Pull EFI fixes from Ard Biesheuvel:
"Another couple of EFI fixes, of which the first two were already in
-next when I sent out the previous PR, but they caused some issues on
non-EFI boots so I let them simmer for a bit longer.
- ensure the EFI ResetSystem and ACPI PRM calls are recognized as
users of the EFI runtime, and therefore protected against
exceptions
- account for the EFI runtime stack in the stacktrace code
- remove Matthew Garrett's MAINTAINERS entry for efivarfs"
* tag 'efi-fixes-for-v6.2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
efi: Remove Matthew Garrett as efivarfs maintainer
arm64: efi: Account for the EFI runtime stack in stack unwinder
arm64: efi: Avoid workqueue to check whether EFI runtime is live
The EFI runtime services run from a dedicated stack now, and so the stack unwinder needs to be informed about this. Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Comparing current_work() against efi_rts_work.work is sufficient to decide whether current is currently running EFI runtime services code at any level in its call stack. However, there are other potential users of the EFI runtime stack, such as the ACPI subsystem, which may invoke efi_call_virt_pointer() directly, and so any sync exceptions occurring in firmware during those calls are currently misidentified. So instead, let's check whether the stashed value of the thread stack pointer points into current's thread stack. This can only be the case if current was interrupted while running EFI runtime code. Note that this implies that we should clear the stashed value after switching back, to avoid false positives. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Pull kvm fixes from Paolo Bonzini:
"ARM:
- Fix the PMCR_EL0 reset value after the PMU rework
- Correctly handle S2 fault triggered by a S1 page table walk by not
always classifying it as a write, as this breaks on R/O memslots
- Document why we cannot exit with KVM_EXIT_MMIO when taking a write
fault from a S1 PTW on a R/O memslot
- Put the Apple M2 on the naughty list for not being able to
correctly implement the vgic SEIS feature, just like the M1 before
it
- Reviewer updates: Alex is stepping down, replaced by Zenghui
x86:
- Fix various rare locking issues in Xen emulation and teach lockdep
to detect them
- Documentation improvements
- Do not return host topology information from KVM_GET_SUPPORTED_CPUID"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: x86/xen: Avoid deadlock by adding kvm->arch.xen.xen_lock leaf node lock
KVM: Ensure lockdep knows about kvm->lock vs. vcpu->mutex ordering rule
KVM: x86/xen: Fix potential deadlock in kvm_xen_update_runstate_guest()
KVM: x86/xen: Fix lockdep warning on "recursive" gpc locking
Documentation: kvm: fix SRCU locking order docs
KVM: x86: Do not return host topology information from KVM_GET_SUPPORTED_CPUID
KVM: nSVM: clarify recalc_intercepts() wrt CR8
MAINTAINERS: Remove myself as a KVM/arm64 reviewer
MAINTAINERS: Add Zenghui Yu as a KVM/arm64 reviewer
KVM: arm64: vgic: Add Apple M2 cpus to the list of broken SEIS implementations
KVM: arm64: Convert FSC_* over to ESR_ELx_FSC_*
KVM: arm64: Document the behaviour of S1PTW faults on RO memslots
KVM: arm64: Fix S1PTW handling on RO memslots
KVM: arm64: PMU: Fix PMCR_EL0 reset value
With only two levels of page-table, the generic 'pud_*' macros are
implemented using dummy operations in pgtable-nopmd.h. Since commit
730a11f982e6 ("arm64/mm: add pud_user_exec() check in
pud_user_accessible_page()"), pud_user_accessible_page() unconditionally
calls pud_user_exec(), which is an arm64-specific helper and therefore
isn't defined by pgtable-nopmd.h. This results in a build failure for
configurations with only two levels of page table:
arch/arm64/include/asm/pgtable.h: In function 'pud_user_accessible_page':
>> arch/arm64/include/asm/pgtable.h:870:51: error: implicit declaration of function 'pud_user_exec'; did you mean 'pmd_user_exec'? [-Werror=implicit-function-declaration]
870 | return pud_leaf(pud) && (pud_user(pud) || pud_user_exec(pud));
| ^~~~~~~~~~~~~
| pmd_user_exec
Fix the problem by defining pud_user_exec() as pud_user() in this case.
Link: https://lore.kernel.org/r/202301080515.z6zEksU4-lkp@intel.com
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Will Deacon <will@kernel.org>
If a Cortex-A715 cpu sees a page mapping permissions change from executable to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers, on the next instruction abort caused by permission fault. Only user-space does executable to non-executable permission transition via mprotect() system call which calls ptep_modify_prot_start() and ptep_modify _prot_commit() helpers, while changing the page mapping. The platform code can override these helpers via __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION. Work around the problem via doing a break-before-make TLB invalidation, for all executable user space mappings, that go through mprotect() system call. This overrides ptep_modify_prot_start() and ptep_modify_prot_commit(), via defining HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION on the platform thus giving an opportunity to intercept user space exec mappings, and do the necessary TLB invalidation. Similar interceptions are also implemented for HugeTLB. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mark Rutland <mark.rutland@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Link: https://lore.kernel.org/r/20230102061651.34745-1-anshuman.khandual@arm.com Signed-off-by: Will Deacon <will@kernel.org>
The inline assembly for arm64's cmpxchg_double*() implementations use a
+Q constraint to hazard against other accesses to the memory location
being exchanged. However, the pointer passed to the constraint is a
pointer to unsigned long, and thus the hazard only applies to the first
8 bytes of the location.
GCC can take advantage of this, assuming that other portions of the
location are unchanged, leading to a number of potential problems.
This is similar to what we fixed back in commit:
fee960bed5e857eb ("arm64: xchg: hazard against entire exchange variable")
... but we forgot to adjust cmpxchg_double*() similarly at the same
time.
The same problem applies, as demonstrated with the following test:
| struct big {
| u64 lo, hi;
| } __aligned(128);
|
| unsigned long foo(struct big *b)
| {
| u64 hi_old, hi_new;
|
| hi_old = b->hi;
| cmpxchg_double_local(&b->lo, &b->hi, 0x12, 0x34, 0x56, 0x78);
| hi_new = b->hi;
|
| return hi_old ^ hi_new;
| }
... which GCC 12.1.0 compiles as:
| 0000000000000000 <foo>:
| 0: d503233f paciasp
| 4: aa0003e4 mov x4, x0
| 8: 1400000e b 40 <foo+0x40>
| c: d2800240 mov x0, #0x12 // #18
| 10: d2800681 mov x1, #0x34 // #52
| 14: aa0003e5 mov x5, x0
| 18: aa0103e6 mov x6, x1
| 1c: d2800ac2 mov x2, #0x56 // #86
| 20: d2800f03 mov x3, #0x78 // #120
| 24: 48207c82 casp x0, x1, x2, x3, [x4]
| 28: ca050000 eor x0, x0, x5
| 2c: ca060021 eor x1, x1, x6
| 30: aa010000 orr x0, x0, x1
| 34: d2800000 mov x0, #0x0 // #0 <--- BANG
| 38: d50323bf autiasp
| 3c: d65f03c0 ret
| 40: d2800240 mov x0, #0x12 // #18
| 44: d2800681 mov x1, #0x34 // #52
| 48: d2800ac2 mov x2, #0x56 // #86
| 4c: d2800f03 mov x3, #0x78 // #120
| 50: f9800091 prfm pstl1strm, [x4]
| 54: c87f1885 ldxp x5, x6, [x4]
| 58: ca0000a5 eor x5, x5, x0
| 5c: ca0100c6 eor x6, x6, x1
| 60: aa0600a6 orr x6, x5, x6
| 64: b5000066 cbnz x6, 70 <foo+0x70>
| 68: c8250c82 stxp w5, x2, x3, [x4]
| 6c: 35ffff45 cbnz w5, 54 <foo+0x54>
| 70: d2800000 mov x0, #0x0 // #0 <--- BANG
| 74: d50323bf autiasp
| 78: d65f03c0 ret
Notice that at the lines with "BANG" comments, GCC has assumed that the
higher 8 bytes are unchanged by the cmpxchg_double() call, and that
`hi_old ^ hi_new` can be reduced to a constant zero, for both LSE and
LL/SC versions of cmpxchg_double().
This patch fixes the issue by passing a pointer to __uint128_t into the
+Q constraint, ensuring that the compiler hazards against the entire 16
bytes being modified.
With this change, GCC 12.1.0 compiles the above test as:
| 0000000000000000 <foo>:
| 0: f9400407 ldr x7, [x0, #8]
| 4: d503233f paciasp
| 8: aa0003e4 mov x4, x0
| c: 1400000f b 48 <foo+0x48>
| 10: d2800240 mov x0, #0x12 // #18
| 14: d2800681 mov x1, #0x34 // #52
| 18: aa0003e5 mov x5, x0
| 1c: aa0103e6 mov x6, x1
| 20: d2800ac2 mov x2, #0x56 // #86
| 24: d2800f03 mov x3, #0x78 // #120
| 28: 48207c82 casp x0, x1, x2, x3, [x4]
| 2c: ca050000 eor x0, x0, x5
| 30: ca060021 eor x1, x1, x6
| 34: aa010000 orr x0, x0, x1
| 38: f9400480 ldr x0, [x4, #8]
| 3c: d50323bf autiasp
| 40: ca0000e0 eor x0, x7, x0
| 44: d65f03c0 ret
| 48: d2800240 mov x0, #0x12 // #18
| 4c: d2800681 mov x1, #0x34 // #52
| 50: d2800ac2 mov x2, #0x56 // #86
| 54: d2800f03 mov x3, #0x78 // #120
| 58: f9800091 prfm pstl1strm, [x4]
| 5c: c87f1885 ldxp x5, x6, [x4]
| 60: ca0000a5 eor x5, x5, x0
| 64: ca0100c6 eor x6, x6, x1
| 68: aa0600a6 orr x6, x5, x6
| 6c: b5000066 cbnz x6, 78 <foo+0x78>
| 70: c8250c82 stxp w5, x2, x3, [x4]
| 74: 35ffff45 cbnz w5, 5c <foo+0x5c>
| 78: f9400480 ldr x0, [x4, #8]
| 7c: d50323bf autiasp
| 80: ca0000e0 eor x0, x7, x0
| 84: d65f03c0 ret
... sampling the high 8 bytes before and after the cmpxchg, and
performing an EOR, as we'd expect.
For backporting, I've tested this atop linux-4.9.y with GCC 5.5.0. Note
that linux-4.9.y is oldest currently supported stable release, and
mandates GCC 5.1+. Unfortunately I couldn't get a GCC 5.1 binary to run
on my machines due to library incompatibilities.
I've also used a standalone test to check that we can use a __uint128_t
pointer in a +Q constraint at least as far back as GCC 4.8.5 and LLVM
3.9.1.
Fixes: 5284e1b4bc8a ("arm64: xchg: Implement cmpxchg_double")
Fixes: e9a4b795652f ("arm64: cmpxchg_dbl: patch in lse instructions when supported by the CPU")
Reported-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/lkml/Y6DEfQXymYVgL3oJ@boqun-archlinux/
Reported-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/lkml/Y6GXoO4qmH9OIZ5Q@hirez.programming.kicks-ass.net/
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: stable@vger.kernel.org
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Steve Capper <steve.capper@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20230104151626.3262137-1-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
After we fixed the uprobe inst endian in aarch_be, the sparse check report
the following warning info:
sparse warnings: (new ones prefixed by >>)
>> kernel/events/uprobes.c:223:25: sparse: sparse: restricted __le32 degrades to integer
>> kernel/events/uprobes.c:574:56: sparse: sparse: incorrect type in argument 4 (different base types)
@@ expected unsigned int [addressable] [usertype] opcode @@ got restricted __le32 [usertype] @@
kernel/events/uprobes.c:574:56: sparse: expected unsigned int [addressable] [usertype] opcode
kernel/events/uprobes.c:574:56: sparse: got restricted __le32 [usertype]
>> kernel/events/uprobes.c:1483:32: sparse: sparse: incorrect type in initializer (different base types)
@@ expected unsigned int [usertype] insn @@ got restricted __le32 [usertype] @@
kernel/events/uprobes.c:1483:32: sparse: expected unsigned int [usertype] insn
kernel/events/uprobes.c:1483:32: sparse: got restricted __le32 [usertype]
use the __le32 to u32 for uprobe_opcode_t, to keep the same.
Fixes: 60f07e22a73d ("arm64:uprobe fix the uprobe SWBP_INSN in big-endian")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: junhua huang <huang.junhua@zte.com.cn>
Link: https://lore.kernel.org/r/202212280954121197626@zte.com.cn
Signed-off-by: Will Deacon <will@kernel.org>
* kvm-arm64/s1ptw-write-fault: : . : Fix S1PTW fault handling that was until then always taken : as a write. From the cover letter: : : `Recent developments on the EFI front have resulted in guests that : simply won't boot if the page tables are in a read-only memslot and : that you're a bit unlucky in the way S2 gets paged in... The core : issue is related to the fact that we treat a S1PTW as a write, which : is close enough to what needs to be done. Until to get to RO memslots. : : The first patch fixes this and is definitely a stable candidate. It : splits the faulting of page tables in two steps (RO translation fault, : followed by a writable permission fault -- should it even happen). : The second one documents the slightly odd behaviour of PTW writes to : RO memslot, which do not result in a KVM_MMIO exit. The last patch is : totally optional, only tangentially related, and randomly repainting : stuff (maybe that's contagious, who knows)." : : . KVM: arm64: Convert FSC_* over to ESR_ELx_FSC_* KVM: arm64: Document the behaviour of S1PTW faults on RO memslots KVM: arm64: Fix S1PTW handling on RO memslots Signed-off-by: Marc Zyngier <maz@kernel.org>
I really hoped that Apple had fixed their not-quite-a-vgic implementation when moving from M1 to M2. Alas, it seems they didn't, and running a buggy EFI version results in the vgic generating SErrors outside of the guest and taking the host down. Apply the same workaround as for M1. Yes, this is all a bit crap. Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230103095022.3230946-2-maz@kernel.org