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* Merge tag 'core_urgent_for_v5.11_rc7' of ↵Linus Torvalds2021-02-072-4/+8
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull syscall entry fixes from Borislav Petkov: - For syscall user dispatch, separate prctl operation from syscall redirection range specification before the API has been made official in 5.11. - Ensure tasks using the generic syscall code do trap after returning from a syscall when single-stepping is requested. * tag 'core_urgent_for_v5.11_rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: entry: Use different define for selector variable in SUD entry: Ensure trap after single-step on system call return
| * entry: Ensure trap after single-step on system call returnGabriel Krisman Bertazi2021-02-062-4/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 299155244770 ("entry: Drop usage of TIF flags in the generic syscall code") introduced a bug on architectures using the generic syscall entry code, in which processes stopped by PTRACE_SYSCALL do not trap on syscall return after receiving a TIF_SINGLESTEP. The reason is that the meaning of TIF_SINGLESTEP flag is overloaded to cause the trap after a system call is executed, but since the above commit, the syscall call handler only checks for the SYSCALL_WORK flags on the exit work. Split the meaning of TIF_SINGLESTEP such that it only means single-step mode, and create a new type of SYSCALL_WORK to request a trap immediately after a syscall in single-step mode. In the current implementation, the SYSCALL_WORK flag shadows the TIF_SINGLESTEP flag for simplicity. Update x86 to flip this bit when a tracer enables single stepping. Fixes: 299155244770 ("entry: Drop usage of TIF flags in the generic syscall code") Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Kyle Huey <me@kylehuey.com> Link: https://lore.kernel.org/r/87h7mtc9pr.fsf_-_@collabora.com
* | Merge tag 'x86_urgent_for_v5.11_rc7' of ↵Linus Torvalds2021-02-079-55/+76
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Borislav Petkov: "I hope this is the last batch of x86/urgent updates for this round: - Remove superfluous EFI PGD range checks which lead to those assertions failing with certain kernel configs and LLVM. - Disable setting breakpoints on facilities involved in #DB exception handling to avoid infinite loops. - Add extra serialization to non-serializing MSRs (IA32_TSC_DEADLINE and x2 APIC MSRs) to adhere to SDM's recommendation and avoid any theoretical issues. - Re-add the EPB MSR reading on turbostat so that it works on older kernels which don't have the corresponding EPB sysfs file. - Add Alder Lake to the list of CPUs which support split lock. - Fix %dr6 register handling in order to be able to set watchpoints with gdb again. - Disable CET instrumentation in the kernel so that gcc doesn't add ENDBR64 to kernel code and thus confuse tracing" * tag 'x86_urgent_for_v5.11_rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/efi: Remove EFI PGD build time checks x86/debug: Prevent data breakpoints on cpu_dr7 x86/debug: Prevent data breakpoints on __per_cpu_offset x86/apic: Add extra serialization for non-serializing MSRs tools/power/turbostat: Fallback to an MSR read for EPB x86/split_lock: Enable the split lock feature on another Alder Lake CPU x86/debug: Fix DR6 handling x86/build: Disable CET instrumentation in the kernel
| * | x86/efi: Remove EFI PGD build time checksBorislav Petkov2021-02-061-19/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With CONFIG_X86_5LEVEL, CONFIG_UBSAN and CONFIG_UBSAN_UNSIGNED_OVERFLOW enabled, clang fails the build with x86_64-linux-ld: arch/x86/platform/efi/efi_64.o: in function `efi_sync_low_kernel_mappings': efi_64.c:(.text+0x22c): undefined reference to `__compiletime_assert_354' which happens due to -fsanitize=unsigned-integer-overflow being enabled: -fsanitize=unsigned-integer-overflow: Unsigned integer overflow, where the result of an unsigned integer computation cannot be represented in its type. Unlike signed integer overflow, this is not undefined behavior, but it is often unintentional. This sanitizer does not check for lossy implicit conversions performed before such a computation (see -fsanitize=implicit-conversion). and that fires when the (intentional) EFI_VA_START/END defines overflow an unsigned long, leading to the assertion expressions not getting optimized away (on GCC they do)... However, those checks are superfluous: the runtime services mapping code already makes sure the ranges don't overshoot EFI_VA_END as the EFI mapping range is hardcoded. On each runtime services call, it is switched to the EFI-specific PGD and even if mappings manage to escape that last PGD, this won't remain unnoticed for long. So rip them out. See https://github.com/ClangBuiltLinux/linux/issues/256 for more info. Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Acked-by: Ard Biesheuvel <ardb@kernel.org> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Nathan Chancellor <nathan@kernel.org> Link: http://lkml.kernel.org/r/20210107223424.4135538-1-arnd@kernel.org
| * | x86/debug: Prevent data breakpoints on cpu_dr7Lai Jiangshan2021-02-051-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | local_db_save() is called at the start of exc_debug_kernel(), reads DR7 and disables breakpoints to prevent recursion. When running in a guest (X86_FEATURE_HYPERVISOR), local_db_save() reads the per-cpu variable cpu_dr7 to check whether a breakpoint is active or not before it accesses DR7. A data breakpoint on cpu_dr7 therefore results in infinite #DB recursion. Disallow data breakpoints on cpu_dr7 to prevent that. Fixes: 84b6a3491567a("x86/entry: Optimize local_db_save() for virt") Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210204152708.21308-2-jiangshanlai@gmail.com
| * | x86/debug: Prevent data breakpoints on __per_cpu_offsetLai Jiangshan2021-02-051-0/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When FSGSBASE is enabled, paranoid_entry() fetches the per-CPU GSBASE value via __per_cpu_offset or pcpu_unit_offsets. When a data breakpoint is set on __per_cpu_offset[cpu] (read-write operation), the specific CPU will be stuck in an infinite #DB loop. RCU will try to send an NMI to the specific CPU, but it is not working either since NMI also relies on paranoid_entry(). Which means it's undebuggable. Fixes: eaad981291ee3("x86/entry/64: Introduce the FIND_PERCPU_BASE macro") Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210204152708.21308-1-jiangshanlai@gmail.com
| * | x86/apic: Add extra serialization for non-serializing MSRsDave Hansen2021-02-045-15/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Jan Kiszka reported that the x2apic_wrmsr_fence() function uses a plain MFENCE while the Intel SDM (10.12.3 MSR Access in x2APIC Mode) calls for MFENCE; LFENCE. Short summary: we have special MSRs that have weaker ordering than all the rest. Add fencing consistent with current SDM recommendations. This is not known to cause any issues in practice, only in theory. Longer story below: The reason the kernel uses a different semantic is that the SDM changed (roughly in late 2017). The SDM changed because folks at Intel were auditing all of the recommended fences in the SDM and realized that the x2apic fences were insufficient. Why was the pain MFENCE judged insufficient? WRMSR itself is normally a serializing instruction. No fences are needed because the instruction itself serializes everything. But, there are explicit exceptions for this serializing behavior written into the WRMSR instruction documentation for two classes of MSRs: IA32_TSC_DEADLINE and the X2APIC MSRs. Back to x2apic: WRMSR is *not* serializing in this specific case. But why is MFENCE insufficient? MFENCE makes writes visible, but only affects load/store instructions. WRMSR is unfortunately not a load/store instruction and is unaffected by MFENCE. This means that a non-serializing WRMSR could be reordered by the CPU to execute before the writes made visible by the MFENCE have even occurred in the first place. This means that an x2apic IPI could theoretically be triggered before there is any (visible) data to process. Does this affect anything in practice? I honestly don't know. It seems quite possible that by the time an interrupt gets to consume the (not yet) MFENCE'd data, it has become visible, mostly by accident. To be safe, add the SDM-recommended fences for all x2apic WRMSRs. This also leaves open the question of the _other_ weakly-ordered WRMSR: MSR_IA32_TSC_DEADLINE. While it has the same ordering architecture as the x2APIC MSRs, it seems substantially less likely to be a problem in practice. While writes to the in-memory Local Vector Table (LVT) might theoretically be reordered with respect to a weakly-ordered WRMSR like TSC_DEADLINE, the SDM has this to say: In x2APIC mode, the WRMSR instruction is used to write to the LVT entry. The processor ensures the ordering of this write and any subsequent WRMSR to the deadline; no fencing is required. But, that might still leave xAPIC exposed. The safest thing to do for now is to add the extra, recommended LFENCE. [ bp: Massage commit message, fix typos, drop accidentally added newline to tools/arch/x86/include/asm/barrier.h. ] Reported-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20200305174708.F77040DD@viggo.jf.intel.com
| * | x86/split_lock: Enable the split lock feature on another Alder Lake CPUFenghua Yu2021-02-011-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add Alder Lake mobile processor to CPU list to enumerate and enable the split lock feature. Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Tony Luck <tony.luck@intel.com> Link: https://lkml.kernel.org/r/20210201190007.4031869-1-fenghua.yu@intel.com
| * | x86/debug: Fix DR6 handlingPeter Zijlstra2021-02-011-21/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Tom reported that one of the GDB test-cases failed, and Boris bisected it to commit: d53d9bc0cf78 ("x86/debug: Change thread.debugreg6 to thread.virtual_dr6") The debugging session led us to commit: 6c0aca288e72 ("x86: Ignore trap bits on single step exceptions") It turns out that TF and data breakpoints are both traps and will be merged, while instruction breakpoints are faults and will not be merged. This means 6c0aca288e72 is wrong, only TF and instruction breakpoints need to be excluded while TF and data breakpoints can be merged. [ bp: Massage commit message. ] Fixes: d53d9bc0cf78 ("x86/debug: Change thread.debugreg6 to thread.virtual_dr6") Fixes: 6c0aca288e72 ("x86: Ignore trap bits on single step exceptions") Reported-by: Tom de Vries <tdevries@suse.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/YBMAbQGACujjfz%2Bi@hirez.programming.kicks-ass.net Link: https://lkml.kernel.org/r/20210128211627.GB4348@worktop.programming.kicks-ass.net
| * | x86/build: Disable CET instrumentation in the kernelJosh Poimboeuf2021-01-291-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With retpolines disabled, some configurations of GCC, and specifically the GCC versions 9 and 10 in Ubuntu will add Intel CET instrumentation to the kernel by default. That breaks certain tracing scenarios by adding a superfluous ENDBR64 instruction before the fentry call, for functions which can be called indirectly. CET instrumentation isn't currently necessary in the kernel, as CET is only supported in user space. Disable it unconditionally and move it into the x86's Makefile as CET/CFI... enablement should be a per-arch decision anyway. [ bp: Massage and extend commit message. ] Fixes: 29be86d7f9cb ("kbuild: add -fcf-protection=none when using retpoline flags") Reported-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Tested-by: Nikolay Borisov <nborisov@suse.com> Cc: <stable@vger.kernel.org> Cc: Seth Forshee <seth.forshee@canonical.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Link: https://lkml.kernel.org/r/20210128215219.6kct3h2eiustncws@treble
* | | Merge tag 'kbuild-fixes-v5.11-2' of ↵Linus Torvalds2021-02-072-2/+2
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild fixes from Masahiro Yamada: - Use the 'python3' command to invoke python scripts because some distributions do not provide the 'python' command any more. - Clean-up and update documents - Use pkg-config to search libcrypto - Fix duplicated debug flags - Ignore some more stubs in scripts/kallsyms.c * tag 'kbuild-fixes-v5.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kallsyms: fix nonconverging kallsyms table with lld kbuild: fix duplicated flags in DEBUG_CFLAGS scripts/clang-tools: switch explicitly to Python 3 kbuild: remove PYTHON variable Documentation/llvm: Add a section about supported architectures Revert "checkpatch: add check for keyword 'boolean' in Kconfig definitions" scripts: use pkg-config to locate libcrypto kconfig: mconf: fix HOSTCC call doc: gcc-plugins: update gcc-plugins.rst kbuild: simplify GCC_PLUGINS enablement in dummy-tools/gcc Documentation/Kbuild: Remove references to gcc-plugin.sh scripts: switch explicitly to Python 3
| * | | kbuild: remove PYTHON variableMasahiro Yamada2021-02-012-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Python retired in 2020, and some distributions do not provide the 'python' command any more. As in commit 51839e29cb59 ("scripts: switch explicitly to Python 3"), we need to use more specific 'python3' to invoke scripts even if they are written in a way compatible with both Python 2 and 3. This commit removes the variable 'PYTHON', and switches the existing users to 'PYTHON3'. BTW, PEP 394 (https://www.python.org/dev/peps/pep-0394/) is a helpful material. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
* | | | Merge tag 'riscv-for-linus-5.11-rc7' of ↵Linus Torvalds2021-02-064-5/+12
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull RISC-V fixes from Palmer Dabbelt: "A handful of fixes for this week: - A fix to avoid evalating the VA twice in virt_addr_valid, which fixes some WARNs under DEBUG_VIRTUAL. - Two fixes related to STRICT_KERNEL_RWX: one that fixes some permissions when strict is disabled, and one to fix some alignment issues when strict is enabled. - A fix to disallow the selection of MAXPHYSMEM_2GB on RV32, which isn't valid any more but may still show up in some oldconfigs. We still have the HiFive Unleashed ethernet phy reset regression, so there will likely be something coming next week" * tag 'riscv-for-linus-5.11-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: RISC-V: Define MAXPHYSMEM_1GB only for RV32 riscv: Align on L1_CACHE_BYTES when STRICT_KERNEL_RWX RISC-V: Fix .init section permission update riscv: virt_addr_valid must check the address belongs to linear mapping
| * | | | RISC-V: Define MAXPHYSMEM_1GB only for RV32Atish Patra2021-02-021-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | MAXPHYSMEM_1GB option was added for RV32 because RV32 only supports 1GB of maximum physical memory. This lead to few compilation errors reported by kernel test robot which created the following configuration combination which are not useful but can be configured. 1. MAXPHYSMEM_1GB & RV64 2, MAXPHYSMEM_2GB & RV32 Fix this by restricting MAXPHYSMEM_1GB for RV32 and MAXPHYSMEM_2GB only for RV64. Fixes: e557793799c5 ("RISC-V: Fix maximum allowed phsyical memory for RV32") Cc: stable@vger.kernel.org Reported-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Randy Dunlap <rdunlap@infradead.org> Tested-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
| * | | | riscv: Align on L1_CACHE_BYTES when STRICT_KERNEL_RWXSebastien Van Cauwenberghe2021-02-021-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allows the sections to be aligned on smaller boundaries and therefore results in a smaller kernel image size. Signed-off-by: Sebastien Van Cauwenberghe <svancau@gmail.com> Reviewed-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
| * | | | RISC-V: Fix .init section permission updateAtish Patra2021-02-021-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | .init section permission should only updated to non-execute if STRICT_KERNEL_RWX is enabled. Otherwise, this will lead to a kernel hang. Fixes: 19a00869028f ("RISC-V: Protect all kernel sections including init early") Cc: stable@vger.kernel.org Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
| * | | | riscv: virt_addr_valid must check the address belongs to linear mappingAlexandre Ghiti2021-02-021-1/+4
| | |_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | virt_addr_valid macro checks that a virtual address is valid, ie that the address belongs to the linear mapping and that the corresponding physical page exists. Add the missing check that ensures the virtual address belongs to the linear mapping, otherwise __virt_to_phys, when compiled with CONFIG_DEBUG_VIRTUAL enabled, raises a WARN that is interpreted as a kernel bug by syzbot. Signed-off-by: Alexandre Ghiti <alex@ghiti.fr> Reviewed-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
* | | | Merge tag 'powerpc-5.11-7' of ↵Linus Torvalds2021-02-068-21/+23
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc fixes from Michael Ellerman: - A fix for a change we made to __kernel_sigtramp_rt64() which confused glibc's backtrace logic, and also changed the semantics of that symbol, which was arguably an ABI break. - A fix for a stack overwrite in our VSX instruction emulation. - A couple of fixes for the Makefile logic in the new C VDSO. Thanks to Masahiro Yamada, Naveen N. Rao, Raoni Fassina Firmino, and Ravi Bangoria. * tag 'powerpc-5.11-7' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/64/signal: Fix regression in __kernel_sigtramp_rt64() semantics powerpc/vdso64: remove meaningless vgettimeofday.o build rule powerpc/vdso: fix unnecessary rebuilds of vgettimeofday.o powerpc/sstep: Fix array out of bound warning
| * | | | powerpc/64/signal: Fix regression in __kernel_sigtramp_rt64() semanticsRaoni Fassina Firmino2021-02-022-2/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 0138ba5783ae ("powerpc/64/signal: Balance return predictor stack in signal trampoline") changed __kernel_sigtramp_rt64() VDSO and trampoline code, and introduced a regression in the way glibc's backtrace()[1] detects the signal-handler stack frame. Apart from the practical implications, __kernel_sigtramp_rt64() was a VDSO function with the semantics that it is a function you can call from userspace to end a signal handling. Now this semantics are no longer valid. I believe the aforementioned change affects all releases since 5.9. This patch tries to fix both the semantics and practical aspect of __kernel_sigtramp_rt64() returning it to the previous code, whilst keeping the intended behaviour of 0138ba5783ae by adding a new symbol to serve as the jump target from the kernel to the trampoline. Now the trampoline has two parts, a new entry point and the old return point. [1] https://lists.ozlabs.org/pipermail/linuxppc-dev/2021-January/223194.html Fixes: 0138ba5783ae ("powerpc/64/signal: Balance return predictor stack in signal trampoline") Cc: stable@vger.kernel.org # v5.9+ Signed-off-by: Raoni Fassina Firmino <raoni@linux.ibm.com> Acked-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Minor tweaks to change log formatting, add stable tag] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210201200505.iz46ubcizipnkcxe@work-tp
| * | | | powerpc/vdso64: remove meaningless vgettimeofday.o build ruleMasahiro Yamada2021-01-301-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | VDSO64 is only built for the 64-bit kernel, hence vgettimeofday.o is built by the generic rule in scripts/Makefile.build. This line does not provide anything useful. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201223171142.707053-2-masahiroy@kernel.org
| * | | | powerpc/vdso: fix unnecessary rebuilds of vgettimeofday.oMasahiro Yamada2021-01-305-11/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | vgettimeofday.o is unnecessarily rebuilt. Adding it to 'targets' is not enough to fix the issue. Kbuild is correctly rebuilding it because the command line is changed. PowerPC builds each vdso directory twice; first in vdso_prepare to generate vdso{32,64}-offsets.h, second as part of the ordinary build process to embed vdso{32,64}.so.dbg into the kernel. The problem shows up when CONFIG_PPC_WERROR=y due to the following line in arch/powerpc/Kbuild: subdir-ccflags-$(CONFIG_PPC_WERROR) := -Werror In the preparation stage, Kbuild directly visits the vdso directories, hence it does not inherit subdir-ccflags-y. In the second descend, Kbuild adds -Werror, which results in the command line flipping with/without -Werror. It implies a potential danger; if a more critical flag that would impact the resulted vdso, the offsets recorded in the headers might be different from real offsets in the embedded vdso images. Removing the unneeded second descend solves the problem. Reported-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/linuxppc-dev/87tuslxhry.fsf@mpe.ellerman.id.au/ Link: https://lore.kernel.org/r/20201223171142.707053-1-masahiroy@kernel.org
| * | | | powerpc/sstep: Fix array out of bound warningRavi Bangoria2021-01-301-6/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Compiling kernel with -Warray-bounds throws below warning: In function 'emulate_vsx_store': warning: array subscript is above array bounds [-Warray-bounds] buf.d[2] = byterev_8(reg->d[1]); ~~~~~^~~ buf.d[3] = byterev_8(reg->d[0]); ~~~~~^~~ Fix it by using temporary array variable 'union vsx_reg buf32[]' in that code block. Also, with element_size = 32, 'union vsx_reg *reg' is an array of size 2. So, use 'reg' as an array instead of pointer in the same code block. Fixes: af99da74333b ("powerpc/sstep: Support VSX vector paired storage access instructions") Suggested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com> Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210129071745.111466-1-ravi.bangoria@linux.ibm.com
* | | | | Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-armLinus Torvalds2021-02-067-78/+77
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull ARM fixes from Russell King: - Fix latent bug with DC21285 (Footbridge PCI bridge) configuration accessors that affects GCC >= 4.9.2 - Fix misplaced tegra_uart_config in decompressor - Ensure signal page contents are initialised - Fix kexec oops * tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm: ARM: kexec: fix oops after TLB are invalidated ARM: ensure the signal page contains defined contents ARM: 9043/1: tegra: Fix misplaced tegra_uart_config in decompressor ARM: footbridge: fix dc21285 PCI configuration accessors
| * | | | | ARM: kexec: fix oops after TLB are invalidatedRussell King2021-02-054-39/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Giancarlo Ferrari reports the following oops while trying to use kexec: Unable to handle kernel paging request at virtual address 80112f38 pgd = fd7ef03e [80112f38] *pgd=0001141e(bad) Internal error: Oops: 80d [#1] PREEMPT SMP ARM ... This is caused by machine_kexec() trying to set the kernel text to be read/write, so it can poke values into the relocation code before copying it - and an interrupt occuring which changes the page tables. The subsequent writes then hit read-only sections that trigger a data abort resulting in the above oops. Fix this by copying the relocation code, and then writing the variables into the destination, thereby avoiding the need to make the kernel text read/write. Reported-by: Giancarlo Ferrari <giancarlo.ferrari89@gmail.com> Tested-by: Giancarlo Ferrari <giancarlo.ferrari89@gmail.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
| * | | | | ARM: ensure the signal page contains defined contentsRussell King2021-02-051-6/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Ensure that the signal page contains our poison instruction to increase the protection against ROP attacks and also contains well defined contents. Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
| * | | | | ARM: 9043/1: tegra: Fix misplaced tegra_uart_config in decompressorDmitry Osipenko2021-01-291-27/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The tegra_uart_config of the DEBUG_LL code is now placed right at the start of the .text section after commit which enabled debug output in the decompressor. Tegra devices are not booting anymore if DEBUG_LL is enabled since tegra_uart_config data is executes as a code. Fix the misplaced tegra_uart_config storage by embedding it into the code. Cc: stable@vger.kernel.org Fixes: 2596a72d3384 ("ARM: 9009/1: uncompress: Enable debug in head.S") Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Dmitry Osipenko <digetx@gmail.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
| * | | | | ARM: footbridge: fix dc21285 PCI configuration accessorsRussell King2021-01-291-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Building with gcc 4.9.2 reveals a latent bug in the PCI accessors for Footbridge platforms, which causes a fatal alignment fault while accessing IO memory. Fix this by making the assembly volatile. Cc: stable@vger.kernel.org Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
* | | | | | Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds2021-02-0512-47/+72
|\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull KVM fixes from Paolo Bonzini: "x86 has lots of small bugfixes, mostly one liners. It's quite late in 5.11-rc but none of them are related to this merge window; it's just bugs coming in at the wrong time. Of note among the others is "KVM: x86: Allow guests to see MSR_IA32_TSX_CTRL even if tsx=off" that fixes a live migration failure seen on distros that hadn't switched to tsx=off right away. ARM: - Avoid clobbering extra registers on initialisation" [ Sean Christopherson notes that commit 943dea8af21b ("KVM: x86: Update emulator context mode if SYSENTER xfers to 64-bit mode") should have had authorship credited to Jonny Barker, not to him. - Linus ] * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: x86: Set so called 'reserved CR3 bits in LM mask' at vCPU reset KVM: x86/mmu: Fix TDP MMU zap collapsible SPTEs KVM: x86: cleanup CR3 reserved bits checks KVM: SVM: Treat SVM as unsupported when running as an SEV guest KVM: x86: Update emulator context mode if SYSENTER xfers to 64-bit mode KVM: x86: Supplement __cr4_reserved_bits() with X86_FEATURE_PCID check KVM/x86: assign hva with the right value to vm_munmap the pages KVM: x86: Allow guests to see MSR_IA32_TSX_CTRL even if tsx=off Fix unsynchronized access to sev members through svm_register_enc_region KVM: Documentation: Fix documentation for nested. KVM: x86: fix CPUID entries returned by KVM_GET_CPUID2 ioctl KVM: arm64: Don't clobber x4 in __do_hyp_init
| * | | | | | KVM: x86: Set so called 'reserved CR3 bits in LM mask' at vCPU resetSean Christopherson2021-02-041-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Set cr3_lm_rsvd_bits, which is effectively an invalid GPA mask, at vCPU reset. The reserved bits check needs to be done even if userspace never configures the guest's CPUID model. Cc: stable@vger.kernel.org Fixes: 0107973a80ad ("KVM: x86: Introduce cr3_lm_rsvd_bits in kvm_vcpu_arch") Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20210204000117.3303214-2-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | KVM: x86/mmu: Fix TDP MMU zap collapsible SPTEsBen Gardon2021-02-041-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is a bug in the TDP MMU function to zap SPTEs which could be replaced with a larger mapping which prevents the function from doing anything. Fix this by correctly zapping the last level SPTEs. Cc: stable@vger.kernel.org Fixes: 14881998566d ("kvm: x86/mmu: Support disabling dirty logging for the tdp MMU") Signed-off-by: Ben Gardon <bgardon@google.com> Message-Id: <20210202185734.1680553-11-bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | KVM: x86: cleanup CR3 reserved bits checksPaolo Bonzini2021-02-033-13/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If not in long mode, the low bits of CR3 are reserved but not enforced to be zero, so remove those checks. If in long mode, however, the MBZ bits extend down to the highest physical address bit of the guest, excluding the encryption bit. Make the checks consistent with the above, and match them between nested_vmcb_checks and KVM_SET_SREGS. Cc: stable@vger.kernel.org Fixes: 761e41693465 ("KVM: nSVM: Check that MBZ bits in CR3 and CR4 are not set on vmrun of nested guests") Fixes: a780a3ea6282 ("KVM: X86: Fix reserved bits check for MOV to CR3") Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | KVM: SVM: Treat SVM as unsupported when running as an SEV guestSean Christopherson2021-02-032-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Don't let KVM load when running as an SEV guest, regardless of what CPUID says. Memory is encrypted with a key that is not accessible to the host (L0), thus it's impossible for L0 to emulate SVM, e.g. it'll see garbage when reading the VMCB. Technically, KVM could decrypt all memory that needs to be accessible to the L0 and use shadow paging so that L0 does not need to shadow NPT, but exposing such information to L0 largely defeats the purpose of running as an SEV guest. This can always be revisited if someone comes up with a use case for running VMs inside SEV guests. Note, VMLOAD, VMRUN, etc... will also #GP on GPAs with C-bit set, i.e. KVM is doomed even if the SEV guest is debuggable and the hypervisor is willing to decrypt the VMCB. This may or may not be fixed on CPUs that have the SVME_ADDR_CHK fix. Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20210202212017.2486595-1-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | KVM: x86: Update emulator context mode if SYSENTER xfers to 64-bit modeSean Christopherson2021-02-021-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Set the emulator context to PROT64 if SYSENTER transitions from 32-bit userspace (compat mode) to a 64-bit kernel, otherwise the RIP update at the end of x86_emulate_insn() will incorrectly truncate the new RIP. Note, this bug is mostly limited to running an Intel virtual CPU model on an AMD physical CPU, as other combinations of virtual and physical CPUs do not trigger full emulation. On Intel CPUs, SYSENTER in compatibility mode is legal, and unconditionally transitions to 64-bit mode. On AMD CPUs, SYSENTER is illegal in compatibility mode and #UDs. If the vCPU is AMD, KVM injects a #UD on SYSENTER in compat mode. If the pCPU is Intel, SYSENTER will execute natively and not trigger #UD->VM-Exit (ignoring guest TLB shenanigans). Fixes: fede8076aab4 ("KVM: x86: handle wrap around 32-bit address space") Cc: stable@vger.kernel.org Signed-off-by: Jonny Barker <jonny@jonnybarker.com> [sean: wrote changelog] Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20210202165546.2390296-1-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | KVM: x86: Supplement __cr4_reserved_bits() with X86_FEATURE_PCID checkVitaly Kuznetsov2021-02-011-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 7a873e455567 ("KVM: selftests: Verify supported CR4 bits can be set before KVM_SET_CPUID2") reveals that KVM allows to set X86_CR4_PCIDE even when PCID support is missing: ==== Test Assertion Failure ==== x86_64/set_sregs_test.c:41: rc pid=6956 tid=6956 - Invalid argument 1 0x000000000040177d: test_cr4_feature_bit at set_sregs_test.c:41 2 0x00000000004014fc: main at set_sregs_test.c:119 3 0x00007f2d9346d041: ?? ??:0 4 0x000000000040164d: _start at ??:? KVM allowed unsupported CR4 bit (0x20000) Add X86_FEATURE_PCID feature check to __cr4_reserved_bits() to make kvm_is_valid_cr4() fail. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20210201142843.108190-1-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | KVM/x86: assign hva with the right value to vm_munmap the pagesZheng Zhan Liang2021-02-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Wanpeng Li <wanpengli@tencent.com> Cc: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Zheng Zhan Liang <zhengzhanliang@huorong.cn> Message-Id: <20210201055310.267029-1-zhengzhanliang@huorong.cn> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | KVM: x86: Allow guests to see MSR_IA32_TSX_CTRL even if tsx=offPaolo Bonzini2021-02-012-13/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Userspace that does not know about KVM_GET_MSR_FEATURE_INDEX_LIST will generally use the default value for MSR_IA32_ARCH_CAPABILITIES. When this happens and the host has tsx=on, it is possible to end up with virtual machines that have HLE and RTM disabled, but TSX_CTRL available. If the fleet is then switched to tsx=off, kvm_get_arch_capabilities() will clear the ARCH_CAP_TSX_CTRL_MSR bit and it will not be possible to use the tsx=off hosts as migration destinations, even though the guests do not have TSX enabled. To allow this migration, allow guests to write to their TSX_CTRL MSR, while keeping the host MSR unchanged for the entire life of the guests. This ensures that TSX remains disabled and also saves MSR reads and writes, and it's okay to do because with tsx=off we know that guests will not have the HLE and RTM features in their CPUID. (If userspace sets bogus CPUID data, we do not expect HLE and RTM to work in guests anyway). Cc: stable@vger.kernel.org Fixes: cbbaa2727aa3 ("KVM: x86: fix presentation of TSX feature in ARCH_CAPABILITIES") Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | Fix unsynchronized access to sev members through svm_register_enc_regionPeter Gonda2021-01-281-7/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Grab kvm->lock before pinning memory when registering an encrypted region; sev_pin_memory() relies on kvm->lock being held to ensure correctness when checking and updating the number of pinned pages. Add a lockdep assertion to help prevent future regressions. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Brijesh Singh <brijesh.singh@amd.com> Cc: Sean Christopherson <seanjc@google.com> Cc: x86@kernel.org Cc: kvm@vger.kernel.org Cc: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org Fixes: 1e80fdc09d12 ("KVM: SVM: Pin guest memory when SEV is active") Signed-off-by: Peter Gonda <pgonda@google.com> V2 - Fix up patch description - Correct file paths svm.c -> sev.c - Add unlock of kvm->lock on sev_pin_memory error V1 - https://lore.kernel.org/kvm/20210126185431.1824530-1-pgonda@google.com/ Message-Id: <20210127161524.2832400-1-pgonda@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | Merge tag 'kvmarm-fixes-5.11-3' of ↵Paolo Bonzini2021-01-281-9/+11
| |\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 fixes for 5.11, take #3 - Avoid clobbering extra registers on initialisation
| | * | | | | | KVM: arm64: Don't clobber x4 in __do_hyp_initAndrew Scull2021-01-251-9/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | arm_smccc_1_1_hvc() only adds write contraints for x0-3 in the inline assembly for the HVC instruction so make sure those are the only registers that change when __do_hyp_init is called. Tested-by: David Brazdil <dbrazdil@google.com> Signed-off-by: Andrew Scull <ascull@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210125145415.122439-3-ascull@google.com
| * | | | | | | KVM: x86: fix CPUID entries returned by KVM_GET_CPUID2 ioctlMichael Roth2021-01-281-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Recent commit 255cbecfe0 modified struct kvm_vcpu_arch to make 'cpuid_entries' a pointer to an array of kvm_cpuid_entry2 entries rather than embedding the array in the struct. KVM_SET_CPUID and KVM_SET_CPUID2 were updated accordingly, but KVM_GET_CPUID2 was missed. As a result, KVM_GET_CPUID2 currently returns random fields from struct kvm_vcpu_arch to userspace rather than the expected CPUID values. Fix this by treating 'cpuid_entries' as a pointer when copying its contents to userspace buffer. Fixes: 255cbecfe0c9 ("KVM: x86: allocate vcpu->arch.cpuid_entries dynamically") Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Michael Roth <michael.roth@amd.com.com> Message-Id: <20210128024451.1816770-1-michael.roth@amd.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | | | | | | | Revert "x86/setup: don't remove E820_TYPE_RAM for pfn 0"Mike Rapoport2021-02-041-9/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit bde9cfa3afe4324ec251e4af80ebf9b7afaf7afe. Changing the first memory page type from E820_TYPE_RESERVED to E820_TYPE_RAM makes it a part of "System RAM" resource rather than a reserved resource and this in turn causes devmem_is_allowed() to treat is as area that can be accessed but it is filled with zeroes instead of the actual data as previously. The change in /dev/mem output causes lilo to fail as was reported at slakware users forum, and probably other legacy applications will experience similar problems. Link: https://www.linuxquestions.org/questions/slackware-14/slackware-current-lilo-vesa-warnings-after-recent-updates-4175689617/#post6214439 Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | | | | Merge tag 'for-linus-5.11-rc7' of ↵Linus Torvalds2021-02-0314-99/+84
|\ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml Pull UML fixes from Richard Weinberger: - Make sure to set a default console, otherwise ttynull is selected - Revert initial ARCH_HAS_SET_MEMORY support, this needs more work - Fix a regression due to ubd refactoring - Various small fixes * tag 'for-linus-5.11-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml: um: time: fix initialization in time-travel mode um: fix os_idle_sleep() to not hang Revert "um: support some of ARCH_HAS_SET_MEMORY" Revert "um: allocate a guard page to helper threads" um: virtio: free vu_dev only with the contained struct device um: kmsg_dumper: always dump when not tty console um: stdio_console: Make preferred console um: return error from ioremap() um: ubd: fix command line handling of ubd
| * | | | | | | | um: time: fix initialization in time-travel modeJohannes Berg2021-01-261-19/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In time-travel mode, since my previous patch, the start time was initialized too late, so that the system would read it before we set it, thus always starting system time at 0 (1970-01-01). This happens because timekeeping_init() reads the time and is called before time_init(). Unfortunately, I didn't see this before because I was testing it only with the RTC patch applied (and enabled), and then the time is read again by the RTC a little - after time_init() this time. Fix this by just doing the initialization whenever necessary. Fixes: 2701c1bd91dd ("um: time: Fix read_persistent_clock64() in time-travel") Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Richard Weinberger <richard@nod.at>
| * | | | | | | | um: fix os_idle_sleep() to not hangJohannes Berg2021-01-261-1/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Changing os_idle_sleep() to use pause() (I accidentally described it as an empty select() in the commit log because I had changed it from that to pause() in a later revision) exposed a race condition in the idle code. The following can happen: timer_settime(0, 0, {it_interval={tv_sec=0, tv_nsec=0}, it_value={tv_sec=0, tv_nsec=624017}}, NULL) = 0 ... <SIGALRM is delivered but we're already on the way to idle> pause() and we now hang forever. This was previously possible as well, but it could never cause UML to hang for more than a second since we could only sleep for that much, so at most you'd notice a "hiccup" in the UML. Obviously, any sort of external interrupt also "saves" it and interrupts pause(). Fix this by properly handling the race, rather than papering over it again: - first, block SIGALRM, and obtain the old signal set - check the timer - suspend, waiting for any signal out of the old set, if, and only if, the timer will fire in the future - restore the old signal mask This ensures race-free operation: as it's blocked, the signal won't be delivered while we're looking at the timer even if it were to be triggered right _after_ we've returned from timer_gettime() with a non-zero value (telling us the timer will trigger). Thus, despite getting to sigsuspend() because timer_gettime() told us we're still waiting, we'll not hang because sigsuspend() will return immediately due to the pending signal. Fixes: 49da38a3ef33 ("um: Simplify os_idle_sleep() and sleep longer") Signed-off-by: Johannes Berg <johannes.berg@intel.com> Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com> Signed-off-by: Richard Weinberger <richard@nod.at>
| * | | | | | | | Revert "um: support some of ARCH_HAS_SET_MEMORY"Johannes Berg2021-01-264-59/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit 963285b0b47a ("um: support some of ARCH_HAS_SET_MEMORY"), as it turns out that it's not only not working (due to um never using the protection bits in the page tables) but also corrupts the page tables if used on a non-vmalloc page, since um never allocates proper page tables for the 'physmem' in the first place. Fixing all this will take more effort, so for now revert it. Reported-by: Benjamin Berg <benjamin@sipsolutions.net> Fixes: 963285b0b47a ("um: support some of ARCH_HAS_SET_MEMORY") Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Richard Weinberger <richard@nod.at>
| * | | | | | | | Revert "um: allocate a guard page to helper threads"Johannes Berg2021-01-264-11/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit ef4459a6da09 ("um: allocate a guard page to helper threads"), it's broken in multiple ways: 1) the free no longer matches the alloc; and 2) more importantly, the set_memory_ro() causes allocation of page tables for the normal memory that doesn't have any, and that later causes corruption and crashes (usually but not always in vfree()). We could fix the first bug and use vmalloc() to work around the second, but set_memory_ro() actually doesn't do anything either so I'll just revert that as well. Reported-by: Benjamin Berg <benjamin@sipsolutions.net> Fixes: ef4459a6da09 ("um: allocate a guard page to helper threads") Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Richard Weinberger <richard@nod.at>
| * | | | | | | | um: virtio: free vu_dev only with the contained struct deviceJohannes Berg2021-01-261-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since struct device is refcounted, we shouldn't free the vu_dev immediately when it's removed from the platform device, but only when the references actually all go away. Move the freeing to the release to accomplish that. Fixes: 5d38f324993f ("um: drivers: Add virtio vhost-user driver") Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Richard Weinberger <richard@nod.at>
| * | | | | | | | um: kmsg_dumper: always dump when not tty consoleThomas Meyer2021-01-261-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the addition of the ttynull console driver, the chance that a console driver was already registerd did increase. Refine the logic when to dump the kernel message buffer: always dump the buffer, when the UML stdio console driver is not active and the preferred console. Signed-off-by: Thomas Meyer <thomas@m3y3r.de> Signed-off-by: Richard Weinberger <richard@nod.at>
| * | | | | | | | um: stdio_console: Make preferred consoleThomas Meyer2021-01-261-3/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The addition of the "ttynull" console driver did break the ordering of the UML stdio console driver. The UML stdio console driver is added in late_initcall (7), whereby the ttynull driver is added in device_initcall (6), which always does make the ttynull driver the default console. Fix it by explicitly adding the UML stdio console as the preferred console, in case no 'console=' command line option was specified. Signed-off-by: Thomas Meyer <thomas@m3y3r.de> Signed-off-by: Richard Weinberger <richard@nod.at>
| * | | | | | | | um: return error from ioremap()Johannes Berg2021-01-261-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Back a few years ago, ioremap() was added to UML so that we'd not break the build for everything all the time. However, for some reason, v1 of the patch got applied, rather than the v2 that returned NULL, which was discussed here: https://lore.kernel.org/lkml/1495726955-27497-1-git-send-email-logang@deltatee.com/ Fix that now. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Richard Weinberger <richard@nod.at>