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  1. 29 Apr, 2019 3 commits
  3. 25 Apr, 2019 1 commit
    • Kees Cook's avatar
      arm64: sysreg: Make mrs_s and msr_s macros work with Clang and LTO · be604c61
      Kees Cook authored 
      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: default avatarAlex Matveev <alxmtvv@gmail.com>
Co-developed-by: default avatarYury Norov <ynorov@caviumnetworks.com>
Co-developed-by: default avatarSami Tolvanen <samitolvanen@google.com>
Reviewed-by: default avatarNick Desaulniers <ndesaulniers@google.com>
Reviewed-by: default avatarMark Rutland <mark.rutland@arm.com>
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      be604c61
  5. 23 Apr, 2019 6 commits
  7. 16 Apr, 2019 11 commits
  9. 12 Apr, 2019 1 commit
  11. 11 Apr, 2019 1 commit
    • Masahiro Yamada's avatar
      arm64: vdso: use $(LD) instead of $(CC) to link VDSO · 691efbed
      Masahiro Yamada authored 
      We use $(LD) to link vmlinux, modules, decompressors, etc.

VDSO is the only exceptional case where $(CC) is used as the linker
driver, but I do not know why we need to do so. VDSO uses a special
linker script, and does not link standard libraries at all.

I changed the Makefile to use $(LD) rather than $(CC). I tested this,
and VDSO worked for me.

Users will be able to use their favorite linker (e.g. lld instead of
of bfd) by passing LD= from the command line.

My plan is to rewrite all VDSO Makefiles to use $(LD), then delete
cc-ldoption.
Signed-off-by: default avatarMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      691efbed
  13. 10 Apr, 2019 1 commit
    • Vincenzo Frascino's avatar
      arm64: compat: Reduce address limit · d2631193
      Vincenzo Frascino authored 
      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: default avatarJann Horn <jannh@google.com>
Signed-off-by: default avatarVincenzo Frascino <vincenzo.frascino@arm.com>
[will: fixed typo in comment]
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      d2631193
  15. 09 Apr, 2019 16 commits
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