kernel/linux.git/tools/objtool/noreturns.h, branch v6.12.80

objtool: Add bch2_trans_unlocked_error() to bcachefs noreturns

2025-01-02T09:34:21+00:00

[ Upstream commit 31ad36a271290648e7c2288a03d7b933d20254d6 ] Fix the following objtool warning during build time: fs/bcachefs/btree_trans_commit.o: warning: objtool: bch2_trans_commit_write_locked.isra.0() falls through to next function do_bch2_trans_commit.isra.0() fs/bcachefs/btree_trans_commit.o: warning: objtool: .text: unexpected end of section ...... fs/bcachefs/btree_update.o: warning: objtool: bch2_trans_update_get_key_cache() falls through to next function flush_new_cached_update() fs/bcachefs/btree_update.o: warning: objtool: flush_new_cached_update() falls through to next function bch2_trans_update_by_path() bch2_trans_unlocked_error() is an Obviously Correct (tm) panic() wrapper, add it to the list of known noreturns. [ mingo: Improved the changelog ] Fixes: fd104e2967b7 ("bcachefs: bch2_trans_verify_not_unlocked()") Signed-off-by: chenchangcheng Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Link: https://lkml.kernel.org/r/20241220074847.3418134-1-ccc194101@163.com Signed-off-by: Sasha Levin

objtool/rust: list `noreturn` Rust functions

2024-08-18T21:34:37+00:00

Rust functions may be `noreturn` (i.e. diverging) by returning the "never" type, `!`, e.g. fn f() -> ! { loop {} } Thus list the known `noreturn` functions to avoid such warnings. Without this, `objtool` would complain if enabled for Rust, e.g.: rust/core.o: warning: objtool: _R...9panic_fmt() falls through to next function _R...18panic_nounwind_fmt() rust/alloc.o: warning: objtool: .text: unexpected end of section In order to do so, we cannot match symbols' names exactly, for two reasons: - Rust mangling scheme [1] contains disambiguators [2] which we cannot predict (e.g. they may vary depending on the compiler version). One possibility to solve this would be to parse v0 and ignore/zero those before comparison. - Some of the diverging functions come from `core`, i.e. the Rust standard library, which may change with each compiler version since they are implementation details (e.g. `panic_internals`). Thus, to workaround both issues, only part of the symbols are matched, instead of using the `NORETURN` macro in `noreturns.h`. Ideally, just like for the C side, we should have a better solution. For instance, the compiler could give us the list via something like: $ rustc --emit=noreturns ... [ Kees agrees this should be automated and Peter says: So it would be fairly simple to make objtool consume a magic section emitted by the compiler.. I think we've asked the compiler folks for that at some point even, but I don't have clear recollections. We will ask upstream Rust about it. And if they agree, then perhaps we can get Clang/GCC to implement something similar too -- for this sort of thing we can take advantage of the shorter cycles of `rustc` as well as their unstable features concept to experiment. Gary proposed using DWARF (though it would need to be available), and wrote a proof of concept script using the `object` and `gimli` crates: https://gist.github.com/nbdd0121/449692570622c2f46a29ad9f47c3379a - Miguel ] Link: https://rust-lang.github.io/rfcs/2603-rust-symbol-name-mangling-v0.html [1] Link: https://doc.rust-lang.org/rustc/symbol-mangling/v0.html#disambiguator [2] Acked-by: Peter Zijlstra (Intel) Tested-by: Alice Ryhl Reviewed-by: Kees Cook Tested-by: Benno Lossin Link: https://lore.kernel.org/r/20240725183325.122827-6-ojeda@kernel.org [ Added `len_mismatch_fail` symbol for new `kernel` crate code merged since then as well as 3 more `core::panicking` symbols that appear in `RUST_DEBUG_ASSERTIONS=y` builds. - Miguel ] Signed-off-by: Miguel Ojeda

x86/syscall: Mark exit[_group] syscall handlers __noreturn

2024-06-28T13:23:38+00:00

The direct-call syscall dispatch function doesn't know that the exit() and exit_group() syscall handlers don't return, so the call sites aren't optimized accordingly. Fix that by marking the exit syscall declarations __noreturn. Fixes the following warnings: vmlinux.o: warning: objtool: x64_sys_call+0x2804: __x64_sys_exit() is missing a __noreturn annotation vmlinux.o: warning: objtool: ia32_sys_call+0x29b6: __ia32_sys_exit_group() is missing a __noreturn annotation Fixes: 1e3ad78334a6 ("x86/syscall: Don't force use of indirect calls for system calls") Closes: https://lkml.kernel.org/lkml/6dba9b32-db2c-4e6d-9500-7a08852f17a3@paulmck-laptop Reported-by: Paul E. McKenney Signed-off-by: Josh Poimboeuf Signed-off-by: Borislav Petkov (AMD) Tested-by: Paul E. McKenney Link: https://lore.kernel.org/r/5d8882bc077d8eadcc7fd1740b56dfb781f12288.1719381528.git.jpoimboe@kernel.org

Merge tag 'mm-nonmm-stable-2024-03-14-09-36' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2024-03-15T01:03:09+00:00

Pull non-MM updates from Andrew Morton: - Kuan-Wei Chiu has developed the well-named series "lib min_heap: Min heap optimizations". - Kuan-Wei Chiu has also sped up the library sorting code in the series "lib/sort: Optimize the number of swaps and comparisons". - Alexey Gladkov has added the ability for code running within an IPC namespace to alter its IPC and MQ limits. The series is "Allow to change ipc/mq sysctls inside ipc namespace". - Geert Uytterhoeven has contributed some dhrystone maintenance work in the series "lib: dhry: miscellaneous cleanups". - Ryusuke Konishi continues nilfs2 maintenance work in the series "nilfs2: eliminate kmap and kmap_atomic calls" "nilfs2: fix kernel bug at submit_bh_wbc()" - Nathan Chancellor has updated our build tools requirements in the series "Bump the minimum supported version of LLVM to 13.0.1". - Muhammad Usama Anjum continues with the selftests maintenance work in the series "selftests/mm: Improve run_vmtests.sh". - Oleg Nesterov has done some maintenance work against the signal code in the series "get_signal: minor cleanups and fix". Plus the usual shower of singleton patches in various parts of the tree. Please see the individual changelogs for details. * tag 'mm-nonmm-stable-2024-03-14-09-36' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (77 commits) nilfs2: prevent kernel bug at submit_bh_wbc() nilfs2: fix failure to detect DAT corruption in btree and direct mappings ocfs2: enable ocfs2_listxattr for special files ocfs2: remove SLAB_MEM_SPREAD flag usage assoc_array: fix the return value in assoc_array_insert_mid_shortcut() buildid: use kmap_local_page() watchdog/core: remove sysctl handlers from public header nilfs2: use div64_ul() instead of do_div() mul_u64_u64_div_u64: increase precision by conditionally swapping a and b kexec: copy only happens before uchunk goes to zero get_signal: don't initialize ksig->info if SIGNAL_GROUP_EXIT/group_exec_task get_signal: hide_si_addr_tag_bits: fix the usage of uninitialized ksig get_signal: don't abuse ksig->info.si_signo and ksig->sig const_structs.checkpatch: add device_type Normalise "name (ad@dr)" MODULE_AUTHORs to "name " dyndbg: replace kstrdup() + strchr() with kstrdup_and_replace() list: leverage list_is_head() for list_entry_is_head() nilfs2: MAINTAINERS: drop unreachable project mirror site smp: make __smp_processor_id() 0-argument macro fat: fix uninitialized field in nostale filehandles ...

fortify: Split reporting and avoid passing string pointer

2024-02-29T21:38:02+00:00

In preparation for KUnit testing and further improvements in fortify failure reporting, split out the report and encode the function and access failure (read or write overflow) into a single u8 argument. This mainly ends up saving a tiny bit of space in the data segment. For a defconfig with FORTIFY_SOURCE enabled: $ size gcc/vmlinux.before gcc/vmlinux.after text data bss dec hex filename 26132309 9760658 2195460 38088427 2452eeb gcc/vmlinux.before 26132386 9748382 2195460 38076228 244ff44 gcc/vmlinux.after Reviewed-by: Alexander Lobakin Signed-off-by: Kees Cook

init: remove obsolete arch_call_rest_init() wrapper

2024-02-22T23:38:55+00:00

Since commit 3570ee046c46b5dc ("s390/smp: keep the original lowcore for CPU 0"), there is no longer any architecture that needs to override arch_call_rest_init(). Remove the weak wrapper around rest_init(), call rest_init() directly, and make rest_init() static. Link: https://lkml.kernel.org/r/aa10868bfb176eef4abb8bb4a710b85330792694.1706106183.git.geert@linux-m68k.org Signed-off-by: Geert Uytterhoeven Cc: Arnd Bergmann Cc: Ilya Leoshkevich Cc: Josh Poimboeuf Cc: Peter Zijlstra Signed-off-by: Andrew Morton

cred: get rid of CONFIG_DEBUG_CREDENTIALS

2023-12-15T22:19:48+00:00

This code is rarely (never?) enabled by distros, and it hasn't caught anything in decades. Let's kill off this legacy debug code. Suggested-by: Linus Torvalds Signed-off-by: Jens Axboe Signed-off-by: Linus Torvalds

Merge tag 'x86_tdx_for_6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2023-11-01T20:28:32+00:00

Pull x86 TDX updates from Dave Hansen: "The majority of this is a rework of the assembly and C wrappers that are used to talk to the TDX module and VMM. This is a nice cleanup in general but is also clearing the way for using this code when Linux is the TDX VMM. There are also some tidbits to make TDX guests play nicer with Hyper-V and to take advantage the hardware TSC. Summary: - Refactor and clean up TDX hypercall/module call infrastructure - Handle retrying/resuming page conversion hypercalls - Make sure to use the (shockingly) reliable TSC in TDX guests" [ TLA reminder: TDX is "Trust Domain Extensions", Intel's guest VM confidentiality technology ] * tag 'x86_tdx_for_6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/tdx: Mark TSC reliable x86/tdx: Fix __noreturn build warning around __tdx_hypercall_failed() x86/virt/tdx: Make TDX_MODULE_CALL handle SEAMCALL #UD and #GP x86/virt/tdx: Wire up basic SEAMCALL functions x86/tdx: Remove 'struct tdx_hypercall_args' x86/tdx: Reimplement __tdx_hypercall() using TDX_MODULE_CALL asm x86/tdx: Make TDX_HYPERCALL asm similar to TDX_MODULE_CALL x86/tdx: Extend TDX_MODULE_CALL to support more TDCALL/SEAMCALL leafs x86/tdx: Pass TDCALL/SEAMCALL input/output registers via a structure x86/tdx: Rename __tdx_module_call() to __tdcall() x86/tdx: Make macros of TDCALLs consistent with the spec x86/tdx: Skip saving output regs when SEAMCALL fails with VMFailInvalid x86/tdx: Zero out the missing RSI in TDX_HYPERCALL macro x86/tdx: Retry partially-completed page conversion hypercalls

objtool: Add bcachefs noreturns

2023-10-19T18:58:29+00:00

Signed-off-by: Kent Overstreet

x86/tdx: Fix noreturn build warning around tdx_hypercall_failed()

2023-09-18T07:11:39+00:00

LKP reported below build warning: vmlinux.o: warning: objtool: __tdx_hypercall+0x128: __tdx_hypercall_failed() is missing a __noreturn annotation The __tdx_hypercall_failed() function definition already has __noreturn annotation, but it turns out the __noreturn must be annotated to the function declaration. PeterZ explains: "FWIW, the reason being that... The point of noreturn is that the caller should know to stop generating code. For that the declaration needs the attribute, because call sites typically do not have access to the function definition in C." Add __noreturn annotation to the declaration of __tdx_hypercall_failed() to fix. It's not a bad idea to document the __noreturn nature at the definition site either, so keep the annotation at the definition. Note is also included by TDX related assembly files. Include only in case of !__ASSEMBLY__ otherwise compiling assembly file would trigger build error. Also, following the objtool documentation, add __tdx_hypercall_failed() to "tools/objtool/noreturns.h". Fixes: c641cfb5c157 ("x86/tdx: Make TDX_HYPERCALL asm similar to TDX_MODULE_CALL") Reported-by: kernel test robot Signed-off-by: Kai Huang Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20230918041858.331234-1-kai.huang@intel.com Closes: https://lore.kernel.org/oe-kbuild-all/202309140828.9RdmlH2Z-lkp@intel.com/