Commit Graph
4278 Commits
Author SHA1 Message Date
Marc ZyngierandGreg Kroah-Hartman cad0406ad7 arm64: Filter out SVE hwcaps when FEAT_SVE isn't implemented
commit 064737920b upstream.

The hwcaps code that exposes SVE features to userspace only
considers ID_AA64ZFR0_EL1, while this is only valid when
ID_AA64PFR0_EL1.SVE advertises that SVE is actually supported.

The expectations are that when ID_AA64PFR0_EL1.SVE is 0, the
ID_AA64ZFR0_EL1 register is also 0. So far, so good.

Things become a bit more interesting if the HW implements SME.
In this case, a few ID_AA64ZFR0_EL1 fields indicate *SME*
features. And these fields overlap with their SVE interpretations.
But the architecture says that the SME and SVE feature sets must
match, so we're still hunky-dory.

This goes wrong if the HW implements SME, but not SVE. In this
case, we end-up advertising some SVE features to userspace, even
if the HW has none. That's because we never consider whether SVE
is actually implemented. Oh well.

Fix it by restricting all SVE capabilities to ID_AA64PFR0_EL1.SVE
being non-zero. The HWCAPS documentation is amended to reflect the
actually checks performed by the kernel.

Fixes: 06a916feca ("arm64: Expose SVE2 features for userspace")
Reported-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: stable@vger.kernel.org
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20250107-arm64-2024-dpisa-v5-1-7578da51fc3d@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-02-21 13:57:26 +01:00
Nathan ChancellorandGreg Kroah-Hartman c1cf034d8d arm64: Handle .ARM.attributes section in linker scripts
commit ca0f4fe7cf upstream.

A recent LLVM commit [1] started generating an .ARM.attributes section
similar to the one that exists for 32-bit, which results in orphan
section warnings (or errors if CONFIG_WERROR is enabled) from the linker
because it is not handled in the arm64 linker scripts.

  ld.lld: error: arch/arm64/kernel/vdso/vgettimeofday.o:(.ARM.attributes) is being placed in '.ARM.attributes'
  ld.lld: error: arch/arm64/kernel/vdso/vgetrandom.o:(.ARM.attributes) is being placed in '.ARM.attributes'

  ld.lld: error: vmlinux.a(lib/vsprintf.o):(.ARM.attributes) is being placed in '.ARM.attributes'
  ld.lld: error: vmlinux.a(lib/win_minmax.o):(.ARM.attributes) is being placed in '.ARM.attributes'
  ld.lld: error: vmlinux.a(lib/xarray.o):(.ARM.attributes) is being placed in '.ARM.attributes'

Discard the new sections in the necessary linker scripts to resolve the
warnings, as the kernel and vDSO do not need to retain it, similar to
the .note.gnu.property section.

Cc: stable@vger.kernel.org
Fixes: b3e5d80d0c ("arm64/build: Warn on orphan section placement")
Link: https://github.com/llvm/llvm-project/commit/ee99c4d4845db66c4daa2373352133f4b237c942 [1]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20250206-arm64-handle-arm-attributes-in-linker-script-v3-1-d53d169913eb@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-02-21 13:57:19 +01:00
Radu RendecandGreg Kroah-Hartman ab90894f33 arm64: cacheinfo: Avoid out-of-bounds write to cacheinfo array
[ Upstream commit 875d742cf5 ]

The loop that detects/populates cache information already has a bounds
check on the array size but does not account for cache levels with
separate data/instructions cache. Fix this by incrementing the index
for any populated leaf (instead of any populated level).

Fixes: 5d425c1865 ("arm64: kernel: add support for cpu cache information")

Signed-off-by: Radu Rendec <rrendec@redhat.com>
Link: https://lore.kernel.org/r/20250206174420.2178724-1-rrendec@redhat.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-21 13:57:07 +01:00
Mark RutlandandGreg Kroah-Hartman 96035c0093 arm64: ptrace: fix partial SETREGSET for NT_ARM_TAGGED_ADDR_CTRL
commit ca62d90085 upstream.

Currently tagged_addr_ctrl_set() doesn't initialize the temporary 'ctrl'
variable, and a SETREGSET call with a length of zero will leave this
uninitialized. Consequently tagged_addr_ctrl_set() will consume an
arbitrary value, potentially leaking up to 64 bits of memory from the
kernel stack. The read is limited to a specific slot on the stack, and
the issue does not provide a write mechanism.

As set_tagged_addr_ctrl() only accepts values where bits [63:4] zero and
rejects other values, a partial SETREGSET attempt will randomly succeed
or fail depending on the value of the uninitialized value, and the
exposure is significantly limited.

Fix this by initializing the temporary value before copying the regset
from userspace, as for other regsets (e.g. NT_PRSTATUS, NT_PRFPREG,
NT_ARM_SYSTEM_CALL). In the case of a zero-length write, the existing
value of the tagged address ctrl will be retained.

The NT_ARM_TAGGED_ADDR_CTRL regset is only visible in the
user_aarch64_view used by a native AArch64 task to manipulate another
native AArch64 task. As get_tagged_addr_ctrl() only returns an error
value when called for a compat task, tagged_addr_ctrl_get() and
tagged_addr_ctrl_set() should never observe an error value from
get_tagged_addr_ctrl(). Add a WARN_ON_ONCE() to both to indicate that
such an error would be unexpected, and error handlnig is not missing in
either case.

Fixes: 2200aa7154 ("arm64: mte: ptrace: Add NT_ARM_TAGGED_ADDR_CTRL regset")
Cc: <stable@vger.kernel.org> # 5.10.x
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20241205121655.1824269-2-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-14 19:59:52 +01:00
Will DeaconandGreg Kroah-Hartman ad654c5bfe arm64: tls: Fix context-switching of tpidrro_el0 when kpti is enabled
commit 67ab51cbdf upstream.

Commit 18011eac28 ("arm64: tls: Avoid unconditional zeroing of
tpidrro_el0 for native tasks") tried to optimise the context switching
of tpidrro_el0 by eliding the clearing of the register when switching
to a native task with kpti enabled, on the erroneous assumption that
the kpti trampoline entry code would already have taken care of the
write.

Although the kpti trampoline does zero the register on entry from a
native task, the check in tls_thread_switch() is on the *next* task and
so we can end up leaving a stale, non-zero value in the register if the
previous task was 32-bit.

Drop the broken optimisation and zero tpidrro_el0 unconditionally when
switching to a native 64-bit task.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: stable@vger.kernel.org
Fixes: 18011eac28 ("arm64: tls: Avoid unconditional zeroing of tpidrro_el0 for native tasks")
Signed-off-by: Will Deacon <will@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20241114095332.23391-1-will@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-09 10:32:50 +01:00
Usama ArifandGreg Kroah-Hartman 1103d3b5a5 of/fdt: add dt_phys arg to early_init_dt_scan and early_init_dt_verify
[ Upstream commit b2473a3597 ]

 __pa() is only intended to be used for linear map addresses and using
it for initial_boot_params which is in fixmap for arm64 will give an
incorrect value. Hence save the physical address when it is known at
boot time when calling early_init_dt_scan for arm64 and use it at kexec
time instead of converting the virtual address using __pa().

Note that arm64 doesn't need the FDT region reserved in the DT as the
kernel explicitly reserves the passed in FDT. Therefore, only a debug
warning is fixed with this change.

Reported-by: Breno Leitao <leitao@debian.org>
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Usama Arif <usamaarif642@gmail.com>
Fixes: ac10be5cdb ("arm64: Use common of_kexec_alloc_and_setup_fdt()")
Link: https://lore.kernel.org/r/20241023171426.452688-1-usamaarif642@gmail.com
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-09 10:31:56 +01:00
Masahiro YamadaandGreg Kroah-Hartman b46bc5b02d arm64: fix .data.rel.ro size assertion when CONFIG_LTO_CLANG
[ Upstream commit 340fd66c85 ]

Commit be2881824a ("arm64/build: Assert for unwanted sections")
introduced an assertion to ensure that the .data.rel.ro section does
not exist.

However, this check does not work when CONFIG_LTO_CLANG is enabled,
because .data.rel.ro matches the .data.[0-9a-zA-Z_]* pattern in the
DATA_MAIN macro.

Move the ASSERT() above the RW_DATA() line.

Fixes: be2881824a ("arm64/build: Assert for unwanted sections")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20241106161843.189927-1-masahiroy@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-09 10:31:44 +01:00
Kristina MartsenkoandGreg Kroah-Hartman 0dd9a53bb9 arm64: probes: Disable kprobes/uprobes on MOPS instructions
[ Upstream commit c56c599d90 ]

FEAT_MOPS instructions require that all three instructions (prologue,
main and epilogue) appear consecutively in memory. Placing a
kprobe/uprobe on one of them doesn't work as only a single instruction
gets executed out-of-line or simulated. So don't allow placing a probe
on a MOPS instruction.

Fixes: b7564127ff ("arm64: mops: detect and enable FEAT_MOPS")
Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>
Link: https://lore.kernel.org/r/20240930161051.3777828-2-kristina.martsenko@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-09 10:31:42 +01:00
Mark RutlandandGreg Kroah-Hartman 701fae8dce arm64: smccc: Remove broken support for SMCCCv1.3 SVE discard hint
commit 8c462d5648 upstream.

SMCCCv1.3 added a hint bit which callers can set in an SMCCC function ID
(AKA "FID") to indicate that it is acceptable for the SMCCC
implementation to discard SVE and/or SME state over a specific SMCCC
call. The kernel support for using this hint is broken and SMCCC calls
may clobber the SVE and/or SME state of arbitrary tasks, though FPSIMD
state is unaffected.

The kernel support is intended to use the hint when there is no SVE or
SME state to save, and to do this it checks whether TIF_FOREIGN_FPSTATE
is set or TIF_SVE is clear in assembly code:

|        ldr     <flags>, [<current_task>, #TSK_TI_FLAGS]
|        tbnz    <flags>, #TIF_FOREIGN_FPSTATE, 1f   // Any live FP state?
|        tbnz    <flags>, #TIF_SVE, 2f               // Does that state include SVE?
|
| 1:     orr     <fid>, <fid>, ARM_SMCCC_1_3_SVE_HINT
| 2:
|        << SMCCC call using FID >>

This is not safe as-is:

(1) SMCCC calls can be made in a preemptible context and preemption can
    result in TIF_FOREIGN_FPSTATE being set or cleared at arbitrary
    points in time. Thus checking for TIF_FOREIGN_FPSTATE provides no
    guarantee.

(2) TIF_FOREIGN_FPSTATE only indicates that the live FP/SVE/SME state in
    the CPU does not belong to the current task, and does not indicate
    that clobbering this state is acceptable.

    When the live CPU state is clobbered it is necessary to update
    fpsimd_last_state.st to ensure that a subsequent context switch will
    reload FP/SVE/SME state from memory rather than consuming the
    clobbered state. This and the SMCCC call itself must happen in a
    critical section with preemption disabled to avoid races.

(3) Live SVE/SME state can exist with TIF_SVE clear (e.g. with only
    TIF_SME set), and checking TIF_SVE alone is insufficient.

Remove the broken support for the SMCCCv1.3 SVE saving hint. This is
effectively a revert of commits:

* cfa7ff959a ("arm64: smccc: Support SMCCC v1.3 SVE register saving hint")
* a7c3acca53 ("arm64: smccc: Save lr before calling __arm_smccc_sve_check()")

... leaving behind the ARM_SMCCC_VERSION_1_3 and ARM_SMCCC_1_3_SVE_HINT
definitions, since these are simply definitions from the SMCCC
specification, and the latter is used in KVM via ARM_SMCCC_CALL_HINTS.

If we want to bring this back in future, we'll probably want to handle
this logic in C where we can use all the usual FPSIMD/SVE/SME helper
functions, and that'll likely require some rework of the SMCCC code
and/or its callers.

Fixes: cfa7ff959a ("arm64: smccc: Support SMCCC v1.3 SVE register saving hint")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: stable@vger.kernel.org
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20241106160448.2712997-1-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-14 13:19:38 +01:00
Mark BrownandGreg Kroah-Hartman 51d11ea025 arm64/sve: Discard stale CPU state when handling SVE traps
commit 751ecf6afd upstream.

The logic for handling SVE traps manipulates saved FPSIMD/SVE state
incorrectly, and a race with preemption can result in a task having
TIF_SVE set and TIF_FOREIGN_FPSTATE clear even though the live CPU state
is stale (e.g. with SVE traps enabled). This has been observed to result
in warnings from do_sve_acc() where SVE traps are not expected while
TIF_SVE is set:

|         if (test_and_set_thread_flag(TIF_SVE))
|                 WARN_ON(1); /* SVE access shouldn't have trapped */

Warnings of this form have been reported intermittently, e.g.

  https://lore.kernel.org/linux-arm-kernel/CA+G9fYtEGe_DhY2Ms7+L7NKsLYUomGsgqpdBj+QwDLeSg=JhGg@mail.gmail.com/
  https://lore.kernel.org/linux-arm-kernel/000000000000511e9a060ce5a45c@google.com/

The race can occur when the SVE trap handler is preempted before and
after manipulating the saved FPSIMD/SVE state, starting and ending on
the same CPU, e.g.

| void do_sve_acc(unsigned long esr, struct pt_regs *regs)
| {
|         // Trap on CPU 0 with TIF_SVE clear, SVE traps enabled
|         // task->fpsimd_cpu is 0.
|         // per_cpu_ptr(&fpsimd_last_state, 0) is task.
|
|         ...
|
|         // Preempted; migrated from CPU 0 to CPU 1.
|         // TIF_FOREIGN_FPSTATE is set.
|
|         get_cpu_fpsimd_context();
|
|         if (test_and_set_thread_flag(TIF_SVE))
|                 WARN_ON(1); /* SVE access shouldn't have trapped */
|
|         sve_init_regs() {
|                 if (!test_thread_flag(TIF_FOREIGN_FPSTATE)) {
|                         ...
|                 } else {
|                         fpsimd_to_sve(current);
|                         current->thread.fp_type = FP_STATE_SVE;
|                 }
|         }
|
|         put_cpu_fpsimd_context();
|
|         // Preempted; migrated from CPU 1 to CPU 0.
|         // task->fpsimd_cpu is still 0
|         // If per_cpu_ptr(&fpsimd_last_state, 0) is still task then:
|         // - Stale HW state is reused (with SVE traps enabled)
|         // - TIF_FOREIGN_FPSTATE is cleared
|         // - A return to userspace skips HW state restore
| }

Fix the case where the state is not live and TIF_FOREIGN_FPSTATE is set
by calling fpsimd_flush_task_state() to detach from the saved CPU
state. This ensures that a subsequent context switch will not reuse the
stale CPU state, and will instead set TIF_FOREIGN_FPSTATE, forcing the
new state to be reloaded from memory prior to a return to userspace.

Fixes: cccb78ce89 ("arm64/sve: Rework SVE access trap to convert state in registers")
Reported-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20241030-arm64-fpsimd-foreign-flush-v1-1-bd7bd66905a2@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-14 13:19:38 +01:00
Mark RutlandandGreg Kroah-Hartman 8165bf83b8 arm64: probes: Fix uprobes for big-endian kernels
commit 13f8f1e05f upstream.

The arm64 uprobes code is broken for big-endian kernels as it doesn't
convert the in-memory instruction encoding (which is always
little-endian) into the kernel's native endianness before analyzing and
simulating instructions. This may result in a few distinct problems:

* The kernel may may erroneously reject probing an instruction which can
  safely be probed.

* The kernel may erroneously erroneously permit stepping an
  instruction out-of-line when that instruction cannot be stepped
  out-of-line safely.

* The kernel may erroneously simulate instruction incorrectly dur to
  interpretting the byte-swapped encoding.

The endianness mismatch isn't caught by the compiler or sparse because:

* The arch_uprobe::{insn,ixol} fields are encoded as arrays of u8, so
  the compiler and sparse have no idea these contain a little-endian
  32-bit value. The core uprobes code populates these with a memcpy()
  which similarly does not handle endianness.

* While the uprobe_opcode_t type is an alias for __le32, both
  arch_uprobe_analyze_insn() and arch_uprobe_skip_sstep() cast from u8[]
  to the similarly-named probe_opcode_t, which is an alias for u32.
  Hence there is no endianness conversion warning.

Fix this by changing the arch_uprobe::{insn,ixol} fields to __le32 and
adding the appropriate __le32_to_cpu() conversions prior to consuming
the instruction encoding. The core uprobes copies these fields as opaque
ranges of bytes, and so is unaffected by this change.

At the same time, remove MAX_UINSN_BYTES and consistently use
AARCH64_INSN_SIZE for clarity.

Tested with the following:

| #include <stdio.h>
| #include <stdbool.h>
|
| #define noinline __attribute__((noinline))
|
| static noinline void *adrp_self(void)
| {
|         void *addr;
|
|         asm volatile(
|         "       adrp    %x0, adrp_self\n"
|         "       add     %x0, %x0, :lo12:adrp_self\n"
|         : "=r" (addr));
| }
|
|
| int main(int argc, char *argv)
| {
|         void *ptr = adrp_self();
|         bool equal = (ptr == adrp_self);
|
|         printf("adrp_self   => %p\n"
|                "adrp_self() => %p\n"
|                "%s\n",
|                adrp_self, ptr, equal ? "EQUAL" : "NOT EQUAL");
|
|         return 0;
| }

.... where the adrp_self() function was compiled to:

| 00000000004007e0 <adrp_self>:
|   4007e0:       90000000        adrp    x0, 400000 <__ehdr_start>
|   4007e4:       911f8000        add     x0, x0, #0x7e0
|   4007e8:       d65f03c0        ret

Before this patch, the ADRP is not recognized, and is assumed to be
steppable, resulting in corruption of the result:

| # ./adrp-self
| adrp_self   => 0x4007e0
| adrp_self() => 0x4007e0
| EQUAL
| # echo 'p /root/adrp-self:0x007e0' > /sys/kernel/tracing/uprobe_events
| # echo 1 > /sys/kernel/tracing/events/uprobes/enable
| # ./adrp-self
| adrp_self   => 0x4007e0
| adrp_self() => 0xffffffffff7e0
| NOT EQUAL

After this patch, the ADRP is correctly recognized and simulated:

| # ./adrp-self
| adrp_self   => 0x4007e0
| adrp_self() => 0x4007e0
| EQUAL
| #
| # echo 'p /root/adrp-self:0x007e0' > /sys/kernel/tracing/uprobe_events
| # echo 1 > /sys/kernel/tracing/events/uprobes/enable
| # ./adrp-self
| adrp_self   => 0x4007e0
| adrp_self() => 0x4007e0
| EQUAL

Fixes: 9842ceae9f ("arm64: Add uprobe support")
Cc: stable@vger.kernel.org
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20241008155851.801546-4-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-10-22 15:46:20 +02:00
Mark RutlandandGreg Kroah-Hartman 173c13e387 arm64: probes: Fix simulate_ldr*_literal()
commit 50f813e576 upstream.

The simulate_ldr_literal() code always loads a 64-bit quantity, and when
simulating a 32-bit load into a 'W' register, it discards the most
significant 32 bits. For big-endian kernels this means that the relevant
bits are discarded, and the value returned is the the subsequent 32 bits
in memory (i.e. the value at addr + 4).

Additionally, simulate_ldr_literal() and simulate_ldrsw_literal() use a
plain C load, which the compiler may tear or elide (e.g. if the target
is the zero register). Today this doesn't happen to matter, but it may
matter in future if trampoline code uses a LDR (literal) or LDRSW
(literal).

Update simulate_ldr_literal() and simulate_ldrsw_literal() to use an
appropriately-sized READ_ONCE() to perform the access, which avoids
these problems.

Fixes: 39a67d49ba ("arm64: kprobes instruction simulation support")
Cc: stable@vger.kernel.org
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20241008155851.801546-3-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-10-22 15:46:20 +02:00
Mark RutlandandGreg Kroah-Hartman 9f1e773547 arm64: probes: Remove broken LDR (literal) uprobe support
commit acc450aa07 upstream.

The simulate_ldr_literal() and simulate_ldrsw_literal() functions are
unsafe to use for uprobes. Both functions were originally written for
use with kprobes, and access memory with plain C accesses. When uprobes
was added, these were reused unmodified even though they cannot safely
access user memory.

There are three key problems:

1) The plain C accesses do not have corresponding extable entries, and
   thus if they encounter a fault the kernel will treat these as
   unintentional accesses to user memory, resulting in a BUG() which
   will kill the kernel thread, and likely lead to further issues (e.g.
   lockup or panic()).

2) The plain C accesses are subject to HW PAN and SW PAN, and so when
   either is in use, any attempt to simulate an access to user memory
   will fault. Thus neither simulate_ldr_literal() nor
   simulate_ldrsw_literal() can do anything useful when simulating a
   user instruction on any system with HW PAN or SW PAN.

3) The plain C accesses are privileged, as they run in kernel context,
   and in practice can access a small range of kernel virtual addresses.
   The instructions they simulate have a range of +/-1MiB, and since the
   simulated instructions must itself be a user instructions in the
   TTBR0 address range, these can address the final 1MiB of the TTBR1
   acddress range by wrapping downwards from an address in the first
   1MiB of the TTBR0 address range.

   In contemporary kernels the last 8MiB of TTBR1 address range is
   reserved, and accesses to this will always fault, meaning this is no
   worse than (1).

   Historically, it was theoretically possible for the linear map or
   vmemmap to spill into the final 8MiB of the TTBR1 address range, but
   in practice this is extremely unlikely to occur as this would
   require either:

   * Having enough physical memory to fill the entire linear map all the
     way to the final 1MiB of the TTBR1 address range.

   * Getting unlucky with KASLR randomization of the linear map such
     that the populated region happens to overlap with the last 1MiB of
     the TTBR address range.

   ... and in either case if we were to spill into the final page there
   would be larger problems as the final page would alias with error
   pointers.

Practically speaking, (1) and (2) are the big issues. Given there have
been no reports of problems since the broken code was introduced, it
appears that no-one is relying on probing these instructions with
uprobes.

Avoid these issues by not allowing uprobes on LDR (literal) and LDRSW
(literal), limiting the use of simulate_ldr_literal() and
simulate_ldrsw_literal() to kprobes. Attempts to place uprobes on LDR
(literal) and LDRSW (literal) will be rejected as
arm_probe_decode_insn() will return INSN_REJECTED. In future we can
consider introducing working uprobes support for these instructions, but
this will require more significant work.

Fixes: 9842ceae9f ("arm64: Add uprobe support")
Cc: stable@vger.kernel.org
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20241008155851.801546-2-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-10-22 15:46:20 +02:00
Mark RutlandandGreg Kroah-Hartman 3c38faa39e arm64: errata: Expand speculative SSBS workaround once more
[ Upstream commit 081eb7932c ]

A number of Arm Ltd CPUs suffer from errata whereby an MSR to the SSBS
special-purpose register does not affect subsequent speculative
instructions, permitting speculative store bypassing for a window of
time.

We worked around this for a number of CPUs in commits:

* 7187bb7d0b ("arm64: errata: Add workaround for Arm errata 3194386 and 3312417")
* 75b3c43eab ("arm64: errata: Expand speculative SSBS workaround")
* 145502cac7ea70b5 ("arm64: errata: Expand speculative SSBS workaround (again)")

Since then, a (hopefully final) batch of updates have been published,
with two more affected CPUs. For the affected CPUs the existing
mitigation is sufficient, as described in their respective Software
Developer Errata Notice (SDEN) documents:

* Cortex-A715 (MP148) SDEN v15.0, erratum 3456084
  https://developer.arm.com/documentation/SDEN-2148827/1500/

* Neoverse-N3 (MP195) SDEN v5.0, erratum 3456111
  https://developer.arm.com/documentation/SDEN-3050973/0500/

Enable the existing mitigation by adding the relevant MIDRs to
erratum_spec_ssbs_list, and update silicon-errata.rst and the
Kconfig text accordingly.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20240930111705.3352047-3-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
[ Mark: fix conflict in silicon-errata.rst ]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-10-10 11:58:02 +02:00
Easwar HariharanandGreg Kroah-Hartman 8f91116f36 arm64: Subscribe Microsoft Azure Cobalt 100 to erratum 3194386
commit 3eddb108ab upstream.

Add the Microsoft Azure Cobalt 100 CPU to the list of CPUs suffering
from erratum 3194386 added in commit 75b3c43eab ("arm64: errata:
Expand speculative SSBS workaround")

CC: Mark Rutland <mark.rutland@arm.com>
CC: James More <james.morse@arm.com>
CC: Will Deacon <will@kernel.org>
CC: stable@vger.kernel.org # 6.6+
Signed-off-by: Easwar Hariharan <eahariha@linux.microsoft.com>
Link: https://lore.kernel.org/r/20241003225239.321774-1-eahariha@linux.microsoft.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-10-10 11:57:52 +02:00
D Scott PhillipsandGreg Kroah-Hartman 0e6774ec01 arm64: errata: Enable the AC03_CPU_38 workaround for ampere1a
commit db0d8a8434 upstream.

The ampere1a cpu is affected by erratum AC04_CPU_10 which is the same
bug as AC03_CPU_38. Add ampere1a to the AC03_CPU_38 workaround midr list.

Cc: <stable@vger.kernel.org>
Signed-off-by: D Scott Phillips <scott@os.amperecomputing.com>
Acked-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20240827211701.2216719-1-scott@os.amperecomputing.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-10-04 16:29:55 +02:00
James MorseandGreg Kroah-Hartman acf9ef8d1b arm64: acpi: Move get_cpu_for_acpi_id() to a header
[ Upstream commit 8d34b6f17b ]

ACPI identifies CPUs by UID. get_cpu_for_acpi_id() maps the ACPI UID
to the Linux CPU number.

The helper to retrieve this mapping is only available in arm64's NUMA
code.

Move it to live next to get_acpi_id_for_cpu().

Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Tested-by: Miguel Luis <miguel.luis@oracle.com>
Tested-by: Vishnu Pajjuri <vishnu@os.amperecomputing.com>
Tested-by: Jianyong Wu <jianyong.wu@arm.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Acked-by: Hanjun Guo <guohanjun@huawei.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Link: https://lore.kernel.org/r/20240529133446.28446-12-Jonathan.Cameron@huawei.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-09-12 11:11:42 +02:00
Samuel HollandandGreg Kroah-Hartman c58f777045 arm64: Fix KASAN random tag seed initialization
[ Upstream commit f75c235565 ]

Currently, kasan_init_sw_tags() is called before setup_per_cpu_areas(),
so per_cpu(prng_state, cpu) accesses the same address regardless of the
value of "cpu", and the same seed value gets copied to the percpu area
for every CPU. Fix this by moving the call to smp_prepare_boot_cpu(),
which is the first architecture hook after setup_per_cpu_areas().

Fixes: 3c9e3aa110 ("kasan: add tag related helper functions")
Fixes: 3f41b60938 ("kasan: fix random seed generation for tag-based mode")
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Link: https://lore.kernel.org/r/20240814091005.969756-1-samuel.holland@sifive.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-29 17:33:30 +02:00
Haibo XuandGreg Kroah-Hartman 0237b5517c arm64: ACPI: NUMA: initialize all values of acpi_early_node_map to NUMA_NO_NODE
commit a21dcf0ea8 upstream.

Currently, only acpi_early_node_map[0] was initialized to NUMA_NO_NODE.
To ensure all the values were properly initialized, switch to initialize
all of them to NUMA_NO_NODE.

Fixes: e189624916 ("arm64: numa: rework ACPI NUMA initialization")
Cc: <stable@vger.kernel.org> # 4.19.x
Reported-by: Andrew Jones <ajones@ventanamicro.com>
Suggested-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Haibo Xu <haibo1.xu@intel.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Sunil V L <sunilvl@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Reviewed-by: Hanjun Guo <guohanjun@huawei.com>
Link: https://lore.kernel.org/r/853d7f74aa243f6f5999e203246f0d1ae92d2b61.1722828421.git.haibo1.xu@intel.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-29 17:33:13 +02:00
Mark RutlandandGreg Kroah-Hartman 745eec68a3 arm64: errata: Expand speculative SSBS workaround (again)
[ Upstream commit adeec61a47 ]

A number of Arm Ltd CPUs suffer from errata whereby an MSR to the SSBS
special-purpose register does not affect subsequent speculative
instructions, permitting speculative store bypassing for a window of
time.

We worked around this for a number of CPUs in commits:

* 7187bb7d0b ("arm64: errata: Add workaround for Arm errata 3194386 and 3312417")
* 75b3c43eab ("arm64: errata: Expand speculative SSBS workaround")

Since then, similar errata have been published for a number of other Arm
Ltd CPUs, for which the same mitigation is sufficient. This is described
in their respective Software Developer Errata Notice (SDEN) documents:

* Cortex-A76 (MP052) SDEN v31.0, erratum 3324349
  https://developer.arm.com/documentation/SDEN-885749/3100/

* Cortex-A77 (MP074) SDEN v19.0, erratum 3324348
  https://developer.arm.com/documentation/SDEN-1152370/1900/

* Cortex-A78 (MP102) SDEN v21.0, erratum 3324344
  https://developer.arm.com/documentation/SDEN-1401784/2100/

* Cortex-A78C (MP138) SDEN v16.0, erratum 3324346
  https://developer.arm.com/documentation/SDEN-1707916/1600/

* Cortex-A78C (MP154) SDEN v10.0, erratum 3324347
  https://developer.arm.com/documentation/SDEN-2004089/1000/

* Cortex-A725 (MP190) SDEN v5.0, erratum 3456106
  https://developer.arm.com/documentation/SDEN-2832921/0500/

* Cortex-X1 (MP077) SDEN v21.0, erratum 3324344
  https://developer.arm.com/documentation/SDEN-1401782/2100/

* Cortex-X1C (MP136) SDEN v16.0, erratum 3324346
  https://developer.arm.com/documentation/SDEN-1707914/1600/

* Neoverse-N1 (MP050) SDEN v32.0, erratum 3324349
  https://developer.arm.com/documentation/SDEN-885747/3200/

* Neoverse-V1 (MP076) SDEN v19.0, erratum 3324341
  https://developer.arm.com/documentation/SDEN-1401781/1900/

Note that due to the manner in which Arm develops IP and tracks errata,
some CPUs share a common erratum number and some CPUs have multiple
erratum numbers for the same HW issue.

On parts without SB, it is necessary to use ISB for the workaround. The
spec_bar() macro used in the mitigation will expand to a "DSB SY; ISB"
sequence in this case, which is sufficient on all affected parts.

Enable the existing mitigation by adding the relevant MIDRs to
erratum_spec_ssbs_list. The list is sorted alphanumerically (involving
moving Neoverse-V3 after Neoverse-V2) so that this is easy to audit and
potentially extend again in future. The Kconfig text is also updated to
clarify the set of affected parts and the mitigation.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20240801101803.1982459-4-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
[ Mark: fix conflicts in silicon-errata.rst ]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-14 13:58:49 +02:00
Mark RutlandandGreg Kroah-Hartman b9bf53354e arm64: errata: Expand speculative SSBS workaround
[ Upstream commit 75b3c43eab ]

A number of Arm Ltd CPUs suffer from errata whereby an MSR to the SSBS
special-purpose register does not affect subsequent speculative
instructions, permitting speculative store bypassing for a window of
time.

We worked around this for Cortex-X4 and Neoverse-V3, in commit:

  7187bb7d0b ("arm64: errata: Add workaround for Arm errata 3194386 and 3312417")

... as per their Software Developer Errata Notice (SDEN) documents:

* Cortex-X4 SDEN v8.0, erratum 3194386:
  https://developer.arm.com/documentation/SDEN-2432808/0800/

* Neoverse-V3 SDEN v6.0, erratum 3312417:
  https://developer.arm.com/documentation/SDEN-2891958/0600/

Since then, similar errata have been published for a number of other Arm Ltd
CPUs, for which the mitigation is the same. This is described in their
respective SDEN documents:

* Cortex-A710 SDEN v19.0, errataum 3324338
  https://developer.arm.com/documentation/SDEN-1775101/1900/?lang=en

* Cortex-A720 SDEN v11.0, erratum 3456091
  https://developer.arm.com/documentation/SDEN-2439421/1100/?lang=en

* Cortex-X2 SDEN v19.0, erratum 3324338
  https://developer.arm.com/documentation/SDEN-1775100/1900/?lang=en

* Cortex-X3 SDEN v14.0, erratum 3324335
  https://developer.arm.com/documentation/SDEN-2055130/1400/?lang=en

* Cortex-X925 SDEN v8.0, erratum 3324334
  https://developer.arm.com/documentation/109108/800/?lang=en

* Neoverse-N2 SDEN v17.0, erratum 3324339
  https://developer.arm.com/documentation/SDEN-1982442/1700/?lang=en

* Neoverse-V2 SDEN v9.0, erratum 3324336
  https://developer.arm.com/documentation/SDEN-2332927/900/?lang=en

Note that due to shared design lineage, some CPUs share the same erratum
number.

Add these to the existing mitigation under CONFIG_ARM64_ERRATUM_3194386.
As listing all of the erratum IDs in the runtime description would be
unwieldy, this is reduced to:

	"SSBS not fully self-synchronizing"

... matching the description of the errata in all of the SDENs.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20240603111812.1514101-6-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
[ Mark: fix conflicts in silicon-errata.rst ]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-14 13:58:49 +02:00
Mark RutlandandGreg Kroah-Hartman 771746afa0 arm64: errata: Unify speculative SSBS errata logic
[ Upstream commit ec76876660 ]

Cortex-X4 erratum 3194386 and Neoverse-V3 erratum 3312417 are identical,
with duplicate Kconfig text and some unsightly ifdeffery. While we try
to share code behind CONFIG_ARM64_WORKAROUND_SPECULATIVE_SSBS, having
separate options results in a fair amount of boilerplate code, and this
will only get worse as we expand the set of affected CPUs.

To reduce this boilerplate, unify the two behind a common Kconfig
option. This removes the duplicate text and Kconfig logic, and removes
the need for the intermediate ARM64_WORKAROUND_SPECULATIVE_SSBS option.
The set of affected CPUs is described as a list so that this can easily
be extended.

I've used ARM64_ERRATUM_3194386 (matching the Neoverse-V3 erratum ID) as
the common option, matching the way we use ARM64_ERRATUM_1319367 to
cover Cortex-A57 erratum 1319537 and Cortex-A72 erratum 1319367.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20240603111812.1514101-5-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
[ Mark: fix conflicts, drop unneeded cpucaps.h ]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-14 13:58:49 +02:00
Mark RutlandandGreg Kroah-Hartman 93696d8f96 arm64: errata: Add workaround for Arm errata 3194386 and 3312417
[ Upstream commit 7187bb7d0b ]

Cortex-X4 and Neoverse-V3 suffer from errata whereby an MSR to the SSBS
special-purpose register does not affect subsequent speculative
instructions, permitting speculative store bypassing for a window of
time. This is described in their Software Developer Errata Notice (SDEN)
documents:

* Cortex-X4 SDEN v8.0, erratum 3194386:
  https://developer.arm.com/documentation/SDEN-2432808/0800/

* Neoverse-V3 SDEN v6.0, erratum 3312417:
  https://developer.arm.com/documentation/SDEN-2891958/0600/

To workaround these errata, it is necessary to place a speculation
barrier (SB) after MSR to the SSBS special-purpose register. This patch
adds the requisite SB after writes to SSBS within the kernel, and hides
the presence of SSBS from EL0 such that userspace software which cares
about SSBS will manipulate this via prctl(PR_GET_SPECULATION_CTRL, ...).

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20240508081400.235362-5-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
[ Mark: fix conflicts, drop unneeded cpucaps.h, fold in user_feature_fixup() ]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-14 13:58:48 +02:00
Will DeaconandGreg Kroah-Hartman dd0aaa9ac4 arm64: jump_label: Ensure patched jump_labels are visible to all CPUs
[ Upstream commit cfb00a3578 ]

Although the Arm architecture permits concurrent modification and
execution of NOP and branch instructions, it still requires some
synchronisation to ensure that other CPUs consistently execute the newly
written instruction:

 >  When the modified instructions are observable, each PE that is
 >  executing the modified instructions must execute an ISB or perform a
 >  context synchronizing event to ensure execution of the modified
 >  instructions

Prior to commit f6cc0c5016 ("arm64: Avoid calling stop_machine() when
patching jump labels"), the arm64 jump_label patching machinery
performed synchronisation using stop_machine() after each modification,
however this was problematic when flipping static keys from atomic
contexts (namely, the arm_arch_timer CPU hotplug startup notifier) and
so we switched to the _nosync() patching routines to avoid "scheduling
while atomic" BUG()s during boot.

In hindsight, the analysis of the issue in f6cc0c5016 isn't quite
right: it cites the use of IPIs in the default patching routines as the
cause of the lockup, whereas stop_machine() does not rely on IPIs and
the I-cache invalidation is performed using __flush_icache_range(),
which elides the call to kick_all_cpus_sync(). In fact, the blocking
wait for other CPUs is what triggers the BUG() and the problem remains
even after f6cc0c5016, for example because we could block on the
jump_label_mutex. Eventually, the arm_arch_timer driver was fixed to
avoid the static key entirely in commit a862fc2254
("clocksource/arm_arch_timer: Remove use of workaround static key").

This all leaves the jump_label patching code in a funny situation on
arm64 as we do not synchronise with other CPUs to reduce the likelihood
of a bug which no longer exists. Consequently, toggling a static key on
one CPU cannot be assumed to take effect on other CPUs, leading to
potential issues, for example with missing preempt notifiers.

Rather than revert f6cc0c5016 and go back to stop_machine() for each
patch site, implement arch_jump_label_transform_apply() and kick all
the other CPUs with an IPI at the end of patching.

Cc: Alexander Potapenko <glider@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Fixes: f6cc0c5016 ("arm64: Avoid calling stop_machine() when patching jump labels")
Signed-off-by: Will Deacon <will@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240731133601.3073-1-will@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-11 12:47:24 +02:00
Wei LiandGreg Kroah-Hartman 69a978c7fe arm64: armv8_deprecated: Fix warning in isndep cpuhp starting process
[ Upstream commit 14951beaec ]

The function run_all_insn_set_hw_mode() is registered as startup callback
of 'CPUHP_AP_ARM64_ISNDEP_STARTING', it invokes set_hw_mode() methods of
all emulated instructions.

As the STARTING callbacks are not expected to fail, if one of the
set_hw_mode() fails, e.g. due to el0 mixed-endian is not supported for
'setend', it will report a warning:

```
CPU[2] cannot support the emulation of setend
CPU 2 UP state arm64/isndep:starting (136) failed (-22)
CPU2: Booted secondary processor 0x0000000002 [0x414fd0c1]
```

To fix it, add a check for INSN_UNAVAILABLE status and skip the process.

Signed-off-by: Wei Li <liwei391@huawei.com>
Tested-by: Huisong Li <lihuisong@huawei.com>
Link: https://lore.kernel.org/r/20240423093501.3460764-1-liwei391@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-25 09:50:43 +02:00
Kees CookandGreg Kroah-Hartman 591c0650b9 randomize_kstack: Remove non-functional per-arch entropy filtering
[ Upstream commit 6db1208bf9 ]

An unintended consequence of commit 9c573cd313 ("randomize_kstack:
Improve entropy diffusion") was that the per-architecture entropy size
filtering reduced how many bits were being added to the mix, rather than
how many bits were being used during the offsetting. All architectures
fell back to the existing default of 0x3FF (10 bits), which will consume
at most 1KiB of stack space. It seems that this is working just fine,
so let's avoid the confusion and update everything to use the default.

The prior intent of the per-architecture limits were:

  arm64: capped at 0x1FF (9 bits), 5 bits effective
  powerpc: uncapped (10 bits), 6 or 7 bits effective
  riscv: uncapped (10 bits), 6 bits effective
  x86: capped at 0xFF (8 bits), 5 (x86_64) or 6 (ia32) bits effective
  s390: capped at 0xFF (8 bits), undocumented effective entropy

Current discussion has led to just dropping the original per-architecture
filters. The additional entropy appears to be safe for arm64, x86,
and s390. Quoting Arnd, "There is no point pretending that 15.75KB is
somehow safe to use while 15.00KB is not."

Co-developed-by: Yuntao Liu <liuyuntao12@huawei.com>
Signed-off-by: Yuntao Liu <liuyuntao12@huawei.com>
Fixes: 9c573cd313 ("randomize_kstack: Improve entropy diffusion")
Link: https://lore.kernel.org/r/20240617133721.377540-1-liuyuntao12@huawei.com
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com> # s390
Link: https://lore.kernel.org/r/20240619214711.work.953-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-05 09:33:54 +02:00
Masahiro YamadaandGreg Kroah-Hartman adacfc6dec kbuild: unify vdso_install rules
[ Upstream commit 56769ba4b2 ]

Currently, there is no standard implementation for vdso_install,
leading to various issues:

 1. Code duplication

    Many architectures duplicate similar code just for copying files
    to the install destination.

    Some architectures (arm, sparc, x86) create build-id symlinks,
    introducing more code duplication.

 2. Unintended updates of in-tree build artifacts

    The vdso_install rule depends on the vdso files to install.
    It may update in-tree build artifacts. This can be problematic,
    as explained in commit 19514fc665 ("arm, kbuild: make
    "make install" not depend on vmlinux").

 3. Broken code in some architectures

    Makefile code is often copied from one architecture to another
    without proper adaptation.

    'make vdso_install' for parisc does not work.

    'make vdso_install' for s390 installs vdso64, but not vdso32.

To address these problems, this commit introduces a generic vdso_install
rule.

Architectures that support vdso_install need to define vdso-install-y
in arch/*/Makefile. vdso-install-y lists the files to install.

For example, arch/x86/Makefile looks like this:

  vdso-install-$(CONFIG_X86_64)           += arch/x86/entry/vdso/vdso64.so.dbg
  vdso-install-$(CONFIG_X86_X32_ABI)      += arch/x86/entry/vdso/vdsox32.so.dbg
  vdso-install-$(CONFIG_X86_32)           += arch/x86/entry/vdso/vdso32.so.dbg
  vdso-install-$(CONFIG_IA32_EMULATION)   += arch/x86/entry/vdso/vdso32.so.dbg

These files will be installed to $(MODLIB)/vdso/ with the .dbg suffix,
if exists, stripped away.

vdso-install-y can optionally take the second field after the colon
separator. This is needed because some architectures install a vdso
file as a different base name.

The following is a snippet from arch/arm64/Makefile.

  vdso-install-$(CONFIG_COMPAT_VDSO)      += arch/arm64/kernel/vdso32/vdso.so.dbg:vdso32.so

This will rename vdso.so.dbg to vdso32.so during installation. If such
architectures change their implementation so that the base names match,
this workaround will go away.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Sven Schnelle <svens@linux.ibm.com> # s390
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Reviewed-by: Guo Ren <guoren@kernel.org>
Acked-by: Helge Deller <deller@gmx.de>  # parisc
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Stable-dep-of: fc2f5f10f9 ("s390/vdso: Create .build-id links for unstripped vdso files")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-12 11:12:32 +02:00
Ard BiesheuvelandGreg Kroah-Hartman e972b6a701 arm64/head: Disable MMU at EL2 before clearing HCR_EL2.E2H
commit 34e526cb7d upstream.

Even though the boot protocol stipulates otherwise, an exception has
been made for the EFI stub, and entering the core kernel with the MMU
enabled is permitted. This allows a substantial amount of cache
maintenance to be elided, wich is significant when fast boot times are
critical (e.g., for booting micro-VMs)

Once the initial ID map has been populated, the MMU is disabled as part
of the logic sequence that puts all system registers into a known state.
Any code that needs to execute within the window where the MMU is off is
cleaned to the PoC explicitly, which includes all of HYP text when
entering at EL2.

However, the current sequence of initializing the EL2 system registers
is not safe: HCR_EL2 is set to its nVHE initial state before SCTLR_EL2
is reprogrammed, and this means that a VHE-to-nVHE switch may occur
while the MMU is enabled. This switch causes some system registers as
well as page table descriptors to be interpreted in a different way,
potentially resulting in spurious exceptions relating to MMU
translation.

So disable the MMU explicitly first when entering in EL2 with the MMU
and caches enabled.

Fixes: 6178617038 ("efi: arm64: enter with MMU and caches enabled")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Cc: <stable@vger.kernel.org> # 6.3.x
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240415075412.2347624-6-ardb+git@google.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-27 17:11:41 +02:00
Mark BrownandGreg Kroah-Hartman 8a44119ca4 arm64/ptrace: Use saved floating point state type to determine SVE layout
commit b017a0cea6 upstream.

The SVE register sets have two different formats, one of which is a wrapped
version of the standard FPSIMD register set and another with actual SVE
register data. At present we check TIF_SVE to see if full SVE register
state should be provided when reading the SVE regset but if we were in a
syscall we may have saved only floating point registers even though that is
set.

Fix this and simplify the logic by checking and using the format which we
recorded when deciding if we should use FPSIMD or SVE format.

Fixes: 8c845e2731 ("arm64/sve: Leave SVE enabled on syscall if we don't context switch")
Cc: <stable@vger.kernel.org> # 6.2.x
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20240325-arm64-ptrace-fp-type-v1-1-8dc846caf11f@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-10 16:36:03 +02:00
Mark BrownandSasha Levin 10a33d1d05 arm64/sve: Lower the maximum allocation for the SVE ptrace regset
[ Upstream commit 2813926261 ]

Doug Anderson observed that ChromeOS crashes are being reported which
include failing allocations of order 7 during core dumps due to ptrace
allocating storage for regsets:

  chrome: page allocation failure: order:7,
          mode:0x40dc0(GFP_KERNEL|__GFP_COMP|__GFP_ZERO),
          nodemask=(null),cpuset=urgent,mems_allowed=0
   ...
  regset_get_alloc+0x1c/0x28
  elf_core_dump+0x3d8/0xd8c
  do_coredump+0xeb8/0x1378

with further investigation showing that this is:

   [   66.957385] DOUG: Allocating 279584 bytes

which is the maximum size of the SVE regset. As Doug observes it is not
entirely surprising that such a large allocation of contiguous memory might
fail on a long running system.

The SVE regset is currently sized to hold SVE registers with a VQ of
SVE_VQ_MAX which is 512, substantially more than the architectural maximum
of 16 which we might see even in a system emulating the limits of the
architecture. Since we don't expose the size we tell the regset core
externally let's define ARCH_SVE_VQ_MAX with the actual architectural
maximum and use that for the regset, we'll still overallocate most of the
time but much less so which will be helpful even if the core is fixed to
not require contiguous allocations.

Specify ARCH_SVE_VQ_MAX in terms of the maximum value that can be written
into ZCR_ELx.LEN (where this is set in the hardware). For consistency
update the maximum SME vector length to be specified in the same style
while we are at it.

We could also teach the ptrace core about runtime discoverable regset sizes
but that would be a more invasive change and this is being observed in
practical systems.

Reported-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20240213-arm64-sve-ptrace-regset-size-v2-1-c7600ca74b9b@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-26 18:19:11 -04:00
Mark BrownandGreg Kroah-Hartman 79491ddfb4 arm64/sme: Restore SMCR_EL1.EZT0 on exit from suspend
[ Upstream commit d7b77a0d56 ]

The fields in SMCR_EL1 reset to an architecturally UNKNOWN value. Since we
do not otherwise manage the traps configured in this register at runtime we
need to reconfigure them after a suspend in case nothing else was kind
enough to preserve them for us. Do so for SMCR_EL1.EZT0.

Fixes: d4913eee15 ("arm64/sme: Add basic enumeration for SME2")
Reported-by: Jackson Cooper-Driver <Jackson.Cooper-Driver@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20240213-arm64-sme-resume-v3-2-17e05e493471@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-01 13:35:08 +01:00
Mark BrownandGreg Kroah-Hartman 7c89238322 arm64/sme: Restore SME registers on exit from suspend
[ Upstream commit 9533864816 ]

The fields in SMCR_EL1 and SMPRI_EL1 reset to an architecturally UNKNOWN
value. Since we do not otherwise manage the traps configured in this
register at runtime we need to reconfigure them after a suspend in case
nothing else was kind enough to preserve them for us.

The vector length will be restored as part of restoring the SME state for
the next SME using task.

Fixes: a1f4ccd25c ("arm64/sme: Provide Kconfig for SME")
Reported-by: Jackson Cooper-Driver <Jackson.Cooper-Driver@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20240213-arm64-sme-resume-v3-1-17e05e493471@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-01 13:35:08 +01:00
Easwar HariharanandGreg Kroah-Hartman 19758688bd arm64: Subscribe Microsoft Azure Cobalt 100 to ARM Neoverse N2 errata
commit fb091ff394 upstream.

Add the MIDR value of Microsoft Azure Cobalt 100, which is a Microsoft
implemented CPU based on r0p0 of the ARM Neoverse N2 CPU, and therefore
suffers from all the same errata.

CC: stable@vger.kernel.org # 5.15+
Signed-off-by: Easwar Hariharan <eahariha@linux.microsoft.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20240214175522.2457857-1-eahariha@linux.microsoft.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-23 09:25:14 +01:00
Mark BrownandGreg Kroah-Hartman 60480c6bc1 arm64/signal: Don't assume that TIF_SVE means we saved SVE state
commit 61da7c8e2a upstream.

When we are in a syscall we will only save the FPSIMD subset even though
the task still has access to the full register set, and on context switch
we will only remove TIF_SVE when loading the register state. This means
that the signal handling code should not assume that TIF_SVE means that
the register state is stored in SVE format, it should instead check the
format that was recorded during save.

Fixes: 8c845e2731 ("arm64/sve: Leave SVE enabled on syscall if we don't context switch")
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240130-arm64-sve-signal-regs-v2-1-9fc6f9502782@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-23 09:25:13 +01:00
Huang ShijieandGreg Kroah-Hartman e50c55c295 arm64: irq: set the correct node for shadow call stack
commit 7b1a09e44d upstream.

The init_irq_stacks() has been changed to use the correct node:
https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git/commit/?id=75b5e0bf90bf

The init_irq_scs() has the same issue with init_irq_stacks():
	cpu_to_node() is not initialized yet, it does not work.

This patch uses early_cpu_to_node() to set the init_irq_scs()
with the correct node.

Signed-off-by: Huang Shijie <shijie@os.amperecomputing.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20231213012046.12014-1-shijie@os.amperecomputing.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-05 20:14:38 +00:00
Huang ShijieandGreg Kroah-Hartman 40a5dce893 arm64: irq: set the correct node for VMAP stack
[ Upstream commit 75b5e0bf90 ]

In current code, init_irq_stacks() will call cpu_to_node().
The cpu_to_node() depends on percpu "numa_node" which is initialized in:
     arch_call_rest_init() --> rest_init() -- kernel_init()
	--> kernel_init_freeable() --> smp_prepare_cpus()

But init_irq_stacks() is called in init_IRQ() which is before
arch_call_rest_init().

So in init_irq_stacks(), the cpu_to_node() does not work, it
always return 0. In NUMA, it makes the node 1 cpu accesses the IRQ stack which
is in the node 0.

This patch fixes it by:
  1.) export the early_cpu_to_node(), and use it in the init_irq_stacks().
  2.) change init_irq_stacks() to __init function.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Huang Shijie <shijie@os.amperecomputing.com>
Link: https://lore.kernel.org/r/20231124031513.81548-1-shijie@os.amperecomputing.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-02-05 20:14:14 +00:00
Mark RutlandandGreg Kroah-Hartman 58eb5c07f4 arm64: entry: fix ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
commit 832dd634bd upstream.

Currently the ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD workaround isn't
quite right, as it is supposed to be applied after the last explicit
memory access, but is immediately followed by an LDR.

The ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD workaround is used to
handle Cortex-A520 erratum 2966298 and Cortex-A510 erratum 3117295,
which are described in:

* https://developer.arm.com/documentation/SDEN2444153/0600/?lang=en
* https://developer.arm.com/documentation/SDEN1873361/1600/?lang=en

In both cases the workaround is described as:

| If pagetable isolation is disabled, the context switch logic in the
| kernel can be updated to execute the following sequence on affected
| cores before exiting to EL0, and after all explicit memory accesses:
|
| 1. A non-shareable TLBI to any context and/or address, including
|    unused contexts or addresses, such as a `TLBI VALE1 Xzr`.
|
| 2. A DSB NSH to guarantee completion of the TLBI.

The important part being that the TLBI+DSB must be placed "after all
explicit memory accesses".

Unfortunately, as-implemented, the TLBI+DSB is immediately followed by
an LDR, as we have:

| alternative_if ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
| 	tlbi	vale1, xzr
| 	dsb	nsh
| alternative_else_nop_endif
| alternative_if_not ARM64_UNMAP_KERNEL_AT_EL0
| 	ldr	lr, [sp, #S_LR]
| 	add	sp, sp, #PT_REGS_SIZE		// restore sp
| 	eret
| alternative_else_nop_endif
|
| [ ... KPTI exception return path ... ]

This patch fixes this by reworking the logic to place the TLBI+DSB
immediately before the ERET, after all explicit memory accesses.

The ERET is currently in a separate alternative block, and alternatives
cannot be nested. To account for this, the alternative block for
ARM64_UNMAP_KERNEL_AT_EL0 is replaced with a single alternative branch
to skip the KPTI logic, with the new shape of the logic being:

| alternative_insn "b .L_skip_tramp_exit_\@", nop, ARM64_UNMAP_KERNEL_AT_EL0
| 	[ ... KPTI exception return path ... ]
| .L_skip_tramp_exit_\@:
|
| 	ldr	lr, [sp, #S_LR]
| 	add	sp, sp, #PT_REGS_SIZE		// restore sp
|
| alternative_if ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
| 	tlbi	vale1, xzr
| 	dsb	nsh
| alternative_else_nop_endif
| 	eret

The new structure means that the workaround is only applied when KPTI is
not in use; this is fine as noted in the documented implications of the
erratum:

| Pagetable isolation between EL0 and higher level ELs prevents the
| issue from occurring.

... and as per the workaround description quoted above, the workaround
is only necessary "If pagetable isolation is disabled".

Fixes: 471470bc70 ("arm64: errata: Add Cortex-A520 speculative unprivileged load workaround")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240116110221.420467-2-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-31 16:18:55 -08:00
Mark BrownandGreg Kroah-Hartman 569156e4fa arm64/sme: Always exit sme_alloc() early with existing storage
commit dc7eb87557 upstream.

When sme_alloc() is called with existing storage and we are not flushing we
will always allocate new storage, both leaking the existing storage and
corrupting the state. Fix this by separating the checks for flushing and
for existing storage as we do for SVE.

Callers that reallocate (eg, due to changing the vector length) should
call sme_free() themselves.

Fixes: 5d0a8d2fba ("arm64/ptrace: Ensure that SME is set up for target when writing SSVE state")
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20240115-arm64-sme-flush-v1-1-7472bd3459b7@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-31 16:18:55 -08:00
Rob HerringandGreg Kroah-Hartman f5da59f2bb arm64: errata: Add Cortex-A510 speculative unprivileged load workaround
commit f827bcdafa upstream.

Implement the workaround for ARM Cortex-A510 erratum 3117295. On an
affected Cortex-A510 core, a speculatively executed unprivileged load
might leak data from a privileged load via a cache side channel. The
issue only exists for loads within a translation regime with the same
translation (e.g. same ASID and VMID). Therefore, the issue only affects
the return to EL0.

The erratum and workaround are the same as ARM Cortex-A520 erratum
2966298, so reuse the existing workaround.

Cc: stable@vger.kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20240110-arm-errata-a510-v1-2-d02bc51aeeee@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-31 16:18:55 -08:00
Rob HerringandGreg Kroah-Hartman 236a9bf2a7 arm64: Rename ARM64_WORKAROUND_2966298
commit 546b7cde9b upstream.

In preparation to apply ARM64_WORKAROUND_2966298 for multiple errata,
rename the kconfig and capability. No functional change.

Cc: stable@vger.kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20240110-arm-errata-a510-v1-1-d02bc51aeeee@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-31 16:18:55 -08:00
Mark BrownandGreg Kroah-Hartman 53cea04da8 arm64/ptrace: Don't flush ZA/ZT storage when writing ZA via ptrace
[ Upstream commit b7c510d049 ]

When writing ZA we currently unconditionally flush the buffer used to store
it as part of ensuring that it is allocated. Since this buffer is shared
with ZT0 this means that a write to ZA when PSTATE.ZA is already set will
corrupt the value of ZT0 on a SME2 system. Fix this by only flushing the
backing storage if PSTATE.ZA was not previously set.

This will mean that short or failed writes may leave stale data in the
buffer, this seems as correct as our current behaviour and unlikely to be
something that userspace will rely on.

Fixes: f90b529bcb ("arm64/sme: Implement ZT0 ptrace support")
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20240115-arm64-fix-ptrace-za-zt-v1-1-48617517028a@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-25 15:36:00 -08:00
Maria YuandGreg Kroah-Hartman e7c5f137e5 arm64: module: Fix PLT counting when CONFIG_RANDOMIZE_BASE=n
commit d35686444f upstream.

The counting of module PLTs has been broken when CONFIG_RANDOMIZE_BASE=n
since commit:

  3e35d303ab ("arm64: module: rework module VA range selection")

Prior to that commit, when CONFIG_RANDOMIZE_BASE=n, the kernel image and
all modules were placed within a 128M region, and no PLTs were necessary
for B or BL. Hence count_plts() and partition_branch_plt_relas() skipped
handling B and BL when CONFIG_RANDOMIZE_BASE=n.

After that commit, modules can be placed anywhere within a 2G window
regardless of CONFIG_RANDOMIZE_BASE, and hence PLTs may be necessary for
B and BL even when CONFIG_RANDOMIZE_BASE=n. Unfortunately that commit
failed to update count_plts() and partition_branch_plt_relas()
accordingly.

Due to this, module_emit_plt_entry() may fail if an insufficient number
of PLT entries have been reserved, resulting in modules failing to load
with -ENOEXEC.

Fix this by counting PLTs regardless of CONFIG_RANDOMIZE_BASE in
count_plts() and partition_branch_plt_relas().

Fixes: 3e35d303ab ("arm64: module: rework module VA range selection")
Signed-off-by: Maria Yu <quic_aiquny@quicinc.com>
Cc: <stable@vger.kernel.org> # 6.5.x
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Fixes: 3e35d303ab ("arm64: module: rework module VA range selection")
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20231024010954.6768-1-quic_aiquny@quicinc.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-28 17:20:00 +00:00
Rob HerringandWill Deacon 471470bc70 arm64: errata: Add Cortex-A520 speculative unprivileged load workaround
Implement the workaround for ARM Cortex-A520 erratum 2966298. On an
affected Cortex-A520 core, a speculatively executed unprivileged load
might leak data from a privileged load via a cache side channel. The
issue only exists for loads within a translation regime with the same
translation (e.g. same ASID and VMID). Therefore, the issue only affects
the return to EL0.

The workaround is to execute a TLBI before returning to EL0 after all
loads of privileged data. A non-shareable TLBI to any address is
sufficient.

The workaround isn't necessary if page table isolation (KPTI) is
enabled, but for simplicity it will be. Page table isolation should
normally be disabled for Cortex-A520 as it supports the CSV3 feature
and the E0PD feature (used when KASLR is enabled).

Cc: stable@vger.kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230921194156.1050055-2-robh@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2023-09-29 16:31:33 +01:00
Kristina MartsenkoandWill Deacon 479965a2b7 arm64: cpufeature: Fix CLRBHB and BC detection
ClearBHB support is indicated by the CLRBHB field in ID_AA64ISAR2_EL1.
Following some refactoring the kernel incorrectly checks the BC field
instead. Fix the detection to use the right field.

(Note: The original ClearBHB support had it as FTR_HIGHER_SAFE, but this
patch uses FTR_LOWER_SAFE, which seems more correct.)

Also fix the detection of BC (hinted conditional branches) to use
FTR_LOWER_SAFE, so that it is not reported on mismatched systems.

Fixes: 356137e68a ("arm64/sysreg: Make BHB clear feature defines match the architecture")
Fixes: 8fcc8285c0 ("arm64/sysreg: Convert ID_AA64ISAR2_EL1 to automatic generation")
Cc: stable@vger.kernel.org
Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230912133429.2606875-1-kristina.martsenko@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2023-09-18 10:45:11 +01:00
Linus Torvalds ca9c7abf95 Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 fixes from Will Deacon:
 "The main one is a fix for a broken strscpy() conversion that landed in
  the merge window and broke early parsing of the kernel command line.

   - Fix an incorrect mask in the CXL PMU driver

   - Fix a regression in early parsing of the kernel command line

   - Fix an IP checksum OoB access reported by syzbot"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: csum: Fix OoB access in IP checksum code for negative lengths
  arm64/sysreg: Fix broken strncpy() -> strscpy() conversion
  perf: CXL: fix mismatched number of counters mask
2023-09-08 12:48:37 -07:00
Linus Torvalds 0c02183427 Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm updates from Paolo Bonzini:
 "ARM:

   - Clean up vCPU targets, always returning generic v8 as the preferred
     target

   - Trap forwarding infrastructure for nested virtualization (used for
     traps that are taken from an L2 guest and are needed by the L1
     hypervisor)

   - FEAT_TLBIRANGE support to only invalidate specific ranges of
     addresses when collapsing a table PTE to a block PTE. This avoids
     that the guest refills the TLBs again for addresses that aren't
     covered by the table PTE.

   - Fix vPMU issues related to handling of PMUver.

   - Don't unnecessary align non-stack allocations in the EL2 VA space

   - Drop HCR_VIRT_EXCP_MASK, which was never used...

   - Don't use smp_processor_id() in kvm_arch_vcpu_load(), but the cpu
     parameter instead

   - Drop redundant call to kvm_set_pfn_accessed() in user_mem_abort()

   - Remove prototypes without implementations

  RISC-V:

   - Zba, Zbs, Zicntr, Zicsr, Zifencei, and Zihpm support for guest

   - Added ONE_REG interface for SATP mode

   - Added ONE_REG interface to enable/disable multiple ISA extensions

   - Improved error codes returned by ONE_REG interfaces

   - Added KVM_GET_REG_LIST ioctl() implementation for KVM RISC-V

   - Added get-reg-list selftest for KVM RISC-V

  s390:

   - PV crypto passthrough enablement (Tony, Steffen, Viktor, Janosch)

     Allows a PV guest to use crypto cards. Card access is governed by
     the firmware and once a crypto queue is "bound" to a PV VM every
     other entity (PV or not) looses access until it is not bound
     anymore. Enablement is done via flags when creating the PV VM.

   - Guest debug fixes (Ilya)

  x86:

   - Clean up KVM's handling of Intel architectural events

   - Intel bugfixes

   - Add support for SEV-ES DebugSwap, allowing SEV-ES guests to use
     debug registers and generate/handle #DBs

   - Clean up LBR virtualization code

   - Fix a bug where KVM fails to set the target pCPU during an IRTE
     update

   - Fix fatal bugs in SEV-ES intrahost migration

   - Fix a bug where the recent (architecturally correct) change to
     reinject #BP and skip INT3 broke SEV guests (can't decode INT3 to
     skip it)

   - Retry APIC map recalculation if a vCPU is added/enabled

   - Overhaul emergency reboot code to bring SVM up to par with VMX, tie
     the "emergency disabling" behavior to KVM actually being loaded,
     and move all of the logic within KVM

   - Fix user triggerable WARNs in SVM where KVM incorrectly assumes the
     TSC ratio MSR cannot diverge from the default when TSC scaling is
     disabled up related code

   - Add a framework to allow "caching" feature flags so that KVM can
     check if the guest can use a feature without needing to search
     guest CPUID

   - Rip out the ancient MMU_DEBUG crud and replace the useful bits with
     CONFIG_KVM_PROVE_MMU

   - Fix KVM's handling of !visible guest roots to avoid premature
     triple fault injection

   - Overhaul KVM's page-track APIs, and KVMGT's usage, to reduce the
     API surface that is needed by external users (currently only
     KVMGT), and fix a variety of issues in the process

  Generic:

   - Wrap kvm_{gfn,hva}_range.pte in a union to allow mmu_notifier
     events to pass action specific data without needing to constantly
     update the main handlers.

   - Drop unused function declarations

  Selftests:

   - Add testcases to x86's sync_regs_test for detecting KVM TOCTOU bugs

   - Add support for printf() in guest code and covert all guest asserts
     to use printf-based reporting

   - Clean up the PMU event filter test and add new testcases

   - Include x86 selftests in the KVM x86 MAINTAINERS entry"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (279 commits)
  KVM: x86/mmu: Include mmu.h in spte.h
  KVM: x86/mmu: Use dummy root, backed by zero page, for !visible guest roots
  KVM: x86/mmu: Disallow guest from using !visible slots for page tables
  KVM: x86/mmu: Harden TDP MMU iteration against root w/o shadow page
  KVM: x86/mmu: Harden new PGD against roots without shadow pages
  KVM: x86/mmu: Add helper to convert root hpa to shadow page
  drm/i915/gvt: Drop final dependencies on KVM internal details
  KVM: x86/mmu: Handle KVM bookkeeping in page-track APIs, not callers
  KVM: x86/mmu: Drop @slot param from exported/external page-track APIs
  KVM: x86/mmu: Bug the VM if write-tracking is used but not enabled
  KVM: x86/mmu: Assert that correct locks are held for page write-tracking
  KVM: x86/mmu: Rename page-track APIs to reflect the new reality
  KVM: x86/mmu: Drop infrastructure for multiple page-track modes
  KVM: x86/mmu: Use page-track notifiers iff there are external users
  KVM: x86/mmu: Move KVM-only page-track declarations to internal header
  KVM: x86: Remove the unused page-track hook track_flush_slot()
  drm/i915/gvt: switch from ->track_flush_slot() to ->track_remove_region()
  KVM: x86: Add a new page-track hook to handle memslot deletion
  drm/i915/gvt: Don't bother removing write-protection on to-be-deleted slot
  KVM: x86: Reject memslot MOVE operations if KVMGT is attached
  ...
2023-09-07 13:52:20 -07:00
Will Deacon ab41a97474 arm64/sysreg: Fix broken strncpy() -> strscpy() conversion
Mostafa reports that commit d232606773 ("arm64/sysreg: refactor
deprecated strncpy") breaks our early command-line parsing because the
original code is working on space-delimited substrings rather than
NUL-terminated strings.

Rather than simply reverting the broken conversion patch, replace the
strscpy() with a simple memcpy() with an explicit NUL-termination of the
result.

Reported-by: Mostafa Saleh <smostafa@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Fixes: d232606773 ("arm64/sysreg: refactor deprecated strncpy")
Signed-off-by: Justin Stitt <justinstitt@google.com>
Link: https://lore.kernel.org/r/20230905-strncpy-arch-arm64-v4-1-bc4b14ddfaef@google.com
Link: https://lore.kernel.org/r/20230831162227.2307863-1-smostafa@google.com
Signed-off-by: Will Deacon <will@kernel.org>
2023-09-06 19:22:54 +01:00
Linus Torvalds df57721f9a Merge tag 'x86_shstk_for_6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 shadow stack support from Dave Hansen:
 "This is the long awaited x86 shadow stack support, part of Intel's
  Control-flow Enforcement Technology (CET).

  CET consists of two related security features: shadow stacks and
  indirect branch tracking. This series implements just the shadow stack
  part of this feature, and just for userspace.

  The main use case for shadow stack is providing protection against
  return oriented programming attacks. It works by maintaining a
  secondary (shadow) stack using a special memory type that has
  protections against modification. When executing a CALL instruction,
  the processor pushes the return address to both the normal stack and
  to the special permission shadow stack. Upon RET, the processor pops
  the shadow stack copy and compares it to the normal stack copy.

  For more information, refer to the links below for the earlier
  versions of this patch set"

Link: https://lore.kernel.org/lkml/20220130211838.8382-1-rick.p.edgecombe@intel.com/
Link: https://lore.kernel.org/lkml/20230613001108.3040476-1-rick.p.edgecombe@intel.com/

* tag 'x86_shstk_for_6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (47 commits)
  x86/shstk: Change order of __user in type
  x86/ibt: Convert IBT selftest to asm
  x86/shstk: Don't retry vm_munmap() on -EINTR
  x86/kbuild: Fix Documentation/ reference
  x86/shstk: Move arch detail comment out of core mm
  x86/shstk: Add ARCH_SHSTK_STATUS
  x86/shstk: Add ARCH_SHSTK_UNLOCK
  x86: Add PTRACE interface for shadow stack
  selftests/x86: Add shadow stack test
  x86/cpufeatures: Enable CET CR4 bit for shadow stack
  x86/shstk: Wire in shadow stack interface
  x86: Expose thread features in /proc/$PID/status
  x86/shstk: Support WRSS for userspace
  x86/shstk: Introduce map_shadow_stack syscall
  x86/shstk: Check that signal frame is shadow stack mem
  x86/shstk: Check that SSP is aligned on sigreturn
  x86/shstk: Handle signals for shadow stack
  x86/shstk: Introduce routines modifying shstk
  x86/shstk: Handle thread shadow stack
  x86/shstk: Add user-mode shadow stack support
  ...
2023-08-31 12:20:12 -07:00
Paolo Bonzini e0fb12c673 Merge tag 'kvmarm-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm64 updates for Linux 6.6

- Add support for TLB range invalidation of Stage-2 page tables,
  avoiding unnecessary invalidations. Systems that do not implement
  range invalidation still rely on a full invalidation when dealing
  with large ranges.

- Add infrastructure for forwarding traps taken from a L2 guest to
  the L1 guest, with L0 acting as the dispatcher, another baby step
  towards the full nested support.

- Simplify the way we deal with the (long deprecated) 'CPU target',
  resulting in a much needed cleanup.

- Fix another set of PMU bugs, both on the guest and host sides,
  as we seem to never have any shortage of those...

- Relax the alignment requirements of EL2 VA allocations for
  non-stack allocations, as we were otherwise wasting a lot of that
  precious VA space.

- The usual set of non-functional cleanups, although I note the lack
  of spelling fixes...
2023-08-31 13:18:53 -04:00
Linus Torvalds 461f35f014 Merge tag 'drm-next-2023-08-30' of git://anongit.freedesktop.org/drm/drm
Pull drm updates from Dave Airlie:
 "The drm core grew a new generic gpu virtual address manager, and new
  execution locking helpers. These are used by nouveau now to provide
  uAPI support for the userspace Vulkan driver. AMD had a bunch of new
  IP core support, loads of refactoring around fbdev, but mostly just
  the usual amount of stuff across the board.

  core:
   - fix gfp flags in drmm_kmalloc

  gpuva:
   - add new generic GPU VA manager (for nouveau initially)

  syncobj:
   - add new DRM_IOCTL_SYNCOBJ_EVENTFD ioctl

  dma-buf:
   - acquire resv lock for mmap() in exporters
   - support dma-buf self import automatically
   - docs fixes

  backlight:
   - fix fbdev interactions

  atomic:
   - improve logging

  prime:
   - remove struct gem_prim_mmap plus driver updates

  gem:
   - drm_exec: add locking over multiple GEM objects
   - fix lockdep checking

  fbdev:
   - make fbdev userspace interfaces optional
   - use linux device instead of fbdev device
   - use deferred i/o helper macros in various drivers
   - Make FB core selectable without drivers
   - Remove obsolete flags FBINFO_DEFAULT and FBINFO_FLAG_DEFAULT
   - Add helper macros and Kconfig tokens for DMA-allocated framebuffer

  ttm:
   - support init_on_free
   - swapout fixes

  panel:
   - panel-edp: Support AUO B116XAB01.4
   - Support Visionox R66451 plus DT bindings
   - ld9040:
      - Backlight support
      - magic improved
      - Kconfig fix
   - Convert to of_device_get_match_data()
   - Fix Kconfig dependencies
   - simple:
      - Set bpc value to fix warning
      - Set connector type for AUO T215HVN01
      - Support Innolux G156HCE-L01 plus DT bindings
   - ili9881: Support TDO TL050HDV35 LCD panel plus DT bindings
   - startek: Support KD070FHFID015 MIPI-DSI panel plus DT bindings
   - sitronix-st7789v:
      - Support Inanbo T28CP45TN89 plus DT bindings
      - Support EDT ET028013DMA plus DT bindings
      - Various cleanups
   - edp: Add timings for N140HCA-EAC
   - Allow panels and touchscreens to power sequence together
   - Fix Innolux G156HCE-L01 LVDS clock

  bridge:
   - debugfs for chains support
   - dw-hdmi:
      - Improve support for YUV420 bus format
      - CEC suspend/resume
      - update EDID on HDMI detect
   - dw-mipi-dsi: Fix enable/disable of DSI controller
   - lt9611uxc: Use MODULE_FIRMWARE()
   - ps8640: Remove broken EDID code
   - samsung-dsim: Fix command transfer
   - tc358764:
      - Handle HS/VS polarity
      - Use BIT() macro
      - Various cleanups
   - adv7511: Fix low refresh rate
   - anx7625:
      - Switch to macros instead of hardcoded values
      - locking fixes
   - tc358767: fix hardware delays
   - sitronix-st7789v:
      - Support panel orientation
      - Support rotation property
      - Add support for Jasonic JT240MHQS-HWT-EK-E3 plus DT bindings

  amdgpu:
   - SDMA 6.1.0 support
   - HDP 6.1 support
   - SMUIO 14.0 support
   - PSP 14.0 support
   - IH 6.1 support
   - Lots of checkpatch cleanups
   - GFX 9.4.3 updates
   - Add USB PD and IFWI flashing documentation
   - GPUVM updates
   - RAS fixes
   - DRR fixes
   - FAMS fixes
   - Virtual display fixes
   - Soft IH fixes
   - SMU13 fixes
   - Rework PSP firmware loading for other IPs
   - Kernel doc fixes
   - DCN 3.0.1 fixes
   - LTTPR fixes
   - DP MST fixes
   - DCN 3.1.6 fixes
   - SMU 13.x fixes
   - PSP 13.x fixes
   - SubVP fixes
   - GC 9.4.3 fixes
   - Display bandwidth calculation fixes
   - VCN4 secure submission fixes
   - Allow building DC on RISC-V
   - Add visible FB info to bo_print_info
   - HBR3 fixes
   - GFX9 MCBP fix
   - GMC10 vmhub index fix
   - GMC11 vmhub index fix
   - Create a new doorbell manager
   - SR-IOV fixes
   - initial freesync panel replay support
   - revert zpos properly until igt regression is fixeed
   - use TTM to manage doorbell BAR
   - Expose both current and average power via hwmon if supported

  amdkfd:
   - Cleanup CRIU dma-buf handling
   - Use KIQ to unmap HIQ
   - GFX 9.4.3 debugger updates
   - GFX 9.4.2 debugger fixes
   - Enable cooperative groups fof gfx11
   - SVM fixes
   - Convert older APUs to use dGPU path like newer APUs
   - Drop IOMMUv2 path as it is no longer used
   - TBA fix for aldebaran

  i915:
   - ICL+ DSI modeset sequence
   - HDCP improvements
   - MTL display fixes and cleanups
   - HSW/BDW PSR1 restored
   - Init DDI ports in VBT order
   - General display refactors
   - Start using plane scale factor for relative data rate
   - Use shmem for dpt objects
   - Expose RPS thresholds in sysfs
   - Apply GuC SLPC min frequency softlimit correctly
   - Extend Wa_14015795083 to TGL, RKL, DG1 and ADL
   - Fix a VMA UAF for multi-gt platform
   - Do not use stolen on MTL due to HW bug
   - Check HuC and GuC version compatibility on MTL
   - avoid infinite GPU waits due to premature release of request memory
   - Fixes and updates for GSC memory allocation
   - Display SDVO fixes
   - Take stolen handling out of FBC code
   - Make i915_coherent_map_type GT-centric
   - Simplify shmem_create_from_object map_type

  msm:
   - SM6125 MDSS support
   - DPU: SM6125 DPU support
   - DSI: runtime PM support, burst mode support
   - DSI PHY: SM6125 support in 14nm DSI PHY driver
   - GPU: prepare for a7xx
   - fix a690 firmware
   - disable relocs on a6xx and newer

  radeon:
   - Lots of checkpatch cleanups

  ast:
   - improve device-model detection
   - Represent BMV as virtual connector
   - Report DP connection status

  nouveau:
   - add new exec/bind interface to support Vulkan
   - document some getparam ioctls
   - improve VRAM detection
   - various fixes/cleanups
   - workraound DPCD issues

  ivpu:
   - MMU updates
   - debugfs support
   - Support vpu4

  virtio:
   - add sync object support

  atmel-hlcdc:
   - Support inverted pixclock polarity

  etnaviv:
   - runtime PM cleanups
   - hang handling fixes

  exynos:
   - use fbdev DMA helpers
   - fix possible NULL ptr dereference

  komeda:
   - always attach encoder

  omapdrm:
   - use fbdev DMA helpers
ingenic:
   - kconfig regmap fixes

  loongson:
   - support display controller

  mediatek:
   - Small mtk-dpi cleanups
   - DisplayPort: support eDP and aux-bus
   - Fix coverity issues
   - Fix potential memory leak if vmap() fail

  mgag200:
   - minor fixes

  mxsfb:
   - support disabling overlay planes

  panfrost:
   - fix sync in IRQ handling

  ssd130x:
   - Support per-controller default resolution plus DT bindings
   - Reduce memory-allocation overhead
   - Improve intermediate buffer size computation
   - Fix allocation of temporary buffers
   - Fix pitch computation
   - Fix shadow plane allocation

  tegra:
   - use fbdev DMA helpers
   - Convert to devm_platform_ioremap_resource()
   - support bridge/connector
   - enable PM

  tidss:
   - Support TI AM625 plus DT bindings
   - Implement new connector model plus driver updates

  vkms:
   - improve write back support
   - docs fixes
   - support gamma LUT

  zynqmp-dpsub:
   - misc fixes"

* tag 'drm-next-2023-08-30' of git://anongit.freedesktop.org/drm/drm: (1327 commits)
  drm/gpuva_mgr: remove unused prev pointer in __drm_gpuva_sm_map()
  drm/tests/drm_kunit_helpers: Place correct function name in the comment header
  drm/nouveau: uapi: don't pass NO_PREFETCH flag implicitly
  drm/nouveau: uvmm: fix unset region pointer on remap
  drm/nouveau: sched: avoid job races between entities
  drm/i915: Fix HPD polling, reenabling the output poll work as needed
  drm: Add an HPD poll helper to reschedule the poll work
  drm/i915: Fix TLB-Invalidation seqno store
  drm/ttm/tests: Fix type conversion in ttm_pool_test
  drm/msm/a6xx: Bail out early if setting GPU OOB fails
  drm/msm/a6xx: Move LLC accessors to the common header
  drm/msm/a6xx: Introduce a6xx_llc_read
  drm/ttm/tests: Require MMU when testing
  drm/panel: simple: Fix Innolux G156HCE-L01 LVDS clock
  Revert "Revert "drm/amdgpu/display: change pipe policy for DCN 2.0""
  drm/amdgpu: Add memory vendor information
  drm/amd: flush any delayed gfxoff on suspend entry
  drm/amdgpu: skip fence GFX interrupts disable/enable for S0ix
  drm/amdgpu: Remove gfxoff check in GFX v9.4.3
  drm/amd/pm: Update pci link speed for smu v13.0.6
  ...
2023-08-30 13:34:34 -07:00