user/sven/linux.git/init, branch v6.12.28

sched/isolation: Make CONFIG_CPU_ISOLATION depend on CONFIG_SMP

2025-05-02T05:59:21Z

[ Upstream commit 975776841e689dd8ba36df9fa72ac3eca3c2957a ] kernel/sched/isolation.c obviously makes no sense without CONFIG_SMP, but the Kconfig entry we have right now: config CPU_ISOLATION bool "CPU isolation" depends on SMP || COMPILE_TEST allows the creation of pointless .config's which cause build failures. Reported-by: kernel test robot Signed-off-by: Oleg Nesterov Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20250330134955.GA7910@redhat.com Closes: https://lore.kernel.org/oe-kbuild-all/202503260646.lrUqD3j5-lkp@intel.com/ Signed-off-by: Sasha Levin

ARM: 9443/1: Require linker to support KEEP within OVERLAY for DCE

2025-04-10T12:39:40Z

commit e7607f7d6d81af71dcc5171278aadccc94d277cd upstream. ld.lld prior to 21.0.0 does not support using the KEEP keyword within an overlay description, which may be needed to avoid discarding necessary sections within an overlay with '--gc-sections', which can be enabled for the kernel via CONFIG_LD_DEAD_CODE_DATA_ELIMINATION. Disallow CONFIG_LD_DEAD_CODE_DATA_ELIMINATION without support for KEEP within OVERLAY and introduce a macro, OVERLAY_KEEP, that can be used to conditionally add KEEP when it is properly supported to avoid breaking old versions of ld.lld. Cc: stable@vger.kernel.org Link: https://github.com/llvm/llvm-project/commit/381599f1fe973afad3094e55ec99b1620dba7d8c Reviewed-by: Linus Walleij Signed-off-by: Nathan Chancellor Signed-off-by: Russell King (Oracle) [nathan: Fix conflict in init/Kconfig due to lack of RUSTC symbols] Signed-off-by: Nathan Chancellor Signed-off-by: Greg Kroah-Hartman

rust: Disallow BTF generation with Rust + LTO

2025-03-22T19:54:23Z

commit 5daa0c35a1f0e7a6c3b8ba9cb721e7d1ace6e619 upstream. The kernel cannot currently self-parse BTF containing Rust debug information. pahole uses the language of the CU to determine whether to filter out debug information when generating the BTF. When LTO is enabled, Rust code can cross CU boundaries, resulting in Rust debug information in CUs labeled as C. This results in a system which cannot parse its own BTF. Signed-off-by: Matthew Maurer Cc: stable@vger.kernel.org Fixes: c1177979af9c ("btf, scripts: Exclude Rust CUs with pahole") Link: https://lore.kernel.org/r/20250108-rust-btf-lto-incompat-v1-1-60243ff6d820@google.com Signed-off-by: Miguel Ojeda Signed-off-by: Greg Kroah-Hartman

Compiler Attributes: disable __counted_by for clang < 19.1.3

2024-12-05T13:02:45Z

commit f06e108a3dc53c0f5234d18de0bd224753db5019 upstream. This patch disables __counted_by for clang versions < 19.1.3 because of the two issues listed below. It does this by introducing CONFIG_CC_HAS_COUNTED_BY. 1. clang < 19.1.2 has a bug that can lead to __bdos returning 0: https://github.com/llvm/llvm-project/pull/110497 2. clang < 19.1.3 has a bug that can lead to __bdos being off by 4: https://github.com/llvm/llvm-project/pull/112636 Fixes: c8248faf3ca2 ("Compiler Attributes: counted_by: Adjust name and identifier expansion") Cc: stable@vger.kernel.org # 6.6.x: 16c31dd7fdf6: Compiler Attributes: counted_by: bump min gcc version Cc: stable@vger.kernel.org # 6.6.x: 2993eb7a8d34: Compiler Attributes: counted_by: fixup clang URL Cc: stable@vger.kernel.org # 6.6.x: 231dc3f0c936: lkdtm/bugs: Improve warning message for compilers without counted_by support Cc: stable@vger.kernel.org # 6.6.x Reported-by: Nathan Chancellor Closes: https://lore.kernel.org/all/20240913164630.GA4091534@thelio-3990X/ Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-lkp/202409260949.a1254989-oliver.sang@intel.com Link: https://lore.kernel.org/all/Zw8iawAF5W2uzGuh@archlinux/T/#m204c09f63c076586a02d194b87dffc7e81b8de7b Suggested-by: Nathan Chancellor Signed-off-by: Jan Hendrik Farr Reviewed-by: Nathan Chancellor Tested-by: Nathan Chancellor Reviewed-by: Miguel Ojeda Reviewed-by: Thorsten Blum Link: https://lore.kernel.org/r/20241029140036.577804-2-kernel@jfarr.cc Signed-off-by: Kees Cook Signed-off-by: Greg Kroah-Hartman

initramfs: avoid filename buffer overrun

2024-12-05T13:01:12Z

[ Upstream commit e017671f534dd3f568db9e47b0583e853d2da9b5 ] The initramfs filename field is defined in Documentation/driver-api/early-userspace/buffer-format.rst as: 37 cpio_file := ALGN(4) + cpio_header + filename + "\0" + ALGN(4) + data ... 55 ============= ================== ========================= 56 Field name Field size Meaning 57 ============= ================== ========================= ... 70 c_namesize 8 bytes Length of filename, including final \0 When extracting an initramfs cpio archive, the kernel's do_name() path handler assumes a zero-terminated path at @collected, passing it directly to filp_open() / init_mkdir() / init_mknod(). If a specially crafted cpio entry carries a non-zero-terminated filename and is followed by uninitialized memory, then a file may be created with trailing characters that represent the uninitialized memory. The ability to create an initramfs entry would imply already having full control of the system, so the buffer overrun shouldn't be considered a security vulnerability. Append the output of the following bash script to an existing initramfs and observe any created /initramfs_test_fname_overrunAA* path. E.g. ./reproducer.sh | gzip >> /myinitramfs It's easiest to observe non-zero uninitialized memory when the output is gzipped, as it'll overflow the heap allocated @out_buf in __gunzip(), rather than the initrd_start+initrd_size block. ---- reproducer.sh ---- nilchar="A" # change to "\0" to properly zero terminate / pad magic="070701" ino=1 mode=$(( 0100777 )) uid=0 gid=0 nlink=1 mtime=1 filesize=0 devmajor=0 devminor=1 rdevmajor=0 rdevminor=0 csum=0 fname="initramfs_test_fname_overrun" namelen=$(( ${#fname} + 1 )) # plus one to account for terminator printf "%s%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%s" \ $magic $ino $mode $uid $gid $nlink $mtime $filesize \ $devmajor $devminor $rdevmajor $rdevminor $namelen $csum $fname termpadlen=$(( 1 + ((4 - ((110 + $namelen) & 3)) % 4) )) printf "%.s${nilchar}" $(seq 1 $termpadlen) ---- reproducer.sh ---- Symlink filename fields handled in do_symlink() won't overrun past the data segment, due to the explicit zero-termination of the symlink target. Fix filename buffer overrun by aborting the initramfs FSM if any cpio entry doesn't carry a zero-terminator at the expected (name_len - 1) offset. Fixes: 1da177e4c3f41 ("Linux-2.6.12-rc2") Signed-off-by: David Disseldorp Link: https://lore.kernel.org/r/20241030035509.20194-2-ddiss@suse.de Signed-off-by: Christian Brauner Signed-off-by: Sasha Levin

cfi: fix conditions for HAVE_CFI_ICALL_NORMALIZE_INTEGERS

2024-10-13T20:23:13Z

The HAVE_CFI_ICALL_NORMALIZE_INTEGERS option has some tricky conditions when KASAN or GCOV are turned on, as in that case we need some clang and rustc fixes [1][2] to avoid boot failures. The intent with the current setup is that you should be able to override the check and turn on the option if your clang/rustc has the fix. However, this override does not work in practice. Thus, use the new RUSTC_LLVM_VERSION to correctly implement the check for whether the fix is available. Additionally, remove KASAN_HW_TAGS from the list of incompatible options. The CFI_ICALL_NORMALIZE_INTEGERS option is incompatible with KASAN because LLVM will emit some constructors when using KASAN that are assigned incorrect CFI tags. These constructors are emitted due to use of -fsanitize=kernel-address or -fsanitize=kernel-hwaddress that are respectively passed when KASAN_GENERIC or KASAN_SW_TAGS are enabled. However, the KASAN_HW_TAGS option relies on hardware support for MTE instead and does not pass either flag. (Note also that KASAN_HW_TAGS does not `select CONSTRUCTORS`.) Link: https://github.com/llvm/llvm-project/pull/104826 [1] Link: https://github.com/rust-lang/rust/pull/129373 [2] Fixes: 4c66f8307ac0 ("cfi: encode cfi normalized integers + kasan/gcov bug in Kconfig") Signed-off-by: Alice Ryhl Reviewed-by: Sami Tolvanen Link: https://lore.kernel.org/r/20241010-icall-detect-vers-v1-2-8f114956aa88@google.com Signed-off-by: Miguel Ojeda

kbuild: rust: add `CONFIG_RUSTC_LLVM_VERSION`

2024-10-13T20:22:28Z

Each version of Rust supports a range of LLVM versions. There are cases where we want to gate a config on the LLVM version instead of the Rust version. Normalized cfi integer tags are one example [1]. The invocation of rustc-version is being moved from init/Kconfig to scripts/Kconfig.include for consistency with cc-version. Link: https://lore.kernel.org/all/20240925-cfi-norm-kasan-fix-v1-1-0328985cdf33@google.com/ [1] Signed-off-by: Gary Guo Link: https://lore.kernel.org/r/20241011114040.3900487-1-gary@garyguo.net [ Added missing `-llvm` to the Usage documentation. - Miguel ] Signed-off-by: Miguel Ojeda

cfi: encode cfi normalized integers + kasan/gcov bug in Kconfig

2024-09-26T19:27:27Z

There is a bug in the LLVM implementation of KASAN and GCOV that makes these options incompatible with the CFI_ICALL_NORMALIZE_INTEGERS option. The bug has already been fixed in llvm/clang [1] and rustc [2]. However, Kconfig currently has no way to gate features on the LLVM version inside rustc, so we cannot write down a precise `depends on` clause in this case. Instead, a `def_bool` option is defined for whether CFI_ICALL_NORMALIZE_INTEGERS is available, and its default value is set to false when GCOV or KASAN are turned on. End users using a patched clang/rustc can turn on the HAVE_CFI_ICALL_NORMALIZE_INTEGERS option directly to override this. An alternative solution is to inspect a binary created by clang or rustc to see whether the faulty CFI tags are in the binary. This would be a precise check, but it would involve hard-coding the *hashed* version of the CFI tag. This is because there's no way to get clang or rustc to output the unhased version of the CFI tag. Relying on the precise hashing algorithm using by CFI seems too fragile, so I have not pursued this option. Besides, this kind of hack is exactly what lead to the LLVM bug in the first place. If the CFI_ICALL_NORMALIZE_INTEGERS option is used without CONFIG_RUST, then we actually can perform a precise check today: just compare the clang version number. This works since clang and llvm are always updated in lockstep. However, encoding this in Kconfig would give the HAVE_CFI_ICALL_NORMALIZE_INTEGERS option a dependency on CONFIG_RUST, which is not possible as the reverse dependency already exists. HAVE_CFI_ICALL_NORMALIZE_INTEGERS is defined to be a `def_bool` instead of `bool` to avoid asking end users whether they want to turn on the option. Turning it on explicitly is something only experts should do, so making it hard to do so is not an issue. I added a `depends on CFI_CLANG` clause to the new Kconfig option. I'm not sure whether that makes sense or not, but it doesn't seem to make a big difference. In a future kernel release, I would like to add a Kconfig option similar to CLANG_VERSION/RUSTC_VERSION for inspecting the version of the LLVM inside rustc. Once that feature lands, this logic will be replaced with a precise version check. This check is not being introduced here to avoid introducing a new _VERSION constant in a fix. Link: https://github.com/llvm/llvm-project/pull/104826 [1] Link: https://github.com/rust-lang/rust/pull/129373 [2] Fixes: ce4a2620985c ("cfi: add CONFIG_CFI_ICALL_NORMALIZE_INTEGERS") Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-lkp/202409231044.4f064459-oliver.sang@intel.com Signed-off-by: Alice Ryhl Reviewed-by: Sami Tolvanen Link: https://lore.kernel.org/r/20240925-cfi-norm-kasan-fix-v1-1-0328985cdf33@google.com Signed-off-by: Miguel Ojeda

rust: KASAN+RETHUNK requires rustc 1.83.0

2024-09-26T19:27:27Z

When enabling both KASAN and RETHUNK, objtool emits the following warnings: rust/core.o: warning: objtool: asan.module_ctor+0x13: 'naked' return found in MITIGATION_RETHUNK build rust/core.o: warning: objtool: asan.module_dtor+0x13: 'naked' return found in MITIGATION_RETHUNK build This is caused by the -Zfunction-return=thunk-extern flag in rustc not informing LLVM about the mitigation at the module level (it does so at the function level only currently, which covers most cases, but both are required), which means that the KASAN functions asan.module_ctor and asan.module_dtor are generated without the rethunk mitigation. The other mitigations that we enabled for Rust (SLS, RETPOLINE) do not have the same bug, as they're being applied through the target-feature functionality instead. This is being fixed for rustc 1.83.0, so update Kconfig to reject this configuration on older compilers. Link: https://github.com/rust-lang/rust/pull/130824 Fixes: d7868550d573 ("x86/rust: support MITIGATION_RETHUNK") Reported-by: Miguel Ojeda Closes: https://lore.kernel.org/all/CANiq72myZL4_poCMuNFevtpYYc0V0embjSuKb7y=C+m3vVA_8g@mail.gmail.com/ Signed-off-by: Alice Ryhl Link: https://lore.kernel.org/r/20240926093849.1192264-1-aliceryhl@google.com [ Reworded to add the details mentioned in the list. - Miguel ] Signed-off-by: Miguel Ojeda

rust: cfi: fix `patchable-function-entry` starting version

2024-09-26T19:27:27Z

The `-Zpatchable-function-entry` flag is available since Rust 1.81.0, not Rust 1.80.0, i.e. commit ac7595fdb1ee ("Support for -Z patchable-function-entry") in upstream Rust. Fixes: ca627e636551 ("rust: cfi: add support for CFI_CLANG with Rust") Reviewed-by: Alice Ryhl Reviewed-by: Fiona Behrens Link: https://lore.kernel.org/r/20240925141944.277936-1-ojeda@kernel.org Signed-off-by: Miguel Ojeda