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  1. 17 5月, 2019 1 次提交
  3. 15 5月, 2019 4 次提交
  5. 30 4月, 2019 9 次提交
  7. 27 4月, 2019 1 次提交
  9. 26 4月, 2019 4 次提交
    • J
      arm64: Always enable ssb vulnerability detection · d42281b6
      由 Jeremy Linton 提交于 
      Ensure we are always able to detect whether or not the CPU is affected
by SSB, so that we can later advertise this to userspace.
Signed-off-by: NJeremy Linton <jeremy.linton@arm.com>
Reviewed-by: NAndre Przywara <andre.przywara@arm.com>
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Tested-by: NStefan Wahren <stefan.wahren@i2se.com>
[will: Use IS_ENABLED instead of #ifdef]
Signed-off-by: NWill Deacon <will.deacon@arm.com>
      d42281b6
    • W
      arm64: futex: Avoid copying out uninitialised stack in failed cmpxchg() · 8e4e0ac0
      由 Will Deacon 提交于 
      Returning an error code from futex_atomic_cmpxchg_inatomic() indicates
that the caller should not make any use of *uval, and should instead act
upon on the value of the error code. Although this is implemented
correctly in our futex code, we needlessly copy uninitialised stack to
*uval in the error case, which can easily be avoided.
Signed-off-by: NWill Deacon <will.deacon@arm.com>
      8e4e0ac0
    • W
      arm64: futex: Bound number of LDXR/STXR loops in FUTEX_WAKE_OP · 03110a5c
      由 Will Deacon 提交于 
      Our futex implementation makes use of LDXR/STXR loops to perform atomic
updates to user memory from atomic context. This can lead to latency
problems if we end up spinning around the LL/SC sequence at the expense
of doing something useful.

Rework our futex atomic operations so that we return -EAGAIN if we fail
to update the futex word after 128 attempts. The core futex code will
reschedule if necessary and we'll try again later.

Cc: <stable@kernel.org>
Fixes: 6170a974 ("arm64: Atomic operations")
Signed-off-by: NWill Deacon <will.deacon@arm.com>
      03110a5c
    • W
      arm64: futex: Fix FUTEX_WAKE_OP atomic ops with non-zero result value · 84ff7a09
      由 Will Deacon 提交于 
      Rather embarrassingly, our futex() FUTEX_WAKE_OP implementation doesn't
explicitly set the return value on the non-faulting path and instead
leaves it holding the result of the underlying atomic operation. This
means that any FUTEX_WAKE_OP atomic operation which computes a non-zero
value will be reported as having failed. Regrettably, I wrote the buggy
code back in 2011 and it was upstreamed as part of the initial arm64
support in 2012.

The reasons we appear to get away with this are:

  1. FUTEX_WAKE_OP is rarely used and therefore doesn't appear to get
     exercised by futex() test applications

  2. If the result of the atomic operation is zero, the system call
     behaves correctly

  3. Prior to version 2.25, the only operation used by GLIBC set the
     futex to zero, and therefore worked as expected. From 2.25 onwards,
     FUTEX_WAKE_OP is not used by GLIBC at all.

Fix the implementation by ensuring that the return value is either 0
to indicate that the atomic operation completed successfully, or -EFAULT
if we encountered a fault when accessing the user mapping.

Cc: <stable@kernel.org>
Fixes: 6170a974 ("arm64: Atomic operations")
Signed-off-by: NWill Deacon <will.deacon@arm.com>
      84ff7a09
  11. 25 4月, 2019 1 次提交
    • K
      arm64: sysreg: Make mrs_s and msr_s macros work with Clang and LTO · be604c61
      由 Kees Cook 提交于 
      Clang's integrated assembler does not allow assembly macros defined
in one inline asm block using the .macro directive to be used across
separate asm blocks. LLVM developers consider this a feature and not a
bug, recommending code refactoring:

  https://bugs.llvm.org/show_bug.cgi?id=19749

As binutils doesn't allow macros to be redefined, this change uses
UNDEFINE_MRS_S and UNDEFINE_MSR_S to define corresponding macros
in-place and workaround gcc and clang limitations on redefining macros
across different assembler blocks.

Specifically, the current state after preprocessing looks like this:

asm volatile(".macro mXX_s ... .endm");
void f()
{
	asm volatile("mXX_s a, b");
}

With GCC, it gives macro redefinition error because sysreg.h is included
in multiple source files, and assembler code for all of them is later
combined for LTO (I've seen an intermediate file with hundreds of
identical definitions).

With clang, it gives macro undefined error because clang doesn't allow
sharing macros between inline asm statements.

I also seem to remember catching another sort of undefined error with
GCC due to reordering of macro definition asm statement and generated
asm code for function that uses the macro.

The solution with defining and undefining for each use, while certainly
not elegant, satisfies both GCC and clang, LTO and non-LTO.
Co-developed-by: NAlex Matveev <alxmtvv@gmail.com>
Co-developed-by: NYury Norov <ynorov@caviumnetworks.com>
Co-developed-by: NSami Tolvanen <samitolvanen@google.com>
Reviewed-by: NNick Desaulniers <ndesaulniers@google.com>
Reviewed-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
      be604c61
  13. 24 4月, 2019 3 次提交
  15. 19 4月, 2019 1 次提交
  17. 17 4月, 2019 1 次提交
  19. 16 4月, 2019 9 次提交
  21. 15 4月, 2019 1 次提交
  23. 13 4月, 2019 1 次提交
  25. 12 4月, 2019 1 次提交
    • W
      arm64: futex: Fix FUTEX_WAKE_OP atomic ops with non-zero result value · 045afc24
      由 Will Deacon 提交于 
      Rather embarrassingly, our futex() FUTEX_WAKE_OP implementation doesn't
explicitly set the return value on the non-faulting path and instead
leaves it holding the result of the underlying atomic operation. This
means that any FUTEX_WAKE_OP atomic operation which computes a non-zero
value will be reported as having failed. Regrettably, I wrote the buggy
code back in 2011 and it was upstreamed as part of the initial arm64
support in 2012.

The reasons we appear to get away with this are:

  1. FUTEX_WAKE_OP is rarely used and therefore doesn't appear to get
     exercised by futex() test applications

  2. If the result of the atomic operation is zero, the system call
     behaves correctly

  3. Prior to version 2.25, the only operation used by GLIBC set the
     futex to zero, and therefore worked as expected. From 2.25 onwards,
     FUTEX_WAKE_OP is not used by GLIBC at all.

Fix the implementation by ensuring that the return value is either 0
to indicate that the atomic operation completed successfully, or -EFAULT
if we encountered a fault when accessing the user mapping.

Cc: <stable@kernel.org>
Fixes: 6170a974 ("arm64: Atomic operations")
Signed-off-by: NWill Deacon <will.deacon@arm.com>
      045afc24
  27. 11 4月, 2019 1 次提交
    • V
      arm64: compat: Reduce address limit · d2631193
      由 Vincenzo Frascino 提交于 
      Currently, compat tasks running on arm64 can allocate memory up to
TASK_SIZE_32 (UL(0x100000000)).

This means that mmap() allocations, if we treat them as returning an
array, are not compliant with the sections 6.5.8 of the C standard
(C99) which states that: "If the expression P points to an element of
an array object and the expression Q points to the last element of the
same array object, the pointer expression Q+1 compares greater than P".

Redefine TASK_SIZE_32 to address the issue.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Jann Horn <jannh@google.com>
Cc: <stable@vger.kernel.org>
Reported-by: NJann Horn <jannh@google.com>
Signed-off-by: NVincenzo Frascino <vincenzo.frascino@arm.com>
[will: fixed typo in comment]
Signed-off-by: NWill Deacon <will.deacon@arm.com>
      d2631193
  29. 09 4月, 2019 2 次提交