[PATCH 0/2] rust: add support for Software Tag-Based KASAN

[Alice Ryhl]

Since my kernel-hwaddress patch to rustc [1] is now landed, I'm sending
this series to enable support for it in the kernel.

[1]: https://github.com/rust-lang/rust/pull/153049

Signed-off-by: Alice Ryhl <alic...@google.com>
---
Alice Ryhl (2):
rust: kasan: do not pass -Zsanitizer-recover
rust: kasan: add support for Software Tag-Based KASAN

init/Kconfig | 2 +-
scripts/Makefile.kasan | 6 +-----
2 files changed, 2 insertions(+), 6 deletions(-)
---
base-commit: 1f318b96cc84d7c2ab792fcc0bfd42a7ca890681
change-id: 20260325-kasan-rust-sw-tags-c5afff30e63a

Best regards,
--
Alice Ryhl <alic...@google.com>

[Alice Ryhl]

We do not pass -fsanitize-recover to clang, so for consistency we should
not pass -Zsanitizer-recover to rustc. Thus, remove these flags.

Fixes: e3117404b411 ("kbuild: rust: Enable KASAN support")

Signed-off-by: Alice Ryhl <alic...@google.com>
---

scripts/Makefile.kasan | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/scripts/Makefile.kasan b/scripts/Makefile.kasan
index 0ba2aac3b8dc..9a9033096c88 100644
--- a/scripts/Makefile.kasan
+++ b/scripts/Makefile.kasan
@@ -49,7 +49,6 @@ CFLAGS_KASAN := $(call cc-option, -fsanitize=kernel-address \
# The minimum supported `rustc` version has a minimum supported LLVM
# version late enough that we can assume support for -asan-mapping-offset.
RUSTFLAGS_KASAN := -Zsanitizer=kernel-address \
- -Zsanitizer-recover=kernel-address \
-Cllvm-args=-asan-mapping-offset=$(KASAN_SHADOW_OFFSET)

# Now, add other parameters enabled similarly in GCC, Clang, and rustc.
@@ -73,8 +72,7 @@ CFLAGS_KASAN := -fsanitize=kernel-hwaddress

# This sets flags that will enable SW_TAGS KASAN once enabled in Rust. These
# will not work today, and is guarded against in dependencies for CONFIG_RUST.
-RUSTFLAGS_KASAN := -Zsanitizer=kernel-hwaddress \
- -Zsanitizer-recover=kernel-hwaddress
+RUSTFLAGS_KASAN := -Zsanitizer=kernel-hwaddress

ifdef CONFIG_KASAN_INLINE
kasan_params += hwasan-mapping-offset=$(KASAN_SHADOW_OFFSET)

--
2.53.0.1018.g2bb0e51243-goog

[Alice Ryhl]

This adds support for Software Tag-Based KASAN (KASAN_SW_TAGS) when
CONFIG_RUST is enabled. This requires that rustc includes support for
the kernel-hwaddress sanitizer, which is available since 1.96.0 [1].

Link: https://github.com/rust-lang/rust/pull/153049 [1]

Signed-off-by: Alice Ryhl <alic...@google.com>
---

init/Kconfig | 2 +-
scripts/Makefile.kasan | 2 --
2 files changed, 1 insertion(+), 3 deletions(-)

diff --git a/init/Kconfig b/init/Kconfig
index 444ce811ea67..545cbe889a52 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -2179,7 +2179,7 @@ config RUST
depends on !CFI || HAVE_CFI_ICALL_NORMALIZE_INTEGERS_RUSTC
select CFI_ICALL_NORMALIZE_INTEGERS if CFI
depends on !CALL_PADDING || RUSTC_VERSION >= 108100
- depends on !KASAN_SW_TAGS
+ depends on !KASAN_SW_TAGS || RUSTC_VERSION >= 109600
depends on !(MITIGATION_RETHUNK && KASAN) || RUSTC_VERSION >= 108300
help
Enables Rust support in the kernel.
diff --git a/scripts/Makefile.kasan b/scripts/Makefile.kasan
index 9a9033096c88..3833e0b3b857 100644
--- a/scripts/Makefile.kasan
+++ b/scripts/Makefile.kasan
@@ -70,8 +70,6 @@ ifdef CONFIG_KASAN_SW_TAGS

CFLAGS_KASAN := -fsanitize=kernel-hwaddress

-# This sets flags that will enable SW_TAGS KASAN once enabled in Rust. These
-# will not work today, and is guarded against in dependencies for CONFIG_RUST.
RUSTFLAGS_KASAN := -Zsanitizer=kernel-hwaddress

ifdef CONFIG_KASAN_INLINE

--
2.53.0.1018.g2bb0e51243-goog

[Danilo Krummrich]

On Wed Mar 25, 2026 at 10:26 AM CET, Alice Ryhl wrote:
> We do not pass -fsanitize-recover to clang, so for consistency we should
> not pass -Zsanitizer-recover to rustc. Thus, remove these flags.

Isn't this because clang forces it regardless? Is this true for rustc as well?

[Danilo Krummrich]

On 3/25/26 10:26 AM, Alice Ryhl wrote:
> This adds support for Software Tag-Based KASAN (KASAN_SW_TAGS) when
> CONFIG_RUST is enabled. This requires that rustc includes support for
> the kernel-hwaddress sanitizer, which is available since 1.96.0 [1].
>
> Link: https://github.com/rust-lang/rust/pull/153049 [1]
> Signed-off-by: Alice Ryhl <alic...@google.com>

Reviewed-by: Danilo Krummrich <da...@kernel.org>

[Alice Ryhl]

I forgot to mention this in commit, but I'm actually a bit confused
about the situation here. If clang forces it somehow, how? I don't think
rustc does anything like that, but not sure. If it doesn't, but clang
does, then maybe rustc should too? Depends on how that happens.

Alice

[Danilo Krummrich]

On Wed Mar 25, 2026 at 12:47 PM CET, Alice Ryhl wrote:
> On Wed, Mar 25, 2026 at 12:06:50PM +0100, Danilo Krummrich wrote:
>> On Wed Mar 25, 2026 at 10:26 AM CET, Alice Ryhl wrote:
>> > We do not pass -fsanitize-recover to clang, so for consistency we should
>> > not pass -Zsanitizer-recover to rustc. Thus, remove these flags.
>>
>> Isn't this because clang forces it regardless? Is this true for rustc as well?
>
> I forgot to mention this in commit, but I'm actually a bit confused
> about the situation here. If clang forces it somehow, how?

I previously had a very brief look at the source code and came across this [1],
where

static const SanitizerMask AlwaysRecoverable = SanitizerKind::KernelAddress |
SanitizerKind::KernelHWAddress |
SanitizerKind::KCFI;

But again, I only had a very brief look and it might well be that I got this
wrong.

[1] https://github.com/llvm/llvm-project/blob/main/clang/lib/Driver/SanitizerArgs.cpp#L750

[Gary Guo]

It looks like there's no similar logic, and Rustc is passing recoverable
settings based on the command line options:

https://github.com/rust-lang/rust/blob/8a703520e80d87d4423c01f9d4fbc9e5f6533a02/compiler/rustc_codegen_llvm/src/back/write.rs#L644

Best,
Gary

[Alice Ryhl]

Based on
https://lore.kernel.org/all/202603271853...@intel.com/
it seems like you all are right. There is a rustc/clang difference here.

Alice

[kernel test robot]

Hi Alice,

kernel test robot noticed the following build errors:

[auto build test ERROR on 1f318b96cc84d7c2ab792fcc0bfd42a7ca890681]

url: https://github.com/intel-lab-lkp/linux/commits/Alice-Ryhl/rust-kasan-do-not-pass-Zsanitizer-recover/20260326-213339
base: 1f318b96cc84d7c2ab792fcc0bfd42a7ca890681
patch link: https://lore.kernel.org/r/20260325-kasan-rust-sw-tags-v1-1-7d3a765a72aa%40google.com
patch subject: [PATCH 1/2] rust: kasan: do not pass -Zsanitizer-recover
config: x86_64-randconfig-071-20260327 (https://download.01.org/0day-ci/archive/20260327/202603271853...@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
rustc: rustc 1.88.0 (6b00bc388 2025-06-23)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260327/202603271853...@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <l...@intel.com>
| Closes: https://lore.kernel.org/r/202603271853...@intel.com/

All errors (new ones prefixed by >>):

>> ld.lld: error: undefined symbol: __asan_report_load8
>>> referenced by kvec.rs:847 (rust/kernel/alloc/kvec.rs:847)
>>> samples/rust/rust_soc.o:(core::ptr::drop_in_place::<kernel::str::CString>) in archive vmlinux.a
>>> referenced by kvec.rs:847 (rust/kernel/alloc/kvec.rs:847)
>>> samples/rust/rust_soc.o:(core::ptr::drop_in_place::<kernel::str::CString>) in archive vmlinux.a
>>> referenced by aref.rs:170 (rust/kernel/sync/aref.rs:170)
>>> samples/rust/rust_soc.o:(<kernel::driver::Registration<kernel::platform::Adapter<rust_soc::SampleSocDriver>>>::post_unbind_callback) in archive vmlinux.a
>>> referenced 3034 more times
--
>> ld.lld: error: undefined symbol: __asan_report_store8
>>> referenced by mod.rs:1655 (/opt/cross/rustc-1.88.0-bindgen-0.72.1/rustup/toolchains/1.88.0-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/ptr/mod.rs:1655)
>>> samples/rust/rust_soc.o:(<kernel::platform::Adapter<rust_soc::SampleSocDriver>>::probe_callback) in archive vmlinux.a
>>> referenced by mod.rs:1655 (/opt/cross/rustc-1.88.0-bindgen-0.72.1/rustup/toolchains/1.88.0-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/ptr/mod.rs:1655)
>>> samples/rust/rust_soc.o:(<kernel::platform::Adapter<rust_soc::SampleSocDriver>>::probe_callback) in archive vmlinux.a
>>> referenced by rust_configfs.rs:86 (samples/rust/rust_configfs.rs:86)
>>> samples/rust/rust_configfs.o:(<rust_configfs::Configuration as kernel::configfs::GroupOperations>::make_group) in archive vmlinux.a
>>> referenced 1783 more times
--
>> ld.lld: error: undefined symbol: __asan_report_load16
>>> referenced by num.rs:648 (/opt/cross/rustc-1.88.0-bindgen-0.72.1/rustup/toolchains/1.88.0-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/fmt/num.rs:648)
>>> rust/core.o:(<u128 as core::fmt::Display>::fmt) in archive vmlinux.a
>>> referenced by num.rs:655 (/opt/cross/rustc-1.88.0-bindgen-0.72.1/rustup/toolchains/1.88.0-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/fmt/num.rs:655)
>>> rust/core.o:(<i128 as core::fmt::Display>::fmt) in archive vmlinux.a
>>> referenced by niche_types.rs:100 (/opt/cross/rustc-1.88.0-bindgen-0.72.1/rustup/toolchains/1.88.0-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/num/niche_types.rs:100)
>>> rust/core.o:(<core::num::niche_types::NonZeroU128Inner as core::fmt::Debug>::fmt) in archive vmlinux.a
>>> referenced 9 more times
--
>> ld.lld: error: undefined symbol: __asan_report_store16
>>> referenced by option.rs:1279 (/opt/cross/rustc-1.88.0-bindgen-0.72.1/rustup/toolchains/1.88.0-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/option.rs:1279)
>>> rust/core.o:(<core::num::nonzero::NonZero<u128> as core::str::traits::FromStr>::from_str) in archive vmlinux.a
>>> referenced by option.rs:1279 (/opt/cross/rustc-1.88.0-bindgen-0.72.1/rustup/toolchains/1.88.0-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/option.rs:1279)
>>> rust/core.o:(<core::num::nonzero::NonZero<i128> as core::str::traits::FromStr>::from_str) in archive vmlinux.a
--
>> ld.lld: error: undefined symbol: __asan_report_load1
>>> referenced by c_str.rs:416 (/opt/cross/rustc-1.88.0-bindgen-0.72.1/rustup/toolchains/1.88.0-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/ffi/c_str.rs:416)
>>> samples/rust/rust_configfs.o:(<kernel::configfs::GroupOperationsVTable<rust_configfs::Configuration, rust_configfs::Child>>::make_group) in archive vmlinux.a
>>> referenced by c_str.rs:416 (/opt/cross/rustc-1.88.0-bindgen-0.72.1/rustup/toolchains/1.88.0-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/ffi/c_str.rs:416)
>>> samples/rust/rust_configfs.o:(<kernel::configfs::GroupOperationsVTable<rust_configfs::Child, rust_configfs::GrandChild>>::make_group) in archive vmlinux.a
>>> referenced by revocable.rs:218 (rust/kernel/revocable.rs:218)
>>> samples/rust/rust_driver_auxiliary.o:(core::ptr::drop_in_place::<kernel::sync::arc::Arc<kernel::revocable::Revocable<kernel::auxiliary::Registration>>>) in archive vmlinux.a
>>> referenced 890 more times
--
>> ld.lld: error: undefined symbol: __asan_report_store4
>>> referenced by mod.rs:1655 (/opt/cross/rustc-1.88.0-bindgen-0.72.1/rustup/toolchains/1.88.0-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/ptr/mod.rs:1655)
>>> samples/rust/rust_configfs.o:(<kernel::configfs::GroupOperationsVTable<rust_configfs::Configuration, rust_configfs::Child>>::make_group) in archive vmlinux.a
>>> referenced by mod.rs:1655 (/opt/cross/rustc-1.88.0-bindgen-0.72.1/rustup/toolchains/1.88.0-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/ptr/mod.rs:1655)
>>> samples/rust/rust_configfs.o:(<kernel::configfs::GroupOperationsVTable<rust_configfs::Child, rust_configfs::GrandChild>>::make_group) in archive vmlinux.a
>>> referenced by result.rs:2050 (/opt/cross/rustc-1.88.0-bindgen-0.72.1/rustup/toolchains/1.88.0-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/result.rs:2050)
>>> samples/rust/rust_configfs.o:(<rust_configfs::Configuration as kernel::configfs::GroupOperations>::make_group) in archive vmlinux.a
>>> referenced 539 more times
--
>> ld.lld: error: undefined symbol: __asan_report_store1
>>> referenced by atomic.rs:3845 (/opt/cross/rustc-1.88.0-bindgen-0.72.1/rustup/toolchains/1.88.0-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/sync/atomic.rs:3845)
>>> samples/rust/rust_driver_auxiliary.o:(core::ptr::drop_in_place::<kernel::devres::Devres<kernel::auxiliary::Registration>>) in archive vmlinux.a
>>> referenced by mod.rs:1655 (/opt/cross/rustc-1.88.0-bindgen-0.72.1/rustup/toolchains/1.88.0-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/ptr/mod.rs:1655)
>> >>> samples/rust/rust_driver_auxiliary.o:(pin_init::pin_init_scope::<kernel::devres::Devres<kernel::auxiliary::Registration>, kernel::error::Error, <kernel::auxiliary::Registration>::new::{closure#0}, core::result::Result<kernel::devres::Devres<kernel::auxiliary::Registration>, kernel::error::Error>>::{closure#0}) in archive vmlinux.a
>>> referenced by atomic.rs:3845 (/opt/cross/rustc-1.88.0-bindgen-0.72.1/rustup/toolchains/1.88.0-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/sync/atomic.rs:3845)
>>> samples/rust/rust_driver_pci.o:(core::ptr::drop_in_place::<kernel::devres::Devres<kernel::pci::io::Bar<16>>>) in archive vmlinux.a
>>> referenced 356 more times
--
>> ld.lld: error: undefined symbol: __asan_report_load4
>>> referenced by lib.rs:1300 (rust/pin-init/src/lib.rs:1300)
>> >>> samples/rust/rust_driver_auxiliary.o:(pin_init::pin_init_scope::<kernel::devres::Devres<kernel::auxiliary::Registration>, kernel::error::Error, <kernel::auxiliary::Registration>::new::{closure#0}, core::result::Result<kernel::devres::Devres<kernel::auxiliary::Registration>, kernel::error::Error>>::{closure#0}) in archive vmlinux.a
>>> referenced by io.rs:261 (rust/kernel/pci/io.rs:261)
>>> samples/rust/rust_driver_pci.o:(core::ptr::drop_in_place::<kernel::devres::Devres<kernel::pci::io::Bar<16>>>) in archive vmlinux.a
>>> referenced by io.rs:261 (rust/kernel/pci/io.rs:261)
>>> samples/rust/rust_driver_pci.o:(core::ptr::drop_in_place::<kernel::sync::arc::Arc<kernel::revocable::Revocable<kernel::pci::io::Bar<16>>>>) in archive vmlinux.a
>>> referenced 320 more times
--
>> ld.lld: error: undefined symbol: __asan_report_store_n
>>> referenced by mod.rs:1655 (/opt/cross/rustc-1.88.0-bindgen-0.72.1/rustup/toolchains/1.88.0-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/ptr/mod.rs:1655)
>> >>> samples/rust/rust_driver_auxiliary.o:(pin_init::pin_init_scope::<kernel::devres::Devres<kernel::auxiliary::Registration>, kernel::error::Error, <kernel::auxiliary::Registration>::new::{closure#0}, core::result::Result<kernel::devres::Devres<kernel::auxiliary::Registration>, kernel::error::Error>>::{closure#0}) in archive vmlinux.a
>>> referenced by mod.rs:1655 (/opt/cross/rustc-1.88.0-bindgen-0.72.1/rustup/toolchains/1.88.0-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/ptr/mod.rs:1655)
>> >>> samples/rust/rust_driver_auxiliary.o:(pin_init::pin_init_scope::<kernel::devres::Devres<kernel::auxiliary::Registration>, kernel::error::Error, <kernel::auxiliary::Registration>::new::{closure#0}, core::result::Result<kernel::devres::Devres<kernel::auxiliary::Registration>, kernel::error::Error>>::{closure#0}) in archive vmlinux.a
>>> referenced by mod.rs:1655 (/opt/cross/rustc-1.88.0-bindgen-0.72.1/rustup/toolchains/1.88.0-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/ptr/mod.rs:1655)
>>> samples/rust/rust_driver_pci.o:(<kernel::pci::Adapter<rust_driver_pci::SampleDriver>>::probe_callback) in archive vmlinux.a
>>> referenced 105 more times
--
>> ld.lld: error: undefined symbol: __asan_report_load2
>>> referenced by pci.rs:372 (rust/kernel/pci.rs:372)
>>> samples/rust/rust_driver_pci.o:(<kernel::pci::Adapter<rust_driver_pci::SampleDriver>>::probe_callback) in archive vmlinux.a
>>> referenced by pci.rs:381 (rust/kernel/pci.rs:381)
>>> samples/rust/rust_driver_pci.o:(<kernel::pci::Adapter<rust_driver_pci::SampleDriver>>::probe_callback) in archive vmlinux.a
>>> referenced by pci.rs:372 (rust/kernel/pci.rs:372)
>>> samples/rust/rust_driver_auxiliary.o:(<rust_driver_auxiliary::AuxiliaryDriver as kernel::auxiliary::Driver>::probe) in archive vmlinux.a
>>> referenced 54 more times
--
>> ld.lld: error: undefined symbol: __asan_report_load_n
>>> referenced by mod.rs:3753 (/opt/cross/rustc-1.88.0-bindgen-0.72.1/rustup/toolchains/1.88.0-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/intrinsics/mod.rs:3753)
>>> drivers/android/binder/rust_binder_main.o:(<[u8]>::copy_from_slice) in archive vmlinux.a
>>> referenced by mod.rs:3753 (/opt/cross/rustc-1.88.0-bindgen-0.72.1/rustup/toolchains/1.88.0-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/intrinsics/mod.rs:3753)
>>> drivers/android/binder/rust_binder_main.o:(<[u8]>::copy_from_slice) in archive vmlinux.a
>>> referenced by mod.rs:864 (/opt/cross/rustc-1.88.0-bindgen-0.72.1/rustup/toolchains/1.88.0-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/mem/mod.rs:864)
>>> drivers/android/binder/rust_binder_main.o:(<rust_binder_main::range_alloc::tree::Descriptor<rust_binder_main::allocation::AllocationInfo>>::try_change_state::<<rust_binder_main::range_alloc::tree::TreeRangeAllocator<rust_binder_main::allocation::AllocationInfo>>::reservation_abort::{closure#1}, (rust_binder_main::range_alloc::Reservation, kernel::rbtree::RBTreeNodeReservation<(usize, usize), ()>)>) in archive vmlinux.a
>>> referenced 81 more times
..

--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

[Alice Ryhl]

This adds support for Software Tag-Based KASAN (KASAN_SW_TAGS) when
CONFIG_RUST is enabled. This requires that rustc includes support for
the kernel-hwaddress sanitizer, which is available since 1.96.0 [1].

Unlike with clang, we need to pass -Zsanitizer-recover in addition to
-Zsanitizer because the option is not implied automatically.

Link: https://github.com/rust-lang/rust/pull/153049 [1]
Reviewed-by: Danilo Krummrich <da...@kernel.org>

Signed-off-by: Alice Ryhl <alic...@google.com>
---

Changes in v2:
- Drop the first patch for -Zsanitizer-recover, and mention why in
commit message for remaining patch.
- Pick up tags.
- Link to v1: https://lore.kernel.org/r/20260325-kasan-rust-sw...@google.com

---
init/Kconfig | 2 +-
scripts/Makefile.kasan | 2 --
2 files changed, 1 insertion(+), 3 deletions(-)

diff --git a/init/Kconfig b/init/Kconfig
index 444ce811ea67..545cbe889a52 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -2179,7 +2179,7 @@ config RUST
depends on !CFI || HAVE_CFI_ICALL_NORMALIZE_INTEGERS_RUSTC
select CFI_ICALL_NORMALIZE_INTEGERS if CFI
depends on !CALL_PADDING || RUSTC_VERSION >= 108100
- depends on !KASAN_SW_TAGS
+ depends on !KASAN_SW_TAGS || RUSTC_VERSION >= 109600
depends on !(MITIGATION_RETHUNK && KASAN) || RUSTC_VERSION >= 108300
help
Enables Rust support in the kernel.
diff --git a/scripts/Makefile.kasan b/scripts/Makefile.kasan

index 0ba2aac3b8dc..91504e81247a 100644
--- a/scripts/Makefile.kasan
+++ b/scripts/Makefile.kasan
@@ -71,8 +71,6 @@ ifdef CONFIG_KASAN_SW_TAGS

CFLAGS_KASAN := -fsanitize=kernel-hwaddress

-# This sets flags that will enable SW_TAGS KASAN once enabled in Rust. These
-# will not work today, and is guarded against in dependencies for CONFIG_RUST.

RUSTFLAGS_KASAN := -Zsanitizer=kernel-hwaddress \
-Zsanitizer-recover=kernel-hwaddress

[Alice Ryhl]

Sashiko is asking what happens when GCC is enabled. I think we just
don't want this enabled together with GCC. Miguel how do we usually
handle such cases? I imagine we have quite a few options that are
probably not compatible with gcc, but I'm not sure we explicitly list
all those cases in Kconfig.

Alice

[Miguel Ojeda]

On Wed, Apr 1, 2026 at 11:13 AM Alice Ryhl <alic...@google.com> wrote:
>
> Sashiko is asking what happens when GCC is enabled. I think we just
> don't want this enabled together with GCC. Miguel how do we usually
> handle such cases? I imagine we have quite a few options that are
> probably not compatible with gcc, but I'm not sure we explicitly list
> all those cases in Kconfig.

For options where it is """OK""" to drop them, one can use the
`bindgen_skip_c_flags` hack in `rust/Makefile` (which is best-effort,
and which we eventually should not have when proper GCC support is
added).

We have `--param=% --param asan-%` there, but to be honest, for things
like that, we may just want to gate it with a `depends on CC_IS_*`
instead.

Cheers,
Miguel