kernel/linux.git/init/Kconfig, branch v6.1.104

rust: SHADOW_CALL_STACK is incompatible with Rust

2024-08-11T10:35:59+00:00

commit f126745da81783fb1d082e67bf14c6795e489a88 upstream. When using the shadow call stack sanitizer, all code must be compiled with the -ffixed-x18 flag, but this flag is not currently being passed to Rust. This results in crashes that are extremely difficult to debug. To ensure that nobody else has to go through the same debugging session that I had to, prevent configurations that enable both SHADOW_CALL_STACK and RUST. It is rather common for people to backport 724a75ac9542 ("arm64: rust: Enable Rust support for AArch64"), so I recommend applying this fix all the way back to 6.1. Cc: stable@vger.kernel.org # 6.1 and later Fixes: 724a75ac9542 ("arm64: rust: Enable Rust support for AArch64") Signed-off-by: Alice Ryhl Acked-by: Miguel Ojeda Link: https://lore.kernel.org/r/20240729-shadow-call-stack-v4-1-2a664b082ea4@google.com Signed-off-by: Catalin Marinas Signed-off-by: Greg Kroah-Hartman

rust: make mutually exclusive with CFI_CLANG

2024-05-02T14:29:27+00:00

commit 8933cf4651e02853ca679be7b2d978dfcdcc5e0c upstream. On RISC-V and arm64, and presumably x86, if CFI_CLANG is enabled, loading a rust module will trigger a kernel panic. Support for sanitisers, including kcfi (CFI_CLANG), is in the works, but for now they're nightly-only options in rustc. Make RUST depend on !CFI_CLANG to prevent configuring a kernel without symmetrical support for kfi. [ Matthew Maurer writes [1]: This patch is fine by me - the last patch needed for KCFI to be functional in Rust just landed upstream last night, so we should revisit this (in the form of enabling it) once we move to `rustc-1.79.0` or later. Ramon de C Valle also gave feedback [2] on the status of KCFI for Rust and created a tracking issue [3] in upstream Rust. - Miguel ] Fixes: 2f7ab1267dc9 ("Kbuild: add Rust support") Cc: stable@vger.kernel.org Signed-off-by: Conor Dooley Acked-by: Nathan Chancellor Link: https://lore.kernel.org/rust-for-linux/CAGSQo024u1gHJgzsO38Xg3c4or+JupoPABQx_+0BLEpPg0cOEA@mail.gmail.com/ [1] Link: https://lore.kernel.org/rust-for-linux/CAOcBZOS2kPyH0Dm7Fuh4GC3=v7nZhyzBj_-dKu3PfAnrHZvaxg@mail.gmail.com/ [2] Link: https://github.com/rust-lang/rust/issues/123479 [3] Link: https://lore.kernel.org/r/20240404-providing-emporium-e652e359c711@spud [ Added feedback from the list, links, and used Cc for the tag. ] Signed-off-by: Miguel Ojeda Signed-off-by: Greg Kroah-Hartman

rust: don't select CONSTRUCTORS

2024-05-02T14:29:27+00:00

commit 7d49f53af4b988b188d3932deac2c9c80fd7d9ce upstream. This was originally part of commit 4b9a68f2e59a0 ("rust: add support for static synchronisation primitives") from the old Rust branch, which used module constructors to initialize globals containing various synchronisation primitives with pin-init. That commit has never been upstreamed, but the `select CONSTRUCTORS` statement ended up being included in the patch that initially added Rust support to the Linux Kernel. We are not using module constructors, so let's remove the select. Signed-off-by: Alice Ryhl Reviewed-by: Benno Lossin Cc: stable@vger.kernel.org Fixes: 2f7ab1267dc9 ("Kbuild: add Rust support") Link: https://lore.kernel.org/r/20240308-constructors-v1-1-4c811342391c@google.com Signed-off-by: Miguel Ojeda Signed-off-by: Greg Kroah-Hartman

init/Kconfig: lower GCC version check for -Warray-bounds

2024-04-03T13:19:40+00:00

commit 3e00f5802fabf2f504070a591b14b648523ede13 upstream. We continue to see false positives from -Warray-bounds even in GCC 10, which is getting reported in a few places[1] still: security/security.c:811:2: warning: `memcpy' offset 32 is out of the bounds [0, 0] [-Warray-bounds] Lower the GCC version check from 11 to 10. Link: https://lkml.kernel.org/r/20240223170824.work.768-kees@kernel.org Reported-by: Lu Yao Closes: https://lore.kernel.org/lkml/20240117014541.8887-1-yaolu@kylinos.cn/ Link: https://lore.kernel.org/linux-next/65d84438.620a0220.7d171.81a7@mx.google.com [1] Signed-off-by: Kees Cook Reviewed-by: Paul Moore Cc: Ard Biesheuvel Cc: Christophe Leroy Cc: Greg Kroah-Hartman Cc: "Gustavo A. R. Silva" Cc: Johannes Weiner Cc: Marc Aurèle La France Cc: Masahiro Yamada Cc: Nathan Chancellor Cc: Nhat Pham Cc: Petr Mladek Cc: Randy Dunlap Cc: Suren Baghdasaryan Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

update workarounds for gcc "asm goto" issue

2024-02-23T08:12:28+00:00

commit 68fb3ca0e408e00db1c3f8fccdfa19e274c033be upstream. In commit 4356e9f841f7 ("work around gcc bugs with 'asm goto' with outputs") I did the gcc workaround unconditionally, because the cause of the bad code generation wasn't entirely clear. In the meantime, Jakub Jelinek debugged the issue, and has come up with a fix in gcc [2], which also got backported to the still maintained branches of gcc-11, gcc-12 and gcc-13. Note that while the fix technically wasn't in the original gcc-14 branch, Jakub says: "while it is true that no GCC 14 snapshots until today (or whenever the fix will be committed) have the fix, for GCC trunk it is up to the distros to use the latest snapshot if they use it at all and would allow better testing of the kernel code without the workaround, so that if there are other issues they won't be discovered years later. Most userland code doesn't actually use asm goto with outputs..." so we will consider gcc-14 to be fixed - if somebody is using gcc snapshots of the gcc-14 before the fix, they should upgrade. Note that while the bug goes back to gcc-11, in practice other gcc changes seem to have effectively hidden it since gcc-12.1 as per a bisect by Jakub. So even a gcc-14 snapshot without the fix likely doesn't show actual problems. Also, make the default 'asm_goto_output()' macro mark the asm as volatile by hand, because of an unrelated gcc issue [1] where it doesn't match the documented behavior ("asm goto is always volatile"). Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103979 [1] Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113921 [2] Link: https://lore.kernel.org/all/20240208220604.140859-1-seanjc@google.com/ Requested-by: Jakub Jelinek Cc: Uros Bizjak Cc: Nick Desaulniers Cc: Sean Christopherson Cc: Andrew Pinski Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

btf, scripts: Exclude Rust CUs with pahole

2024-01-20T10:50:10+00:00

commit c1177979af9c616661a126a80dd486ad0543b836 upstream. Version 1.24 of pahole has the capability to exclude compilation units (CUs) of specific languages [1] [2]. Rust, as of writing, is not currently supported by pahole and if it's used with a build that has BTF debugging enabled it results in malformed kernel and module binaries [3]. So it's better for pahole to exclude Rust CUs until support for it arrives. Co-developed-by: Eric Curtin Signed-off-by: Eric Curtin Signed-off-by: Martin Rodriguez Reboredo Signed-off-by: Daniel Borkmann Tested-by: Eric Curtin Reviewed-by: Neal Gompa Acked-by: Miguel Ojeda Acked-by: Arnaldo Carvalho de Melo Link: https://git.kernel.org/pub/scm/devel/pahole/pahole.git/commit/?id=49358dfe2aaae4e90b072332c3e324019826783f [1] Link: https://git.kernel.org/pub/scm/devel/pahole/pahole.git/commit/?id=8ee363790b7437283c53090a85a9fec2f0b0fbc4 [2] Link: https://github.com/Rust-for-Linux/linux/issues/735 [3] Link: https://lore.kernel.org/bpf/20230111152050.559334-1-yakoyoku@gmail.com Signed-off-by: Jiri Olsa Signed-off-by: Greg Kroah-Hartman

sched/psi: Select KERNFS as needed

2023-09-13T07:42:28+00:00

[ Upstream commit 98dfdd9ee93995a408192dbbf3dd219ba23e3738 ] Users of KERNFS should select it to enforce its being built, so do this to prevent a build error. In file included from ../kernel/sched/build_utility.c:97: ../kernel/sched/psi.c: In function 'psi_trigger_poll': ../kernel/sched/psi.c:1479:17: error: implicit declaration of function 'kernfs_generic_poll' [-Werror=implicit-function-declaration] 1479 | kernfs_generic_poll(t->of, wait); Fixes: aff037078eca ("sched/psi: use kernfs polling functions for PSI trigger polling") Reported-by: kernel test robot Signed-off-by: Randy Dunlap Signed-off-by: Peter Zijlstra (Intel) Acked-by: Suren Baghdasaryan Link: lore.kernel.org/r/202307310732.r65EQFY0-lkp@intel.com Signed-off-by: Sasha Levin

gcc: disable '-Warray-bounds' for gcc-13 too

2023-04-26T12:28:43+00:00

commit 0da6e5fd6c3726723e275603426e09178940dace upstream. We started disabling '-Warray-bounds' for gcc-12 originally on s390, because it resulted in some warnings that weren't realistically fixable (commit 8b202ee21839: "s390: disable -Warray-bounds"). That s390-specific issue was then found to be less common elsewhere, but generic (see f0be87c42cbd: "gcc-12: disable '-Warray-bounds' universally for now"), and then later expanded the version check was expanded to gcc-11 (5a41237ad1d4: "gcc: disable -Warray-bounds for gcc-11 too"). And it turns out that I was much too optimistic in thinking that it's all going to go away, and here we are with gcc-13 showing all the same issues. So instead of expanding this one version at a time, let's just disable it for gcc-11+, and put an end limit to it only when we actually find a solution. Yes, I'm sure some of this is because the kernel just does odd things (like our "container_of()" use, but also knowingly playing games with things like linker tables and array layouts). And yes, some of the warnings are likely signs of real bugs, but when there are hundreds of false positives, that doesn't really help. Oh well. Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

gcc: disable -Warray-bounds for gcc-11 too

2023-01-14T09:33:43+00:00

commit 5a41237ad1d4b62008f93163af1d9b1da90729d8 upstream. We had already disabled this warning for gcc-12 due to bugs in the value range analysis, but it turns out we end up having some similar problems with gcc-11.3 too, so let's disable it there too. Older gcc versions end up being increasingly less relevant, and hopefully clang and newer version of gcc (ie gcc-13) end up working reliably enough that we still get the build coverage even when we disable this for some versions. Link: https://lore.kernel.org/all/20221227002941.GA2691687@roeck-us.net/ Link: https://lore.kernel.org/all/D8BDBF66-E44C-45D4-9758-BAAA4F0C1998@kernel.org/ Cc: Kees Cook Cc: Vlastimil Babka Cc: Guenter Roeck Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

init/Kconfig: fix CC_HAS_ASM_GOTO_TIED_OUTPUT test with dash

2022-11-22T13:42:38+00:00

When using dash as /bin/sh, the CC_HAS_ASM_GOTO_TIED_OUTPUT test fails with a syntax error which is not the one we are looking for: : In function ‘foo’: :1:29: warning: missing terminating " character :1:29: error: missing terminating " character :2:5: error: expected ‘:’ before ‘+’ token :2:7: warning: missing terminating " character :2:7: error: missing terminating " character :2:5: error: expected declaration or statement at end of input Removing '\n' solves this. Fixes: 1aa0e8b144b6 ("Kconfig: Add option for asm goto w/ tied outputs to workaround clang-13 bug") Signed-off-by: Alexandre Belloni Reviewed-by: Sean Christopherson Signed-off-by: Masahiro Yamada