diff mbox series

[RFC,09/20] int128: move __uint128_t compiler test to Kconfig

Message ID 20190929173850.26055-10-ard.biesheuvel@linaro.org
State Superseded
Headers show
Series crypto: wireguard with crypto API library interface | expand

Commit Message

Ard Biesheuvel Sept. 29, 2019, 5:38 p.m. UTC
In order to use 128-bit integer arithmetic in C code, the architecture
needs to have declared support for it by setting ARCH_SUPPORTS_INT128,
and it requires a version of the toolchain that supports this at build
time. This is why all existing tests for ARCH_SUPPORTS_INT128 also test
whether __SIZEOF_INT128__ is defined, since this is only the case for
compilers that can support 128-bit integers.

Let's fold this additional test into the Kconfig declaration of
ARCH_SUPPORTS_INT128 so that we can also use the symbol in Makefiles,
e.g., to decide whether a certain object needs to be included in the
first place.

Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

---
 arch/arm64/Kconfig | 2 +-
 arch/riscv/Kconfig | 2 +-
 arch/x86/Kconfig   | 2 +-
 crypto/ecc.c       | 2 +-
 init/Kconfig       | 4 ++++
 lib/ubsan.c        | 2 +-
 lib/ubsan.h        | 2 +-
 7 files changed, 10 insertions(+), 6 deletions(-)

-- 
2.17.1

Comments

Masahiro Yamada Sept. 30, 2019, 11 a.m. UTC | #1
On Mon, Sep 30, 2019 at 2:41 AM Ard Biesheuvel
<ard.biesheuvel@linaro.org> wrote:
>

> In order to use 128-bit integer arithmetic in C code, the architecture

> needs to have declared support for it by setting ARCH_SUPPORTS_INT128,

> and it requires a version of the toolchain that supports this at build

> time. This is why all existing tests for ARCH_SUPPORTS_INT128 also test

> whether __SIZEOF_INT128__ is defined, since this is only the case for

> compilers that can support 128-bit integers.

>

> Let's fold this additional test into the Kconfig declaration of

> ARCH_SUPPORTS_INT128 so that we can also use the symbol in Makefiles,

> e.g., to decide whether a certain object needs to be included in the

> first place.

>

> Cc: Masahiro Yamada <yamada.masahiro@socionext.com>

> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>



Do you still need CONFIG_ARCH_SUPPORTS_INT128 ?

I do not know which part in lib/ubsan.c or crypto/ecc.c
is arch-dependent...





> ---

>  arch/arm64/Kconfig | 2 +-

>  arch/riscv/Kconfig | 2 +-

>  arch/x86/Kconfig   | 2 +-

>  crypto/ecc.c       | 2 +-

>  init/Kconfig       | 4 ++++

>  lib/ubsan.c        | 2 +-

>  lib/ubsan.h        | 2 +-

>  7 files changed, 10 insertions(+), 6 deletions(-)

>

> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig

> index 3adcec05b1f6..a0f764e2f299 100644

> --- a/arch/arm64/Kconfig

> +++ b/arch/arm64/Kconfig

> @@ -69,7 +69,7 @@ config ARM64

>         select ARCH_USE_QUEUED_SPINLOCKS

>         select ARCH_SUPPORTS_MEMORY_FAILURE

>         select ARCH_SUPPORTS_ATOMIC_RMW

> -       select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000 || CC_IS_CLANG

> +       select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && (GCC_VERSION >= 50000 || CC_IS_CLANG)

>         select ARCH_SUPPORTS_NUMA_BALANCING

>         select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT

>         select ARCH_WANT_FRAME_POINTERS

> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig

> index 59a4727ecd6c..99be78ac7b33 100644

> --- a/arch/riscv/Kconfig

> +++ b/arch/riscv/Kconfig

> @@ -127,7 +127,7 @@ config ARCH_RV32I

>  config ARCH_RV64I

>         bool "RV64I"

>         select 64BIT

> -       select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000

> +       select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && GCC_VERSION >= 50000

>         select HAVE_FUNCTION_TRACER

>         select HAVE_FUNCTION_GRAPH_TRACER

>         select HAVE_FTRACE_MCOUNT_RECORD

> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig

> index 222855cc0158..97f74a2e1cf3 100644

> --- a/arch/x86/Kconfig

> +++ b/arch/x86/Kconfig

> @@ -24,7 +24,7 @@ config X86_64

>         depends on 64BIT

>         # Options that are inherently 64-bit kernel only:

>         select ARCH_HAS_GIGANTIC_PAGE

> -       select ARCH_SUPPORTS_INT128

> +       select ARCH_SUPPORTS_INT128 if CC_HAS_INT128

>         select ARCH_USE_CMPXCHG_LOCKREF

>         select HAVE_ARCH_SOFT_DIRTY

>         select MODULES_USE_ELF_RELA

> diff --git a/crypto/ecc.c b/crypto/ecc.c

> index dfe114bc0c4a..6e6aab6c987c 100644

> --- a/crypto/ecc.c

> +++ b/crypto/ecc.c

> @@ -336,7 +336,7 @@ static u64 vli_usub(u64 *result, const u64 *left, u64 right,

>  static uint128_t mul_64_64(u64 left, u64 right)

>  {

>         uint128_t result;

> -#if defined(CONFIG_ARCH_SUPPORTS_INT128) && defined(__SIZEOF_INT128__)

> +#if defined(CONFIG_ARCH_SUPPORTS_INT128)

>         unsigned __int128 m = (unsigned __int128)left * right;

>

>         result.m_low  = m;

> diff --git a/init/Kconfig b/init/Kconfig

> index bd7d650d4a99..f5566a985b9e 100644

> --- a/init/Kconfig

> +++ b/init/Kconfig

> @@ -780,6 +780,10 @@ config ARCH_SUPPORTS_NUMA_BALANCING

>  config ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH

>         bool

>

> +config CC_HAS_INT128

> +       def_bool y

> +       depends on !$(cc-option,-D__SIZEOF_INT128__=0)

> +

>  #

>  # For architectures that know their GCC __int128 support is sound

>  #

> diff --git a/lib/ubsan.c b/lib/ubsan.c

> index e7d31735950d..b652cc14dd60 100644

> --- a/lib/ubsan.c

> +++ b/lib/ubsan.c

> @@ -119,7 +119,7 @@ static void val_to_string(char *str, size_t size, struct type_descriptor *type,

>  {

>         if (type_is_int(type)) {

>                 if (type_bit_width(type) == 128) {

> -#if defined(CONFIG_ARCH_SUPPORTS_INT128) && defined(__SIZEOF_INT128__)

> +#if defined(CONFIG_ARCH_SUPPORTS_INT128)

>                         u_max val = get_unsigned_val(type, value);

>

>                         scnprintf(str, size, "0x%08x%08x%08x%08x",

> diff --git a/lib/ubsan.h b/lib/ubsan.h

> index b8fa83864467..7b56c09473a9 100644

> --- a/lib/ubsan.h

> +++ b/lib/ubsan.h

> @@ -78,7 +78,7 @@ struct invalid_value_data {

>         struct type_descriptor *type;

>  };

>

> -#if defined(CONFIG_ARCH_SUPPORTS_INT128) && defined(__SIZEOF_INT128__)

> +#if defined(CONFIG_ARCH_SUPPORTS_INT128)

>  typedef __int128 s_max;

>  typedef unsigned __int128 u_max;

>  #else

> --

> 2.17.1

>

>

> _______________________________________________

> linux-arm-kernel mailing list

> linux-arm-kernel@lists.infradead.org

> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel




-- 
Best Regards
Masahiro Yamada
Ard Biesheuvel Sept. 30, 2019, 11:49 a.m. UTC | #2
On Mon, 30 Sep 2019 at 13:01, Masahiro Yamada
<yamada.masahiro@socionext.com> wrote:
>

> On Mon, Sep 30, 2019 at 2:41 AM Ard Biesheuvel

> <ard.biesheuvel@linaro.org> wrote:

> >

> > In order to use 128-bit integer arithmetic in C code, the architecture

> > needs to have declared support for it by setting ARCH_SUPPORTS_INT128,

> > and it requires a version of the toolchain that supports this at build

> > time. This is why all existing tests for ARCH_SUPPORTS_INT128 also test

> > whether __SIZEOF_INT128__ is defined, since this is only the case for

> > compilers that can support 128-bit integers.

> >

> > Let's fold this additional test into the Kconfig declaration of

> > ARCH_SUPPORTS_INT128 so that we can also use the symbol in Makefiles,

> > e.g., to decide whether a certain object needs to be included in the

> > first place.

> >

> > Cc: Masahiro Yamada <yamada.masahiro@socionext.com>

> > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

>

>

> Do you still need CONFIG_ARCH_SUPPORTS_INT128 ?

>


arm64 needs GCC 5 or later for int128_t support, since older versions
emit support library function calls that we don't implement.

I guess we could fold that into the CC_HAS_INT128 test as well though

> I do not know which part in lib/ubsan.c or crypto/ecc.c

> is arch-dependent...

>

>

>

>

>

> > ---

> >  arch/arm64/Kconfig | 2 +-

> >  arch/riscv/Kconfig | 2 +-

> >  arch/x86/Kconfig   | 2 +-

> >  crypto/ecc.c       | 2 +-

> >  init/Kconfig       | 4 ++++

> >  lib/ubsan.c        | 2 +-

> >  lib/ubsan.h        | 2 +-

> >  7 files changed, 10 insertions(+), 6 deletions(-)

> >

> > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig

> > index 3adcec05b1f6..a0f764e2f299 100644

> > --- a/arch/arm64/Kconfig

> > +++ b/arch/arm64/Kconfig

> > @@ -69,7 +69,7 @@ config ARM64

> >         select ARCH_USE_QUEUED_SPINLOCKS

> >         select ARCH_SUPPORTS_MEMORY_FAILURE

> >         select ARCH_SUPPORTS_ATOMIC_RMW

> > -       select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000 || CC_IS_CLANG

> > +       select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && (GCC_VERSION >= 50000 || CC_IS_CLANG)

> >         select ARCH_SUPPORTS_NUMA_BALANCING

> >         select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT

> >         select ARCH_WANT_FRAME_POINTERS

> > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig

> > index 59a4727ecd6c..99be78ac7b33 100644

> > --- a/arch/riscv/Kconfig

> > +++ b/arch/riscv/Kconfig

> > @@ -127,7 +127,7 @@ config ARCH_RV32I

> >  config ARCH_RV64I

> >         bool "RV64I"

> >         select 64BIT

> > -       select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000

> > +       select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && GCC_VERSION >= 50000

> >         select HAVE_FUNCTION_TRACER

> >         select HAVE_FUNCTION_GRAPH_TRACER

> >         select HAVE_FTRACE_MCOUNT_RECORD

> > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig

> > index 222855cc0158..97f74a2e1cf3 100644

> > --- a/arch/x86/Kconfig

> > +++ b/arch/x86/Kconfig

> > @@ -24,7 +24,7 @@ config X86_64

> >         depends on 64BIT

> >         # Options that are inherently 64-bit kernel only:

> >         select ARCH_HAS_GIGANTIC_PAGE

> > -       select ARCH_SUPPORTS_INT128

> > +       select ARCH_SUPPORTS_INT128 if CC_HAS_INT128

> >         select ARCH_USE_CMPXCHG_LOCKREF

> >         select HAVE_ARCH_SOFT_DIRTY

> >         select MODULES_USE_ELF_RELA

> > diff --git a/crypto/ecc.c b/crypto/ecc.c

> > index dfe114bc0c4a..6e6aab6c987c 100644

> > --- a/crypto/ecc.c

> > +++ b/crypto/ecc.c

> > @@ -336,7 +336,7 @@ static u64 vli_usub(u64 *result, const u64 *left, u64 right,

> >  static uint128_t mul_64_64(u64 left, u64 right)

> >  {

> >         uint128_t result;

> > -#if defined(CONFIG_ARCH_SUPPORTS_INT128) && defined(__SIZEOF_INT128__)

> > +#if defined(CONFIG_ARCH_SUPPORTS_INT128)

> >         unsigned __int128 m = (unsigned __int128)left * right;

> >

> >         result.m_low  = m;

> > diff --git a/init/Kconfig b/init/Kconfig

> > index bd7d650d4a99..f5566a985b9e 100644

> > --- a/init/Kconfig

> > +++ b/init/Kconfig

> > @@ -780,6 +780,10 @@ config ARCH_SUPPORTS_NUMA_BALANCING

> >  config ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH

> >         bool

> >

> > +config CC_HAS_INT128

> > +       def_bool y

> > +       depends on !$(cc-option,-D__SIZEOF_INT128__=0)

> > +

> >  #

> >  # For architectures that know their GCC __int128 support is sound

> >  #

> > diff --git a/lib/ubsan.c b/lib/ubsan.c

> > index e7d31735950d..b652cc14dd60 100644

> > --- a/lib/ubsan.c

> > +++ b/lib/ubsan.c

> > @@ -119,7 +119,7 @@ static void val_to_string(char *str, size_t size, struct type_descriptor *type,

> >  {

> >         if (type_is_int(type)) {

> >                 if (type_bit_width(type) == 128) {

> > -#if defined(CONFIG_ARCH_SUPPORTS_INT128) && defined(__SIZEOF_INT128__)

> > +#if defined(CONFIG_ARCH_SUPPORTS_INT128)

> >                         u_max val = get_unsigned_val(type, value);

> >

> >                         scnprintf(str, size, "0x%08x%08x%08x%08x",

> > diff --git a/lib/ubsan.h b/lib/ubsan.h

> > index b8fa83864467..7b56c09473a9 100644

> > --- a/lib/ubsan.h

> > +++ b/lib/ubsan.h

> > @@ -78,7 +78,7 @@ struct invalid_value_data {

> >         struct type_descriptor *type;

> >  };

> >

> > -#if defined(CONFIG_ARCH_SUPPORTS_INT128) && defined(__SIZEOF_INT128__)

> > +#if defined(CONFIG_ARCH_SUPPORTS_INT128)

> >  typedef __int128 s_max;

> >  typedef unsigned __int128 u_max;

> >  #else

> > --

> > 2.17.1

> >

> >

> > _______________________________________________

> > linux-arm-kernel mailing list

> > linux-arm-kernel@lists.infradead.org

> > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

>

>

>

> --

> Best Regards

> Masahiro Yamada
diff mbox series

Patch

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 3adcec05b1f6..a0f764e2f299 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -69,7 +69,7 @@  config ARM64
 	select ARCH_USE_QUEUED_SPINLOCKS
 	select ARCH_SUPPORTS_MEMORY_FAILURE
 	select ARCH_SUPPORTS_ATOMIC_RMW
-	select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000 || CC_IS_CLANG
+	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && (GCC_VERSION >= 50000 || CC_IS_CLANG)
 	select ARCH_SUPPORTS_NUMA_BALANCING
 	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT
 	select ARCH_WANT_FRAME_POINTERS
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 59a4727ecd6c..99be78ac7b33 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -127,7 +127,7 @@  config ARCH_RV32I
 config ARCH_RV64I
 	bool "RV64I"
 	select 64BIT
-	select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000
+	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && GCC_VERSION >= 50000
 	select HAVE_FUNCTION_TRACER
 	select HAVE_FUNCTION_GRAPH_TRACER
 	select HAVE_FTRACE_MCOUNT_RECORD
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 222855cc0158..97f74a2e1cf3 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -24,7 +24,7 @@  config X86_64
 	depends on 64BIT
 	# Options that are inherently 64-bit kernel only:
 	select ARCH_HAS_GIGANTIC_PAGE
-	select ARCH_SUPPORTS_INT128
+	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
 	select ARCH_USE_CMPXCHG_LOCKREF
 	select HAVE_ARCH_SOFT_DIRTY
 	select MODULES_USE_ELF_RELA
diff --git a/crypto/ecc.c b/crypto/ecc.c
index dfe114bc0c4a..6e6aab6c987c 100644
--- a/crypto/ecc.c
+++ b/crypto/ecc.c
@@ -336,7 +336,7 @@  static u64 vli_usub(u64 *result, const u64 *left, u64 right,
 static uint128_t mul_64_64(u64 left, u64 right)
 {
 	uint128_t result;
-#if defined(CONFIG_ARCH_SUPPORTS_INT128) && defined(__SIZEOF_INT128__)
+#if defined(CONFIG_ARCH_SUPPORTS_INT128)
 	unsigned __int128 m = (unsigned __int128)left * right;
 
 	result.m_low  = m;
diff --git a/init/Kconfig b/init/Kconfig
index bd7d650d4a99..f5566a985b9e 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -780,6 +780,10 @@  config ARCH_SUPPORTS_NUMA_BALANCING
 config ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
 	bool
 
+config CC_HAS_INT128
+	def_bool y
+	depends on !$(cc-option,-D__SIZEOF_INT128__=0)
+
 #
 # For architectures that know their GCC __int128 support is sound
 #
diff --git a/lib/ubsan.c b/lib/ubsan.c
index e7d31735950d..b652cc14dd60 100644
--- a/lib/ubsan.c
+++ b/lib/ubsan.c
@@ -119,7 +119,7 @@  static void val_to_string(char *str, size_t size, struct type_descriptor *type,
 {
 	if (type_is_int(type)) {
 		if (type_bit_width(type) == 128) {
-#if defined(CONFIG_ARCH_SUPPORTS_INT128) && defined(__SIZEOF_INT128__)
+#if defined(CONFIG_ARCH_SUPPORTS_INT128)
 			u_max val = get_unsigned_val(type, value);
 
 			scnprintf(str, size, "0x%08x%08x%08x%08x",
diff --git a/lib/ubsan.h b/lib/ubsan.h
index b8fa83864467..7b56c09473a9 100644
--- a/lib/ubsan.h
+++ b/lib/ubsan.h
@@ -78,7 +78,7 @@  struct invalid_value_data {
 	struct type_descriptor *type;
 };
 
-#if defined(CONFIG_ARCH_SUPPORTS_INT128) && defined(__SIZEOF_INT128__)
+#if defined(CONFIG_ARCH_SUPPORTS_INT128)
 typedef __int128 s_max;
 typedef unsigned __int128 u_max;
 #else