projects/linux·commit d054796f

Merge tag 'rust-fixes-7.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux

d054796f · Linus Torvalds <[email protected]> · 2026-06-06 09:44:42 -07:00

Pull Rust fixes from Miguel Ojeda:
 "Toolchain and infrastructure:

   - Fix 'rustc-option' (the Makefile one) when cross-compiling that
     leads to build or boot failures in certain configs

   - Work around a Rust compiler bug (already fixed for Rust 1.98.0)
     thats lead to boot failures in certain configs due to missing
     'uwtable' LLVM module flags

   - Support a Rust compiler change (starting with Rust 1.98.0) in the
     unstable target specification JSON files

   - Forbid Rust + arm + KASAN configs, which do not build

  'kernel' crate:

   - Fix NOMMU build by adding a missing helper"

* tag 'rust-fixes-7.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux:
  rust: x86: support Rust >= 1.98.0 target spec
  rust: arm64: set uwtable llvm module flag for CONFIG_UNWIND_TABLES
  rust: helpers: add is_vmalloc_addr wrapper for NOMMU builds
  rust: kasan/kbuild: fix rustc-option when cross-compiling
  ARM: Do not select HAVE_RUST when KASAN is enabled
Commit
d054796f8bb7d0aa9068d83feda76fe3b215f991
Parents
76351eff · 905b06d3

Merge commit. Changes below are compared with the first parent: 76351eff.

Changes

8 files changed · +31 −5

FileStatusAddDelContent
Makefilemodified+2−1View file
arch/arm/Kconfigmodified+1−1View file
arch/arm64/Makefilemodified+3−0View file
arch/x86/Makefilemodified+4−0View file
arch/x86/Makefile.ummodified+8−0View file
rust/helpers/vmalloc.cmodified+6−0View file
scripts/Makefile.compilermodified+1−1View file
scripts/generate_rust_target.rsmodified+6−2View file

Makefile

View file
diff --git a/Makefile b/Makefile
index d8da451..e3aabcd 100644
--- a/Makefile
+++ b/Makefile
@@ -607,6 +607,7 @@ KBUILD_RUSTFLAGS := $(rust_common_flags) \
-Crelocation-model=static \
-Zfunction-sections=n \
-Wclippy::float_arithmetic
+KBUILD_RUSTFLAGS_OPTION_CHKS :=
KBUILD_AFLAGS_KERNEL :=
KBUILD_CFLAGS_KERNEL :=
@@ -643,7 +644,7 @@ export KBUILD_USERCFLAGS KBUILD_USERLDFLAGS
export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
-export KBUILD_RUSTFLAGS RUSTFLAGS_KERNEL RUSTFLAGS_MODULE
+export KBUILD_RUSTFLAGS RUSTFLAGS_KERNEL RUSTFLAGS_MODULE KBUILD_RUSTFLAGS_OPTION_CHKS
export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_RUSTFLAGS_MODULE KBUILD_LDFLAGS_MODULE
export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL KBUILD_RUSTFLAGS_KERNEL

arch/arm/Kconfig

View file
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 71fc5dd..73e6647 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -136,7 +136,7 @@ config ARM
select MMU_GATHER_RCU_TABLE_FREE if SMP && ARM_LPAE
select HAVE_REGS_AND_STACK_ACCESS_API
select HAVE_RSEQ
- select HAVE_RUST if CPU_LITTLE_ENDIAN && CPU_32v7
+ select HAVE_RUST if CPU_LITTLE_ENDIAN && CPU_32v7 && !KASAN
select HAVE_STACKPROTECTOR
select HAVE_SYSCALL_TRACEPOINTS
select HAVE_UID16

arch/arm64/Makefile

View file
diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index 73a10f6..6b005c8 100644
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -63,6 +63,9 @@ else
KBUILD_CFLAGS += -fasynchronous-unwind-tables
KBUILD_AFLAGS += -fasynchronous-unwind-tables
KBUILD_RUSTFLAGS += -Cforce-unwind-tables=y -Zuse-sync-unwind=n
+# Work around rustc bug on compilers without
+# https://github.com/rust-lang/rust/pull/156973.
+KBUILD_RUSTFLAGS += $(if $(call rustc-min-version,109800),,-Zllvm_module_flag=uwtable:u32:2:max)
endif
ifeq ($(CONFIG_STACKPROTECTOR_PER_TASK),y)

arch/x86/Makefile

View file
diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index 46fec0b..1d526a5 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -77,6 +77,10 @@ KBUILD_CFLAGS += -mno-sse -mno-mmx -mno-sse2 -mno-3dnow -mno-avx -mno-sse4a
KBUILD_RUSTFLAGS += --target=$(objtree)/scripts/target.json
KBUILD_RUSTFLAGS += -Ctarget-feature=-sse,-sse2,-sse3,-ssse3,-sse4.1,-sse4.2,-avx,-avx2
+# The target.json file is not available when invoking rustc-option, so use the
+# built-in target when checking whether flags are supported instead.
+KBUILD_RUSTFLAGS_OPTION_CHKS += --target=x86_64-unknown-none
+
#
# CFLAGS for compiling floating point code inside the kernel.
#

arch/x86/Makefile.um

View file
diff --git a/arch/x86/Makefile.um b/arch/x86/Makefile.um
index 19c13af..9adecd6 100644
--- a/arch/x86/Makefile.um
+++ b/arch/x86/Makefile.um
@@ -14,6 +14,14 @@ endif
KBUILD_RUSTFLAGS += --target=$(objtree)/scripts/target.json
+# The target.json file is not available when invoking rustc-option, so use the
+# built-in target when checking whether flags are supported instead.
+ifeq ($(CONFIG_X86_32),y)
+KBUILD_RUSTFLAGS_OPTION_CHKS += --target=i686-unknown-linux-gnu
+else
+KBUILD_RUSTFLAGS_OPTION_CHKS += --target=x86_64-unknown-linux-gnu
+endif
+
ifeq ($(CONFIG_X86_32),y)
START := 0x8048000

rust/helpers/vmalloc.c

View file
diff --git a/rust/helpers/vmalloc.c b/rust/helpers/vmalloc.c
index 326b030..6aed132 100644
--- a/rust/helpers/vmalloc.c
+++ b/rust/helpers/vmalloc.c
@@ -1,5 +1,6 @@
// SPDX-License-Identifier: GPL-2.0
+#include <linux/mm.h>
#include <linux/vmalloc.h>
__rust_helper void *__must_check __realloc_size(2)
@@ -8,3 +9,8 @@ rust_helper_vrealloc_node_align(const void *p, size_t size, unsigned long align,
{
return vrealloc_node_align(p, size, align, flags, node);
}
+
+__rust_helper bool rust_helper_is_vmalloc_addr(const void *x)
+{
+ return is_vmalloc_addr(x);
+}

scripts/Makefile.compiler

View file
diff --git a/scripts/Makefile.compiler b/scripts/Makefile.compiler
index ef91910..06bbe29 100644
--- a/scripts/Makefile.compiler
+++ b/scripts/Makefile.compiler
@@ -80,7 +80,7 @@ ld-option = $(call try-run, $(LD) $(KBUILD_LDFLAGS) $(1) -v,$(1),$(2),$(3))
# TODO: remove RUSTC_BOOTSTRAP=1 when we raise the minimum GNU Make version to 4.4
__rustc-option = $(call try-run,\
echo '$(pound)![allow(missing_docs)]$(pound)![feature(no_core)]$(pound)![no_core]' | RUSTC_BOOTSTRAP=1\
- $(1) --sysroot=/dev/null $(filter-out --sysroot=/dev/null --target=%,$(2)) $(3)\
+ $(1) --sysroot=/dev/null $(KBUILD_RUSTFLAGS_OPTION_CHKS) $(filter-out --sysroot=/dev/null --target=%target.json,$(2)) $(3)\
--crate-type=rlib --out-dir=$(TMPOUT) --emit=obj=- - >/dev/null,$(3),$(4))
# rustc-option

scripts/generate_rust_target.rs

View file
diff --git a/scripts/generate_rust_target.rs b/scripts/generate_rust_target.rs
index 38b3416..16f7e85 100644
--- a/scripts/generate_rust_target.rs
+++ b/scripts/generate_rust_target.rs
@@ -196,7 +196,9 @@ fn main() {
}
} else if cfg.has("X86_64") {
ts.push("arch", "x86_64");
- if cfg.rustc_version_atleast(1, 86, 0) {
+ if cfg.rustc_version_atleast(1, 98, 0) {
+ ts.push("rustc-abi", "softfloat");
+ } else if cfg.rustc_version_atleast(1, 86, 0) {
ts.push("rustc-abi", "x86-softfloat");
}
ts.push(
@@ -236,7 +238,9 @@ fn main() {
panic!("32-bit x86 only works under UML");
}
ts.push("arch", "x86");
- if cfg.rustc_version_atleast(1, 86, 0) {
+ if cfg.rustc_version_atleast(1, 98, 0) {
+ ts.push("rustc-abi", "softfloat");
+ } else if cfg.rustc_version_atleast(1, 86, 0) {
ts.push("rustc-abi", "x86-softfloat");
}
ts.push(