From: Josh Poimboeuf <jpoimboe@kernel.org>
To: x86@kernel.org
Cc: linux-kernel@vger.kernel.org,
Peter Zijlstra <peterz@infradead.org>,
Gary Guo <gary@garyguo.net>,
rust-for-linux@vger.kernel.org, Ard Biesheuvel <ardb@kernel.org>,
Miguel Ojeda <ojeda@kernel.org>,
Nathan Chancellor <nathan@kernel.org>,
Nicolas Schier <nsc@kernel.org>,
linux-kbuild@vger.kernel.org, Huacai Chen <chenhuacai@kernel.org>
Subject: [PATCH 06/27] objtool: Ignore traps after noreturn calls in STT_CODE
Date: Thu, 27 Aug 2026 21:51:35 -0700 [thread overview]
Message-ID: <44e198b8eb0f377b5e2c61cf6bb753d735201bd7.1787890035.git.jpoimboe@kernel.org> (raw)
In-Reply-To: <cover.1787890035.git.jpoimboe@kernel.org>
Objtool doesn't do unreachable warnings for traps after noreturn calls,
but only in functions. Loongarch assembly STT_CODE can have the same
pattern:
bl start_kernel
ASM_BUG()
Ignore those as well.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
tools/objtool/check.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 4528f017277d2..7333b0ed86818 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -4269,12 +4269,6 @@ static bool ignore_unreachable_insn(struct objtool_file *file, struct instructio
!strcmp(insn->sec->name, ".altinstr_aux"))
return true;
- if (!func)
- return false;
-
- if (func->static_call_tramp)
- return true;
-
/*
* CONFIG_UBSAN_TRAP inserts a UD2 when it sees
* __builtin_unreachable(). The BUG() macro has an unreachable() after
@@ -4290,6 +4284,12 @@ static bool ignore_unreachable_insn(struct objtool_file *file, struct instructio
insn->jump_dest && insn->jump_dest->type == INSN_BUG)))
return true;
+ if (!func)
+ return false;
+
+ if (func->static_call_tramp)
+ return true;
+
/*
* Check if this (or a subsequent) instruction is related to
* CONFIG_UBSAN or CONFIG_KASAN.
--
2.55.0
next prev parent reply other threads:[~2026-08-28 4:52 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-28 4:51 [PATCH 00/27] objtool: dynamically detect noreturns Josh Poimboeuf
2026-08-28 4:51 ` [PATCH 01/27] objtool: Remove obsolete noreturns.h entries Josh Poimboeuf
2026-08-28 4:51 ` [PATCH 02/27] kbuild: Add CONFIG_OBJTOOL_DEFERRED Josh Poimboeuf
2026-08-28 4:51 ` [PATCH 03/27] kbuild: Add CONFIG_OBJTOOL_CONTROL_FLOW Josh Poimboeuf
2026-08-28 4:51 ` [PATCH 04/27] objtool: Fix dead end detection for sibling calls Josh Poimboeuf
2026-08-28 4:51 ` [PATCH 05/27] objtool: Refactor the noreturn/dead-end detection Josh Poimboeuf
2026-08-28 4:51 ` Josh Poimboeuf [this message]
2026-08-28 4:51 ` [PATCH 07/27] objtool: Make .discard.stack_frame_non_standard non-allocatable Josh Poimboeuf
2026-08-28 4:51 ` [PATCH 08/27] efi/libstub: Drop .discard.addressable from the stub objects Josh Poimboeuf
2026-08-28 4:51 ` [PATCH 09/27] efi/loongarch: Mark loongarch efi_boot_kernel() non-standard for objtool Josh Poimboeuf
2026-08-28 4:51 ` [PATCH 10/27] objtool: Add ANNOTATE_IGNORE_NORETURN() Josh Poimboeuf
2026-08-28 4:51 ` [PATCH 11/27] LoongArch: Annotate reboot and kexec paths as returnable Josh Poimboeuf
2026-08-28 4:51 ` [PATCH 12/27] kbuild: Defer running objtool to link time for all CFG features Josh Poimboeuf
2026-08-28 17:57 ` Nathan Chancellor
2026-08-28 18:19 ` Josh Poimboeuf
2026-08-28 19:27 ` Nathan Chancellor
2026-08-28 4:51 ` [PATCH 13/27] rust: Annotate the intrinsic stubs as returnable Josh Poimboeuf
2026-08-28 4:51 ` [PATCH 14/27] panic: Mark abort() __noreturn Josh Poimboeuf
2026-08-28 4:51 ` [PATCH 15/27] x86/xen: Ignore noreturn status of weak mem_map_via_hcall() Josh Poimboeuf
2026-08-28 4:51 ` [PATCH 16/27] objtool: Detect noreturns in weak functions Josh Poimboeuf
2026-08-28 4:51 ` [PATCH 17/27] x86/entry: Make rewind_stack_and_make_dead() a real function Josh Poimboeuf
2026-08-28 4:51 ` [PATCH 18/27] x86/xen: Make xen_cpu_bringup_again() " Josh Poimboeuf
2026-08-28 4:51 ` [PATCH 19/27] x86/xen: Make xen_start_kernel() noreturn Josh Poimboeuf
2026-08-28 4:51 ` [PATCH 20/27] x86/boot: Rework how pi startup symbols get exposed to vmlinux Josh Poimboeuf
2026-08-28 4:51 ` [PATCH 21/27] objtool: Fix noreturn detection for non-sibling jumps to SYM_CODE Josh Poimboeuf
2026-08-28 4:51 ` [PATCH 22/27] objtool: Add options to write/read exported noreturns to/from a file Josh Poimboeuf
2026-08-28 4:51 ` [PATCH 23/27] kbuild: Do the per-module objtool pass right before linking Josh Poimboeuf
2026-08-28 4:51 ` [PATCH 24/27] kbuild: Generate the noreturn list and validate modules against it Josh Poimboeuf
2026-08-28 4:51 ` [PATCH 25/27] objtool: Add ANNOTATE_EXPORTED_NORETURN() Josh Poimboeuf
2026-08-28 4:51 ` [PATCH 26/27] objtool: Annotate all module-exported noreturns and remove noreturns.h Josh Poimboeuf
2026-08-28 4:51 ` [PATCH 27/27] objtool: Warn about missing/stale ANNOTATE_EXPORTED_NORETURN() usage Josh Poimboeuf
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