From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2AAC5CAC5B1 for ; Wed, 24 Sep 2025 14:22:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=t7nIw84Rl79y66+K3kgQqOWSKjjzBQe7De/659OAugM=; b=gtMWIYDbdEt8gtOpTQW9wCXVEd nredQcySsrZ0wlmLS860kcoDclAYLFx19UPM8bgWTlsuFHkv2ZHuBgRCXbrs5y8FKujKOc3ZLrU7b ltExj0liOhSPeIhUCP47VVjPsMm1oGlvT7/4iqFS7gdqRsOxr2uwbITs88UTeqP1B0YnTXdOSylhg IN6Y20/yfWuKhnppl6/H7oCf/J84lMe0XP+gH1aCfKfb4jdY/cJeXYiLS9kEl5eDAItt8U8BeDvh3 rWZUjHVSqQmugz4Killuz7e30kkkWh/cS2l6OEr2xBvHY5SFnh36uNA734oqG0tfjlKJwx/5Xv5II dttCFDjw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1v1QNf-00000000b15-3fey; Wed, 24 Sep 2025 14:22:03 +0000 Received: from s3.sipsolutions.net ([2a01:4f8:242:246e::2] helo=sipsolutions.net) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1v1QNc-00000000ast-34Ru for linux-um@lists.infradead.org; Wed, 24 Sep 2025 14:22:02 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sipsolutions.net; s=mail; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Content-Type:Sender :Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-To: Resent-Cc:Resent-Message-ID; bh=t7nIw84Rl79y66+K3kgQqOWSKjjzBQe7De/659OAugM=; t=1758723720; x=1759933320; b=KDgV9bM432Q/60IpnEeD+KMrFEldXzIDvoeq+VRPiTxTwn9 JfbQWITmrocU1442/BY14eqi5DR8A3d1jUDEU8mnGjawh7QufJ45kyopI3ISF06LFfkPCIexcwBBY YfVG8HmJfp8rwTw85/9FzoNaX/nSyUFC8S8a+/GPilIg2wqy5Y0C4gOrb3rb07MO6g0MnFo4BYMKR pLe+9+WFMZzrsAdcvxMMZgq4lpySO8zjn2Wk63HvCwlMVKA012+ZTDDzDXJ7x4b1IKEUklM5OjpTa TGgJuNoAzoTxP6LQ1SzQ3FgLlYVgcjpedkiHcer5cNtYDb9dRPPkbxxa4L4+9/9Q==; Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.98.2) (envelope-from ) id 1v1QNZ-000000090Bz-1P4q; Wed, 24 Sep 2025 16:21:58 +0200 From: Benjamin Berg To: linux-um@lists.infradead.org, Willy Tarreau , =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= , linux-kselftest@vger.kernel.org, Arnaldo Carvalho de Melo Cc: linux-kernel@vger.kernel.org, Benjamin Berg Subject: [PATCH v3 08/12] um: add infrastructure to build files using nolibc Date: Wed, 24 Sep 2025 16:20:55 +0200 Message-ID: <20250924142059.527768-9-benjamin@sipsolutions.net> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20250924142059.527768-1-benjamin@sipsolutions.net> References: <20250924142059.527768-1-benjamin@sipsolutions.net> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250924_072200_788335_022CDFD1 X-CRM114-Status: GOOD ( 14.38 ) X-BeenThere: linux-um@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-um" Errors-To: linux-um-bounces+linux-um=archiver.kernel.org@lists.infradead.org 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. Leave the syscall definition for kernel code for now, but guard it as it is a macro in nolibc. Signed-off-by: Benjamin Berg --- v3: - Change the syscall guard to use __KERNEL__ v2: - Do not include nolibc.h via CFLAGS - Make syscall guard more explicit - Remove __UM_NOLIBC__ define, it is not needed - Fix out-of-tree building --- arch/um/Makefile | 20 +++++++++++++++++++- arch/um/include/shared/os.h | 2 ++ arch/um/include/shared/user.h | 1 - arch/um/scripts/Makefile.rules | 8 +++++++- 4 files changed, 28 insertions(+), 3 deletions(-) diff --git a/arch/um/Makefile b/arch/um/Makefile index f7c509262568..c3a81df50911 100644 --- a/arch/um/Makefile +++ b/arch/um/Makefile @@ -78,6 +78,24 @@ 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 $(srctree)/tools/include \ + -D__EXPORTED_HEADERS__ \ + -D__UM_HOST__ \ + -DNOLIBC_NO_RUNTIME \ + -DNOLIBC_IGNORE_ERRNO \ + -nostdlib -nostdinc -static \ + -I$(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 $(objtree)/include/generated/autoconf.h \ + -include $(srctree)/tools/include/linux/kconfig.h \ + -include $(srctree)/include/linux/kern_levels.h \ + -include $(srctree)/$(ARCH_DIR)/include/shared/user.h + #This will adjust *FLAGS accordingly to the platform. include $(srctree)/$(ARCH_DIR)/Makefile-os-Linux @@ -160,4 +178,4 @@ 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..5dae5635b1f8 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); +#ifdef __KERNEL__ long syscall(long number, ...); +#endif /* irqflags tracing */ extern void block_signals_trace(void); diff --git a/arch/um/include/shared/user.h b/arch/um/include/shared/user.h index c9b853e1282f..e32bdd032029 100644 --- a/arch/um/include/shared/user.h +++ b/arch/um/include/shared/user.h @@ -16,7 +16,6 @@ */ #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0])) -#include #include extern void panic(const char *fmt, ...) diff --git a/arch/um/scripts/Makefile.rules b/arch/um/scripts/Makefile.rules index b4a2e0058503..5f07551935c3 100644 --- a/arch/um/scripts/Makefile.rules +++ b/arch/um/scripts/Makefile.rules @@ -11,6 +11,12 @@ USER_OBJS := $(foreach file,$(USER_OBJS),$(obj)/$(file)) $(USER_OBJS:.o=.%): \ c_flags = -Wp,-MD,$(depfile) $(USER_CFLAGS) $(CFLAGS_$(basetarget).o) +# Similar USER_OBJS but compiled against nolibc (may include kernel headers?) +NOLIBC_OBJS := $(foreach file,$(NOLIBC_OBJS),$(obj)/$(file)) + +$(NOLIBC_OBJS:.o=.%): \ + c_flags = -Wp,-MD,$(depfile) $(NOLIBC_CFLAGS) $(CFLAGS_$(basetarget).o) + # These are like USER_OBJS but filter USER_CFLAGS through unprofile instead of # using it directly. UNPROFILE_OBJS := $(foreach file,$(UNPROFILE_OBJS),$(obj)/$(file)) @@ -18,7 +24,7 @@ UNPROFILE_OBJS := $(foreach file,$(UNPROFILE_OBJS),$(obj)/$(file)) $(UNPROFILE_OBJS:.o=.%): \ c_flags = -Wp,-MD,$(depfile) $(call unprofile,$(USER_CFLAGS)) $(CFLAGS_$(basetarget).o) -$(USER_OBJS) $(UNPROFILE_OBJS): \ +$(USER_OBJS) $(NOLIBC_OBJS) $(UNPROFILE_OBJS): \ CHECKFLAGS := $(patsubst $(NOSTDINC_FLAGS),,$(CHECKFLAGS)) # The stubs can't try to call mcount or update basic block data -- 2.51.0