new sys-off handler API
powerpc: Use do_kernel_power_off()
xen/x86: Use do_kernel_power_off()
parisc: Use do_kernel_power_off()
...
Pull misc updates from Andrew Morton:
"The non-MM patch queue for this merge window.
Not a lot of material this cycle. Many singleton patches against
various subsystems. Most notably some maintenance work in ocfs2
and initramfs"
* tag 'mm-nonmm-stable-2022-05-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (65 commits)
kcov: update pos before writing pc in trace function
ocfs2: dlmfs: fix error handling of user_dlm_destroy_lock
ocfs2: dlmfs: don't clear USER_LOCK_ATTACHED when destroying lock
fs/ntfs: remove redundant variable idx
fat: remove time truncations in vfat_create/vfat_mkdir
fat: report creation time in statx
fat: ignore ctime updates, and keep ctime identical to mtime in memory
fat: split fat_truncate_time() into separate functions
MAINTAINERS: add Muchun as a memcg reviewer
proc/sysctl: make protected_* world readable
ia64: mca: drop redundant spinlock initialization
tty: fix deadlock caused by calling printk() under tty_port->lock
relay: remove redundant assignment to pointer buf
fs/ntfs3: validate BOOT sectors_per_clusters
lib/string_helpers: fix not adding strarray to device's resource list
kernel/crash_core.c: remove redundant check of ck_cmdline
ELF, uapi: fixup ELF_ST_TYPE definition
ipc/mqueue: use get_tree_nodev() in mqueue_get_tree()
ipc: update semtimedop() to use hrtimer
ipc/sem: remove redundant assignments
...
Pull kvm updates from Paolo Bonzini:
"S390:
- ultravisor communication device driver
- fix TEID on terminating storage key ops
RISC-V:
- Added Sv57x4 support for G-stage page table
- Added range based local HFENCE functions
- Added remote HFENCE functions based on VCPU requests
- Added ISA extension registers in ONE_REG interface
- Updated KVM RISC-V maintainers entry to cover selftests support
ARM:
- Add support for the ARMv8.6 WFxT extension
- Guard pages for the EL2 stacks
- Trap and emulate AArch32 ID registers to hide unsupported features
- Ability to select and save/restore the set of hypercalls exposed to
the guest
- Support for PSCI-initiated suspend in collaboration with userspace
- GICv3 register-based LPI invalidation support
- Move host PMU event merging into the vcpu data structure
- GICv3 ITS save/restore fixes
- The usual set of small-scale cleanups and fixes
x86:
- New ioctls to get/set TSC frequency for a whole VM
- Allow userspace to opt out of hypercall patching
- Only do MSR filtering for MSRs accessed by rdmsr/wrmsr
AMD SEV improvements:
- Add KVM_EXIT_SHUTDOWN metadata for SEV-ES
- V_TSC_AUX support
Nested virtualization improvements for AMD:
- Support for "nested nested" optimizations (nested vVMLOAD/VMSAVE,
nested vGIF)
- Allow AVIC to co-exist with a nested guest running
- Fixes for LBR virtualizations when a nested guest is running, and
nested LBR virtualization support
- PAUSE filtering for nested hypervisors
Guest support:
- Decoupling of vcpu_is_preempted from PV spinlocks"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (199 commits)
KVM: x86: Fix the intel_pt PMI handling wrongly considered from guest
KVM: selftests: x86: Sync the new name of the test case to .gitignore
Documentation: kvm: reorder ARM-specific section about KVM_SYSTEM_EVENT_SUSPEND
x86, kvm: use correct GFP flags for preemption disabled
KVM: LAPIC: Drop pending LAPIC timer injection when canceling the timer
x86/kvm: Alloc dummy async #PF token outside of raw spinlock
KVM: x86: avoid calling x86 emulator without a decoded instruction
KVM: SVM: Use kzalloc for sev ioctl interfaces to prevent kernel data leak
x86/fpu: KVM: Set the base guest FPU uABI size to sizeof(struct kvm_xsave)
s390/uv_uapi: depend on CONFIG_S390
KVM: selftests: x86: Fix test failure on arch lbr capable platforms
KVM: LAPIC: Trace LAPIC timer expiration on every vmentry
KVM: s390: selftest: Test suppression indication on key prot exception
KVM: s390: Don't indicate suppression on dirtying, failing memop
selftests: drivers/s390x: Add uvdevice tests
drivers/s390/char: Add Ultravisor io device
MAINTAINERS: Update KVM RISC-V entry to cover selftests support
RISC-V: KVM: Introduce ISA extension register
RISC-V: KVM: Cleanup stale TLB entries when host CPU changes
RISC-V: KVM: Add remote HFENCE functions based on VCPU requests
...
KVM/riscv changes for 5.19
- Added Sv57x4 support for G-stage page table
- Added range based local HFENCE functions
- Added remote HFENCE functions based on VCPU requests
- Added ISA extension registers in ONE_REG interface
- Updated KVM RISC-V maintainers entry to cover selftests support
Pull power management updates from Rafael Wysocki:
"These add support for 'artificial' Energy Models in which power
numbers for different entities may be in different scales, add support
for some new hardware, fix bugs and clean up code in multiple places.
Specifics:
- Update the Energy Model support code to allow the Energy Model to
be artificial, which means that the power values may not be on a
uniform scale with other devices providing power information, and
update the cpufreq_cooling and devfreq_cooling thermal drivers to
support artificial Energy Models (Lukasz Luba).
- Make DTPM check the Energy Model type (Lukasz Luba).
- Fix policy counter decrementation in cpufreq if Energy Model is in
use (Pierre Gondois).
- Add CPU-based scaling support to passive devfreq governor (Saravana
Kannan, Chanwoo Choi).
- Update the rk3399_dmc devfreq driver (Brian Norris).
- Export dev_pm_ops instead of suspend() and resume() in the IIO
chemical scd30 driver (Jonathan Cameron).
- Add namespace variants of EXPORT[_GPL]_SIMPLE_DEV_PM_OPS and
PM-runtime counterparts (Jonathan Cameron).
- Move symbol exports in the IIO chemical scd30 driver into the
IIO_SCD30 namespace (Jonathan Cameron).
- Avoid device PM-runtime usage count underflows (Rafael Wysocki).
- Allow dynamic debug to control printing of PM messages (David
Cohen).
- Fix some kernel-doc comments in hibernation code (Yang Li, Haowen
Bai).
- Preserve ACPI-table override during hibernation (Amadeusz
Sławiński).
- Improve support for suspend-to-RAM for PSCI OSI mode (Ulf Hansson).
- Make Intel RAPL power capping driver support the RaptorLake and
AlderLake N processors (Zhang Rui, Sumeet Pawnikar).
- Remove redundant store to value after multiply in the RAPL power
capping driver (Colin Ian King).
- Add AlderLake processor support to the intel_idle driver (Zhang
Rui).
- Fix regression leading to no genpd governor in the PSCI cpuidle
driver and fix the riscv-sbi cpuidle driver to allow a genpd
governor to be used (Ulf Hansson).
- Fix cpufreq governor clean up code to avoid using kfree() directly
to free kobject-based items (Kevin Hao).
- Prepare cpufreq for powerpc's asm/prom.h cleanup (Christophe
Leroy).
- Make intel_pstate notify frequency invariance code when no_turbo is
turned on and off (Chen Yu).
- Add Sapphire Rapids OOB mode support to intel_pstate (Srinivas
Pandruvada).
- Make cpufreq avoid unnecessary frequency updates due to mismatch
between hardware and the frequency table (Viresh Kumar).
- Make remove_cpu_dev_symlink() clear the real_cpus mask to simplify
code (Viresh Kumar).
- Rearrange cpufreq_offline() and cpufreq_remove_dev() to make the
calling convention for some driver callbacks consistent (Rafael
Wysocki).
- Avoid accessing half-initialized cpufreq policies from the show()
and store() sysfs functions (Schspa Shi).
- Rearrange cpufreq_offline() to make the calling convention for some
driver callbacks consistent (Schspa Shi).
- Update CPPC handling in cpufreq (Pierre Gondois).
- Extend dev_pm_domain_detach() doc (Krzysztof Kozlowski).
- Move genpd's time-accounting to ktime_get_mono_fast_ns() (Ulf
Hansson).
- Improve the way genpd deals with its governors (Ulf Hansson).
- Update the turbostat utility to version 2022.04.16 (Len Brown, Dan
Merillat, Sumeet Pawnikar, Zephaniah E. Loss-Cutler-Hull, Chen Yu)"
* tag 'pm-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (94 commits)
PM: domains: Trust domain-idle-states from DT to be correct by genpd
PM: domains: Measure power-on/off latencies in genpd based on a governor
PM: domains: Allocate governor data dynamically based on a genpd governor
PM: domains: Clean up some code in pm_genpd_init() and genpd_remove()
PM: domains: Fix initialization of genpd's next_wakeup
PM: domains: Fixup QoS latency measurements for IRQ safe devices in genpd
PM: domains: Measure suspend/resume latencies in genpd based on governor
PM: domains: Move the next_wakeup variable into the struct gpd_timing_data
PM: domains: Allocate gpd_timing_data dynamically based on governor
PM: domains: Skip another warning in irq_safe_dev_in_sleep_domain()
PM: domains: Rename irq_safe_dev_in_no_sleep_domain() in genpd
PM: domains: Don't check PM_QOS_FLAG_NO_POWER_OFF in genpd
PM: domains: Drop redundant code for genpd always-on governor
PM: domains: Add GENPD_FLAG_RPM_ALWAYS_ON for the always-on governor
powercap: intel_rapl: remove redundant store to value after multiply
cpufreq: CPPC: Enable dvfs_possible_from_any_cpu
cpufreq: CPPC: Enable fast_switch
ACPI: CPPC: Assume no transition latency if no PCCT
ACPI: bus: Set CPPC _OSC bits for all and when CPPC_LIB is supported
ACPI: CPPC: Check _OSC for flexible address space
...
Pull perf events updates from Ingo Molnar:
"Platform PMU changes:
- x86/intel:
- Add new Intel Alder Lake and Raptor Lake support
- x86/amd:
- AMD Zen4 IBS extensions support
- Add AMD PerfMonV2 support
- Add AMD Fam19h Branch Sampling support
Generic changes:
- signal: Deliver SIGTRAP on perf event asynchronously if blocked
Perf instrumentation can be driven via SIGTRAP, but this causes a
problem when SIGTRAP is blocked by a task & terminate the task.
Allow user-space to request these signals asynchronously (after
they get unblocked) & also give the information to the signal
handler when this happens:
"To give user space the ability to clearly distinguish
synchronous from asynchronous signals, introduce
siginfo_t::si_perf_flags and TRAP_PERF_FLAG_ASYNC (opted for
flags in case more binary information is required in future).
The resolution to the problem is then to (a) no longer force the
signal (avoiding the terminations), but (b) tell user space via
si_perf_flags if the signal was synchronous or not, so that such
signals can be handled differently (e.g. let user space decide
to ignore or consider the data imprecise). "
- Unify/standardize the /sys/devices/cpu/events/* output format.
- Misc fixes & cleanups"
* tag 'perf-core-2022-05-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits)
perf/x86/amd/core: Fix reloading events for SVM
perf/x86/amd: Run AMD BRS code only on supported hw
perf/x86/amd: Fix AMD BRS period adjustment
perf/x86/amd: Remove unused variable 'hwc'
perf/ibs: Fix comment
perf/amd/ibs: Advertise zen4_ibs_extensions as pmu capability attribute
perf/amd/ibs: Add support for L3 miss filtering
perf/amd/ibs: Use ->is_visible callback for dynamic attributes
perf/amd/ibs: Cascade pmu init functions' return value
perf/x86/uncore: Add new Alder Lake and Raptor Lake support
perf/x86/uncore: Clean up uncore_pci_ids[]
perf/x86/cstate: Add new Alder Lake and Raptor Lake support
perf/x86/msr: Add new Alder Lake and Raptor Lake support
perf/x86: Add new Alder Lake and Raptor Lake support
perf/amd/ibs: Use interrupt regs ip for stack unwinding
perf/x86/amd/core: Add PerfMonV2 overflow handling
perf/x86/amd/core: Add PerfMonV2 counter control
perf/x86/amd/core: Detect available counters
perf/x86/amd/core: Detect PerfMonV2 support
x86/msr: Add PerfCntrGlobal* registers
...
Pull locking updates from Ingo Molnar:
- rwsem cleanups & optimizations/fixes:
- Conditionally wake waiters in reader/writer slowpaths
- Always try to wake waiters in out_nolock path
- Add try_cmpxchg64() implementation, with arch optimizations - and use
it to micro-optimize sched_clock_{local,remote}()
- Various force-inlining fixes to address objdump instrumentation-check
warnings
- Add lock contention tracepoints:
lock:contention_begin
lock:contention_end
- Misc smaller fixes & cleanups
* tag 'locking-core-2022-05-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/clock: Use try_cmpxchg64 in sched_clock_{local,remote}
locking/atomic/x86: Introduce arch_try_cmpxchg64
locking/atomic: Add generic try_cmpxchg64 support
futex: Remove a PREEMPT_RT_FULL reference.
locking/qrwlock: Change "queue rwlock" to "queued rwlock"
lockdep: Delete local_irq_enable_in_hardirq()
locking/mutex: Make contention tracepoints more consistent wrt adaptive spinning
locking: Apply contention tracepoints in the slow path
locking: Add lock contention tracepoints
locking/rwsem: Always try to wake waiters in out_nolock path
locking/rwsem: Conditionally wake waiters in reader/writer slowpaths
locking/rwsem: No need to check for handoff bit if wait queue empty
lockdep: Fix -Wunused-parameter for _THIS_IP_
x86/mm: Force-inline __phys_addr_nodebug()
x86/kvm/svm: Force-inline GHCB accessors
task_stack, x86/cea: Force-inline stack helpers
Pull arm64 updates from Catalin Marinas:
- Initial support for the ARMv9 Scalable Matrix Extension (SME).
SME takes the approach used for vectors in SVE and extends this to
provide architectural support for matrix operations. No KVM support
yet, SME is disabled in guests.
- Support for crashkernel reservations above ZONE_DMA via the
'crashkernel=X,high' command line option.
- btrfs search_ioctl() fix for live-lock with sub-page faults.
- arm64 perf updates: support for the Hisilicon "CPA" PMU for
monitoring coherent I/O traffic, support for Arm's CMN-650 and
CMN-700 interconnect PMUs, minor driver fixes, kerneldoc cleanup.
- Kselftest updates for SME, BTI, MTE.
- Automatic generation of the system register macros from a 'sysreg'
file describing the register bitfields.
- Update the type of the function argument holding the ESR_ELx register
value to unsigned long to match the architecture register size
(originally 32-bit but extended since ARMv8.0).
- stacktrace cleanups.
- ftrace cleanups.
- Miscellaneous updates, most notably: arm64-specific huge_ptep_get(),
avoid executable mappings in kexec/hibernate code, drop TLB flushing
from get_clear_flush() (and rename it to get_clear_contig()),
ARCH_NR_GPIO bumped to 2048 for ARCH_APPLE.
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (145 commits)
arm64/sysreg: Generate definitions for FAR_ELx
arm64/sysreg: Generate definitions for DACR32_EL2
arm64/sysreg: Generate definitions for CSSELR_EL1
arm64/sysreg: Generate definitions for CPACR_ELx
arm64/sysreg: Generate definitions for CONTEXTIDR_ELx
arm64/sysreg: Generate definitions for CLIDR_EL1
arm64/sve: Move sve_free() into SVE code section
arm64: Kconfig.platforms: Add comments
arm64: Kconfig: Fix indentation and add comments
arm64: mm: avoid writable executable mappings in kexec/hibernate code
arm64: lds: move special code sections out of kernel exec segment
arm64/hugetlb: Implement arm64 specific huge_ptep_get()
arm64/hugetlb: Use ptep_get() to get the pte value of a huge page
arm64: kdump: Do not allocate crash low memory if not needed
arm64/sve: Generate ZCR definitions
arm64/sme: Generate defintions for SVCR
arm64/sme: Generate SMPRI_EL1 definitions
arm64/sme: Automatically generate SMPRIMAP_EL2 definitions
arm64/sme: Automatically generate SMIDR_EL1 defines
arm64/sme: Automatically generate defines for SMCR
...
Merge cpufreq updates for 5.19-rc1:
- Fix cpufreq governor clean up code to avoid using kfree() directly
to free kobject-based items (Kevin Hao).
- Prepare cpufreq for powerpc's asm/prom.h cleanup (Christophe Leroy).
- Make intel_pstate notify frequency invariance code when no_turbo is
turned on and off (Chen Yu).
- Add Sapphire Rapids OOB mode support to intel_pstate (Srinivas
Pandruvada).
- Make cpufreq avoid unnecessary frequency updates due to mismatch
between hardware and the frequency table (Viresh Kumar).
- Make remove_cpu_dev_symlink() clear the real_cpus mask to simplify
code (Viresh Kumar).
- Rearrange cpufreq_offline() and cpufreq_remove_dev() to make the
calling convention for some driver callbacks consistent (Rafael
Wysocki).
- Avoid accessing half-initialized cpufreq policies from the show()
and store() sysfs functions (Schspa Shi).
- Rearrange cpufreq_offline() to make the calling convention for some
driver callbacks consistent (Schspa Shi).
- Update CPPC handling in cpufreq (Pierre Gondois):
* Add per_cpu efficiency_class to the CPPC driver.
* Make the CPPC driver Register EM based on efficiency class
information.
* Adjust _OSC for flexible address space in the ACPI platform
initialization code and always set CPPC _OSC bits if CPPC_LIB is
supported.
* Assume no transition latency if no PCCT in the CPPC driver.
* Add fast_switch and dvfs_possible_from_any_cpu support to the CPPC
driver.
* pm-cpufreq:
cpufreq: CPPC: Enable dvfs_possible_from_any_cpu
cpufreq: CPPC: Enable fast_switch
ACPI: CPPC: Assume no transition latency if no PCCT
ACPI: bus: Set CPPC _OSC bits for all and when CPPC_LIB is supported
ACPI: CPPC: Check _OSC for flexible address space
cpufreq: make interface functions and lock holding state clear
cpufreq: Abort show()/store() for half-initialized policies
cpufreq: Rearrange locking in cpufreq_remove_dev()
cpufreq: Split cpufreq_offline()
cpufreq: Reorganize checks in cpufreq_offline()
cpufreq: Clear real_cpus mask from remove_cpu_dev_symlink()
cpufreq: intel_pstate: Support Sapphire Rapids OOB mode
Revert "cpufreq: Fix possible race in cpufreq online error path"
cpufreq: CPPC: Register EM based on efficiency class information
cpufreq: CPPC: Add per_cpu efficiency_class
cpufreq: Avoid unnecessary frequency updates due to mismatch
cpufreq: Fix possible race in cpufreq online error path
cpufreq: intel_pstate: Handle no_turbo in frequency invariance
cpufreq: Prepare cleanup of powerpc's asm/prom.h
cpufreq: governor: Use kobject release() method to free dbs_data
* for-next/esr-elx-64-bit:
: Treat ESR_ELx as a 64-bit register.
KVM: arm64: uapi: Add kvm_debug_exit_arch.hsr_high
KVM: arm64: Treat ESR_EL2 as a 64-bit register
arm64: Treat ESR_ELx as a 64-bit register
arm64: compat: Do not treat syscall number as ESR_ELx for a bad syscall
arm64: Make ESR_ELx_xVC_IMM_MASK compatible with assembly
