Eric Lee / smarc-fsl-linux-kernel

21 Aug, 2020

1 commit

01 May, 2020

1 commit

  • 34fdce698   x86: Change {JMP,CALL}_NOSPEC argument ... Browse Code »

    In order to change the {JMP,CALL}_NOSPEC macros to call out-of-line
    versions of the retpoline magic, we need to remove the '%' from the
    argument, such that we can paste it onto symbol names.

    Signed-off-by: Peter Zijlstra (Intel)
    Acked-by: Josh Poimboeuf
    Link: https://lkml.kernel.org/r/20200428191700.151623523@infradead.org

    Peter Zijlstra
     

18 Oct, 2019

2 commits

  • 6d685e531   x86/asm/32: Change all ENTRY+ENDPROC to SYM_FUNC_* ... Browse Code »

    These are all functions which are invoked from elsewhere, so annotate
    them as global using the new SYM_FUNC_START and their ENDPROC's by
    SYM_FUNC_END.

    Now, ENTRY/ENDPROC can be forced to be undefined on X86, so do so.

    Signed-off-by: Jiri Slaby
    Signed-off-by: Borislav Petkov
    Cc: Allison Randal
    Cc: Andrey Ryabinin
    Cc: Andy Lutomirski
    Cc: Andy Shevchenko
    Cc: Ard Biesheuvel
    Cc: Bill Metzenthen
    Cc: Boris Ostrovsky
    Cc: Darren Hart
    Cc: "David S. Miller"
    Cc: Greg Kroah-Hartman
    Cc: Herbert Xu
    Cc: "H. Peter Anvin"
    Cc: Ingo Molnar
    Cc: linux-arch@vger.kernel.org
    Cc: linux-crypto@vger.kernel.org
    Cc: linux-efi
    Cc: linux-efi@vger.kernel.org
    Cc: linux-pm@vger.kernel.org
    Cc: Mark Rutland
    Cc: Matt Fleming
    Cc: Pavel Machek
    Cc: platform-driver-x86@vger.kernel.org
    Cc: "Rafael J. Wysocki"
    Cc: Thomas Gleixner
    Cc: Will Deacon
    Cc: x86-ml
    Link: https://lkml.kernel.org/r/20191011115108.12392-28-jslaby@suse.cz

    Jiri Slaby
     
  • 6dcc5627f   x86/asm: Change all ENTRY+ENDPROC to SYM_FUNC_* ... Browse Code »

    These are all functions which are invoked from elsewhere, so annotate
    them as global using the new SYM_FUNC_START and their ENDPROC's by
    SYM_FUNC_END.

    Make sure ENTRY/ENDPROC is not defined on X86_64, given these were the
    last users.

    Signed-off-by: Jiri Slaby
    Signed-off-by: Borislav Petkov
    Reviewed-by: Rafael J. Wysocki [hibernate]
    Reviewed-by: Boris Ostrovsky [xen bits]
    Acked-by: Herbert Xu [crypto]
    Cc: Allison Randal
    Cc: Andrey Ryabinin
    Cc: Andy Lutomirski
    Cc: Andy Shevchenko
    Cc: Ard Biesheuvel
    Cc: Armijn Hemel
    Cc: Cao jin
    Cc: Darren Hart
    Cc: Dave Hansen
    Cc: "David S. Miller"
    Cc: Enrico Weigelt
    Cc: Greg Kroah-Hartman
    Cc: Herbert Xu
    Cc: "H. Peter Anvin"
    Cc: Ingo Molnar
    Cc: Jim Mattson
    Cc: Joerg Roedel
    Cc: Josh Poimboeuf
    Cc: Juergen Gross
    Cc: Kate Stewart
    Cc: "Kirill A. Shutemov"
    Cc: kvm ML
    Cc: Len Brown
    Cc: linux-arch@vger.kernel.org
    Cc: linux-crypto@vger.kernel.org
    Cc: linux-efi
    Cc: linux-efi@vger.kernel.org
    Cc: linux-pm@vger.kernel.org
    Cc: Mark Rutland
    Cc: Matt Fleming
    Cc: Paolo Bonzini
    Cc: Pavel Machek
    Cc: Peter Zijlstra
    Cc: platform-driver-x86@vger.kernel.org
    Cc: "Radim Krčmář"
    Cc: Sean Christopherson
    Cc: Stefano Stabellini
    Cc: "Steven Rostedt (VMware)"
    Cc: Thomas Gleixner
    Cc: Vitaly Kuznetsov
    Cc: Wanpeng Li
    Cc: Wei Huang
    Cc: x86-ml
    Cc: xen-devel@lists.xenproject.org
    Cc: Xiaoyao Li
    Link: https://lkml.kernel.org/r/20191011115108.12392-25-jslaby@suse.cz

    Jiri Slaby
     

31 May, 2019

1 commit

  • 2874c5fd2   treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 ... Browse Code »

    Based on 1 normalized pattern(s):

    this program is free software you can redistribute it and or modify
    it under the terms of the gnu general public license as published by
    the free software foundation either version 2 of the license or at
    your option any later version

    extracted by the scancode license scanner the SPDX license identifier

    GPL-2.0-or-later

    has been chosen to replace the boilerplate/reference in 3029 file(s).

    Signed-off-by: Thomas Gleixner
    Reviewed-by: Allison Randal
    Cc: linux-spdx@vger.kernel.org
    Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
    Signed-off-by: Greg Kroah-Hartman

    Thomas Gleixner
     

03 Sep, 2018

1 commit

  • 75045f77f   x86/extable: Introduce _ASM_EXTABLE_UA for uaccess fixups ... Browse Code »

    Currently, most fixups for attempting to access userspace memory are
    handled using _ASM_EXTABLE, which is also used for various other types of
    fixups (e.g. safe MSR access, IRET failures, and a bunch of other things).
    In order to make it possible to add special safety checks to uaccess fixups
    (in particular, checking whether the fault address is actually in
    userspace), introduce a new exception table handler ex_handler_uaccess()
    and wire it up to all the user access fixups (excluding ones that
    already use _ASM_EXTABLE_EX).

    Signed-off-by: Jann Horn
    Signed-off-by: Thomas Gleixner
    Tested-by: Kees Cook
    Cc: Andy Lutomirski
    Cc: kernel-hardening@lists.openwall.com
    Cc: dvyukov@google.com
    Cc: Masami Hiramatsu
    Cc: "Naveen N. Rao"
    Cc: Anil S Keshavamurthy
    Cc: "David S. Miller"
    Cc: Alexander Viro
    Cc: linux-fsdevel@vger.kernel.org
    Cc: Borislav Petkov
    Link: https://lkml.kernel.org/r/20180828201421.157735-5-jannh@google.com

    Jann Horn
     

12 Jan, 2018

1 commit

  • 5096732f6   x86/retpoline/checksum32: Convert assembler indirect jumps ... Browse Code »

    Convert all indirect jumps in 32bit checksum assembler code to use
    non-speculative sequences when CONFIG_RETPOLINE is enabled.

    Signed-off-by: David Woodhouse
    Signed-off-by: Thomas Gleixner
    Acked-by: Arjan van de Ven
    Acked-by: Ingo Molnar
    Cc: gnomes@lxorguk.ukuu.org.uk
    Cc: Rik van Riel
    Cc: Andi Kleen
    Cc: Josh Poimboeuf
    Cc: thomas.lendacky@amd.com
    Cc: Peter Zijlstra
    Cc: Linus Torvalds
    Cc: Jiri Kosina
    Cc: Andy Lutomirski
    Cc: Dave Hansen
    Cc: Kees Cook
    Cc: Tim Chen
    Cc: Greg Kroah-Hartman
    Cc: Paul Turner
    Link: https://lkml.kernel.org/r/1515707194-20531-11-git-send-email-dwmw@amazon.co.uk

    David Woodhouse
     

08 Aug, 2016

1 commit

02 Jun, 2015

1 commit

  • 131484c8d   x86/debug: Remove perpetually broken, unmaintainable dwarf annotations ... Browse Code »

    So the dwarf2 annotations in low level assembly code have
    become an increasing hindrance: unreadable, messy macros
    mixed into some of the most security sensitive code paths
    of the Linux kernel.

    These debug info annotations don't even buy the upstream
    kernel anything: dwarf driven stack unwinding has caused
    problems in the past so it's out of tree, and the upstream
    kernel only uses the much more robust framepointers based
    stack unwinding method.

    In addition to that there's a steady, slow bitrot going
    on with these annotations, requiring frequent fixups.
    There's no tooling and no functionality upstream that
    keeps it correct.

    So burn down the sick forest, allowing new, healthier growth:

    27 files changed, 350 insertions(+), 1101 deletions(-)

    Someone who has the willingness and time to do this
    properly can attempt to reintroduce dwarf debuginfo in x86
    assembly code plus dwarf unwinding from first principles,
    with the following conditions:

    - it should be maximally readable, and maximally low-key to
    'ordinary' code reading and maintenance.

    - find a build time method to insert dwarf annotations
    automatically in the most common cases, for pop/push
    instructions that manipulate the stack pointer. This could
    be done for example via a preprocessing step that just
    looks for common patterns - plus special annotations for
    the few cases where we want to depart from the default.
    We have hundreds of CFI annotations, so automating most of
    that makes sense.

    - it should come with build tooling checks that ensure that
    CFI annotations are sensible. We've seen such efforts from
    the framepointer side, and there's no reason it couldn't be
    done on the dwarf side.

    Cc: Andy Lutomirski
    Cc: Borislav Petkov
    Cc: Brian Gerst
    Cc: Denys Vlasenko
    Cc: Frédéric Weisbecker
    Cc: Jan Beulich
    Cc: Josh Poimboeuf
    Cc: Linus Torvalds
    Cc: Peter Zijlstra
    Cc: Thomas Gleixner
    Cc: linux-kernel@vger.kernel.org
    Signed-off-by: Ingo Molnar

    Ingo Molnar
     

07 Mar, 2015

1 commit

  • 3e1aa7cb5   x86/asm: Optimize unnecessarily wide TEST instructions ... Browse Code »

    By the nature of the TEST operation, it is often possible to test
    a narrower part of the operand:

    "testl $3, mem" -> "testb $3, mem",
    "testq $3, %rcx" -> "testb $3, %cl"

    This results in shorter instructions, because the TEST instruction
    has no sign-entending byte-immediate forms unlike other ALU ops.

    Note that this change does not create any LCP (Length-Changing Prefix)
    stalls, which happen when adding a 0x66 prefix, which happens when
    16-bit immediates are used, which changes such TEST instructions:

    [test_opcode] [modrm] [imm32]

    to:

    [0x66] [test_opcode] [modrm] [imm16]

    where [imm16] has a *different length* now: 2 bytes instead of 4.
    This confuses the decoder and slows down execution.

    REX prefixes were carefully designed to almost never hit this case:
    adding REX prefix does not change instruction length except MOVABS
    and MOV [addr],RAX instruction.

    This patch does not add instructions which would use a 0x66 prefix,
    code changes in assembly are:

    -48 f7 07 01 00 00 00 testq $0x1,(%rdi)
    +f6 07 01 testb $0x1,(%rdi)
    -48 f7 c1 01 00 00 00 test $0x1,%rcx
    +f6 c1 01 test $0x1,%cl
    -48 f7 c1 02 00 00 00 test $0x2,%rcx
    +f6 c1 02 test $0x2,%cl
    -41 f7 c2 01 00 00 00 test $0x1,%r10d
    +41 f6 c2 01 test $0x1,%r10b
    -48 f7 c1 04 00 00 00 test $0x4,%rcx
    +f6 c1 04 test $0x4,%cl
    -48 f7 c1 08 00 00 00 test $0x8,%rcx
    +f6 c1 08 test $0x8,%cl

    Linus further notes:

    "There are no stalls from using 8-bit instruction forms.

    Now, changing from 64-bit or 32-bit 'test' instructions to 8-bit ones
    *could* cause problems if it ends up having forwarding issues, so that
    instead of just forwarding the result, you end up having to wait for
    it to be stable in the L1 cache (or possibly the register file). The
    forwarding from the store buffer is simplest and most reliable if the
    read is done at the exact same address and the exact same size as the
    write that gets forwarded.

    But that's true only if:

    (a) the write was very recent and is still in the write queue. I'm
    not sure that's the case here anyway.

    (b) on at least most Intel microarchitectures, you have to test a
    different byte than the lowest one (so forwarding a 64-bit write
    to a 8-bit read ends up working fine, as long as the 8-bit read
    is of the low 8 bits of the written data).

    A very similar issue *might* show up for registers too, not just
    memory writes, if you use 'testb' with a high-byte register (where
    instead of forwarding the value from the original producer it needs to
    go through the register file and then shifted). But it's mainly a
    problem for store buffers.

    But afaik, the way Denys changed the test instructions, neither of the
    above issues should be true.

    The real problem for store buffer forwarding tends to be "write 8
    bits, read 32 bits". That can be really surprisingly expensive,
    because the read ends up having to wait until the write has hit the
    cacheline, and we might talk tens of cycles of latency here. But
    "write 32 bits, read the low 8 bits" *should* be fast on pretty much
    all x86 chips, afaik."

    Signed-off-by: Denys Vlasenko
    Acked-by: Andy Lutomirski
    Acked-by: Linus Torvalds
    Cc: Borislav Petkov
    Cc: Frederic Weisbecker
    Cc: H. Peter Anvin
    Cc: H. Peter Anvin
    Cc: Kees Cook
    Cc: Oleg Nesterov
    Cc: Steven Rostedt
    Cc: Will Drewry
    Link: http://lkml.kernel.org/r/1425675332-31576-1-git-send-email-dvlasenk@redhat.com
    Signed-off-by: Ingo Molnar

    Denys Vlasenko
     

05 Mar, 2015

1 commit

  • 49db46a67   x86/asm: Introduce push/pop macros which generate CFI_REL_OFFSET and CFI_RESTORE ... Browse Code »

    Sequences:

    pushl_cfi %reg
    CFI_REL_OFFSET reg, 0

    and:

    popl_cfi %reg
    CFI_RESTORE reg

    happen quite often. This patch adds macros which generate them.

    No assembly changes (verified with objdump -dr vmlinux.o).

    Signed-off-by: Denys Vlasenko
    Signed-off-by: Andy Lutomirski
    Cc: Alexei Starovoitov
    Cc: Borislav Petkov
    Cc: Frederic Weisbecker
    Cc: H. Peter Anvin
    Cc: Kees Cook
    Cc: Linus Torvalds
    Cc: Oleg Nesterov
    Cc: Will Drewry
    Link: http://lkml.kernel.org/r/1421017655-25561-1-git-send-email-dvlasenk@redhat.com
    Link: http://lkml.kernel.org/r/2202eb90f175cf45d1b2d1c64dbb5676a8ad07ad.1424989793.git.luto@amacapital.net
    Signed-off-by: Ingo Molnar

    Denys Vlasenko
     

15 Apr, 2013

1 commit

21 Apr, 2012

1 commit

01 Mar, 2011

1 commit

11 Oct, 2007

1 commit