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 v2 03/27] kbuild: Add CONFIG_OBJTOOL_CONTROL_FLOW
Date: Tue, 8 Sep 2026 13:33:15 -0700 [thread overview]
Message-ID: <311f4e2f9aa6b2274e5a0758d5b8712874a86371.1788899473.git.jpoimboe@kernel.org> (raw)
In-Reply-To: <cover.1788899473.git.jpoimboe@kernel.org>
Add a config option for when objtool reverse engineers the control flow
graph of every function.
No functional change.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
lib/Kconfig.debug | 10 ++++++++--
lib/Kconfig.ubsan | 2 +-
2 files changed, 9 insertions(+), 3 deletions(-)
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 566e5be4c3f57..5e58671be8fbd 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -588,8 +588,14 @@ config NOINSTR_VALIDATION
select OBJTOOL
default y
-# For when objtool defers its work to the linked image (vmlinux.o or module.o)
-# rather than running on individual translation units.
+# Objtool reverse-engineers the control flow graph
+config OBJTOOL_CONTROL_FLOW
+ def_bool y
+ depends on OBJTOOL
+ depends on UNWINDER_ORC || STACK_VALIDATION || HAVE_UACCESS_VALIDATION
+
+# Objtool defers its work to the linked image (vmlinux.o or module.o) rather
+# than running on individual translation units.
config OBJTOOL_DEFERRED
def_bool y
depends on OBJTOOL
diff --git a/lib/Kconfig.ubsan b/lib/Kconfig.ubsan
index 1ecaae7064d2a..61e8c86ef63be 100644
--- a/lib/Kconfig.ubsan
+++ b/lib/Kconfig.ubsan
@@ -110,7 +110,7 @@ config UBSAN_UNREACHABLE
bool "Perform checking for unreachable code"
# objtool already handles unreachable checking and gets angry about
# seeing UBSan instrumentation located in unreachable places.
- depends on !(OBJTOOL && (STACK_VALIDATION || UNWINDER_ORC || HAVE_UACCESS_VALIDATION))
+ depends on !OBJTOOL_CONTROL_FLOW
depends on $(cc-option,-fsanitize=unreachable)
help
This option enables -fsanitize=unreachable which checks for control
--
2.55.0
next prev parent reply other threads:[~2026-09-08 20:34 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-08 20:33 [PATCH v2 00/27] objtool: dynamically detect noreturns Josh Poimboeuf
2026-09-08 20:33 ` [PATCH v2 01/27] objtool: Remove obsolete noreturns.h entries Josh Poimboeuf
2026-09-08 20:33 ` [PATCH v2 02/27] kbuild: Add CONFIG_OBJTOOL_DEFERRED Josh Poimboeuf
2026-09-10 19:22 ` Julian Braha
2026-09-08 20:33 ` Josh Poimboeuf [this message]
2026-09-08 20:33 ` [PATCH v2 04/27] objtool: Fix dead end detection for sibling calls Josh Poimboeuf
2026-09-08 20:33 ` [PATCH v2 05/27] objtool: Refactor the noreturn/dead-end detection Josh Poimboeuf
2026-09-08 20:33 ` [PATCH v2 06/27] objtool: Ignore traps after noreturn calls in STT_CODE Josh Poimboeuf
2026-09-08 20:33 ` [PATCH v2 07/27] objtool: Make .discard.stack_frame_non_standard non-allocatable Josh Poimboeuf
2026-09-08 20:33 ` [PATCH v2 08/27] efi/libstub: Drop .discard.addressable from the stub objects Josh Poimboeuf
2026-09-08 20:33 ` [PATCH v2 09/27] efi/loongarch: Mark loongarch efi_boot_kernel() non-standard for objtool Josh Poimboeuf
2026-09-08 20:33 ` [PATCH v2 10/27] objtool: Add ANNOTATE_IGNORE_NORETURN() Josh Poimboeuf
2026-09-08 20:33 ` [PATCH v2 11/27] LoongArch: Annotate reboot and kexec paths as returnable Josh Poimboeuf
2026-09-08 20:33 ` [PATCH v2 12/27] kbuild: Defer running objtool to link time for all CFG features Josh Poimboeuf
2026-09-08 20:33 ` [PATCH v2 13/27] rust: Annotate the intrinsic stubs as returnable Josh Poimboeuf
2026-09-08 20:33 ` [PATCH v2 14/27] panic: Mark abort() __noreturn Josh Poimboeuf
2026-09-08 20:33 ` [PATCH v2 15/27] x86/xen: Ignore noreturn status of weak mem_map_via_hcall() Josh Poimboeuf
2026-09-08 20:33 ` [PATCH v2 16/27] objtool: Detect noreturns in weak functions Josh Poimboeuf
2026-09-08 20:33 ` [PATCH v2 17/27] x86/entry: Make rewind_stack_and_make_dead() a real function Josh Poimboeuf
2026-09-08 20:33 ` [PATCH v2 18/27] x86/xen: Make xen_cpu_bringup_again() " Josh Poimboeuf
2026-09-08 20:33 ` [PATCH v2 19/27] x86/xen: Make xen_start_kernel() noreturn Josh Poimboeuf
2026-09-08 20:33 ` [PATCH v2 20/27] x86/boot: Rework how pi startup symbols get exposed to vmlinux Josh Poimboeuf
2026-09-08 20:33 ` [PATCH v2 21/27] objtool: Fix noreturn detection for non-sibling jumps to SYM_CODE Josh Poimboeuf
2026-09-08 20:33 ` [PATCH v2 22/27] objtool: Add options to write/read exported noreturns to/from a file Josh Poimboeuf
2026-09-08 20:33 ` [PATCH v2 23/27] kbuild: Do the per-module objtool pass right before linking Josh Poimboeuf
2026-09-08 20:33 ` [PATCH v2 24/27] kbuild: Generate the noreturn list and validate modules against it Josh Poimboeuf
2026-09-08 20:33 ` [PATCH v2 25/27] objtool: Add ANNOTATE_EXPORTED_NORETURN() Josh Poimboeuf
2026-09-08 20:33 ` [PATCH v2 26/27] objtool: Annotate all module-exported noreturns and remove noreturns.h Josh Poimboeuf
2026-09-08 20:33 ` [PATCH v2 27/27] objtool: Warn about missing/stale ANNOTATE_EXPORTED_NORETURN() usage Josh Poimboeuf
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