Commit Graph

5 Commits

Author SHA1 Message Date
Linus Torvalds b64bb1d758 arm64 updates for 3.19
Changes include:
  - Support for alternative instruction patching from Andre
  - seccomp from Akashi
  - Some AArch32 instruction emulation, required by the Android folks
  - Optimisations for exception entry/exit code, cmpxchg, pcpu atomics
  - mmu_gather range calculations moved into core code
  - EFI updates from Ard, including long-awaited SMBIOS support
  - /proc/cpuinfo fixes to align with the format used by arch/arm/
  - A few non-critical fixes across the architecture
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Will Deacon:
 "Here's the usual mixed bag of arm64 updates, also including some
  related EFI changes (Acked by Matt) and the MMU gather range cleanup
  (Acked by you).

  Changes include:
   - support for alternative instruction patching from Andre
   - seccomp from Akashi
   - some AArch32 instruction emulation, required by the Android folks
   - optimisations for exception entry/exit code, cmpxchg, pcpu atomics
   - mmu_gather range calculations moved into core code
   - EFI updates from Ard, including long-awaited SMBIOS support
   - /proc/cpuinfo fixes to align with the format used by arch/arm/
   - a few non-critical fixes across the architecture"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (70 commits)
  arm64: remove the unnecessary arm64_swiotlb_init()
  arm64: add module support for alternatives fixups
  arm64: perf: Prevent wraparound during overflow
  arm64/include/asm: Fixed a warning about 'struct pt_regs'
  arm64: Provide a namespace to NCAPS
  arm64: bpf: lift restriction on last instruction
  arm64: Implement support for read-mostly sections
  arm64: compat: align cacheflush syscall with arch/arm
  arm64: add seccomp support
  arm64: add SIGSYS siginfo for compat task
  arm64: add seccomp syscall for compat task
  asm-generic: add generic seccomp.h for secure computing mode 1
  arm64: ptrace: allow tracer to skip a system call
  arm64: ptrace: add NT_ARM_SYSTEM_CALL regset
  arm64: Move some head.text functions to executable section
  arm64: jump labels: NOP out NOP -> NOP replacement
  arm64: add support to dump the kernel page tables
  arm64: Add FIX_HOLE to permanent fixed addresses
  arm64: alternatives: fix pr_fmt string for consistency
  arm64: vmlinux.lds.S: don't discard .exit.* sections at link-time
  ...
2014-12-09 13:12:47 -08:00
Mark Rutland 9b0b26580a arm64: efi: Fix stub cache maintenance
While efi-entry.S mentions that efi_entry() will have relocated the
kernel image, it actually means that efi_entry will have placed a copy
of the kernel in the appropriate location, and until this is branched to
at the end of efi_entry.S, all instructions are executed from the
original image.

Thus while the flush in efi_entry.S does ensure that the copy is visible
to noncacheable accesses, it does not guarantee that this is true for
the image instructions are being executed from. This could have
disasterous effects when the MMU and caches are disabled if the image
has not been naturally evicted to the PoC.

Additionally, due to a missing dsb following the ic ialluis, the new
kernel image is not necessarily clean in the I-cache when it is branched
to, with similar potentially disasterous effects.

This patch adds additional flushing to ensure that the currently
executing stub text is flushed to the PoC and is thus visible to
noncacheable accesses. As it is placed after the instructions cache
maintenance for the new image and __flush_dcache_area already contains a
dsb, we do not need to add a separate barrier to ensure completion of
the icache maintenance.

Comments are updated to clarify the situation with regard to the two
images and the maintenance required for both.

Fixes: 3c7f255039
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Joel Schopp <joel.schopp@amd.com>
Reviewed-by: Roy Franz <roy.franz@linaro.org>
Tested-by: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Ian Campbell <ijc@hellion.org.uk>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Mark Salter <msalter@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-11-13 14:47:59 +00:00
Ard Biesheuvel 95b395963f arm64/efi: efistub: jump to 'stext' directly, not through the header
After the EFI stub has done its business, it jumps into the kernel by
branching to offset #0 of the loaded Image, which is where it expects
to find the header containing a 'branch to stext' instruction.

However, the UEFI spec 2.1.1 states the following regarding PE/COFF
image loading:
"A UEFI image is loaded into memory through the LoadImage() Boot
Service. This service loads an image with a PE32+ format into memory.
This PE32+ loader is required to load all sections of the PE32+ image
into memory."

In other words, it is /not/ required to load parts of the image that are
not covered by a PE/COFF section, so it may not have loaded the header
at the expected offset, as it is not covered by any PE/COFF section.

So instead, jump to 'stext' directly, which is at the base of the
PE/COFF .text section, by supplying a symbol 'stext_offset' to
efi-entry.o which contains the relative offset of stext into the Image.
Also replace other open coded calculations of the same value with a
reference to 'stext_offset'

Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Roy Franz <roy.franz@linaro.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
2014-11-05 09:02:59 +01:00
Marc Zyngier 974c8e450b arm64: fix el2_setup check of CurrentEL
The CurrentEL system register reports the Current Exception Level
of the CPU. It doesn't say anything about the stack handling, and
yet we compare it to PSR_MODE_EL2t and PSR_MODE_EL2h.

It works by chance because PSR_MODE_EL2t happens to match the right
bits, but that's otherwise a very bad idea. Just check for the EL
value instead.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
[catalin.marinas@arm.com: fixed arch/arm64/kernel/efi-entry.S]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-07-04 16:16:52 +01:00
Mark Salter 3c7f255039 arm64: efi: add EFI stub
This patch adds PE/COFF header fields to the start of the kernel
Image so that it appears as an EFI application to UEFI firmware.
An EFI stub is included to allow direct booting of the kernel
Image.

Signed-off-by: Mark Salter <msalter@redhat.com>
[Add support in PE/COFF header for signed images]
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-04-30 19:57:04 +01:00