From a28a4d4723c11fe5fd3e725f5eb1b3472e80fe12 Mon Sep 17 00:00:00 2001 From: Alexander Potapenko Date: Thu, 15 Sep 2022 17:03:53 +0200 Subject: [PATCH] kmsan: add iomap support Functions from lib/iomap.c interact with hardware, so KMSAN must ensure that: - every read function returns an initialized value - every write function checks values before sending them to hardware. Link: https://lkml.kernel.org/r/20220915150417.722975-20-glider@google.com Signed-off-by: Alexander Potapenko Cc: Alexander Viro Cc: Alexei Starovoitov Cc: Andrey Konovalov Cc: Andrey Konovalov Cc: Andy Lutomirski Cc: Arnd Bergmann Cc: Borislav Petkov Cc: Christoph Hellwig Cc: Christoph Lameter Cc: David Rientjes Cc: Dmitry Vyukov Cc: Eric Biggers Cc: Eric Biggers Cc: Eric Dumazet Cc: Greg Kroah-Hartman Cc: Herbert Xu Cc: Ilya Leoshkevich Cc: Ingo Molnar Cc: Jens Axboe Cc: Joonsoo Kim Cc: Kees Cook Cc: Marco Elver Cc: Mark Rutland Cc: Matthew Wilcox Cc: Michael S. Tsirkin Cc: Pekka Enberg Cc: Peter Zijlstra Cc: Petr Mladek Cc: Stephen Rothwell Cc: Steven Rostedt Cc: Thomas Gleixner Cc: Vasily Gorbik Cc: Vegard Nossum Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- lib/iomap.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) diff --git a/lib/iomap.c b/lib/iomap.c index fbaa3e8f19d6..4f8b31baa575 100644 --- a/lib/iomap.c +++ b/lib/iomap.c @@ -6,6 +6,7 @@ */ #include #include +#include #include @@ -70,26 +71,35 @@ static void bad_io_access(unsigned long port, const char *access) #define mmio_read64be(addr) swab64(readq(addr)) #endif +/* + * Here and below, we apply __no_kmsan_checks to functions reading data from + * hardware, to ensure that KMSAN marks their return values as initialized. + */ +__no_kmsan_checks unsigned int ioread8(const void __iomem *addr) { IO_COND(addr, return inb(port), return readb(addr)); return 0xff; } +__no_kmsan_checks unsigned int ioread16(const void __iomem *addr) { IO_COND(addr, return inw(port), return readw(addr)); return 0xffff; } +__no_kmsan_checks unsigned int ioread16be(const void __iomem *addr) { IO_COND(addr, return pio_read16be(port), return mmio_read16be(addr)); return 0xffff; } +__no_kmsan_checks unsigned int ioread32(const void __iomem *addr) { IO_COND(addr, return inl(port), return readl(addr)); return 0xffffffff; } +__no_kmsan_checks unsigned int ioread32be(const void __iomem *addr) { IO_COND(addr, return pio_read32be(port), return mmio_read32be(addr)); @@ -142,18 +152,21 @@ static u64 pio_read64be_hi_lo(unsigned long port) return lo | (hi << 32); } +__no_kmsan_checks u64 ioread64_lo_hi(const void __iomem *addr) { IO_COND(addr, return pio_read64_lo_hi(port), return readq(addr)); return 0xffffffffffffffffULL; } +__no_kmsan_checks u64 ioread64_hi_lo(const void __iomem *addr) { IO_COND(addr, return pio_read64_hi_lo(port), return readq(addr)); return 0xffffffffffffffffULL; } +__no_kmsan_checks u64 ioread64be_lo_hi(const void __iomem *addr) { IO_COND(addr, return pio_read64be_lo_hi(port), @@ -161,6 +174,7 @@ u64 ioread64be_lo_hi(const void __iomem *addr) return 0xffffffffffffffffULL; } +__no_kmsan_checks u64 ioread64be_hi_lo(const void __iomem *addr) { IO_COND(addr, return pio_read64be_hi_lo(port), @@ -188,22 +202,32 @@ EXPORT_SYMBOL(ioread64be_hi_lo); void iowrite8(u8 val, void __iomem *addr) { + /* Make sure uninitialized memory isn't copied to devices. */ + kmsan_check_memory(&val, sizeof(val)); IO_COND(addr, outb(val,port), writeb(val, addr)); } void iowrite16(u16 val, void __iomem *addr) { + /* Make sure uninitialized memory isn't copied to devices. */ + kmsan_check_memory(&val, sizeof(val)); IO_COND(addr, outw(val,port), writew(val, addr)); } void iowrite16be(u16 val, void __iomem *addr) { + /* Make sure uninitialized memory isn't copied to devices. */ + kmsan_check_memory(&val, sizeof(val)); IO_COND(addr, pio_write16be(val,port), mmio_write16be(val, addr)); } void iowrite32(u32 val, void __iomem *addr) { + /* Make sure uninitialized memory isn't copied to devices. */ + kmsan_check_memory(&val, sizeof(val)); IO_COND(addr, outl(val,port), writel(val, addr)); } void iowrite32be(u32 val, void __iomem *addr) { + /* Make sure uninitialized memory isn't copied to devices. */ + kmsan_check_memory(&val, sizeof(val)); IO_COND(addr, pio_write32be(val,port), mmio_write32be(val, addr)); } EXPORT_SYMBOL(iowrite8); @@ -239,24 +263,32 @@ static void pio_write64be_hi_lo(u64 val, unsigned long port) void iowrite64_lo_hi(u64 val, void __iomem *addr) { + /* Make sure uninitialized memory isn't copied to devices. */ + kmsan_check_memory(&val, sizeof(val)); IO_COND(addr, pio_write64_lo_hi(val, port), writeq(val, addr)); } void iowrite64_hi_lo(u64 val, void __iomem *addr) { + /* Make sure uninitialized memory isn't copied to devices. */ + kmsan_check_memory(&val, sizeof(val)); IO_COND(addr, pio_write64_hi_lo(val, port), writeq(val, addr)); } void iowrite64be_lo_hi(u64 val, void __iomem *addr) { + /* Make sure uninitialized memory isn't copied to devices. */ + kmsan_check_memory(&val, sizeof(val)); IO_COND(addr, pio_write64be_lo_hi(val, port), mmio_write64be(val, addr)); } void iowrite64be_hi_lo(u64 val, void __iomem *addr) { + /* Make sure uninitialized memory isn't copied to devices. */ + kmsan_check_memory(&val, sizeof(val)); IO_COND(addr, pio_write64be_hi_lo(val, port), mmio_write64be(val, addr)); } @@ -328,14 +360,20 @@ static inline void mmio_outsl(void __iomem *addr, const u32 *src, int count) void ioread8_rep(const void __iomem *addr, void *dst, unsigned long count) { IO_COND(addr, insb(port,dst,count), mmio_insb(addr, dst, count)); + /* KMSAN must treat values read from devices as initialized. */ + kmsan_unpoison_memory(dst, count); } void ioread16_rep(const void __iomem *addr, void *dst, unsigned long count) { IO_COND(addr, insw(port,dst,count), mmio_insw(addr, dst, count)); + /* KMSAN must treat values read from devices as initialized. */ + kmsan_unpoison_memory(dst, count * 2); } void ioread32_rep(const void __iomem *addr, void *dst, unsigned long count) { IO_COND(addr, insl(port,dst,count), mmio_insl(addr, dst, count)); + /* KMSAN must treat values read from devices as initialized. */ + kmsan_unpoison_memory(dst, count * 4); } EXPORT_SYMBOL(ioread8_rep); EXPORT_SYMBOL(ioread16_rep); @@ -343,14 +381,20 @@ EXPORT_SYMBOL(ioread32_rep); void iowrite8_rep(void __iomem *addr, const void *src, unsigned long count) { + /* Make sure uninitialized memory isn't copied to devices. */ + kmsan_check_memory(src, count); IO_COND(addr, outsb(port, src, count), mmio_outsb(addr, src, count)); } void iowrite16_rep(void __iomem *addr, const void *src, unsigned long count) { + /* Make sure uninitialized memory isn't copied to devices. */ + kmsan_check_memory(src, count * 2); IO_COND(addr, outsw(port, src, count), mmio_outsw(addr, src, count)); } void iowrite32_rep(void __iomem *addr, const void *src, unsigned long count) { + /* Make sure uninitialized memory isn't copied to devices. */ + kmsan_check_memory(src, count * 4); IO_COND(addr, outsl(port, src,count), mmio_outsl(addr, src, count)); } EXPORT_SYMBOL(iowrite8_rep);