On Mon, Sep 30, 2019 at 2:41 AM Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> 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@xxxxxxxxxxxxx> > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> 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@xxxxxxxxxxxxxxxxxxx > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel -- Best Regards Masahiro Yamada