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 09/27] efi/loongarch: Mark loongarch efi_boot_kernel() non-standard for objtool
Date: Thu, 27 Aug 2026 21:51:38 -0700 [thread overview]
Message-ID: <b7da3bfec527a7de6399b60c500a1fa1aea2175a.1787890035.git.jpoimboe@kernel.org> (raw)
In-Reply-To: <cover.1787890035.git.jpoimboe@kernel.org>
efi_boot_kernel() ends with a tail call through a __noreturn function
pointer, so the compiler emits nothing after it. Objtool can't tell that
in indirect call doesn't return, so it sees execution fall off the end
of the function:
vmlinux.o: warning: objtool: __efistub_efi_boot_kernel() falls through to next function __efistub_efi_get_memory_map()
This is boot code for which objtool/ORC coverage doesn't matter, so tell
objtool to ignore it.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
drivers/firmware/efi/libstub/loongarch.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/firmware/efi/libstub/loongarch.c b/drivers/firmware/efi/libstub/loongarch.c
index 2b0c87dc99088..737de9afd6a40 100644
--- a/drivers/firmware/efi/libstub/loongarch.c
+++ b/drivers/firmware/efi/libstub/loongarch.c
@@ -5,6 +5,7 @@
* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
*/
+#include <linux/objtool.h>
#include <asm/efi.h>
#include <asm/addrspace.h>
#include "efistub.h"
@@ -103,3 +104,10 @@ efi_status_t efi_boot_kernel(void *handle, efi_loaded_image_t *image,
real_kernel_entry(true, (unsigned long)cmdline_ptr,
(unsigned long)efi_system_table);
}
+
+/*
+ * Objtool has no way of knowing the real_kernel_entry() indirect call is
+ * noreturn. Just tell it to ignore this function: it's boot code anyway, so
+ * ORC coverage isn't needed.
+ */
+STACK_FRAME_NON_STANDARD(efi_boot_kernel);
--
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 ` [PATCH 06/27] objtool: Ignore traps after noreturn calls in STT_CODE Josh Poimboeuf
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 ` Josh Poimboeuf [this message]
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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