From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 767D2524C; Wed, 3 Jul 2024 11:06:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720004783; cv=none; b=OOmKM56LD5Ioxq1fk4VgAyN246HmFkwLfgA9oNrRYhRgUzMRrJBhsK9emWWHQizYKPDL/g3VXsZ9hub3Hskt5/FbixV/beT7OHyCrI5uruc9Hz/teLXMhRA6r9qVb+msX9I5b0f+qCkwKxUMJTVYRhStOARr5MUY9ZOhJXN6NGg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720004783; c=relaxed/simple; bh=dwr9TqTdWb9stdE7ctEWe354KtRw9FGgdRXdl3NYeNw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=LKatrfQYq/9hbNb/YTylgDuJD7FIJ3Md0LkTuZc44q2ms7KxO1U7grx7FMFWP8Wf4cfZLiZfbHqbPlTeWQWxBIhO12JZIOhLpsbr3ajUzP3mYeRFOz4HYGgPAMlOwUs+cST00ksboTKBH/nmFRQbxkko9HoS573e/sXxyr5K8Lk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=zjnuB8Ek; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="zjnuB8Ek" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F34BDC2BD10; Wed, 3 Jul 2024 11:06:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1720004783; bh=dwr9TqTdWb9stdE7ctEWe354KtRw9FGgdRXdl3NYeNw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zjnuB8EkfcXgXMYrol6Y0+YMYES5GnA7YYfh0YwpwZ/7LBI0d+srT8PgCTnYd8Klq DYB3WV81z1T0/FGaDeHtJ31D4OoX8T+bnmaV31vTCwWjpo2tnar30Q9Q9sf1l3Y9RY fWURj49y4muU5gHnotaZ80JSm24Ffx2MjUfnQeIA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Naresh Kamboju , Michael Ellerman , Sasha Levin Subject: [PATCH 5.10 126/290] powerpc/io: Avoid clang null pointer arithmetic warnings Date: Wed, 3 Jul 2024 12:38:27 +0200 Message-ID: <20240703102908.947115265@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240703102904.170852981@linuxfoundation.org> References: <20240703102904.170852981@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Michael Ellerman [ Upstream commit 03c0f2c2b2220fc9cf8785cd7b61d3e71e24a366 ] With -Wextra clang warns about pointer arithmetic using a null pointer. When building with CONFIG_PCI=n, that triggers a warning in the IO accessors, eg: In file included from linux/arch/powerpc/include/asm/io.h:672: linux/arch/powerpc/include/asm/io-defs.h:23:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 23 | DEF_PCI_AC_RET(inb, u8, (unsigned long port), (port), pio, port) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ... linux/arch/powerpc/include/asm/io.h:591:53: note: expanded from macro '__do_inb' 591 | #define __do_inb(port) readb((PCI_IO_ADDR)_IO_BASE + port); | ~~~~~~~~~~~~~~~~~~~~~ ^ That is because when CONFIG_PCI=n, _IO_BASE is defined as 0. Although _IO_BASE is defined as plain 0, the cast (PCI_IO_ADDR) converts it to void * before the addition with port happens. Instead the addition can be done first, and then the cast. The resulting value will be the same, but avoids the warning, and also avoids void pointer arithmetic which is apparently non-standard. Reported-by: Naresh Kamboju Closes: https://lore.kernel.org/all/CA+G9fYtEh8zmq8k8wE-8RZwW-Qr927RLTn+KqGnq1F=ptaaNsA@mail.gmail.com Signed-off-by: Michael Ellerman Link: https://msgid.link/20240503075619.394467-1-mpe@ellerman.id.au Signed-off-by: Sasha Levin --- arch/powerpc/include/asm/io.h | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) diff --git a/arch/powerpc/include/asm/io.h b/arch/powerpc/include/asm/io.h index 0182b291248ac..058d21f493fad 100644 --- a/arch/powerpc/include/asm/io.h +++ b/arch/powerpc/include/asm/io.h @@ -541,12 +541,12 @@ __do_out_asm(_rec_outl, "stwbrx") #define __do_inw(port) _rec_inw(port) #define __do_inl(port) _rec_inl(port) #else /* CONFIG_PPC32 */ -#define __do_outb(val, port) writeb(val,(PCI_IO_ADDR)_IO_BASE+port); -#define __do_outw(val, port) writew(val,(PCI_IO_ADDR)_IO_BASE+port); -#define __do_outl(val, port) writel(val,(PCI_IO_ADDR)_IO_BASE+port); -#define __do_inb(port) readb((PCI_IO_ADDR)_IO_BASE + port); -#define __do_inw(port) readw((PCI_IO_ADDR)_IO_BASE + port); -#define __do_inl(port) readl((PCI_IO_ADDR)_IO_BASE + port); +#define __do_outb(val, port) writeb(val,(PCI_IO_ADDR)(_IO_BASE+port)); +#define __do_outw(val, port) writew(val,(PCI_IO_ADDR)(_IO_BASE+port)); +#define __do_outl(val, port) writel(val,(PCI_IO_ADDR)(_IO_BASE+port)); +#define __do_inb(port) readb((PCI_IO_ADDR)(_IO_BASE + port)); +#define __do_inw(port) readw((PCI_IO_ADDR)(_IO_BASE + port)); +#define __do_inl(port) readl((PCI_IO_ADDR)(_IO_BASE + port)); #endif /* !CONFIG_PPC32 */ #ifdef CONFIG_EEH @@ -562,12 +562,12 @@ __do_out_asm(_rec_outl, "stwbrx") #define __do_writesw(a, b, n) _outsw(PCI_FIX_ADDR(a),(b),(n)) #define __do_writesl(a, b, n) _outsl(PCI_FIX_ADDR(a),(b),(n)) -#define __do_insb(p, b, n) readsb((PCI_IO_ADDR)_IO_BASE+(p), (b), (n)) -#define __do_insw(p, b, n) readsw((PCI_IO_ADDR)_IO_BASE+(p), (b), (n)) -#define __do_insl(p, b, n) readsl((PCI_IO_ADDR)_IO_BASE+(p), (b), (n)) -#define __do_outsb(p, b, n) writesb((PCI_IO_ADDR)_IO_BASE+(p),(b),(n)) -#define __do_outsw(p, b, n) writesw((PCI_IO_ADDR)_IO_BASE+(p),(b),(n)) -#define __do_outsl(p, b, n) writesl((PCI_IO_ADDR)_IO_BASE+(p),(b),(n)) +#define __do_insb(p, b, n) readsb((PCI_IO_ADDR)(_IO_BASE+(p)), (b), (n)) +#define __do_insw(p, b, n) readsw((PCI_IO_ADDR)(_IO_BASE+(p)), (b), (n)) +#define __do_insl(p, b, n) readsl((PCI_IO_ADDR)(_IO_BASE+(p)), (b), (n)) +#define __do_outsb(p, b, n) writesb((PCI_IO_ADDR)(_IO_BASE+(p)),(b),(n)) +#define __do_outsw(p, b, n) writesw((PCI_IO_ADDR)(_IO_BASE+(p)),(b),(n)) +#define __do_outsl(p, b, n) writesl((PCI_IO_ADDR)(_IO_BASE+(p)),(b),(n)) #define __do_memset_io(addr, c, n) \ _memset_io(PCI_FIX_ADDR(addr), c, n) -- 2.43.0