From nobody Mon Feb 9 17:56:48 2026 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 1E3811CFBC; Tue, 16 Apr 2024 15:33:39 +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=1713281620; cv=none; b=DRUK/eqv7ejfAIlqPVHNecQAn4BSW5XsFc8BGhgo5r4Cy2crQnuMV1P7v+XFpywc6XyZotGYmjfZ1cmaAqw+6gmtzBWPmecVYlSe8npDwK9ATWptwpgmeBcBUGjYyQI6MiD5vmCoE3VE8o8+8TlIX/ND6SAWa3WKzWthh4qcMaE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713281620; c=relaxed/simple; bh=KMJrLPwQ9g082JII6rT2LfmDOh7BKYUjdsOItQoJrbA=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=PNrziygVlTfcBr3SXudU+4v2SFv3sNPFxrjPNHzLQWPDNKKg985W77JhK99h5BdRZwjq0u3JgnFzfMPOnML3IYEsgOqJ0uzqw3dRAsOcBWPhlYW/wjPFwzYuaj81W47xX+ysGrL5uK121cgYpYds0vFwkwJKjm1UvIUPZUrksNE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=rz1Szidj; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="rz1Szidj" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 56E27C113CE; Tue, 16 Apr 2024 15:33:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1713281619; bh=KMJrLPwQ9g082JII6rT2LfmDOh7BKYUjdsOItQoJrbA=; h=From:To:Cc:Subject:Date:From; b=rz1SzidjBfUZzeyqxX7pwf2W9793w97eV5Ag4zUuf/4q0uW+dUi0b4LJUuwWkaTkJ 1zH2VKTR3L4P2cPrlQ0SNENy4AdjcrlmMcSoXl+x5KMpgWiyj92Y0YyNzT8CDXHJ2m pdPUv6ra+ko40LbtrVW8jNgJvXzZc5ChEsnRYIe8Y+QnDWCXGOrn1bo+bBze6RoHFg htoLEPNxFd9M1fY4OGjFfJWwMwn2w4lURkW85s5MuyGnBbh+HdNav3yFFxmVp7XgEd dLxMkKhOn7lycivhlOPRTqm6zxj8+7WMCB29r9uHPOVFMUV/uO2bo2HA9JOsH/tQNF L1RYfVNjfw7lA== From: Arnd Bergmann To: Michael Ellerman Cc: Arnd Bergmann , Naresh Kamboju , linux-kernel@vger.kernel.org, linuxppc-dev , "Aneesh Kumar K . V" , Anders Roxell , Kees Cook , Niklas Schnelle , clang-built-linux , Nick Desaulniers , Nathan Chancellor , Jeff Xu , "Naveen N . Rao" , Dan Carpenter , Nicholas Piggin , Christophe Leroy , Bill Wendling , Justin Stitt , Baoquan He , "Mike Rapoport (IBM)" Subject: [PATCH] powerpc: drop port I/O helpers for CONFIG_HAS_IOPORT=n Date: Tue, 16 Apr 2024 17:33:01 +0200 Message-Id: <20240416153331.1617772-1-arnd@kernel.org> X-Mailer: git-send-email 2.39.2 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Arnd Bergmann Calling inb()/outb() on powerpc when CONFIG_PCI is disabled causes a NULL pointer dereference, which is bad for a number of reasons. After my patch to turn on -Werror in linux-next, this caused a compiler-time warning with clang: In file included from arch/powerpc/include/asm/io.h:672: arch/powerpc/include/asm/io-defs.h:43:1: error: performing pointer arithmetic on a null pointer has undefined behavior [-Werror,-Wnull-pointer-arithmetic] 43 | DEF_PCI_AC_NORET(insb, (unsigned long p, void *b, unsigned long c), | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 44 | (p, b, c), pio, p) | ~~~~~~~~~~~~~~~~~~ In this configuration, CONFIG_HAS_IOPORT is already disabled, and all drivers that use inb()/outb() should now depend on that (some patches are still in the process of getting marged). Hide all references to inb()/outb() in the powerpc code and the definitions when HAS_IOPORT is disabled to remove the possible NULL pointer access. The same should happin in asm-generic in the near future, but for now the empty inb() macros are still defined to ensure the generic version does not get pulled in. Signed-off-by: Arnd Bergmann Reported-by: Naresh Kamboju -- Cc: linux-kernel@vger.kernel.org> Cc: linuxppc-dev Cc: Aneesh Kumar K.V Cc: Anders Roxell Cc: Kees Cook Cc: Niklas Schnelle Cc: clang-built-linux Cc: Nick Desaulniers Cc: Nathan Chancellor Cc: Jeff Xu Cc: Naveen N. Rao Cc: Dan Carpenter --- arch/powerpc/include/asm/dma.h | 12 ++++++++---- arch/powerpc/include/asm/io-defs.h | 4 ++++ arch/powerpc/include/asm/io.h | 19 +++++++++++++++---- arch/powerpc/kernel/iomap.c | 4 ++++ arch/powerpc/kernel/traps.c | 2 +- 5 files changed, 32 insertions(+), 9 deletions(-) diff --git a/arch/powerpc/include/asm/dma.h b/arch/powerpc/include/asm/dma.h index d97c66d9ae34..004a868f82c9 100644 --- a/arch/powerpc/include/asm/dma.h +++ b/arch/powerpc/include/asm/dma.h @@ -3,6 +3,12 @@ #define _ASM_POWERPC_DMA_H #ifdef __KERNEL__ =20 +/* The maximum address that we can perform a DMA transfer to on this platf= orm */ +/* Doesn't really apply... */ +#define MAX_DMA_ADDRESS (~0UL) + +#ifdef CONFIG_HAS_IOPORT + /* * Defines for using and allocating dma channels. * Written by Hennus Bergman, 1992. @@ -26,10 +32,6 @@ #define MAX_DMA_CHANNELS 8 #endif =20 -/* The maximum address that we can perform a DMA transfer to on this platf= orm */ -/* Doesn't really apply... */ -#define MAX_DMA_ADDRESS (~0UL) - #ifdef HAVE_REALLY_SLOW_DMA_CONTROLLER #define dma_outb outb_p #else @@ -340,5 +342,7 @@ extern int request_dma(unsigned int dmanr, const char *= device_id); /* release it again */ extern void free_dma(unsigned int dmanr); =20 +#endif + #endif /* __KERNEL__ */ #endif /* _ASM_POWERPC_DMA_H */ diff --git a/arch/powerpc/include/asm/io-defs.h b/arch/powerpc/include/asm/= io-defs.h index faf8617cc574..8d2209af7759 100644 --- a/arch/powerpc/include/asm/io-defs.h +++ b/arch/powerpc/include/asm/io-defs.h @@ -20,12 +20,14 @@ DEF_PCI_AC_NORET(writeq, (u64 val, PCI_IO_ADDR addr), (= val, addr), mem, addr) DEF_PCI_AC_NORET(writeq_be, (u64 val, PCI_IO_ADDR addr), (val, addr), mem,= addr) #endif /* __powerpc64__ */ =20 +#ifdef CONFIG_HAS_IOPORT DEF_PCI_AC_RET(inb, u8, (unsigned long port), (port), pio, port) DEF_PCI_AC_RET(inw, u16, (unsigned long port), (port), pio, port) DEF_PCI_AC_RET(inl, u32, (unsigned long port), (port), pio, port) DEF_PCI_AC_NORET(outb, (u8 val, unsigned long port), (val, port), pio, por= t) DEF_PCI_AC_NORET(outw, (u16 val, unsigned long port), (val, port), pio, po= rt) DEF_PCI_AC_NORET(outl, (u32 val, unsigned long port), (val, port), pio, po= rt) +#endif =20 DEF_PCI_AC_NORET(readsb, (const PCI_IO_ADDR a, void *b, unsigned long c), (a, b, c), mem, a) @@ -40,6 +42,7 @@ DEF_PCI_AC_NORET(writesw, (PCI_IO_ADDR a, const void *b, = unsigned long c), DEF_PCI_AC_NORET(writesl, (PCI_IO_ADDR a, const void *b, unsigned long c), (a, b, c), mem, a) =20 +#ifdef CONFIG_HAS_IOPORT DEF_PCI_AC_NORET(insb, (unsigned long p, void *b, unsigned long c), (p, b, c), pio, p) DEF_PCI_AC_NORET(insw, (unsigned long p, void *b, unsigned long c), @@ -52,6 +55,7 @@ DEF_PCI_AC_NORET(outsw, (unsigned long p, const void *b, = unsigned long c), (p, b, c), pio, p) DEF_PCI_AC_NORET(outsl, (unsigned long p, const void *b, unsigned long c), (p, b, c), pio, p) +#endif =20 DEF_PCI_AC_NORET(memset_io, (PCI_IO_ADDR a, int c, unsigned long n), (a, c, n), mem, a) diff --git a/arch/powerpc/include/asm/io.h b/arch/powerpc/include/asm/io.h index 08c550ed49be..86c212fcbc0c 100644 --- a/arch/powerpc/include/asm/io.h +++ b/arch/powerpc/include/asm/io.h @@ -37,7 +37,6 @@ extern struct pci_dev *isa_bridge_pcidev; * define properly based on the platform */ #ifndef CONFIG_PCI -#define _IO_BASE 0 #define _ISA_MEM_BASE 0 #define PCI_DRAM_OFFSET 0 #elif defined(CONFIG_PPC32) @@ -486,8 +485,7 @@ static inline u64 __raw_rm_readq(volatile void __iomem = *paddr) * to port it over */ =20 -#ifdef CONFIG_PPC32 - +#if defined(CONFIG_PPC32) && defined(CONFIG_HAS_IOPORT) #define __do_in_asm(name, op) \ static inline unsigned int name(unsigned int port) \ { \ @@ -534,7 +532,7 @@ __do_out_asm(_rec_outb, "stbx") __do_out_asm(_rec_outw, "sthbrx") __do_out_asm(_rec_outl, "stwbrx") =20 -#endif /* CONFIG_PPC32 */ +#endif /* CONFIG_PPC32 && CONFIG_HAS_IOPORT */ =20 /* The "__do_*" operations below provide the actual "base" implementation * for each of the defined accessors. Some of them use the out_* functions @@ -577,6 +575,7 @@ __do_out_asm(_rec_outl, "stwbrx") #define __do_readq_be(addr) in_be64(PCI_FIX_ADDR(addr)) #endif /* !defined(CONFIG_EEH) */ =20 +#ifdef CONFIG_HAS_IOPORT #ifdef CONFIG_PPC32 #define __do_outb(val, port) _rec_outb(val, port) #define __do_outw(val, port) _rec_outw(val, port) @@ -592,6 +591,7 @@ __do_out_asm(_rec_outl, "stwbrx") #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 */ +#endif =20 #ifdef CONFIG_EEH #define __do_readsb(a, b, n) eeh_readsb(PCI_FIX_ADDR(a), (b), (n)) @@ -606,12 +606,14 @@ __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)) =20 +#ifdef CONFIG_HAS_IOPORT #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)) +#endif =20 #define __do_memset_io(addr, c, n) \ _memset_io(PCI_FIX_ADDR(addr), c, n) @@ -689,6 +691,7 @@ static inline void name at \ #define writesb writesb #define writesw writesw #define writesl writesl + #define inb inb #define inw inw #define inl inl @@ -848,8 +851,16 @@ static inline void iosync(void) #define inl_p(port) inl(port) #define outl_p(val, port) (udelay(1), outl((val), (port))) =20 +#define insb_p insb +#define insw_p insw +#define insl_p insl +#define outsb_p outsb +#define outsw_p outsw +#define outsl_p outsl =20 +#ifdef CONFIG_HAS_IOPORT #define IO_SPACE_LIMIT ~(0UL) +#endif =20 /** * ioremap - map bus memory into CPU space diff --git a/arch/powerpc/kernel/iomap.c b/arch/powerpc/kernel/iomap.c index 72862a4d3a5d..33e36fda1ea8 100644 --- a/arch/powerpc/kernel/iomap.c +++ b/arch/powerpc/kernel/iomap.c @@ -13,7 +13,11 @@ =20 void __iomem *ioport_map(unsigned long port, unsigned int len) { +#ifdef CONFIG_HAS_IOPORT return (void __iomem *) (port + _IO_BASE); +#else + return NULL; +#endif } EXPORT_SYMBOL(ioport_map); =20 diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c index f23430adb68a..b1c34242d394 100644 --- a/arch/powerpc/kernel/traps.c +++ b/arch/powerpc/kernel/traps.c @@ -531,7 +531,7 @@ DEFINE_INTERRUPT_HANDLER_NMI(system_reset_exception) */ static inline int check_io_access(struct pt_regs *regs) { -#ifdef CONFIG_PPC32 +#if defined(CONFIG_PPC32) && defined(CONFIG_HAS_IOPORT) unsigned long msr =3D regs->msr; const struct exception_table_entry *entry; unsigned int *nip =3D (unsigned int *)regs->nip; --=20 2.39.2