From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from todd.t-8ch.de (todd.t-8ch.de [159.69.126.157]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2C3691400C; Mon, 15 Sep 2025 08:57:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=159.69.126.157 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757926674; cv=none; b=ZFi6b3mcDg5hGEsQ5WXI/CNL/PCb3Z43i8xc1KvmOuZSjeA909L7f+U/zLm87R+ytpfkLpa6qUCX5Qr5Q7MgiGhhefl1oh6fIndd3RPqFFp8pcyfMjpY8NMwRSijOZWxnrTiAXkDjSLv0+2poBuMYkkgPRZhO3kM9mZCc7qnBpk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757926674; c=relaxed/simple; bh=e0SMJFBpOy5/d3qbT4HP8L3kb/X4vlvHNxXtwRTDE3g=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=FgCiFIoH88onmwS5AKajgcBNAisz82Zy1oRaVGkSzuIBOn59t+pOmCBGUy3elvaw4mcuQswuyGfgCNrr5AG4OVuvUqkudQRONNcfedIiF2ULohfHZJI0s02Iil07cY9YUhBoUD06AH+OAdB1DDEj77XW2u2WGdXqoLSy5iaR8Og= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=weissschuh.net; spf=pass smtp.mailfrom=weissschuh.net; dkim=pass (1024-bit key) header.d=weissschuh.net header.i=@weissschuh.net header.b=IjnophdE; arc=none smtp.client-ip=159.69.126.157 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=weissschuh.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=weissschuh.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=weissschuh.net header.i=@weissschuh.net header.b="IjnophdE" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=weissschuh.net; s=mail; t=1757926670; bh=e0SMJFBpOy5/d3qbT4HP8L3kb/X4vlvHNxXtwRTDE3g=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=IjnophdEcujlUxbWSM/TmsAayR8h17N0bfCB5Bo5m9oxaCnRWX00C6D3uvqSsSA0U 7EKIYetgs+W+HrCHcY+te2d8/JAkiqDQDvxKpWD/cep8t/L0MCct2eaQGPgq89kqkQ q1vM9YBNxwwZhla4y8JfEkiOB9iPHN/mUy0WcDx4= Date: Mon, 15 Sep 2025 10:57:51 +0200 From: Thomas =?utf-8?Q?Wei=C3=9Fschuh?= To: Benjamin Berg Cc: linux-um@lists.infradead.org, Willy Tarreau , linux-kselftest@vger.kernel.org, Arnaldo Carvalho de Melo , linux-kernel@vger.kernel.org, Tiwei Bie , Benjamin Berg Subject: Re: [PATCH 7/9] um: add infrastructure to build files using nolibc Message-ID: <31a81a3a-e6f2-49b1-9a07-4b11df9e4091@t-8ch.de> References: <20250915071115.1429196-1-benjamin@sipsolutions.net> <20250915071115.1429196-8-benjamin@sipsolutions.net> Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250915071115.1429196-8-benjamin@sipsolutions.net> On 2025-09-15 09:11:13+0200, Benjamin Berg wrote: > From: Benjamin Berg > > Add NOLIBC_CFLAGS and NOLIBC_OBJS to build files against nolibc rather > than libc. With this it is possible to move to nolibc in smaller steps. > > Set NOLIBC_IGNORE_ERRNO, as the nolibc errno implementation is overly > simple and cannot handle threading. nolibc provides sys_* functions that > do not emulate the libc errno behaviour and can be used instead. > > Guard the syscall definition as it is a macro in nolibc. > > Signed-off-by: Benjamin Berg > --- > arch/um/Makefile | 21 ++++++++++++++++++++- > arch/um/include/shared/os.h | 2 ++ > arch/um/scripts/Makefile.rules | 8 +++++++- > 3 files changed, 29 insertions(+), 2 deletions(-) > > diff --git a/arch/um/Makefile b/arch/um/Makefile > index a3f27d791cc0..54aa26fcc32b 100644 > --- a/arch/um/Makefile > +++ b/arch/um/Makefile > @@ -78,6 +78,25 @@ USER_CFLAGS = $(patsubst $(KERNEL_DEFINES),,$(patsubst -I%,,$(KBUILD_CFLAGS))) \ > -include $(srctree)/include/linux/kern_levels.h \ > -include $(srctree)/$(ARCH_DIR)/include/shared/user.h > > +NOLIBC_CFLAGS = $(patsubst $(KERNEL_DEFINES),,$(patsubst -I%,,$(KBUILD_CFLAGS))) \ > + $(ARCH_INCLUDE) $(MODE_INCLUDE) $(filter -I%,$(CFLAGS)) \ > + -I $(srctree)/tools/include \ > + -D__EXPORTED_HEADERS__ \ > + -D__UM_HOST__ -D__UM_NOLIBC__ \ > + -DNOLIBC_NO_STARTCODE \ > + -DNOLIBC_IGNORE_ERRNO \ > + -nostdlib -nostdinc -static \ > + -I$(srctree)/include/uapi \ > + -I$(srctree)/$(HOST_DIR)/include/uapi \ > + -I$(objtree)/$(HOST_DIR)/include/generated/uapi \ > + -I $(srctree)/tools/include/nolibc \ > + -I $(srctree)/usr/include \ > + -include $(srctree)/include/generated/autoconf.h \ > + -include $(srctree)/tools/include/linux/kconfig.h \ > + -include $(srctree)/include/linux/kern_levels.h \ > + -include $(srctree)/tools/include/nolibc/nolibc.h \ This is not needed. It doesn't hurt though. > + -include $(srctree)/$(ARCH_DIR)/include/shared/user.h > + > #This will adjust *FLAGS accordingly to the platform. > include $(srctree)/$(ARCH_DIR)/Makefile-os-Linux > > @@ -157,4 +176,4 @@ archclean: > -o -name '*.gcov' \) -type f -print | xargs rm -f > $(Q)$(MAKE) -f $(srctree)/Makefile ARCH=$(HEADER_ARCH) clean > > -export HEADER_ARCH SUBARCH USER_CFLAGS CFLAGS_NO_HARDENING DEV_NULL_PATH > +export HEADER_ARCH SUBARCH USER_CFLAGS NOLIBC_CFLAGS CFLAGS_NO_HARDENING DEV_NULL_PATH > diff --git a/arch/um/include/shared/os.h b/arch/um/include/shared/os.h > index b35cc8ce333b..3e9f3ae61658 100644 > --- a/arch/um/include/shared/os.h > +++ b/arch/um/include/shared/os.h > @@ -327,7 +327,9 @@ extern int __ignore_sigio_fd(int fd); > /* tty.c */ > extern int get_pty(void); > > +#ifndef syscall You could use 'ifndef NOLIBC' to make the reason clear. > long syscall(long number, ...); > +#endif > > /* irqflags tracing */ > extern void block_signals_trace(void); (...)