linux.git/arch/x86/include/asm, branch v5.9 Linux kernel source tree x86/irq: Make run_on_irqstack_cond() typesafe 2020-09-22T20:13:34+00:00 Thomas Gleixner tglx@linutronix.de 2020-09-22T07:58:52+00:00 a7b3474cbb2864d5500d5e4f48dd57c903975cab Sami reported that run_on_irqstack_cond() requires the caller to cast functions to mismatching types, which trips indirect call Control-Flow Integrity (CFI) in Clang. Instead of disabling CFI on that function, provide proper helpers for the three call variants. The actual ASM code stays the same as that is out of reach. [ bp: Fix __run_on_irqstack() prototype to match. ] Fixes: 931b94145981 ("x86/entry: Provide helpers for executing on the irqstack") Reported-by: Nathan Chancellor <natechancellor@gmail.com> Reported-by: Sami Tolvanen <samitolvanen@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Tested-by: Sami Tolvanen <samitolvanen@google.com> Cc: <stable@vger.kernel.org> Link: https://github.com/ClangBuiltLinux/linux/issues/1052 Link: https://lkml.kernel.org/r/87pn6eb5tv.fsf@nanos.tec.linutronix.de 
Sami reported that run_on_irqstack_cond() requires the caller to cast
functions to mismatching types, which trips indirect call Control-Flow
Integrity (CFI) in Clang.

Instead of disabling CFI on that function, provide proper helpers for
the three call variants. The actual ASM code stays the same as that is
out of reach.

 [ bp: Fix __run_on_irqstack() prototype to match. ]

Fixes: 931b94145981 ("x86/entry: Provide helpers for executing on the irqstack")
Reported-by: Nathan Chancellor <natechancellor@gmail.com>
Reported-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Sami Tolvanen <samitolvanen@google.com>
Cc: <stable@vger.kernel.org>
Link: https://github.com/ClangBuiltLinux/linux/issues/1052
Link: https://lkml.kernel.org/r/87pn6eb5tv.fsf@nanos.tec.linutronix.de
Merge tag 'x86_urgent_for_v5.9_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2020-09-20T22:06:43+00:00 Linus Torvalds torvalds@linux-foundation.org 2020-09-20T22:06:43+00:00 217eee7231e4b70995bfc24d279c61f6fefbf5d6 Pull x86 fixes from Borislav Petkov: - A defconfig fix (Daniel Díaz) - Disable relocation relaxation for the compressed kernel when not built as -pie as in that case kernels built with clang and linked with LLD fail to boot due to the linker optimizing some instructions in non-PIE form; the gory details in the commit message (Arvind Sankar) - A fix for the "bad bp value" warning issued by the frame-pointer unwinder (Josh Poimboeuf) * tag 'x86_urgent_for_v5.9_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/unwind/fp: Fix FP unwinding in ret_from_fork x86/boot/compressed: Disable relocation relaxation x86/defconfigs: Explicitly unset CONFIG_64BIT in i386_defconfig 
Pull x86 fixes from Borislav Petkov:

 - A defconfig fix (Daniel Díaz)

 - Disable relocation relaxation for the compressed kernel when not
   built as -pie as in that case kernels built with clang and linked
   with LLD fail to boot due to the linker optimizing some instructions
   in non-PIE form; the gory details in the commit message (Arvind
   Sankar)

 - A fix for the "bad bp value" warning issued by the frame-pointer
   unwinder (Josh Poimboeuf)

* tag 'x86_urgent_for_v5.9_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/unwind/fp: Fix FP unwinding in ret_from_fork
  x86/boot/compressed: Disable relocation relaxation
  x86/defconfigs: Explicitly unset CONFIG_64BIT in i386_defconfig
x86/unwind/fp: Fix FP unwinding in ret_from_fork 2020-09-18T07:59:40+00:00 Josh Poimboeuf jpoimboe@redhat.com 2020-09-14T17:04:22+00:00 6f9885a36c006d798319661fa849f9c2922223b9 There have been some reports of "bad bp value" warnings printed by the frame pointer unwinder: WARNING: kernel stack regs at 000000005bac7112 in sh:1014 has bad 'bp' value 0000000000000000 This warning happens when unwinding from an interrupt in ret_from_fork(). If entry code gets interrupted, the state of the frame pointer (rbp) may be undefined, which can confuse the unwinder, resulting in warnings like the above. There's an in_entry_code() check which normally silences such warnings for entry code. But in this case, ret_from_fork() is getting interrupted. It recently got moved out of .entry.text, so the in_entry_code() check no longer works. It could be moved back into .entry.text, but that would break the noinstr validation because of the call to schedule_tail(). Instead, initialize each new task's RBP to point to the task's entry regs via an encoded frame pointer. That will allow the unwinder to reach the end of the stack gracefully. Fixes: b9f6976bfb94 ("x86/entry/64: Move non entry code into .text section") Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org> Reported-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/f366bbf5a8d02e2318ee312f738112d0af74d16f.1600103007.git.jpoimboe@redhat.com 
There have been some reports of "bad bp value" warnings printed by the
frame pointer unwinder:

  WARNING: kernel stack regs at 000000005bac7112 in sh:1014 has bad 'bp' value 0000000000000000

This warning happens when unwinding from an interrupt in
ret_from_fork(). If entry code gets interrupted, the state of the
frame pointer (rbp) may be undefined, which can confuse the unwinder,
resulting in warnings like the above.

There's an in_entry_code() check which normally silences such
warnings for entry code. But in this case, ret_from_fork() is getting
interrupted. It recently got moved out of .entry.text, so the
in_entry_code() check no longer works.

It could be moved back into .entry.text, but that would break the
noinstr validation because of the call to schedule_tail().

Instead, initialize each new task's RBP to point to the task's entry
regs via an encoded frame pointer.  That will allow the unwinder to
reach the end of the stack gracefully.

Fixes: b9f6976bfb94 ("x86/entry/64: Move non entry code into .text section")
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Reported-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/f366bbf5a8d02e2318ee312f738112d0af74d16f.1600103007.git.jpoimboe@redhat.com
ACPI: processor: Use CPUIDLE_FLAG_TLB_FLUSHED 2020-09-16T17:36:25+00:00 Peter Zijlstra peterz@infradead.org 2020-09-15T10:31:59+00:00 a889a23a98fee183c9b6b0b14b2fd70583429c5e Make acpi_processor_idle() use the generic TLB flushing code. This again removes RCU usage after rcu_idle_enter(). (XXX make every C3 invalidate TLBs, not just C3-BM) Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Borislav Petkov <bp@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Make acpi_processor_idle() use the generic TLB flushing code.
This again removes RCU usage after rcu_idle_enter().

(XXX make every C3 invalidate TLBs, not just C3-BM)

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
x86/entry: Fix AC assertion 2020-09-04T13:09:29+00:00 Peter Zijlstra peterz@infradead.org 2020-09-02T13:25:50+00:00 662a0221893a3d58aa72719671844264306f6e4b The WARN added in commit 3c73b81a9164 ("x86/entry, selftests: Further improve user entry sanity checks") unconditionally triggers on a IVB machine because it does not support SMAP. For !SMAP hardware the CLAC/STAC instructions are patched out and thus if userspace sets AC, it is still have set after entry. Fixes: 3c73b81a9164 ("x86/entry, selftests: Further improve user entry sanity checks") Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Daniel Thompson <daniel.thompson@linaro.org> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200902133200.666781610@infradead.org 
The WARN added in commit 3c73b81a9164 ("x86/entry, selftests: Further
improve user entry sanity checks") unconditionally triggers on a IVB
machine because it does not support SMAP.

For !SMAP hardware the CLAC/STAC instructions are patched out and thus if
userspace sets AC, it is still have set after entry.

Fixes: 3c73b81a9164 ("x86/entry, selftests: Further improve user entry sanity checks")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Daniel Thompson <daniel.thompson@linaro.org>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200902133200.666781610@infradead.org
tracing/kprobes, x86/ptrace: Fix regs argument order for i386 2020-09-04T12:40:42+00:00 Vamshi K Sthambamkadi vamshi.k.sthambamkadi@gmail.com 2020-08-28T11:32:46+00:00 2356bb4b8221d7dc8c7beb810418122ed90254c9 On i386, the order of parameters passed on regs is eax,edx,and ecx (as per regparm(3) calling conventions). Change the mapping in regs_get_kernel_argument(), so that arg1=ax arg2=dx, and arg3=cx. Running the selftests testcase kprobes_args_use.tc shows the result as passed. Fixes: 3c88ee194c28 ("x86: ptrace: Add function argument access API") Signed-off-by: Vamshi K Sthambamkadi <vamshi.k.sthambamkadi@gmail.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20200828113242.GA1424@cosmos 
On i386, the order of parameters passed on regs is eax,edx,and ecx
(as per regparm(3) calling conventions).

Change the mapping in regs_get_kernel_argument(), so that arg1=ax
arg2=dx, and arg3=cx.

Running the selftests testcase kprobes_args_use.tc shows the result
as passed.

Fixes: 3c88ee194c28 ("x86: ptrace: Add function argument access API")
Signed-off-by: Vamshi K Sthambamkadi <vamshi.k.sthambamkadi@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20200828113242.GA1424@cosmos
cpuidle: Make CPUIDLE_FLAG_TLB_FLUSHED generic 2020-08-26T10:41:53+00:00 Peter Zijlstra peterz@infradead.org 2020-08-12T10:22:17+00:00 bf9282dc26e7fe2a0736edc568762f0f05d12416 This allows moving the leave_mm() call into generic code before rcu_idle_enter(). Gets rid of more trace_*_rcuidle() users. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Marco Elver <elver@google.com> Link: https://lkml.kernel.org/r/20200821085348.369441600@infradead.org 
This allows moving the leave_mm() call into generic code before
rcu_idle_enter(). Gets rid of more trace_*_rcuidle() users.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Marco Elver <elver@google.com>
Link: https://lkml.kernel.org/r/20200821085348.369441600@infradead.org
Merge tag 'efi-urgent-2020-08-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2020-08-23T18:08:32+00:00 Linus Torvalds torvalds@linux-foundation.org 2020-08-23T18:08:32+00:00 10c091b62e7fc3133d652b7212904348398b302e Pull EFI fixes from Thomas Gleixner: - Enforce NX on RO data in mixed EFI mode - Destroy workqueue in an error handling path to prevent UAF - Stop argument parser at '--' which is the delimiter for init - Treat a NULL command line pointer as empty instead of dereferncing it unconditionally. - Handle an unterminated command line correctly - Cleanup the 32bit code leftovers and remove obsolete documentation * tag 'efi-urgent-2020-08-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: Documentation: efi: remove description of efi=old_map efi/x86: Move 32-bit code into efi_32.c efi/libstub: Handle unterminated cmdline efi/libstub: Handle NULL cmdline efi/libstub: Stop parsing arguments at "--" efi: add missed destroy_workqueue when efisubsys_init fails efi/x86: Mark kernel rodata non-executable for mixed mode 
Pull EFI fixes from Thomas Gleixner:

 - Enforce NX on RO data in mixed EFI mode

 - Destroy workqueue in an error handling path to prevent UAF

 - Stop argument parser at '--' which is the delimiter for init

 - Treat a NULL command line pointer as empty instead of dereferncing it
   unconditionally.

 - Handle an unterminated command line correctly

 - Cleanup the 32bit code leftovers and remove obsolete documentation

* tag 'efi-urgent-2020-08-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  Documentation: efi: remove description of efi=old_map
  efi/x86: Move 32-bit code into efi_32.c
  efi/libstub: Handle unterminated cmdline
  efi/libstub: Handle NULL cmdline
  efi/libstub: Stop parsing arguments at "--"
  efi: add missed destroy_workqueue when efisubsys_init fails
  efi/x86: Mark kernel rodata non-executable for mixed mode
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm 2020-08-22T17:03:05+00:00 Linus Torvalds torvalds@linux-foundation.org 2020-08-22T17:03:05+00:00 b2d9e99622796576eb6faa236b2d1f592cc43ace Pull kvm fixes from Paolo Bonzini: - PAE and PKU bugfixes for x86 - selftests fix for new binutils - MMU notifier fix for arm64 * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: arm64: Only reschedule if MMU_NOTIFIER_RANGE_BLOCKABLE is not set KVM: Pass MMU notifier range flags to kvm_unmap_hva_range() kvm: x86: Toggling CR4.PKE does not load PDPTEs in PAE mode kvm: x86: Toggling CR4.SMAP does not load PDPTEs in PAE mode KVM: x86: fix access code passed to gva_to_gpa selftests: kvm: Use a shorter encoding to clear RAX 
Pull kvm fixes from Paolo Bonzini:

 - PAE and PKU bugfixes for x86

 - selftests fix for new binutils

 - MMU notifier fix for arm64

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: arm64: Only reschedule if MMU_NOTIFIER_RANGE_BLOCKABLE is not set
  KVM: Pass MMU notifier range flags to kvm_unmap_hva_range()
  kvm: x86: Toggling CR4.PKE does not load PDPTEs in PAE mode
  kvm: x86: Toggling CR4.SMAP does not load PDPTEs in PAE mode
  KVM: x86: fix access code passed to gva_to_gpa
  selftests: kvm: Use a shorter encoding to clear RAX
KVM: Pass MMU notifier range flags to kvm_unmap_hva_range() 2020-08-21T22:03:47+00:00 Will Deacon will@kernel.org 2020-08-11T10:27:24+00:00 fdfe7cbd58806522e799e2a50a15aee7f2cbb7b6 The 'flags' field of 'struct mmu_notifier_range' is used to indicate whether invalidate_range_{start,end}() are permitted to block. In the case of kvm_mmu_notifier_invalidate_range_start(), this field is not forwarded on to the architecture-specific implementation of kvm_unmap_hva_range() and therefore the backend cannot sensibly decide whether or not to block. Add an extra 'flags' parameter to kvm_unmap_hva_range() so that architectures are aware as to whether or not they are permitted to block. Cc: <stable@vger.kernel.org> Cc: Marc Zyngier <maz@kernel.org> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will@kernel.org> Message-Id: <20200811102725.7121-2-will@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> 
The 'flags' field of 'struct mmu_notifier_range' is used to indicate
whether invalidate_range_{start,end}() are permitted to block. In the
case of kvm_mmu_notifier_invalidate_range_start(), this field is not
forwarded on to the architecture-specific implementation of
kvm_unmap_hva_range() and therefore the backend cannot sensibly decide
whether or not to block.

Add an extra 'flags' parameter to kvm_unmap_hva_range() so that
architectures are aware as to whether or not they are permitted to block.

Cc: <stable@vger.kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: James Morse <james.morse@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
Message-Id: <20200811102725.7121-2-will@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>