diff mbox

[3/3] arm64: use -mno-implicit-float instead of -mgeneral-regs-only

Message ID 20171129000011.55235-4-samitolvanen@google.com
State New, archived
Headers show

Commit Message

Sami Tolvanen Nov. 29, 2017, midnight UTC
From: Greg Hackmann <ghackmann@google.com>

LLVM bug 30792 causes clang's AArch64 backend to crash compiling
arch/arm64/crypto/aes-ce-cipher.c.  Replacing -mgeneral-regs-only with
-mno-implicit-float is the suggested workaround.

Signed-off-by: Greg Hackmann <ghackmann@google.com>
Cc: Matthias Kaehlcke <mka@chromium.org>
[added clang-ifversion to enable the workaround only for clang <6.0]
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
---
 arch/arm64/Makefile | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

Comments

Ard Biesheuvel Nov. 29, 2017, 12:15 p.m. UTC | #1
On 29 November 2017 at 00:00, Sami Tolvanen <samitolvanen@google.com> wrote:
> From: Greg Hackmann <ghackmann@google.com>
>
> LLVM bug 30792 causes clang's AArch64 backend to crash compiling
> arch/arm64/crypto/aes-ce-cipher.c.  Replacing -mgeneral-regs-only with
> -mno-implicit-float is the suggested workaround.
>

Do we still need these patches now that the AES code has been fixed?

> Signed-off-by: Greg Hackmann <ghackmann@google.com>
> Cc: Matthias Kaehlcke <mka@chromium.org>
> [added clang-ifversion to enable the workaround only for clang <6.0]
> Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
> ---
>  arch/arm64/Makefile | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
> index b35788c909f1..d2efb5a0212f 100644
> --- a/arch/arm64/Makefile
> +++ b/arch/arm64/Makefile
> @@ -49,7 +49,10 @@ $(warning Detected assembler with broken .inst; disassembly will be unreliable)
>    endif
>  endif
>
> -KBUILD_CFLAGS  += -mgeneral-regs-only $(lseinstr) $(brokengasinst)
> +# This is a workaround for https://bugs.llvm.org/show_bug.cgi?id=30792.
> +KBUILD_CFLAGS  += $(call clang-ifversion, -lt, 0600, -mno-implicit-float, -mgeneral-regs-only)
> +
> +KBUILD_CFLAGS  += $(lseinstr) $(brokengasinst)
>  KBUILD_CFLAGS  += -fno-asynchronous-unwind-tables
>  KBUILD_CFLAGS  += $(call cc-option, -mpc-relative-literal-loads)
>  KBUILD_AFLAGS  += $(lseinstr) $(brokengasinst)
> --
> 2.15.0.417.g466bffb3ac-goog
>
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Sami Tolvanen Nov. 29, 2017, 4:22 p.m. UTC | #2
On Wed, Nov 29, 2017 at 12:15:14PM +0000, Ard Biesheuvel wrote:
> Do we still need these patches now that the AES code has been fixed?

With your AES patch that Herbert just applied, this patch is no longer
needed. Version macros in the first two patches will still be useful in
future though.

Sami
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Nick Desaulniers Nov. 29, 2017, 5:26 p.m. UTC | #3
On Wed, Nov 29, 2017 at 8:22 AM, Sami Tolvanen <samitolvanen@google.com> wrote:
> On Wed, Nov 29, 2017 at 12:15:14PM +0000, Ard Biesheuvel wrote:
>> Do we still need these patches now that the AES code has been fixed?
>
> With your AES patch that Herbert just applied, this patch is no longer
> needed. Version macros in the first two patches will still be useful in
> future though.

Matthias, maybe for your recommended Clang patch sets, you can replace
this patch with
https://www.spinics.net/lists/arm-kernel/msg617947.html?
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diff mbox

Patch

diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index b35788c909f1..d2efb5a0212f 100644
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -49,7 +49,10 @@  $(warning Detected assembler with broken .inst; disassembly will be unreliable)
   endif
 endif
 
-KBUILD_CFLAGS	+= -mgeneral-regs-only $(lseinstr) $(brokengasinst)
+# This is a workaround for https://bugs.llvm.org/show_bug.cgi?id=30792.
+KBUILD_CFLAGS	+= $(call clang-ifversion, -lt, 0600, -mno-implicit-float, -mgeneral-regs-only)
+
+KBUILD_CFLAGS	+= $(lseinstr) $(brokengasinst)
 KBUILD_CFLAGS	+= -fno-asynchronous-unwind-tables
 KBUILD_CFLAGS	+= $(call cc-option, -mpc-relative-literal-loads)
 KBUILD_AFLAGS	+= $(lseinstr) $(brokengasinst)