linux.git/arch/arm64/kernel/entry.S, branch v6.8 Linux kernel source tree arm64: entry: simplify kernel_exit logic 2024-01-18T11:00:09+00:00 Mark Rutland mark.rutland@arm.com 2024-01-16T11:02:21+00:00 da59f1d051d57e85eca49401a3a36d5a622babde For historical reasons, the non-KPTI exception return path is duplicated for EL1 and EL0, with the structure: .if \el == 0 [ KPTI handling ] ldr lr, [sp, #S_LR] add sp, sp, #PT_REGS_SIZE // restore sp [ EL0 exception return workaround ] eret .else ldr lr, [sp, #S_LR] add sp, sp, #PT_REGS_SIZE // restore sp [ EL1 exception return workaround ] eret .endif sb This would be simpler and clearer with the common portions factored out, e.g. .if \el == 0 [ KPTI handling ] .endif ldr lr, [sp, #S_LR] add sp, sp, #PT_REGS_SIZE // restore sp .if \el == 0 [ EL0 exception return workaround ] .else [ EL1 exception return workaround ] .endif eret sb This expands to the same code, but is simpler for a human to follow as it avoids duplicates the restore of LR+SP, and makes it clear that the ERET is associated with the SB. There should be no functional change as a result of this patch. 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> Link: https://lore.kernel.org/r/20240116110221.420467-3-mark.rutland@arm.com Signed-off-by: Will Deacon <will@kernel.org> 
For historical reasons, the non-KPTI exception return path is duplicated for
EL1 and EL0, with the structure:

	.if \el == 0
	[ KPTI handling ]
	ldr     lr, [sp, #S_LR]
 	add	sp, sp, #PT_REGS_SIZE		// restore sp
	[ EL0 exception return workaround ]
	eret
	.else
	ldr     lr, [sp, #S_LR]
 	add	sp, sp, #PT_REGS_SIZE		// restore sp
	[ EL1 exception return workaround ]
	eret
	.endif
	sb

This would be simpler and clearer with the common portions factored out,
e.g.

	.if \el == 0
	[ KPTI handling ]
	.endif

	ldr     lr, [sp, #S_LR]
 	add	sp, sp, #PT_REGS_SIZE		// restore sp

	.if \el == 0
	[ EL0 exception return workaround ]
	.else
	[ EL1 exception return workaround ]
	.endif

	eret
	sb

This expands to the same code, but is simpler for a human to follow as
it avoids duplicates the restore of LR+SP, and makes it clear that the
ERET is associated with the SB.

There should be no functional change as a result of this patch.

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>
Link: https://lore.kernel.org/r/20240116110221.420467-3-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
arm64: entry: fix ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 2024-01-18T11:00:09+00:00 Mark Rutland mark.rutland@arm.com 2024-01-16T11:02:20+00:00 832dd634bd1b4e3bbe9f10b9c9ba5db6f6f2b97f 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: 471470bc7052 ("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> 
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: 471470bc7052 ("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>
arm64: Rename ARM64_WORKAROUND_2966298 2024-01-12T12:51:33+00:00 Rob Herring robh@kernel.org 2024-01-10T17:29:20+00:00 546b7cde9b1dd36089649101b75266564600ffe5 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> 
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>
arm64: errata: Add Cortex-A520 speculative unprivileged load workaround 2023-09-29T15:31:33+00:00 Rob Herring robh@kernel.org 2023-09-21T19:41:52+00:00 471470bc7052d28ce125901877dd10e4c048e513 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> 
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>
arm64: sdei: abort running SDEI handlers during crash 2023-08-04T16:35:33+00:00 D Scott Phillips scott@os.amperecomputing.com 2023-06-27T00:29:39+00:00 5cd474e57368f0957c343bb21e309cf82826b1ef Interrupts are blocked in SDEI context, per the SDEI spec: "The client interrupts cannot preempt the event handler." If we crashed in the SDEI handler-running context (as with ACPI's AGDI) then we need to clean up the SDEI state before proceeding to the crash kernel so that the crash kernel can have working interrupts. Track the active SDEI handler per-cpu so that we can COMPLETE_AND_RESUME the handler, discarding the interrupted context. Fixes: f5df26961853 ("arm64: kernel: Add arch-specific SDEI entry code and CPU masking") Signed-off-by: D Scott Phillips <scott@os.amperecomputing.com> Cc: stable@vger.kernel.org Reviewed-by: James Morse <james.morse@arm.com> Tested-by: Mihai Carabas <mihai.carabas@oracle.com> Link: https://lore.kernel.org/r/20230627002939.2758-1-scott@os.amperecomputing.com Signed-off-by: Will Deacon <will@kernel.org> 
Interrupts are blocked in SDEI context, per the SDEI spec: "The client
interrupts cannot preempt the event handler." If we crashed in the SDEI
handler-running context (as with ACPI's AGDI) then we need to clean up the
SDEI state before proceeding to the crash kernel so that the crash kernel
can have working interrupts.

Track the active SDEI handler per-cpu so that we can COMPLETE_AND_RESUME
the handler, discarding the interrupted context.

Fixes: f5df26961853 ("arm64: kernel: Add arch-specific SDEI entry code and CPU masking")
Signed-off-by: D Scott Phillips <scott@os.amperecomputing.com>
Cc: stable@vger.kernel.org
Reviewed-by: James Morse <james.morse@arm.com>
Tested-by: Mihai Carabas <mihai.carabas@oracle.com>
Link: https://lore.kernel.org/r/20230627002939.2758-1-scott@os.amperecomputing.com
Signed-off-by: Will Deacon <will@kernel.org>
arm64: entry: Simplify tramp_alias macro and tramp_exit routine 2023-05-25T15:55:19+00:00 Ard Biesheuvel ardb@kernel.org 2023-04-18T14:36:04+00:00 211ceca377f40ff46aef8ceb6e26cf4e7efecaf1 The tramp_alias macro constructs the virtual alias of a symbol in the trampoline text mapping, based on its kernel text address, and does so in a way that is more convoluted than necessary. So let's simplify that. Also, now that the address of the vector table is kept in a per-CPU variable, there is no need to defer the load and the assignment of VBAR_EL1 to tramp_exit(). This means we can use a PC-relative reference to the per-CPU variable instead of storing its absolute address in a global variable in the trampoline rodata. And given that tramp_alias no longer needs a temp register, this means we can restore X30 earlier as well, and only leave X29 for tramp_exit() to restore. While at it, give some related symbols static linkage, considering that they are only referenced from the object file that defines them. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20230418143604.1176437-3-ardb@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> 
The tramp_alias macro constructs the virtual alias of a symbol in the
trampoline text mapping, based on its kernel text address, and does so
in a way that is more convoluted than necessary. So let's simplify that.

Also, now that the address of the vector table is kept in a per-CPU
variable, there is no need to defer the load and the assignment of
VBAR_EL1 to tramp_exit(). This means we can use a PC-relative reference
to the per-CPU variable instead of storing its absolute address in a
global variable in the trampoline rodata.

And given that tramp_alias no longer needs a temp register, this means
we can restore X30 earlier as well, and only leave X29 for tramp_exit()
to restore.

While at it, give some related symbols static linkage, considering that
they are only referenced from the object file that defines them.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20230418143604.1176437-3-ardb@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
arm64: entry: Preserve/restore X29 even for compat tasks 2023-05-25T15:55:19+00:00 Ard Biesheuvel ardb@kernel.org 2023-04-18T14:36:03+00:00 0936243cabf0caf46f1a42606325ab93cfa05a6a Currently, the KPTI trampoline code for returning to user space takes care to only preserve X29 into FAR_EL1 for native tasks, as compat tasks don't have access to this register anyway, and so preserving it is not necessary. It also means it does not need to be restored, and so we have two code paths for returning back to user space: the native one that restores X29 from FAR_EL1, and the compat one that leaves X29 clobbered, containing the value of TTBR1_EL1, which carries a physical address pointing somewhere into the kernel image. This is needlessly complex, and given that FAR_EL1 becomes UNKNOWN after an exception return anway, the only benefit of avoiding the preserve and restore is that we can skip the system register write and read. So let's simplify this, and collapse the two code paths into one that always preserves X29 into FAR_EL1, and always restores it again after the TTBR switch. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20230418143604.1176437-2-ardb@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> 
Currently, the KPTI trampoline code for returning to user space takes
care to only preserve X29 into FAR_EL1 for native tasks, as compat tasks
don't have access to this register anyway, and so preserving it is not
necessary. It also means it does not need to be restored, and so we have
two code paths for returning back to user space: the native one that
restores X29 from FAR_EL1, and the compat one that leaves X29 clobbered,
containing the value of TTBR1_EL1, which carries a physical address
pointing somewhere into the kernel image.

This is needlessly complex, and given that FAR_EL1 becomes UNKNOWN after
an exception return anway, the only benefit of avoiding the preserve and
restore is that we can skip the system register write and read.

So let's simplify this, and collapse the two code paths into one that
always preserves X29 into FAR_EL1, and always restores it again after
the TTBR switch.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20230418143604.1176437-2-ardb@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Merge branches 'for-next/sysreg', 'for-next/sme', 'for-next/kselftest', 'for-next/misc', 'for-next/sme2', 'for-next/tpidr2', 'for-next/scs', 'for-next/compat-hwcap', 'for-next/ftrace', 'for-next/efi-boot-mmu-on', 'for-next/ptrauth' and 'for-next/pseudo-nmi', remote-tracking branch 'arm64/for-next/perf' into for-next/core 2023-02-10T18:51:49+00:00 Catalin Marinas catalin.marinas@arm.com 2023-02-10T18:51:49+00:00 156010ed9c2ac1e9df6c11b1f688cf8a6e0152e6 * arm64/for-next/perf: perf: arm_spe: Print the version of SPE detected perf: arm_spe: Add support for SPEv1.2 inverted event filtering perf: Add perf_event_attr::config3 drivers/perf: fsl_imx8_ddr_perf: Remove set-but-not-used variable perf: arm_spe: Support new SPEv1.2/v8.7 'not taken' event perf: arm_spe: Use new PMSIDR_EL1 register enums perf: arm_spe: Drop BIT() and use FIELD_GET/PREP accessors arm64/sysreg: Convert SPE registers to automatic generation arm64: Drop SYS_ from SPE register defines perf: arm_spe: Use feature numbering for PMSEVFR_EL1 defines perf/marvell: Add ACPI support to TAD uncore driver perf/marvell: Add ACPI support to DDR uncore driver perf/arm-cmn: Reset DTM_PMU_CONFIG at probe drivers/perf: hisi: Extract initialization of "cpa_pmu->pmu" drivers/perf: hisi: Simplify the parameters of hisi_pmu_init() drivers/perf: hisi: Advertise the PERF_PMU_CAP_NO_EXCLUDE capability * for-next/sysreg: : arm64 sysreg and cpufeature fixes/updates KVM: arm64: Use symbolic definition for ISR_EL1.A arm64/sysreg: Add definition of ISR_EL1 arm64/sysreg: Add definition for ICC_NMIAR1_EL1 arm64/cpufeature: Remove 4 bit assumption in ARM64_FEATURE_MASK() arm64/sysreg: Fix errors in 32 bit enumeration values arm64/cpufeature: Fix field sign for DIT hwcap detection * for-next/sme: : SME-related updates arm64/sme: Optimise SME exit on syscall entry arm64/sme: Don't use streaming mode to probe the maximum SME VL arm64/ptrace: Use system_supports_tpidr2() to check for TPIDR2 support * for-next/kselftest: (23 commits) : arm64 kselftest fixes and improvements kselftest/arm64: Don't require FA64 for streaming SVE+ZA tests kselftest/arm64: Copy whole EXTRA context kselftest/arm64: Fix enumeration of systems without 128 bit SME for SSVE+ZA kselftest/arm64: Fix enumeration of systems without 128 bit SME kselftest/arm64: Don't require FA64 for streaming SVE tests kselftest/arm64: Limit the maximum VL we try to set via ptrace kselftest/arm64: Correct buffer size for SME ZA storage kselftest/arm64: Remove the local NUM_VL definition kselftest/arm64: Verify simultaneous SSVE and ZA context generation kselftest/arm64: Verify that SSVE signal context has SVE_SIG_FLAG_SM set kselftest/arm64: Remove spurious comment from MTE test Makefile kselftest/arm64: Support build of MTE tests with clang kselftest/arm64: Initialise current at build time in signal tests kselftest/arm64: Don't pass headers to the compiler as source kselftest/arm64: Remove redundant _start labels from FP tests kselftest/arm64: Fix .pushsection for strings in FP tests kselftest/arm64: Run BTI selftests on systems without BTI kselftest/arm64: Fix test numbering when skipping tests kselftest/arm64: Skip non-power of 2 SVE vector lengths in fp-stress kselftest/arm64: Only enumerate power of two VLs in syscall-abi ... * for-next/misc: : Miscellaneous arm64 updates arm64/mm: Intercept pfn changes in set_pte_at() Documentation: arm64: correct spelling arm64: traps: attempt to dump all instructions arm64: Apply dynamic shadow call stack patching in two passes arm64: el2_setup.h: fix spelling typo in comments arm64: Kconfig: fix spelling arm64: cpufeature: Use kstrtobool() instead of strtobool() arm64: Avoid repeated AA64MMFR1_EL1 register read on pagefault path arm64: make ARCH_FORCE_MAX_ORDER selectable * for-next/sme2: (23 commits) : Support for arm64 SME 2 and 2.1 arm64/sme: Fix __finalise_el2 SMEver check kselftest/arm64: Remove redundant _start labels from zt-test kselftest/arm64: Add coverage of SME 2 and 2.1 hwcaps kselftest/arm64: Add coverage of the ZT ptrace regset kselftest/arm64: Add SME2 coverage to syscall-abi kselftest/arm64: Add test coverage for ZT register signal frames kselftest/arm64: Teach the generic signal context validation about ZT kselftest/arm64: Enumerate SME2 in the signal test utility code kselftest/arm64: Cover ZT in the FP stress test kselftest/arm64: Add a stress test program for ZT0 arm64/sme: Add hwcaps for SME 2 and 2.1 features arm64/sme: Implement ZT0 ptrace support arm64/sme: Implement signal handling for ZT arm64/sme: Implement context switching for ZT0 arm64/sme: Provide storage for ZT0 arm64/sme: Add basic enumeration for SME2 arm64/sme: Enable host kernel to access ZT0 arm64/sme: Manually encode ZT0 load and store instructions arm64/esr: Document ISS for ZT0 being disabled arm64/sme: Document SME 2 and SME 2.1 ABI ... * for-next/tpidr2: : Include TPIDR2 in the signal context kselftest/arm64: Add test case for TPIDR2 signal frame records kselftest/arm64: Add TPIDR2 to the set of known signal context records arm64/signal: Include TPIDR2 in the signal context arm64/sme: Document ABI for TPIDR2 signal information * for-next/scs: : arm64: harden shadow call stack pointer handling arm64: Stash shadow stack pointer in the task struct on interrupt arm64: Always load shadow stack pointer directly from the task struct * for-next/compat-hwcap: : arm64: Expose compat ARMv8 AArch32 features (HWCAPs) arm64: Add compat hwcap SSBS arm64: Add compat hwcap SB arm64: Add compat hwcap I8MM arm64: Add compat hwcap ASIMDBF16 arm64: Add compat hwcap ASIMDFHM arm64: Add compat hwcap ASIMDDP arm64: Add compat hwcap FPHP and ASIMDHP * for-next/ftrace: : Add arm64 support for DYNAMICE_FTRACE_WITH_CALL_OPS arm64: avoid executing padding bytes during kexec / hibernation arm64: Implement HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS arm64: ftrace: Update stale comment arm64: patching: Add aarch64_insn_write_literal_u64() arm64: insn: Add helpers for BTI arm64: Extend support for CONFIG_FUNCTION_ALIGNMENT ACPI: Don't build ACPICA with '-Os' Compiler attributes: GCC cold function alignment workarounds ftrace: Add DYNAMIC_FTRACE_WITH_CALL_OPS * for-next/efi-boot-mmu-on: : Permit arm64 EFI boot with MMU and caches on arm64: kprobes: Drop ID map text from kprobes blacklist arm64: head: Switch endianness before populating the ID map efi: arm64: enter with MMU and caches enabled arm64: head: Clean the ID map and the HYP text to the PoC if needed arm64: head: avoid cache invalidation when entering with the MMU on arm64: head: record the MMU state at primary entry arm64: kernel: move identity map out of .text mapping arm64: head: Move all finalise_el2 calls to after __enable_mmu * for-next/ptrauth: : arm64 pointer authentication cleanup arm64: pauth: don't sign leaf functions arm64: unify asm-arch manipulation * for-next/pseudo-nmi: : Pseudo-NMI code generation optimisations arm64: irqflags: use alternative branches for pseudo-NMI logic arm64: add ARM64_HAS_GIC_PRIO_RELAXED_SYNC cpucap arm64: make ARM64_HAS_GIC_PRIO_MASKING depend on ARM64_HAS_GIC_CPUIF_SYSREGS arm64: rename ARM64_HAS_IRQ_PRIO_MASKING to ARM64_HAS_GIC_PRIO_MASKING arm64: rename ARM64_HAS_SYSREG_GIC_CPUIF to ARM64_HAS_GIC_CPUIF_SYSREGS 
* arm64/for-next/perf:
  perf: arm_spe: Print the version of SPE detected
  perf: arm_spe: Add support for SPEv1.2 inverted event filtering
  perf: Add perf_event_attr::config3
  drivers/perf: fsl_imx8_ddr_perf: Remove set-but-not-used variable
  perf: arm_spe: Support new SPEv1.2/v8.7 'not taken' event
  perf: arm_spe: Use new PMSIDR_EL1 register enums
  perf: arm_spe: Drop BIT() and use FIELD_GET/PREP accessors
  arm64/sysreg: Convert SPE registers to automatic generation
  arm64: Drop SYS_ from SPE register defines
  perf: arm_spe: Use feature numbering for PMSEVFR_EL1 defines
  perf/marvell: Add ACPI support to TAD uncore driver
  perf/marvell: Add ACPI support to DDR uncore driver
  perf/arm-cmn: Reset DTM_PMU_CONFIG at probe
  drivers/perf: hisi: Extract initialization of "cpa_pmu->pmu"
  drivers/perf: hisi: Simplify the parameters of hisi_pmu_init()
  drivers/perf: hisi: Advertise the PERF_PMU_CAP_NO_EXCLUDE capability

* for-next/sysreg:
  : arm64 sysreg and cpufeature fixes/updates
  KVM: arm64: Use symbolic definition for ISR_EL1.A
  arm64/sysreg: Add definition of ISR_EL1
  arm64/sysreg: Add definition for ICC_NMIAR1_EL1
  arm64/cpufeature: Remove 4 bit assumption in ARM64_FEATURE_MASK()
  arm64/sysreg: Fix errors in 32 bit enumeration values
  arm64/cpufeature: Fix field sign for DIT hwcap detection

* for-next/sme:
  : SME-related updates
  arm64/sme: Optimise SME exit on syscall entry
  arm64/sme: Don't use streaming mode to probe the maximum SME VL
  arm64/ptrace: Use system_supports_tpidr2() to check for TPIDR2 support

* for-next/kselftest: (23 commits)
  : arm64 kselftest fixes and improvements
  kselftest/arm64: Don't require FA64 for streaming SVE+ZA tests
  kselftest/arm64: Copy whole EXTRA context
  kselftest/arm64: Fix enumeration of systems without 128 bit SME for SSVE+ZA
  kselftest/arm64: Fix enumeration of systems without 128 bit SME
  kselftest/arm64: Don't require FA64 for streaming SVE tests
  kselftest/arm64: Limit the maximum VL we try to set via ptrace
  kselftest/arm64: Correct buffer size for SME ZA storage
  kselftest/arm64: Remove the local NUM_VL definition
  kselftest/arm64: Verify simultaneous SSVE and ZA context generation
  kselftest/arm64: Verify that SSVE signal context has SVE_SIG_FLAG_SM set
  kselftest/arm64: Remove spurious comment from MTE test Makefile
  kselftest/arm64: Support build of MTE tests with clang
  kselftest/arm64: Initialise current at build time in signal tests
  kselftest/arm64: Don't pass headers to the compiler as source
  kselftest/arm64: Remove redundant _start labels from FP tests
  kselftest/arm64: Fix .pushsection for strings in FP tests
  kselftest/arm64: Run BTI selftests on systems without BTI
  kselftest/arm64: Fix test numbering when skipping tests
  kselftest/arm64: Skip non-power of 2 SVE vector lengths in fp-stress
  kselftest/arm64: Only enumerate power of two VLs in syscall-abi
  ...

* for-next/misc:
  : Miscellaneous arm64 updates
  arm64/mm: Intercept pfn changes in set_pte_at()
  Documentation: arm64: correct spelling
  arm64: traps: attempt to dump all instructions
  arm64: Apply dynamic shadow call stack patching in two passes
  arm64: el2_setup.h: fix spelling typo in comments
  arm64: Kconfig: fix spelling
  arm64: cpufeature: Use kstrtobool() instead of strtobool()
  arm64: Avoid repeated AA64MMFR1_EL1 register read on pagefault path
  arm64: make ARCH_FORCE_MAX_ORDER selectable

* for-next/sme2: (23 commits)
  : Support for arm64 SME 2 and 2.1
  arm64/sme: Fix __finalise_el2 SMEver check
  kselftest/arm64: Remove redundant _start labels from zt-test
  kselftest/arm64: Add coverage of SME 2 and 2.1 hwcaps
  kselftest/arm64: Add coverage of the ZT ptrace regset
  kselftest/arm64: Add SME2 coverage to syscall-abi
  kselftest/arm64: Add test coverage for ZT register signal frames
  kselftest/arm64: Teach the generic signal context validation about ZT
  kselftest/arm64: Enumerate SME2 in the signal test utility code
  kselftest/arm64: Cover ZT in the FP stress test
  kselftest/arm64: Add a stress test program for ZT0
  arm64/sme: Add hwcaps for SME 2 and 2.1 features
  arm64/sme: Implement ZT0 ptrace support
  arm64/sme: Implement signal handling for ZT
  arm64/sme: Implement context switching for ZT0
  arm64/sme: Provide storage for ZT0
  arm64/sme: Add basic enumeration for SME2
  arm64/sme: Enable host kernel to access ZT0
  arm64/sme: Manually encode ZT0 load and store instructions
  arm64/esr: Document ISS for ZT0 being disabled
  arm64/sme: Document SME 2 and SME 2.1 ABI
  ...

* for-next/tpidr2:
  : Include TPIDR2 in the signal context
  kselftest/arm64: Add test case for TPIDR2 signal frame records
  kselftest/arm64: Add TPIDR2 to the set of known signal context records
  arm64/signal: Include TPIDR2 in the signal context
  arm64/sme: Document ABI for TPIDR2 signal information

* for-next/scs:
  : arm64: harden shadow call stack pointer handling
  arm64: Stash shadow stack pointer in the task struct on interrupt
  arm64: Always load shadow stack pointer directly from the task struct

* for-next/compat-hwcap:
  : arm64: Expose compat ARMv8 AArch32 features (HWCAPs)
  arm64: Add compat hwcap SSBS
  arm64: Add compat hwcap SB
  arm64: Add compat hwcap I8MM
  arm64: Add compat hwcap ASIMDBF16
  arm64: Add compat hwcap ASIMDFHM
  arm64: Add compat hwcap ASIMDDP
  arm64: Add compat hwcap FPHP and ASIMDHP

* for-next/ftrace:
  : Add arm64 support for DYNAMICE_FTRACE_WITH_CALL_OPS
  arm64: avoid executing padding bytes during kexec / hibernation
  arm64: Implement HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS
  arm64: ftrace: Update stale comment
  arm64: patching: Add aarch64_insn_write_literal_u64()
  arm64: insn: Add helpers for BTI
  arm64: Extend support for CONFIG_FUNCTION_ALIGNMENT
  ACPI: Don't build ACPICA with '-Os'
  Compiler attributes: GCC cold function alignment workarounds
  ftrace: Add DYNAMIC_FTRACE_WITH_CALL_OPS

* for-next/efi-boot-mmu-on:
  : Permit arm64 EFI boot with MMU and caches on
  arm64: kprobes: Drop ID map text from kprobes blacklist
  arm64: head: Switch endianness before populating the ID map
  efi: arm64: enter with MMU and caches enabled
  arm64: head: Clean the ID map and the HYP text to the PoC if needed
  arm64: head: avoid cache invalidation when entering with the MMU on
  arm64: head: record the MMU state at primary entry
  arm64: kernel: move identity map out of .text mapping
  arm64: head: Move all finalise_el2 calls to after __enable_mmu

* for-next/ptrauth:
  : arm64 pointer authentication cleanup
  arm64: pauth: don't sign leaf functions
  arm64: unify asm-arch manipulation

* for-next/pseudo-nmi:
  : Pseudo-NMI code generation optimisations
  arm64: irqflags: use alternative branches for pseudo-NMI logic
  arm64: add ARM64_HAS_GIC_PRIO_RELAXED_SYNC cpucap
  arm64: make ARM64_HAS_GIC_PRIO_MASKING depend on ARM64_HAS_GIC_CPUIF_SYSREGS
  arm64: rename ARM64_HAS_IRQ_PRIO_MASKING to ARM64_HAS_GIC_PRIO_MASKING
  arm64: rename ARM64_HAS_SYSREG_GIC_CPUIF to ARM64_HAS_GIC_CPUIF_SYSREGS
arm64: add ARM64_HAS_GIC_PRIO_RELAXED_SYNC cpucap 2023-01-31T16:06:17+00:00 Mark Rutland mark.rutland@arm.com 2023-01-30T14:54:28+00:00 8bf0a8048b155eebc05aa8896f4c378a4c538214 When Priority Mask Hint Enable (PMHE) == 0b1, the GIC may use the PMR value to determine whether to signal an IRQ to a PE, and consequently after a change to the PMR value, a DSB SY may be required to ensure that interrupts are signalled to a CPU in finite time. When PMHE == 0b0, interrupts are always signalled to the relevant PE, and all masking occurs locally, without requiring a DSB SY. Since commit: f226650494c6aa87 ("arm64: Relax ICC_PMR_EL1 accesses when ICC_CTLR_EL1.PMHE is clear") ... we handle this dynamically: in most cases a static key is used to determine whether to issue a DSB SY, but the entry code must read from ICC_CTLR_EL1 as static keys aren't accessible from plain assembly. It would be much nicer to use an alternative instruction sequence for the DSB, as this would avoid the need to read from ICC_CTLR_EL1 in the entry code, and for most other code this will result in simpler code generation with fewer instructions and fewer branches. This patch adds a new ARM64_HAS_GIC_PRIO_RELAXED_SYNC cpucap which is only set when ICC_CTLR_EL1.PMHE == 0b0 (and GIC priority masking is in use). This allows us to replace the existing users of the `gic_pmr_sync` static key with alternative sequences which default to a DSB SY and are relaxed to a NOP when PMHE is not in use. The entry assembly management of the PMR is slightly restructured to use a branch (rather than multiple NOPs) when priority masking is not in use. This is more in keeping with other alternatives in the entry assembly, and permits the use of a separate alternatives for the PMHE-dependent DSB SY (and removal of the conditional branch this currently requires). For consistency I've adjusted both the save and restore paths. According to bloat-o-meter, when building defconfig + CONFIG_ARM64_PSEUDO_NMI=y this shrinks the kernel text by ~4KiB: | add/remove: 4/2 grow/shrink: 42/310 up/down: 332/-5032 (-4700) The resulting vmlinux is ~66KiB smaller, though the resulting Image size is unchanged due to padding and alignment: | [mark@lakrids:~/src/linux]% ls -al vmlinux-* | -rwxr-xr-x 1 mark mark 137508344 Jan 17 14:11 vmlinux-after | -rwxr-xr-x 1 mark mark 137575440 Jan 17 13:49 vmlinux-before | [mark@lakrids:~/src/linux]% ls -al Image-* | -rw-r--r-- 1 mark mark 38777344 Jan 17 14:11 Image-after | -rw-r--r-- 1 mark mark 38777344 Jan 17 13:49 Image-before Prior to this patch we did not verify the state of ICC_CTLR_EL1.PMHE on secondary CPUs. As of this patch this is verified by the cpufeature code when using GIC priority masking (i.e. when using pseudo-NMIs). Note that since commit: 7e3a57fa6ca831fa ("arm64: Document ICC_CTLR_EL3.PMHE setting requirements") ... Documentation/arm64/booting.rst specifies: | - ICC_CTLR_EL3.PMHE (bit 6) must be set to the same value across | all CPUs the kernel is executing on, and must stay constant | for the lifetime of the kernel. ... so that should not adversely affect any compliant systems, and as we'll only check for the absense of PMHE when using pseudo-NMIs, this will only fire when such mismatch will adversely affect the system. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Cc: Mark Brown <broonie@kernel.org> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20230130145429.903791-5-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> 
When Priority Mask Hint Enable (PMHE) == 0b1, the GIC may use the PMR
value to determine whether to signal an IRQ to a PE, and consequently
after a change to the PMR value, a DSB SY may be required to ensure that
interrupts are signalled to a CPU in finite time. When PMHE == 0b0,
interrupts are always signalled to the relevant PE, and all masking
occurs locally, without requiring a DSB SY.

Since commit:

  f226650494c6aa87 ("arm64: Relax ICC_PMR_EL1 accesses when ICC_CTLR_EL1.PMHE is clear")

... we handle this dynamically: in most cases a static key is used to
determine whether to issue a DSB SY, but the entry code must read from
ICC_CTLR_EL1 as static keys aren't accessible from plain assembly.

It would be much nicer to use an alternative instruction sequence for
the DSB, as this would avoid the need to read from ICC_CTLR_EL1 in the
entry code, and for most other code this will result in simpler code
generation with fewer instructions and fewer branches.

This patch adds a new ARM64_HAS_GIC_PRIO_RELAXED_SYNC cpucap which is
only set when ICC_CTLR_EL1.PMHE == 0b0 (and GIC priority masking is in
use). This allows us to replace the existing users of the
`gic_pmr_sync` static key with alternative sequences which default to a
DSB SY and are relaxed to a NOP when PMHE is not in use.

The entry assembly management of the PMR is slightly restructured to use
a branch (rather than multiple NOPs) when priority masking is not in
use. This is more in keeping with other alternatives in the entry
assembly, and permits the use of a separate alternatives for the
PMHE-dependent DSB SY (and removal of the conditional branch this
currently requires). For consistency I've adjusted both the save and
restore paths.

According to bloat-o-meter, when building defconfig +
CONFIG_ARM64_PSEUDO_NMI=y this shrinks the kernel text by ~4KiB:

| add/remove: 4/2 grow/shrink: 42/310 up/down: 332/-5032 (-4700)

The resulting vmlinux is ~66KiB smaller, though the resulting Image size
is unchanged due to padding and alignment:

| [mark@lakrids:~/src/linux]% ls -al vmlinux-*
| -rwxr-xr-x 1 mark mark 137508344 Jan 17 14:11 vmlinux-after
| -rwxr-xr-x 1 mark mark 137575440 Jan 17 13:49 vmlinux-before
| [mark@lakrids:~/src/linux]% ls -al Image-*
| -rw-r--r-- 1 mark mark 38777344 Jan 17 14:11 Image-after
| -rw-r--r-- 1 mark mark 38777344 Jan 17 13:49 Image-before

Prior to this patch we did not verify the state of ICC_CTLR_EL1.PMHE on
secondary CPUs. As of this patch this is verified by the cpufeature code
when using GIC priority masking (i.e. when using pseudo-NMIs).

Note that since commit:

  7e3a57fa6ca831fa ("arm64: Document ICC_CTLR_EL3.PMHE setting requirements")

... Documentation/arm64/booting.rst specifies:

|      - ICC_CTLR_EL3.PMHE (bit 6) must be set to the same value across
|        all CPUs the kernel is executing on, and must stay constant
|        for the lifetime of the kernel.

... so that should not adversely affect any compliant systems, and as
we'll only check for the absense of PMHE when using pseudo-NMIs, this
will only fire when such mismatch will adversely affect the system.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20230130145429.903791-5-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
arm64: rename ARM64_HAS_IRQ_PRIO_MASKING to ARM64_HAS_GIC_PRIO_MASKING 2023-01-31T16:06:17+00:00 Mark Rutland mark.rutland@arm.com 2023-01-30T14:54:26+00:00 c888b7bd916c4d85e06a6c3e507d5d68b229518f Subsequent patches will add more GIC-related cpucaps. When we do so, it would be nice to give them a consistent HAS_GIC_* prefix. In preparation for doing so, this patch renames the existing ARM64_HAS_IRQ_PRIO_MASKING cap to ARM64_HAS_GIC_PRIO_MASKING. The cpucaps file was hand-modified; all other changes were scripted with: find . -type f -name '*.[chS]' -print0 | \ xargs -0 sed -i 's/ARM64_HAS_IRQ_PRIO_MASKING/ARM64_HAS_GIC_PRIO_MASKING/' There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Cc: Mark Brown <broonie@kernel.org> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20230130145429.903791-3-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> 
Subsequent patches will add more GIC-related cpucaps. When we do so, it
would be nice to give them a consistent HAS_GIC_* prefix.

In preparation for doing so, this patch renames the existing
ARM64_HAS_IRQ_PRIO_MASKING cap to ARM64_HAS_GIC_PRIO_MASKING.

The cpucaps file was hand-modified; all other changes were scripted
with:

  find . -type f -name '*.[chS]' -print0 | \
    xargs -0 sed -i 's/ARM64_HAS_IRQ_PRIO_MASKING/ARM64_HAS_GIC_PRIO_MASKING/'

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20230130145429.903791-3-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>