1

Rust fixes for v6.12 (2nd)

Toolchain and infrastructure:
 
  - Fix several issues with the 'rustc-option' macro. It includes a
    refactor from Masahiro of three '{cc,rust}-*' macros, which is not
    a fix but avoids repeating the same commands (which would be several
    lines in the case of 'rustc-option').
 
  - Fix conditions for 'CONFIG_HAVE_CFI_ICALL_NORMALIZE_INTEGERS'. It
    includes the addition of 'CONFIG_RUSTC_LLVM_VERSION', which is not a
    fix but is needed for the actual fix.
 
 And a trivial grammar fix.
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Merge tag 'rust-fixes-6.12-2' of https://github.com/Rust-for-Linux/linux

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

   - Fix several issues with the 'rustc-option' macro. It includes a
     refactor from Masahiro of three '{cc,rust}-*' macros, which is not
     a fix but avoids repeating the same commands (which would be
     several lines in the case of 'rustc-option').

   - Fix conditions for 'CONFIG_HAVE_CFI_ICALL_NORMALIZE_INTEGERS'. It
     includes the addition of 'CONFIG_RUSTC_LLVM_VERSION', which is not
     a fix but is needed for the actual fix.

  And a trivial grammar fix"

* tag 'rust-fixes-6.12-2' of https://github.com/Rust-for-Linux/linux:
  cfi: fix conditions for HAVE_CFI_ICALL_NORMALIZE_INTEGERS
  kbuild: rust: add `CONFIG_RUSTC_LLVM_VERSION`
  kbuild: fix issues with rustc-option
  kbuild: refactor cc-option-yn, cc-disable-warning, rust-option-yn macros
  lib/Kconfig.debug: fix grammar in RUST_BUILD_ASSERT_ALLOW
This commit is contained in:
Linus Torvalds 2024-10-19 08:32:47 -07:00
commit 4e6bd4a33a
6 changed files with 51 additions and 24 deletions

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@ -838,7 +838,7 @@ config CFI_CLANG
config CFI_ICALL_NORMALIZE_INTEGERS
bool "Normalize CFI tags for integers"
depends on CFI_CLANG
depends on HAVE_CFI_ICALL_NORMALIZE_INTEGERS
depends on HAVE_CFI_ICALL_NORMALIZE_INTEGERS_CLANG
help
This option normalizes the CFI tags for integer types so that all
integer types of the same size and signedness receive the same CFI
@ -851,21 +851,19 @@ config CFI_ICALL_NORMALIZE_INTEGERS
This option is necessary for using CFI with Rust. If unsure, say N.
config HAVE_CFI_ICALL_NORMALIZE_INTEGERS
def_bool !GCOV_KERNEL && !KASAN
depends on CFI_CLANG
config HAVE_CFI_ICALL_NORMALIZE_INTEGERS_CLANG
def_bool y
depends on $(cc-option,-fsanitize=kcfi -fsanitize-cfi-icall-experimental-normalize-integers)
help
Is CFI_ICALL_NORMALIZE_INTEGERS supported with the set of compilers
currently in use?
# With GCOV/KASAN we need this fix: https://github.com/llvm/llvm-project/pull/104826
depends on CLANG_VERSION >= 190000 || (!GCOV_KERNEL && !KASAN_GENERIC && !KASAN_SW_TAGS)
This option defaults to false if GCOV or KASAN is enabled, as there is
an LLVM bug that makes normalized integers tags incompatible with
KASAN and GCOV. Kconfig currently does not have the infrastructure to
detect whether your rustc compiler contains the fix for this bug, so
it is assumed that it doesn't. If your compiler has the fix, you can
explicitly enable this option in your config file. The Kconfig logic
needed to detect this will be added in a future kernel release.
config HAVE_CFI_ICALL_NORMALIZE_INTEGERS_RUSTC
def_bool y
depends on HAVE_CFI_ICALL_NORMALIZE_INTEGERS_CLANG
depends on RUSTC_VERSION >= 107900
# With GCOV/KASAN we need this fix: https://github.com/rust-lang/rust/pull/129373
depends on (RUSTC_LLVM_VERSION >= 190000 && RUSTC_VERSION >= 108200) || \
(!GCOV_KERNEL && !KASAN_GENERIC && !KASAN_SW_TAGS)
config CFI_PERMISSIVE
bool "Use CFI in permissive mode"

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@ -62,7 +62,7 @@ config LLD_VERSION
config RUSTC_VERSION
int
default $(shell,$(srctree)/scripts/rustc-version.sh $(RUSTC))
default $(rustc-version)
help
It does not depend on `RUST` since that one may need to use the version
in a `depends on`.
@ -78,6 +78,10 @@ config RUST_IS_AVAILABLE
In particular, the Makefile target 'rustavailable' is useful to check
why the Rust toolchain is not being detected.
config RUSTC_LLVM_VERSION
int
default $(rustc-llvm-version)
config CC_CAN_LINK
bool
default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m64-flag)) if 64BIT
@ -1946,7 +1950,7 @@ config RUST
depends on !GCC_PLUGIN_RANDSTRUCT
depends on !RANDSTRUCT
depends on !DEBUG_INFO_BTF || PAHOLE_HAS_LANG_EXCLUDE
depends on !CFI_CLANG || RUSTC_VERSION >= 107900 && HAVE_CFI_ICALL_NORMALIZE_INTEGERS
depends on !CFI_CLANG || HAVE_CFI_ICALL_NORMALIZE_INTEGERS_RUSTC
select CFI_ICALL_NORMALIZE_INTEGERS if CFI_CLANG
depends on !CALL_PADDING || RUSTC_VERSION >= 108100
depends on !KASAN_SW_TAGS

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@ -3060,7 +3060,7 @@ config RUST_BUILD_ASSERT_ALLOW
bool "Allow unoptimized build-time assertions"
depends on RUST
help
Controls how are `build_error!` and `build_assert!` handled during build.
Controls how `build_error!` and `build_assert!` are handled during the build.
If calls to them exist in the binary, it may indicate a violated invariant
or that the optimizer failed to verify the invariant during compilation.

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@ -65,6 +65,9 @@ cc-option-bit = $(if-success,$(CC) -Werror $(1) -E -x c /dev/null -o /dev/null,$
m32-flag := $(cc-option-bit,-m32)
m64-flag := $(cc-option-bit,-m64)
rustc-version := $(shell,$(srctree)/scripts/rustc-version.sh $(RUSTC))
rustc-llvm-version := $(shell,$(srctree)/scripts/rustc-llvm-version.sh $(RUSTC))
# $(rustc-option,<flag>)
# Return y if the Rust compiler supports <flag>, n otherwise
# Calls to this should be guarded so that they are not evaluated if

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@ -53,13 +53,11 @@ cc-option = $(call __cc-option, $(CC),\
# cc-option-yn
# Usage: flag := $(call cc-option-yn,-march=winchip-c6)
cc-option-yn = $(call try-run,\
$(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
cc-option-yn = $(if $(call cc-option,$1),y,n)
# cc-disable-warning
# Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)
cc-disable-warning = $(call try-run,\
$(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
cc-disable-warning = $(if $(call cc-option,-W$(strip $1)),-Wno-$(strip $1))
# gcc-min-version
# Usage: cflags-$(call gcc-min-version, 70100) += -foo
@ -75,8 +73,11 @@ ld-option = $(call try-run, $(LD) $(KBUILD_LDFLAGS) $(1) -v,$(1),$(2),$(3))
# __rustc-option
# Usage: MY_RUSTFLAGS += $(call __rustc-option,$(RUSTC),$(MY_RUSTFLAGS),-Cinstrument-coverage,-Zinstrument-coverage)
# TODO: remove RUSTC_BOOTSTRAP=1 when we raise the minimum GNU Make version to 4.4
__rustc-option = $(call try-run,\
$(1) $(2) $(3) --crate-type=rlib /dev/null --out-dir=$$TMPOUT -o "$$TMP",$(3),$(4))
echo '#![allow(missing_docs)]#![feature(no_core)]#![no_core]' | RUSTC_BOOTSTRAP=1\
$(1) --sysroot=/dev/null $(filter-out --sysroot=/dev/null,$(2)) $(3)\
--crate-type=rlib --out-dir=$(TMPOUT) --emit=obj=- - >/dev/null,$(3),$(4))
# rustc-option
# Usage: rustflags-y += $(call rustc-option,-Cinstrument-coverage,-Zinstrument-coverage)
@ -85,5 +86,4 @@ rustc-option = $(call __rustc-option, $(RUSTC),\
# rustc-option-yn
# Usage: flag := $(call rustc-option-yn,-Cinstrument-coverage)
rustc-option-yn = $(call try-run,\
$(RUSTC) $(KBUILD_RUSTFLAGS) $(1) --crate-type=rlib /dev/null --out-dir=$$TMPOUT -o "$$TMP",y,n)
rustc-option-yn = $(if $(call rustc-option,$1),y,n)

22
scripts/rustc-llvm-version.sh Executable file
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@ -0,0 +1,22 @@
#!/bin/sh
# SPDX-License-Identifier: GPL-2.0
#
# Usage: $ ./rustc-llvm-version.sh rustc
#
# Print the LLVM version that the Rust compiler uses in a 6 digit form.
# Convert the version string x.y.z to a canonical up-to-6-digits form.
get_canonical_version()
{
IFS=.
set -- $1
echo $((10000 * $1 + 100 * $2 + $3))
}
if output=$("$@" --version --verbose 2>/dev/null | grep LLVM); then
set -- $output
get_canonical_version $3
else
echo 0
exit 1
fi