From 3cfdbc2274139bbcc09a44f8aa18d08c0abfd51e Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 16 Apr 2024 17:33:01 +0200 Subject: [PATCH] powerpc: drop port I/O helpers for CONFIG_HAS_IOPORT=n 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 Closes: https://lore.kernel.org/all/CA+G9fYtEh8zmq8k8wE-8RZwW-Qr927RLTn+KqGnq1F=ptaaNsA@mail.gmail.com Signed-off-by: Michael Ellerman Link: https://msgid.link/20240416153331.1617772-1-arnd@kernel.org --- 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 d97c66d9ae340..004a868f82c95 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__ +/* The maximum address that we can perform a DMA transfer to on this platform */ +/* 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 -/* The maximum address that we can perform a DMA transfer to on this platform */ -/* 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); +#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 faf8617cc574a..8d2209af77592 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__ */ +#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, port) DEF_PCI_AC_NORET(outw, (u16 val, unsigned long port), (val, port), pio, port) DEF_PCI_AC_NORET(outl, (u32 val, unsigned long port), (val, port), pio, port) +#endif 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) +#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 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 08c550ed49be6..86c212fcbc0c2 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 */ -#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") -#endif /* CONFIG_PPC32 */ +#endif /* CONFIG_PPC32 && CONFIG_HAS_IOPORT */ /* 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) */ +#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 #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)) +#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 #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))) +#define insb_p insb +#define insw_p insw +#define insl_p insl +#define outsb_p outsb +#define outsw_p outsw +#define outsl_p outsl +#ifdef CONFIG_HAS_IOPORT #define IO_SPACE_LIMIT ~(0UL) +#endif /** * ioremap - map bus memory into CPU space diff --git a/arch/powerpc/kernel/iomap.c b/arch/powerpc/kernel/iomap.c index 72862a4d3a5db..33e36fda1ea80 100644 --- a/arch/powerpc/kernel/iomap.c +++ b/arch/powerpc/kernel/iomap.c @@ -13,7 +13,11 @@ 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); diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c index f23430adb68ad..b1c34242d3941 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 = regs->msr; const struct exception_table_entry *entry; unsigned int *nip = (unsigned int *)regs->nip;