From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=209.85.208.177 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794532041; b=R71l0Tbmmumqz8IKkEZcfrqKTMWSvpZf1QNlUXMYQyqx8huZJPa5l/qhu+mZ2h1R7/2B ygU4MEniNO/IqTArGmrSO8fBbf9EMO9zOet/vYNCB7zEsXoly0y+rzDQ2dz69LbAsvgxu G1WQAcd7uFTITZ2u4A4k2GUH4iV9+HxxbLVZd2p1em4jyz3opxDYVruwm11XQe3KVW5Ta o0+sBHUiQM9eAbAFO5pc1jdIJYKjBYGSiGVKzBHwb6gkf1VNOLTpX2ED1mfxHMvbRQ0YE KWkgPqdc+y9SuAVR37fKIACqKmeVpFtYjwmpW+21uwpq6B2froeOSg/foVOEB2tSDBw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794532041; h=DMARC-Filter:Received:DKIM-Signature:X-Google-DKIM-Signature: X-Gm-Message-State:X-Gm-Gg:X-Received:Received:From:To:Cc:Subject: Date:Message-ID:X-Mailer:In-Reply-To:References:MIME-Version: Content-Transfer-Encoding; bh=c/cWqKIWduZoLOjk/RHPTZ+tnDRCPdJt/8RzdamyTqU=; b=CbG+iifpZ4B1wl4LgoV+EYRRAdmE+JuOIbEHuDkvjHP/nGPpZlkh+RXpG2l1q++wwNs4 ex4kzl8jUG3Il7EKlRjwGfQGv+QDgfygsbdtOtFStRfsHm6ZbNfqqSvleAqZ5dDZ1hQhD VezlUcoxgZTeqXzKVg8XlPm2drKoFvNu/HxbXuzqwzyb2vRZ16xff0LX9Cv6YxfEYMnvy QlouH2P8NVnHOqEv9QvJthM/c8d2lYzEezecumYxgrjLAjQiSF6uzImweycZhyacz4Yuh 0c/6YjQVnNME7tXRxBUPFG8m5v+4WCaMvG9hV6TaC9sZRixJRmjynSTKoQdHkzvykbA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20260707 header.b=Eq09Izgm; arc=none smtp.remote-ip=209.85.208.177 Received: from mail-lj1-f177.google.com (mail-lj1-f177.google.com [209.85.208.177]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F3AD5606A333 for ; Fri, 13 Nov 2026 01:07:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org F3AD5606A333 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20260707 header.b=Eq09Izgm Received: by mail-lj1-f177.google.com with SMTP id 38308e7fff4ca-3ab46699a09so5446721fa.0 for ; Thu, 12 Nov 2026 17:07:20 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20260707; t=1794532039; x=1795136839; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=c/cWqKIWduZoLOjk/RHPTZ+tnDRCPdJt/8RzdamyTqU=; b=Eq09Izgmr6L0mJQZ0HGFPuN0Br7L2lg0TYPw5RX5lMCWkxrGZLtvtY/8JVMh+7FffG 2dLOX6yFXpe2n2Bhh5GSqYgsbdxgGb7z7Z17hHWQCgnAQW8NXry7apdnZyJI4lNWzP4f LYbV1NLTJFGYgWD4LitRiCjz25d5SbJFx/roCW34TlLX2Z6JHm7P0w7gMm/ozo7EBqQd fXzfsAdl/HCoQhZLgLZS03JQswxaEyqAInfAUV50YAX+ZZV+ZMtsY6tKCRUg/nCBdDu6 zCsulkh4onxu8Eq/wGYIfooBilcdqPvnPTWyqIHlxNisBWz2mkRL2BnxsYw7DvLLToi2 8Yxg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1794532039; x=1795136839; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=c/cWqKIWduZoLOjk/RHPTZ+tnDRCPdJt/8RzdamyTqU=; b=D6rTATJVTXSu7WJ7kWmNyCelNcisMnbHEZ3PazAggPhl/oA/VLwlqBKFu2KiJjtymi RQ5/lf1jABeTch+13YJ6XyCyfNdS1Hj24+UxssoHFt/9rHWBlIJroByzjeB6kLoL8Oy8 tCWK21uXltubfxFph1Ff0MwtoN0uvp6OO7dyC1+M4haLZ4oh0CdE4BwXRR97LKsuY/WZ oGsAAfV2IDAW3fbQDKuitLU1AnIvAcIjGjxvQyXB1mgymB3VrAmqv9c/fDyVxGqgAJX0 ngXGwRx/W4vtIqhQ4KZ3DXwl8ghOaqtyUEvXhAd0uo8yeZdwTezF7LUv+qFjBW3Mx+Gu rrAA== X-Gm-Message-State: APuU4Z8bo8E13dgjYMbWUsWqrJN46KVX5Or+pnbP1YCItenEhWoJY3Ya corCh2geGzLFGm1/BwC+Wz6RTbUUwKJ+2KVOFVqXVi/oFbIxiAJ3CUD0 X-Gm-Gg: AYBFou1v93b8Rrs+BztL6RVF++ZrYkjc3XkFc1CVbrIZ5q7hFcHUOhdhok5U8vE3HHe ctGScJGRR2ZraSErgVBmSfzUY5TZ9kNI0dgYQl8gDsPMbHHGWGycnGIzyqJr3iwCTxK0XdQzaTH fNBtQpBeqBwn3kSVegJAwZ/OO6KLxO7WRqvAuCHEizOSlIk1/8lnfzHUSmE4z/p1KVyxSkcnV3B z0qF8dccw5rb5I50NIi2OX+rHnXISU1GRgOTHgVzvDMSUdbZDLRm0Ty0lUrjhT/59vYzbfrh9zq XOaRSo/s97laSFr2G+BX23rbn2sqRfYudbiAS19PY1S52wpqUBXiAcg8WNkqOgzhgldQUZCDCPa SxYdrsSkfmB0V6R+joRca2HOsIMJtZ3RNnmpE7o4gO4xbA5voTywt5OQsboOLvkLq6t4X4KuoH7 DV/cSoSG4U5eP/ZgSgYWL4h/o1r3OQGbkgUWIalMTj43cCjxMtVyes/ckuKmustUf6vOofdLSCq K9i90/8goL00I5cw2f19Enru91X48QnoN7MxViI4iMazo/tEm0s0fKYdzxDWQZ2UCGplI1JSr5h QAnv9EftLC7RDpTbWTnjYlRuv7ta3OKAZ3OTs73HfWr1eoFCw7Uso+NdxMelay4lnHqkRByO+2y 6hz8f4+ooqA== X-Received: by 2002:a05:651c:a348:b0:3ac:dda0:efdc with SMTP id 38308e7fff4ca-3ae2b5074cbmr3651751fa.16.1794532039095; Thu, 12 Nov 2026 17:07:19 -0800 (PST) Received: from SafoStation ([31.40.65.49]) by smtp.gmail.com with ESMTPSA id 38308e7fff4ca-3ae2b7d183bsm3133941fa.31.2026.11.12.17.07.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 12 Nov 2026 17:07:16 -0800 (PST) From: Safocl Stollmannovic To: Ard Biesheuvel , Ilias Apalodimas , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , "Rafael J. Wysocki" , Pavel Machek , Richard Weinberger , Anton Ivanov , Johannes Berg Cc: linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org, linux-pm@vger.kernel.org, linux-um@lists.infradead.org Subject: [PATCH v2 07/10] x86: fix duplicate extern declarations Date: Fri, 13 Nov 2026 05:06:12 +0400 Message-ID: <20261113010631.139191-8-safocl88@gmail.com> X-Mailer: git-send-email 2.56.1 In-Reply-To: <20261113010631.139191-1-safocl88@gmail.com> References: <20261113010631.139191-1-safocl88@gmail.com> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Compiling a kernel module with a C++ compiler results in a "duplicate extern specifier" error. This occurs because the code contains `extern asmlinkage`, and `asmlinkage` expands to `extern C` when processed by a C++ compiler. Since the code already contains sections that respond to a C++ compiler, I believe it is a perfectly valid approach to gradually move toward a state where kernel modules can be compiled by a C++ compiler without any issues. The `extern` specifier must be removed. Link: https://bugzilla.kernel.org/show_bug.cgi?id=222257 Signed-off-by: Safocl Stollmannovic --- arch/x86/include/asm/efi.h | 2 +- arch/x86/include/asm/gsseg.h | 2 +- arch/x86/include/asm/preempt.h | 8 ++++---- arch/x86/include/asm/processor.h | 2 +- arch/x86/include/asm/suspend.h | 2 +- arch/x86/um/sys_call_table_32.c | 4 ++-- arch/x86/um/sys_call_table_64.c | 4 ++-- 7 files changed, 12 insertions(+), 12 deletions(-) diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h index be58b7f5c..f5cb179b8 100644 --- a/arch/x86/include/asm/efi.h +++ b/arch/x86/include/asm/efi.h @@ -94,7 +94,7 @@ static inline void efi_fpu_end(void) #else /* !CONFIG_X86_32 */ #define EFI_X86_KERNEL_ALLOC_LIMIT EFI_ALLOC_LIMIT -extern asmlinkage u64 __efi_call(void *fp, ...); +asmlinkage u64 __efi_call(void *fp, ...); extern bool efi_disable_ibt_for_runtime; diff --git a/arch/x86/include/asm/gsseg.h b/arch/x86/include/asm/gsseg.h index ab6a595ce..81ef16081 100644 --- a/arch/x86/include/asm/gsseg.h +++ b/arch/x86/include/asm/gsseg.h @@ -12,7 +12,7 @@ #ifdef CONFIG_X86_64 -extern asmlinkage void asm_load_gs_index(u16 selector); +asmlinkage void asm_load_gs_index(u16 selector); /* Replace with "lkgs %di" once binutils support LKGS instruction */ #define LKGS_DI _ASM_BYTES(0xf2,0x0f,0x00,0xf7) diff --git a/arch/x86/include/asm/preempt.h b/arch/x86/include/asm/preempt.h index d16d9c2f7..135695ae3 100644 --- a/arch/x86/include/asm/preempt.h +++ b/arch/x86/include/asm/preempt.h @@ -134,11 +134,11 @@ static __always_inline bool should_resched(int preempt_offset) #ifdef CONFIG_PREEMPTION -extern asmlinkage void preempt_schedule(void); -extern asmlinkage void preempt_schedule_thunk(void); +asmlinkage void preempt_schedule(void); +asmlinkage void preempt_schedule_thunk(void); -extern asmlinkage void preempt_schedule_notrace(void); -extern asmlinkage void preempt_schedule_notrace_thunk(void); +asmlinkage void preempt_schedule_notrace(void); +asmlinkage void preempt_schedule_notrace_thunk(void); #define __preempt_schedule() \ asm volatile ("call preempt_schedule_thunk" : ASM_CALL_CONSTRAINT); diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 77488ff5e..68d7292af 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -455,7 +455,7 @@ static inline unsigned long cpu_kernelmode_gs_base(int cpu) #endif } -extern asmlinkage void entry_SYSCALL32_ignore(void); +asmlinkage void entry_SYSCALL32_ignore(void); /* Save actual FS/GS selectors and bases to current->thread */ void current_save_fsgs(void); diff --git a/arch/x86/include/asm/suspend.h b/arch/x86/include/asm/suspend.h index a892494ca..e29c071b9 100644 --- a/arch/x86/include/asm/suspend.h +++ b/arch/x86/include/asm/suspend.h @@ -11,4 +11,4 @@ extern unsigned long temp_pgt __visible; extern unsigned long relocated_restore_code __visible; extern int relocate_restore_code(void); /* Defined in hibernate_asm_32/64.S */ -extern asmlinkage __visible int restore_image(void); +asmlinkage __visible int restore_image(void); diff --git a/arch/x86/um/sys_call_table_32.c b/arch/x86/um/sys_call_table_32.c index 51655133e..f79c0138e 100644 --- a/arch/x86/um/sys_call_table_32.c +++ b/arch/x86/um/sys_call_table_32.c @@ -9,7 +9,7 @@ #include #include -extern asmlinkage long sys_ni_syscall(unsigned long, unsigned long, +asmlinkage long sys_ni_syscall(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long); @@ -28,7 +28,7 @@ extern asmlinkage long sys_ni_syscall(unsigned long, unsigned long, #define __SYSCALL_WITH_COMPAT(nr, native, compat) __SYSCALL(nr, native) #define __SYSCALL_NORETURN __SYSCALL -#define __SYSCALL(nr, sym) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long); +#define __SYSCALL(nr, sym) asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long); #include #undef __SYSCALL diff --git a/arch/x86/um/sys_call_table_64.c b/arch/x86/um/sys_call_table_64.c index 943d414f2..555e65e66 100644 --- a/arch/x86/um/sys_call_table_64.c +++ b/arch/x86/um/sys_call_table_64.c @@ -9,7 +9,7 @@ #include #include -extern asmlinkage long sys_ni_syscall(unsigned long, unsigned long, +asmlinkage long sys_ni_syscall(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long); @@ -24,7 +24,7 @@ extern asmlinkage long sys_ni_syscall(unsigned long, unsigned long, #define __SYSCALL_NORETURN __SYSCALL -#define __SYSCALL(nr, sym) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long); +#define __SYSCALL(nr, sym) asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long); #include #undef __SYSCALL -- 2.56.1