| Message ID | 20240529093336.4075206-1-davidgow@google.com |
|---|---|
| State | Accepted |
| Headers | show |
| Series | arch: um: rust: Use the generated target.json again | expand |
On Wed, May 29, 2024 at 05:33:35PM +0800, David Gow wrote: > The Rust compiler can take a target config from 'target.json', which is > generated by scripts/generate_rust_target.rs. It used to be that all > Linux architectures used this to generate a target.json, but now > architectures must opt-in to this, or they will default to the Rust > compiler's built-in target definition. > > This is mostly okay for (64-bit) x86 and UML, except that it can > generate SSE instructions, which we can't use in the kernel. So > re-instate the custom target.json, which disables SSE (and generally > enables the 'soft-float' feature). This fixes the following compile > error: > > error: <unknown>:0:0: in function _RNvMNtCs5QSdWC790r4_4core3f32f7next_up float (float): SSE register return with SSE disabled > > Fixes: f82811e22b48 ("rust: Refactor the build target to allow the use of builtin targets") > Signed-off-by: David Gow <davidgow@google.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Regards, Boqun > --- > arch/x86/Makefile.um | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/arch/x86/Makefile.um b/arch/x86/Makefile.um > index 2106a2bd152b..a46b1397ad01 100644 > --- a/arch/x86/Makefile.um > +++ b/arch/x86/Makefile.um > @@ -9,6 +9,7 @@ core-y += arch/x86/crypto/ > # > ifeq ($(CONFIG_CC_IS_CLANG),y) > KBUILD_CFLAGS += -mno-sse -mno-mmx -mno-sse2 -mno-3dnow -mno-avx > +KBUILD_RUSTFLAGS += --target=$(objtree)/scripts/target.json > KBUILD_RUSTFLAGS += -Ctarget-feature=-sse,-sse2,-sse3,-ssse3,-sse4.1,-sse4.2,-avx,-avx2 > endif > > -- > 2.45.1.288.g0e0cd299f1-goog >
On Wed, May 29, 2024 at 11:33 AM David Gow <davidgow@google.com> wrote: > > The Rust compiler can take a target config from 'target.json', which is > generated by scripts/generate_rust_target.rs. It used to be that all > Linux architectures used this to generate a target.json, but now > architectures must opt-in to this, or they will default to the Rust > compiler's built-in target definition. > > This is mostly okay for (64-bit) x86 and UML, except that it can > generate SSE instructions, which we can't use in the kernel. So > re-instate the custom target.json, which disables SSE (and generally > enables the 'soft-float' feature). This fixes the following compile > error: > > error: <unknown>:0:0: in function _RNvMNtCs5QSdWC790r4_4core3f32f7next_up float (float): SSE register return with SSE disabled > > Fixes: f82811e22b48 ("rust: Refactor the build target to allow the use of builtin targets") > Signed-off-by: David Gow <davidgow@google.com> I guess this should go through UML, but please let me know otherwise (I don't see it in next). Tested-by: Miguel Ojeda <ojeda@kernel.org> Reviewed-by: Miguel Ojeda <ojeda@kernel.org> Should this have a Cc: stable@vger.kernel.org too? Thanks! Cheers, Miguel
----- Ursprüngliche Mail ----- > Von: "Miguel Ojeda" <miguel.ojeda.sandonis@gmail.com> >> Fixes: f82811e22b48 ("rust: Refactor the build target to allow the use of >> builtin targets") >> Signed-off-by: David Gow <davidgow@google.com> > > I guess this should go through UML, but please let me know otherwise Yeah, that's the plan. > Tested-by: Miguel Ojeda <ojeda@kernel.org> > Reviewed-by: Miguel Ojeda <ojeda@kernel.org> > > Should this have a > > Cc: stable@vger.kernel.org > > too? Ok! Thanks, //richard
diff --git a/arch/x86/Makefile.um b/arch/x86/Makefile.um index 2106a2bd152b..a46b1397ad01 100644 --- a/arch/x86/Makefile.um +++ b/arch/x86/Makefile.um @@ -9,6 +9,7 @@ core-y += arch/x86/crypto/ # ifeq ($(CONFIG_CC_IS_CLANG),y) KBUILD_CFLAGS += -mno-sse -mno-mmx -mno-sse2 -mno-3dnow -mno-avx +KBUILD_RUSTFLAGS += --target=$(objtree)/scripts/target.json KBUILD_RUSTFLAGS += -Ctarget-feature=-sse,-sse2,-sse3,-ssse3,-sse4.1,-sse4.2,-avx,-avx2 endif
The Rust compiler can take a target config from 'target.json', which is generated by scripts/generate_rust_target.rs. It used to be that all Linux architectures used this to generate a target.json, but now architectures must opt-in to this, or they will default to the Rust compiler's built-in target definition. This is mostly okay for (64-bit) x86 and UML, except that it can generate SSE instructions, which we can't use in the kernel. So re-instate the custom target.json, which disables SSE (and generally enables the 'soft-float' feature). This fixes the following compile error: error: <unknown>:0:0: in function _RNvMNtCs5QSdWC790r4_4core3f32f7next_up float (float): SSE register return with SSE disabled Fixes: f82811e22b48 ("rust: Refactor the build target to allow the use of builtin targets") Signed-off-by: David Gow <davidgow@google.com> --- arch/x86/Makefile.um | 1 + 1 file changed, 1 insertion(+)