kernel/git/stable/linux-stable.git/arch/arm64/include, branch linux-5.6.y

KVM: arm64: Save the host's PtrAuth keys in non-preemptible context

2020-06-17T14:42:09+00:00

commit ef3e40a7ea8dbe2abd0a345032cd7d5023b9684f upstream. When using the PtrAuth feature in a guest, we need to save the host's keys before allowing the guest to program them. For that, we dump them in a per-CPU data structure (the so called host context). But both call sites that do this are in preemptible context, which may end up in disaster should the vcpu thread get preempted before reentering the guest. Instead, save the keys eagerly on each vcpu_load(). This has an increased overhead, but is at least safe. Cc: stable@vger.kernel.org Reviewed-by: Mark Rutland Signed-off-by: Marc Zyngier Signed-off-by: Greg Kroah-Hartman

KVM: arm64: Synchronize sysreg state on injecting an AArch32 exception

2020-06-17T14:42:08+00:00

commit 0370964dd3ff7d3d406f292cb443a927952cbd05 upstream. On a VHE system, the EL1 state is left in the CPU most of the time, and only syncronized back to memory when vcpu_put() is called (most of the time on preemption). Which means that when injecting an exception, we'd better have a way to either: (1) write directly to the EL1 sysregs (2) synchronize the state back to memory, and do the changes there For an AArch64, we already do (1), so we are safe. Unfortunately, doing the same thing for AArch32 would be pretty invasive. Instead, we can easily implement (2) by calling the put/load architectural backends, and keep preemption disabled. We can then reload the state back into EL1. Cc: stable@vger.kernel.org Reported-by: James Morse Signed-off-by: Marc Zyngier Signed-off-by: Greg Kroah-Hartman

KVM: arm64: Make vcpu_cp1x() work on Big Endian hosts

2020-06-17T14:42:05+00:00

commit 3204be4109ad681523e3461ce64454c79278450a upstream. AArch32 CP1x registers are overlayed on their AArch64 counterparts in the vcpu struct. This leads to an interesting problem as they are stored in their CPU-local format, and thus a CP1x register doesn't "hit" the lower 32bit portion of the AArch64 register on a BE host. To workaround this unfortunate situation, introduce a bias trick in the vcpu_cp1x() accessors which picks the correct half of the 64bit register. Cc: stable@vger.kernel.org Reported-by: James Morse Tested-by: James Morse Acked-by: James Morse Signed-off-by: Marc Zyngier Signed-off-by: Greg Kroah-Hartman

arm64: acpi: fix UBSAN warning

2020-06-17T14:41:58+00:00

commit a194c33f45f83068ef13bf1d16e26d4ca3ecc098 upstream. Will reported a UBSAN warning: UBSAN: null-ptr-deref in arch/arm64/kernel/smp.c:596:6 member access within null pointer of type 'struct acpi_madt_generic_interrupt' CPU: 0 PID: 0 Comm: swapper Not tainted 5.7.0-rc6-00124-g96bc42ff0a82 #1 Call trace: dump_backtrace+0x0/0x384 show_stack+0x28/0x38 dump_stack+0xec/0x174 handle_null_ptr_deref+0x134/0x174 __ubsan_handle_type_mismatch_v1+0x84/0xa4 acpi_parse_gic_cpu_interface+0x60/0xe8 acpi_parse_entries_array+0x288/0x498 acpi_table_parse_entries_array+0x178/0x1b4 acpi_table_parse_madt+0xa4/0x110 acpi_parse_and_init_cpus+0x38/0x100 smp_init_cpus+0x74/0x258 setup_arch+0x350/0x3ec start_kernel+0x98/0x6f4 This is from the use of the ACPI_OFFSET in arch/arm64/include/asm/acpi.h. Replace its use with offsetof from include/linux/stddef.h which should implement the same logic using __builtin_offsetof, so that UBSAN wont warn. Reported-by: Will Deacon Suggested-by: Ard Biesheuvel Signed-off-by: Nick Desaulniers Reviewed-by: Jeremy Linton Acked-by: Lorenzo Pieralisi Cc: stable@vger.kernel.org Link: https://lore.kernel.org/lkml/20200521100952.GA5360@willie-the-truck/ Link: https://lore.kernel.org/r/20200608203818.189423-1-ndesaulniers@google.com Signed-off-by: Will Deacon Signed-off-by: Greg Kroah-Hartman

arm64: Delete the space separator in __emit_inst

2020-05-02T06:51:02+00:00

[ Upstream commit c9a4ef66450145a356a626c833d3d7b1668b3ded ] In assembly, many instances of __emit_inst(x) expand to a directive. In a few places __emit_inst(x) is used as an assembler macro argument. For example, in arch/arm64/kvm/hyp/entry.S ALTERNATIVE(nop, SET_PSTATE_PAN(1), ARM64_HAS_PAN, CONFIG_ARM64_PAN) expands to the following by the C preprocessor: alternative_insn nop, .inst (0xd500401f | ((0) << 16 | (4) << 5) | ((!!1) << 8)), 4, 1 Both comma and space are separators, with an exception that content inside a pair of parentheses/quotes is not split, so the clang integrated assembler splits the arguments to: nop, .inst, (0xd500401f | ((0) << 16 | (4) << 5) | ((!!1) << 8)), 4, 1 GNU as preprocesses the input with do_scrub_chars(). Its arm64 backend (along with many other non-x86 backends) sees: alternative_insn nop,.inst(0xd500401f|((0)<<16|(4)<<5)|((!!1)<<8)),4,1 # .inst(...) is parsed as one argument while its x86 backend sees: alternative_insn nop,.inst (0xd500401f|((0)<<16|(4)<<5)|((!!1)<<8)),4,1 # The extra space before '(' makes the whole .inst (...) parsed as two arguments The non-x86 backend's behavior is considered unintentional (https://sourceware.org/bugzilla/show_bug.cgi?id=25750). So drop the space separator inside `.inst (...)` to make the clang integrated assembler work. Suggested-by: Ilie Halip Signed-off-by: Fangrui Song Reviewed-by: Mark Rutland Link: https://github.com/ClangBuiltLinux/linux/issues/939 Signed-off-by: Catalin Marinas Signed-off-by: Sasha Levin

Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

2020-03-27T17:50:31+00:00

Pull arm64 fix from Will Deacon: "Fix defconfig build when using Clang's integrated assembler" * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: alternative: fix build with clang integrated assembler

Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

2020-03-20T16:28:25+00:00

Pull arm64 fixes from Will Deacon: - Fix panic() when it occurs during secondary CPU startup - Fix "kpti=off" when KASLR is enabled - Fix howler in compat syscall table for vDSO clock_getres() fallback * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: compat: Fix syscall number of compat_clock_getres arm64: kpti: Fix "kpti=off" when KASLR is enabled arm64: smp: fix crash_smp_send_stop() behaviour arm64: smp: fix smp_send_stop() behaviour

arm64: alternative: fix build with clang integrated assembler

2020-03-20T10:01:28+00:00

Building an arm64 defconfig with clang's integrated assembler, this error occurs: :2:2: error: unrecognized instruction mnemonic _ASM_EXTABLE 9999b, 9f ^ arch/arm64/mm/cache.S:50:1: note: while in macro instantiation user_alt 9f, "dc cvau, x4", "dc civac, x4", 0 ^ While GNU as seems fine with case-sensitive macro instantiations, clang doesn't, so use the actual macro name (_asm_extable) as in the rest of the file. Also checked that the generated assembly matches the GCC output. Reviewed-by: Nick Desaulniers Tested-by: Nick Desaulniers Fixes: 290622efc76e ("arm64: fix "dc cvau" cache operation on errata-affected core") Link: https://github.com/ClangBuiltLinux/linux/issues/924 Signed-off-by: Ilie Halip Signed-off-by: Will Deacon

arm64: compat: Fix syscall number of compat_clock_getres

2020-03-19T19:23:46+00:00

The syscall number of compat_clock_getres was erroneously set to 247 (__NR_io_cancel!) instead of 264. This causes the vDSO fallback of clock_getres() to land on the wrong syscall for compat tasks. Fix the numbering. Cc: Fixes: 53c489e1dfeb6 ("arm64: compat: Add missing syscall numbers") Acked-by: Catalin Marinas Reviewed-by: Nick Desaulniers Signed-off-by: Vincenzo Frascino Signed-off-by: Will Deacon

arm64: kpti: Fix "kpti=off" when KASLR is enabled

2020-03-19T08:28:43+00:00

Enabling KASLR forces the use of non-global page-table entries for kernel mappings, as this is a decision that we have to make very early on before mapping the kernel proper. When used in conjunction with the "kpti=off" command-line option, it is possible to use non-global kernel mappings but with the kpti trampoline disabled. Since commit 09e3c22a86f6 ("arm64: Use a variable to store non-global mappings decision"), arm64_kernel_unmapped_at_el0() reflects only the use of non-global mappings and does not take into account whether the kpti trampoline is enabled. This breaks context switching of the TPIDRRO_EL0 register for 64-bit tasks, where the clearing of the register is deferred to the ret-to-user code, but it also breaks the ARM SPE PMU driver which helpfully recommends passing "kpti=off" on the command line! Report whether or not KPTI is actually enabled in arm64_kernel_unmapped_at_el0() and check the 'arm64_use_ng_mappings' global variable directly when determining the protection flags for kernel mappings. Cc: Mark Brown Reported-by: Hongbo Yao Tested-by: Hongbo Yao Fixes: 09e3c22a86f6 ("arm64: Use a variable to store non-global mappings decision") Signed-off-by: Will Deacon