[kbuild-all] drivers/accessibility/speakup/speakup_acntpc.c:262:14: warning: performing pointer arithmetic on a null pointer has undefined behavior

Thursday, 11 February 2021

Hi Samuel,

First bad commit (maybe != root cause):

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   e0756cfc7d7cd08c98a53b6009c091a3f6a50be6
commit: 2067fd92d75b6d9085a43caf050bca5d88c491b8 staging/speakup: Move out of staging
date:   7 months ago
config: riscv-randconfig-r006-20210211 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project
c9439ca36342fb6013187d0a69aef92736951476)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O
~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install riscv cross compiling tool for clang build
        # apt-get install binutils-riscv64-linux-gnu
        #
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit...
        git remote add linus
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
        git fetch --no-tags linus master
        git checkout 2067fd92d75b6d9085a43caf050bca5d88c491b8
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=riscv 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp(a)intel.com&gt;

All warnings (new ones prefixed by >>):

   In file included from drivers/accessibility/speakup/speakup_acntpc.c:19:
   In file included from drivers/accessibility/speakup/spk_priv.h:16:
   In file included from drivers/accessibility/speakup/spk_types.h:17:
   In file included from include/linux/io.h:13:
   In file included from arch/riscv/include/asm/io.h:148:
   include/asm-generic/io.h:556:9: warning: performing pointer arithmetic on a null
pointer has undefined behavior [-Wnull-pointer-arithmetic]
           return inb(addr);
                  ^~~~~~~~~
   arch/riscv/include/asm/io.h:54:76: note: expanded from macro 'inb'
   #define inb(c)          ({ u8  __v; __io_pbr(); __v = readb_cpu((void*)(PCI_IOBASE +
(c))); __io_par(__v); __v; })
                                                                           ~~~~~~~~~~ ^
   arch/riscv/include/asm/mmio.h:93:48: note: expanded from macro 'readb_cpu'
   #define readb_cpu(c)            ({ u8  __r = __raw_readb(c); __r; })
                                                            ^
   In file included from drivers/accessibility/speakup/speakup_acntpc.c:19:
   In file included from drivers/accessibility/speakup/spk_priv.h:16:
   In file included from drivers/accessibility/speakup/spk_types.h:17:
   In file included from include/linux/io.h:13:
   In file included from arch/riscv/include/asm/io.h:148:
   include/asm-generic/io.h:564:9: warning: performing pointer arithmetic on a null
pointer has undefined behavior [-Wnull-pointer-arithmetic]
           return inw(addr);
                  ^~~~~~~~~
   arch/riscv/include/asm/io.h:55:76: note: expanded from macro 'inw'
   #define inw(c)          ({ u16 __v; __io_pbr(); __v = readw_cpu((void*)(PCI_IOBASE +
(c))); __io_par(__v); __v; })
                                                                           ~~~~~~~~~~ ^
   arch/riscv/include/asm/mmio.h:94:76: note: expanded from macro 'readw_cpu'
   #define readw_cpu(c)            ({ u16 __r = le16_to_cpu((__force
__le16)__raw_readw(c)); __r; })
                                                                                        ^
   include/uapi/linux/byteorder/little_endian.h:36:51: note: expanded from macro
'__le16_to_cpu'
   #define __le16_to_cpu(x) ((__force __u16)(__le16)(x))
                                                     ^
   In file included from drivers/accessibility/speakup/speakup_acntpc.c:19:
   In file included from drivers/accessibility/speakup/spk_priv.h:16:
   In file included from drivers/accessibility/speakup/spk_types.h:17:
   In file included from include/linux/io.h:13:
   In file included from arch/riscv/include/asm/io.h:148:
   include/asm-generic/io.h:572:9: warning: performing pointer arithmetic on a null
pointer has undefined behavior [-Wnull-pointer-arithmetic]
           return inl(addr);
                  ^~~~~~~~~
   arch/riscv/include/asm/io.h:56:76: note: expanded from macro 'inl'
   #define inl(c)          ({ u32 __v; __io_pbr(); __v = readl_cpu((void*)(PCI_IOBASE +
(c))); __io_par(__v); __v; })
                                                                           ~~~~~~~~~~ ^
   arch/riscv/include/asm/mmio.h:95:76: note: expanded from macro 'readl_cpu'
   #define readl_cpu(c)            ({ u32 __r = le32_to_cpu((__force
__le32)__raw_readl(c)); __r; })
                                                                                        ^
   include/uapi/linux/byteorder/little_endian.h:34:51: note: expanded from macro
'__le32_to_cpu'
   #define __le32_to_cpu(x) ((__force __u32)(__le32)(x))
                                                     ^
   In file included from drivers/accessibility/speakup/speakup_acntpc.c:19:
   In file included from drivers/accessibility/speakup/spk_priv.h:16:
   In file included from drivers/accessibility/speakup/spk_types.h:17:
   In file included from include/linux/io.h:13:
   In file included from arch/riscv/include/asm/io.h:148:
   include/asm-generic/io.h:580:2: warning: performing pointer arithmetic on a null
pointer has undefined behavior [-Wnull-pointer-arithmetic]
           outb(value, addr);
           ^~~~~~~~~~~~~~~~~
   arch/riscv/include/asm/io.h:58:68: note: expanded from macro 'outb'
   #define outb(v,c)       ({ __io_pbw(); writeb_cpu((v),(void*)(PCI_IOBASE + (c)));
__io_paw(); })
                                                                 ~~~~~~~~~~ ^
   arch/riscv/include/asm/mmio.h:97:52: note: expanded from macro 'writeb_cpu'
   #define writeb_cpu(v, c)        ((void)__raw_writeb((v), (c)))
                                                             ^
   In file included from drivers/accessibility/speakup/speakup_acntpc.c:19:
   In file included from drivers/accessibility/speakup/spk_priv.h:16:
   In file included from drivers/accessibility/speakup/spk_types.h:17:
   In file included from include/linux/io.h:13:
   In file included from arch/riscv/include/asm/io.h:148:
   include/asm-generic/io.h:588:2: warning: performing pointer arithmetic on a null
pointer has undefined behavior [-Wnull-pointer-arithmetic]
           outw(value, addr);
           ^~~~~~~~~~~~~~~~~
   arch/riscv/include/asm/io.h:59:68: note: expanded from macro 'outw'
   #define outw(v,c)       ({ __io_pbw(); writew_cpu((v),(void*)(PCI_IOBASE + (c)));
__io_paw(); })
                                                                 ~~~~~~~~~~ ^
   arch/riscv/include/asm/mmio.h:98:76: note: expanded from macro 'writew_cpu'
   #define writew_cpu(v, c)        ((void)__raw_writew((__force u16)cpu_to_le16(v), (c)))
                                                                                     ^
   In file included from drivers/accessibility/speakup/speakup_acntpc.c:19:
   In file included from drivers/accessibility/speakup/spk_priv.h:16:
   In file included from drivers/accessibility/speakup/spk_types.h:17:
   In file included from include/linux/io.h:13:
   In file included from arch/riscv/include/asm/io.h:148:
   include/asm-generic/io.h:596:2: warning: performing pointer arithmetic on a null
pointer has undefined behavior [-Wnull-pointer-arithmetic]
           outl(value, addr);
           ^~~~~~~~~~~~~~~~~
   arch/riscv/include/asm/io.h:60:68: note: expanded from macro 'outl'
   #define outl(v,c)       ({ __io_pbw(); writel_cpu((v),(void*)(PCI_IOBASE + (c)));
__io_paw(); })
                                                                 ~~~~~~~~~~ ^
   arch/riscv/include/asm/mmio.h:99:76: note: expanded from macro 'writel_cpu'
   #define writel_cpu(v, c)        ((void)__raw_writel((__force u32)cpu_to_le32(v), (c)))
                                                                                     ^
   In file included from drivers/accessibility/speakup/speakup_acntpc.c:19:
   In file included from drivers/accessibility/speakup/spk_priv.h:16:
   In file included from drivers/accessibility/speakup/spk_types.h:17:
   In file included from include/linux/io.h:13:
   In file included from arch/riscv/include/asm/io.h:148:
   include/asm-generic/io.h:1017:55: warning: performing pointer arithmetic on a null
pointer has undefined behavior [-Wnull-pointer-arithmetic]
           return (port > MMIO_UPPER_LIMIT) ? NULL : PCI_IOBASE + port;
                                                     ~~~~~~~~~~ ^
...
> drivers/accessibility/speakup/speakup_acntpc.c:262:14: warning:
performing pointer arithmetic on a null pointer has undefined behavior
[-Wnull-pointer-arithmetic]                    port_val = inw(speakup_info.port_tts
- 1);
                              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   arch/riscv/include/asm/io.h:55:76: note: expanded from macro 'inw'
   #define inw(c)          ({ u16 __v; __io_pbr(); __v = readw_cpu((void*)(PCI_IOBASE +
(c))); __io_par(__v); __v; })
                                                                           ~~~~~~~~~~ ^
   arch/riscv/include/asm/mmio.h:94:76: note: expanded from macro 'readw_cpu'
   #define readw_cpu(c)            ({ u16 __r = le16_to_cpu((__force
__le16)__raw_readw(c)); __r; })
                                                                                        ^
   include/uapi/linux/byteorder/little_endian.h:36:51: note: expanded from macro
'__le16_to_cpu'
   #define __le16_to_cpu(x) ((__force __u16)(__le16)(x))
                                                     ^
   drivers/accessibility/speakup/speakup_acntpc.c:273:15: warning: performing pointer
arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
                           port_val = inw(synth_portlist[i]) & 0xfffc;
                                      ^~~~~~~~~~~~~~~~~~~~~~
   arch/riscv/include/asm/io.h:55:76: note: expanded from macro 'inw'
   #define inw(c)          ({ u16 __v; __io_pbr(); __v = readw_cpu((void*)(PCI_IOBASE +
(c))); __io_par(__v); __v; })
                                                                           ~~~~~~~~~~ ^
   arch/riscv/include/asm/mmio.h:94:76: note: expanded from macro 'readw_cpu'
   #define readw_cpu(c)            ({ u16 __r = le16_to_cpu((__force
__le16)__raw_readw(c)); __r; })
                                                                                        ^
   include/uapi/linux/byteorder/little_endian.h:36:51: note: expanded from macro
'__le16_to_cpu'
   #define __le16_to_cpu(x) ((__force __u16)(__le16)(x))
                                                     ^
   9 warnings generated.
--
   In file included from drivers/accessibility/speakup/speakup_dtlk.c:18:
   In file included from drivers/accessibility/speakup/spk_priv.h:16:
   In file included from drivers/accessibility/speakup/spk_types.h:17:
   In file included from include/linux/io.h:13:
   In file included from arch/riscv/include/asm/io.h:148:
   include/asm-generic/io.h:556:9: warning: performing pointer arithmetic on a null
pointer has undefined behavior [-Wnull-pointer-arithmetic]
           return inb(addr);
                  ^~~~~~~~~
   arch/riscv/include/asm/io.h:54:76: note: expanded from macro 'inb'
   #define inb(c)          ({ u8  __v; __io_pbr(); __v = readb_cpu((void*)(PCI_IOBASE +
(c))); __io_par(__v); __v; })
                                                                           ~~~~~~~~~~ ^
   arch/riscv/include/asm/mmio.h:93:48: note: expanded from macro 'readb_cpu'
   #define readb_cpu(c)            ({ u8  __r = __raw_readb(c); __r; })
                                                            ^
   In file included from drivers/accessibility/speakup/speakup_dtlk.c:18:
   In file included from drivers/accessibility/speakup/spk_priv.h:16:
   In file included from drivers/accessibility/speakup/spk_types.h:17:
   In file included from include/linux/io.h:13:
   In file included from arch/riscv/include/asm/io.h:148:
   include/asm-generic/io.h:564:9: warning: performing pointer arithmetic on a null
pointer has undefined behavior [-Wnull-pointer-arithmetic]
           return inw(addr);
                  ^~~~~~~~~
   arch/riscv/include/asm/io.h:55:76: note: expanded from macro 'inw'
   #define inw(c)          ({ u16 __v; __io_pbr(); __v = readw_cpu((void*)(PCI_IOBASE +
(c))); __io_par(__v); __v; })
                                                                           ~~~~~~~~~~ ^
   arch/riscv/include/asm/mmio.h:94:76: note: expanded from macro 'readw_cpu'
   #define readw_cpu(c)            ({ u16 __r = le16_to_cpu((__force
__le16)__raw_readw(c)); __r; })
                                                                                        ^
   include/uapi/linux/byteorder/little_endian.h:36:51: note: expanded from macro
'__le16_to_cpu'
   #define __le16_to_cpu(x) ((__force __u16)(__le16)(x))
                                                     ^
   In file included from drivers/accessibility/speakup/speakup_dtlk.c:18:
   In file included from drivers/accessibility/speakup/spk_priv.h:16:
   In file included from drivers/accessibility/speakup/spk_types.h:17:
   In file included from include/linux/io.h:13:
   In file included from arch/riscv/include/asm/io.h:148:
   include/asm-generic/io.h:572:9: warning: performing pointer arithmetic on a null
pointer has undefined behavior [-Wnull-pointer-arithmetic]
           return inl(addr);
                  ^~~~~~~~~
   arch/riscv/include/asm/io.h:56:76: note: expanded from macro 'inl'
   #define inl(c)          ({ u32 __v; __io_pbr(); __v = readl_cpu((void*)(PCI_IOBASE +
(c))); __io_par(__v); __v; })
                                                                           ~~~~~~~~~~ ^
   arch/riscv/include/asm/mmio.h:95:76: note: expanded from macro 'readl_cpu'
   #define readl_cpu(c)            ({ u32 __r = le32_to_cpu((__force
__le32)__raw_readl(c)); __r; })
                                                                                        ^
   include/uapi/linux/byteorder/little_endian.h:34:51: note: expanded from macro
'__le32_to_cpu'
   #define __le32_to_cpu(x) ((__force __u32)(__le32)(x))
                                                     ^
   In file included from drivers/accessibility/speakup/speakup_dtlk.c:18:
   In file included from drivers/accessibility/speakup/spk_priv.h:16:
   In file included from drivers/accessibility/speakup/spk_types.h:17:
   In file included from include/linux/io.h:13:
   In file included from arch/riscv/include/asm/io.h:148:
   include/asm-generic/io.h:580:2: warning: performing pointer arithmetic on a null
pointer has undefined behavior [-Wnull-pointer-arithmetic]
           outb(value, addr);
           ^~~~~~~~~~~~~~~~~
   arch/riscv/include/asm/io.h:58:68: note: expanded from macro 'outb'
   #define outb(v,c)       ({ __io_pbw(); writeb_cpu((v),(void*)(PCI_IOBASE + (c)));
__io_paw(); })
                                                                 ~~~~~~~~~~ ^
   arch/riscv/include/asm/mmio.h:97:52: note: expanded from macro 'writeb_cpu'
   #define writeb_cpu(v, c)        ((void)__raw_writeb((v), (c)))
                                                             ^
   In file included from drivers/accessibility/speakup/speakup_dtlk.c:18:
   In file included from drivers/accessibility/speakup/spk_priv.h:16:
   In file included from drivers/accessibility/speakup/spk_types.h:17:
   In file included from include/linux/io.h:13:
   In file included from arch/riscv/include/asm/io.h:148:
   include/asm-generic/io.h:588:2: warning: performing pointer arithmetic on a null
pointer has undefined behavior [-Wnull-pointer-arithmetic]
           outw(value, addr);
           ^~~~~~~~~~~~~~~~~
   arch/riscv/include/asm/io.h:59:68: note: expanded from macro 'outw'
   #define outw(v,c)       ({ __io_pbw(); writew_cpu((v),(void*)(PCI_IOBASE + (c)));
__io_paw(); })
                                                                 ~~~~~~~~~~ ^
   arch/riscv/include/asm/mmio.h:98:76: note: expanded from macro 'writew_cpu'
   #define writew_cpu(v, c)        ((void)__raw_writew((__force u16)cpu_to_le16(v), (c)))
                                                                                     ^
   In file included from drivers/accessibility/speakup/speakup_dtlk.c:18:
   In file included from drivers/accessibility/speakup/spk_priv.h:16:
   In file included from drivers/accessibility/speakup/spk_types.h:17:
   In file included from include/linux/io.h:13:
   In file included from arch/riscv/include/asm/io.h:148:
   include/asm-generic/io.h:596:2: warning: performing pointer arithmetic on a null
pointer has undefined behavior [-Wnull-pointer-arithmetic]
           outl(value, addr);
           ^~~~~~~~~~~~~~~~~
   arch/riscv/include/asm/io.h:60:68: note: expanded from macro 'outl'
   #define outl(v,c)       ({ __io_pbw(); writel_cpu((v),(void*)(PCI_IOBASE + (c)));
__io_paw(); })
                                                                 ~~~~~~~~~~ ^
   arch/riscv/include/asm/mmio.h:99:76: note: expanded from macro 'writel_cpu'
   #define writel_cpu(v, c)        ((void)__raw_writel((__force u32)cpu_to_le32(v), (c)))
                                                                                     ^
   In file included from drivers/accessibility/speakup/speakup_dtlk.c:18:
   In file included from drivers/accessibility/speakup/spk_priv.h:16:
   In file included from drivers/accessibility/speakup/spk_types.h:17:
   In file included from include/linux/io.h:13:
   In file included from arch/riscv/include/asm/io.h:148:
   include/asm-generic/io.h:1017:55: warning: performing pointer arithmetic on a null
pointer has undefined behavior [-Wnull-pointer-arithmetic]
           return (port > MMIO_UPPER_LIMIT) ? NULL : PCI_IOBASE + port;
                                                     ~~~~~~~~~~ ^
...
> drivers/accessibility/speakup/speakup_dtlk.c:334:14: warning:
performing pointer arithmetic on a null pointer has undefined behavior
[-Wnull-pointer-arithmetic]                    port_val = inw(speakup_info.port_tts
- 1);
                              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   arch/riscv/include/asm/io.h:55:76: note: expanded from macro 'inw'
   #define inw(c)          ({ u16 __v; __io_pbr(); __v = readw_cpu((void*)(PCI_IOBASE +
(c))); __io_par(__v); __v; })
                                                                           ~~~~~~~~~~ ^
   arch/riscv/include/asm/mmio.h:94:76: note: expanded from macro 'readw_cpu'
   #define readw_cpu(c)            ({ u16 __r = le16_to_cpu((__force
__le16)__raw_readw(c)); __r; })
                                                                                        ^
   include/uapi/linux/byteorder/little_endian.h:36:51: note: expanded from macro
'__le16_to_cpu'
   #define __le16_to_cpu(x) ((__force __u16)(__le16)(x))
                                                     ^
   drivers/accessibility/speakup/speakup_dtlk.c:341:15: warning: performing pointer
arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
                           port_val = inw(synth_portlist[i]) & 0xfbff;
                                      ^~~~~~~~~~~~~~~~~~~~~~
   arch/riscv/include/asm/io.h:55:76: note: expanded from macro 'inw'
   #define inw(c)          ({ u16 __v; __io_pbr(); __v = readw_cpu((void*)(PCI_IOBASE +
(c))); __io_par(__v); __v; })
                                                                           ~~~~~~~~~~ ^
   arch/riscv/include/asm/mmio.h:94:76: note: expanded from macro 'readw_cpu'
   #define readw_cpu(c)            ({ u16 __r = le16_to_cpu((__force
__le16)__raw_readw(c)); __r; })
                                                                                        ^
   include/uapi/linux/byteorder/little_endian.h:36:51: note: expanded from macro
'__le16_to_cpu'
   #define __le16_to_cpu(x) ((__force __u16)(__le16)(x))
                                                     ^
   9 warnings generated.
--
   In file included from drivers/accessibility/speakup/speakup_keypc.c:17:
   In file included from drivers/accessibility/speakup/spk_priv.h:16:
   In file included from drivers/accessibility/speakup/spk_types.h:17:
   In file included from include/linux/io.h:13:
   In file included from arch/riscv/include/asm/io.h:148:
   include/asm-generic/io.h:556:9: warning: performing pointer arithmetic on a null
pointer has undefined behavior [-Wnull-pointer-arithmetic]
           return inb(addr);
                  ^~~~~~~~~
   arch/riscv/include/asm/io.h:54:76: note: expanded from macro 'inb'
   #define inb(c)          ({ u8  __v; __io_pbr(); __v = readb_cpu((void*)(PCI_IOBASE +
(c))); __io_par(__v); __v; })
                                                                           ~~~~~~~~~~ ^
   arch/riscv/include/asm/mmio.h:93:48: note: expanded from macro 'readb_cpu'
   #define readb_cpu(c)            ({ u8  __r = __raw_readb(c); __r; })
                                                            ^
   In file included from drivers/accessibility/speakup/speakup_keypc.c:17:
   In file included from drivers/accessibility/speakup/spk_priv.h:16:
   In file included from drivers/accessibility/speakup/spk_types.h:17:
   In file included from include/linux/io.h:13:
   In file included from arch/riscv/include/asm/io.h:148:
   include/asm-generic/io.h:564:9: warning: performing pointer arithmetic on a null
pointer has undefined behavior [-Wnull-pointer-arithmetic]
           return inw(addr);
                  ^~~~~~~~~
   arch/riscv/include/asm/io.h:55:76: note: expanded from macro 'inw'
   #define inw(c)          ({ u16 __v; __io_pbr(); __v = readw_cpu((void*)(PCI_IOBASE +
(c))); __io_par(__v); __v; })
                                                                           ~~~~~~~~~~ ^
   arch/riscv/include/asm/mmio.h:94:76: note: expanded from macro 'readw_cpu'
   #define readw_cpu(c)            ({ u16 __r = le16_to_cpu((__force
__le16)__raw_readw(c)); __r; })
                                                                                        ^
   include/uapi/linux/byteorder/little_endian.h:36:51: note: expanded from macro
'__le16_to_cpu'
   #define __le16_to_cpu(x) ((__force __u16)(__le16)(x))
                                                     ^
   In file included from drivers/accessibility/speakup/speakup_keypc.c:17:
   In file included from drivers/accessibility/speakup/spk_priv.h:16:
   In file included from drivers/accessibility/speakup/spk_types.h:17:
   In file included from include/linux/io.h:13:
   In file included from arch/riscv/include/asm/io.h:148:
   include/asm-generic/io.h:572:9: warning: performing pointer arithmetic on a null
pointer has undefined behavior [-Wnull-pointer-arithmetic]
           return inl(addr);
                  ^~~~~~~~~
   arch/riscv/include/asm/io.h:56:76: note: expanded from macro 'inl'
   #define inl(c)          ({ u32 __v; __io_pbr(); __v = readl_cpu((void*)(PCI_IOBASE +
(c))); __io_par(__v); __v; })
                                                                           ~~~~~~~~~~ ^
   arch/riscv/include/asm/mmio.h:95:76: note: expanded from macro 'readl_cpu'
   #define readl_cpu(c)            ({ u32 __r = le32_to_cpu((__force
__le32)__raw_readl(c)); __r; })
                                                                                        ^
   include/uapi/linux/byteorder/little_endian.h:34:51: note: expanded from macro
'__le32_to_cpu'
   #define __le32_to_cpu(x) ((__force __u32)(__le32)(x))
                                                     ^
   In file included from drivers/accessibility/speakup/speakup_keypc.c:17:
   In file included from drivers/accessibility/speakup/spk_priv.h:16:
   In file included from drivers/accessibility/speakup/spk_types.h:17:
   In file included from include/linux/io.h:13:
   In file included from arch/riscv/include/asm/io.h:148:
   include/asm-generic/io.h:580:2: warning: performing pointer arithmetic on a null
pointer has undefined behavior [-Wnull-pointer-arithmetic]
           outb(value, addr);
           ^~~~~~~~~~~~~~~~~
   arch/riscv/include/asm/io.h:58:68: note: expanded from macro 'outb'
   #define outb(v,c)       ({ __io_pbw(); writeb_cpu((v),(void*)(PCI_IOBASE + (c)));
__io_paw(); })
                                                                 ~~~~~~~~~~ ^
   arch/riscv/include/asm/mmio.h:97:52: note: expanded from macro 'writeb_cpu'
   #define writeb_cpu(v, c)        ((void)__raw_writeb((v), (c)))
                                                             ^
   In file included from drivers/accessibility/speakup/speakup_keypc.c:17:
   In file included from drivers/accessibility/speakup/spk_priv.h:16:
   In file included from drivers/accessibility/speakup/spk_types.h:17:
   In file included from include/linux/io.h:13:
   In file included from arch/riscv/include/asm/io.h:148:
   include/asm-generic/io.h:588:2: warning: performing pointer arithmetic on a null
pointer has undefined behavior [-Wnull-pointer-arithmetic]
           outw(value, addr);
           ^~~~~~~~~~~~~~~~~
   arch/riscv/include/asm/io.h:59:68: note: expanded from macro 'outw'
   #define outw(v,c)       ({ __io_pbw(); writew_cpu((v),(void*)(PCI_IOBASE + (c)));
__io_paw(); })
                                                                 ~~~~~~~~~~ ^
   arch/riscv/include/asm/mmio.h:98:76: note: expanded from macro 'writew_cpu'
   #define writew_cpu(v, c)        ((void)__raw_writew((__force u16)cpu_to_le16(v), (c)))
                                                                                     ^
   In file included from drivers/accessibility/speakup/speakup_keypc.c:17:
   In file included from drivers/accessibility/speakup/spk_priv.h:16:
   In file included from drivers/accessibility/speakup/spk_types.h:17:
   In file included from include/linux/io.h:13:
   In file included from arch/riscv/include/asm/io.h:148:
   include/asm-generic/io.h:596:2: warning: performing pointer arithmetic on a null
pointer has undefined behavior [-Wnull-pointer-arithmetic]
           outl(value, addr);
           ^~~~~~~~~~~~~~~~~
   arch/riscv/include/asm/io.h:60:68: note: expanded from macro 'outl'
   #define outl(v,c)       ({ __io_pbw(); writel_cpu((v),(void*)(PCI_IOBASE + (c)));
__io_paw(); })
                                                                 ~~~~~~~~~~ ^
   arch/riscv/include/asm/mmio.h:99:76: note: expanded from macro 'writel_cpu'
   #define writel_cpu(v, c)        ((void)__raw_writel((__force u32)cpu_to_le32(v), (c)))
                                                                                     ^
   In file included from drivers/accessibility/speakup/speakup_keypc.c:17:
   In file included from drivers/accessibility/speakup/spk_priv.h:16:
   In file included from drivers/accessibility/speakup/spk_types.h:17:
   In file included from include/linux/io.h:13:
   In file included from arch/riscv/include/asm/io.h:148:
   include/asm-generic/io.h:1017:55: warning: performing pointer arithmetic on a null
pointer has undefined behavior [-Wnull-pointer-arithmetic]
           return (port > MMIO_UPPER_LIMIT) ? NULL : PCI_IOBASE + port;
                                                     ~~~~~~~~~~ ^
...
> drivers/accessibility/speakup/speakup_keypc.c:268:14: warning:
performing pointer arithmetic on a null pointer has undefined behavior
[-Wnull-pointer-arithmetic]                    port_val = inb(synth_port);
                              ^~~~~~~~~~~~~~~
   arch/riscv/include/asm/io.h:54:76: note: expanded from macro 'inb'
   #define inb(c)          ({ u8  __v; __io_pbr(); __v = readb_cpu((void*)(PCI_IOBASE +
(c))); __io_par(__v); __v; })
                                                                           ~~~~~~~~~~ ^
   arch/riscv/include/asm/mmio.h:93:48: note: expanded from macro 'readb_cpu'
   #define readb_cpu(c)            ({ u8  __r = __raw_readb(c); __r; })
                                                            ^
   drivers/accessibility/speakup/speakup_keypc.c:278:15: warning: performing pointer
arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
                           port_val = inb(synth_portlist[i]);
                                      ^~~~~~~~~~~~~~~~~~~~~~
   arch/riscv/include/asm/io.h:54:76: note: expanded from macro 'inb'
   #define inb(c)          ({ u8  __v; __io_pbr(); __v = readb_cpu((void*)(PCI_IOBASE +
(c))); __io_par(__v); __v; })
                                                                           ~~~~~~~~~~ ^
   arch/riscv/include/asm/mmio.h:93:48: note: expanded from macro 'readb_cpu'
   #define readb_cpu(c)            ({ u8  __r = __raw_readb(c); __r; })
                                                            ^
   9 warnings generated.
..

vim +262 drivers/accessibility/speakup/speakup_acntpc.c

c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
246  
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
247  static int synth_probe(struct spk_synth *synth)
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
248  {
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
249  	unsigned int port_val = 0;
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
250  	int i = 0;
8e69a811068657 drivers/staging/speakup/speakup_acntpc.c Domagoj Trsan       2014-09-09 
251  
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
252  	pr_info("Probing for %s.\n", synth->long_name);
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
253  	if (port_forced) {
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
254  		speakup_info.port_tts = port_forced;
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
255  		pr_info("probe forced to %x by kernel command line\n",
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
256  			speakup_info.port_tts);
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
257  		if (synth_request_region(speakup_info.port_tts - 1,
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
258  					 SYNTH_IO_EXTENT)) {
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
259  			pr_warn("sorry, port already reserved\n");
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
260  			return -EBUSY;
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
261  		}
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07
@262  		port_val = inw(speakup_info.port_tts - 1);
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
263  		synth_port_control = speakup_info.port_tts - 1;
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
264  	} else {
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
265  		for (i = 0; synth_portlist[i]; i++) {
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
266  			if (synth_request_region(synth_portlist[i],
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
267  						 SYNTH_IO_EXTENT)) {
bf4a4bacb051c2 drivers/staging/speakup/speakup_acntpc.c Christopher Brannon 2010-10-14 
268  				pr_warn
bf4a4bacb051c2 drivers/staging/speakup/speakup_acntpc.c Christopher Brannon 2010-10-14 
269  				    ("request_region: failed with 0x%x, %d\n",
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
270  				     synth_portlist[i], SYNTH_IO_EXTENT);
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
271  				continue;
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
272  			}
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
273  			port_val = inw(synth_portlist[i]) & 0xfffc;
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
274  			if (port_val == 0x53fc) {
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
275  				/* 'S' and out&input bits */
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
276  				synth_port_control = synth_portlist[i];
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
277  				speakup_info.port_tts = synth_port_control + 1;
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
278  				break;
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
279  			}
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
280  		}
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
281  	}
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
282  	port_val &= 0xfffc;
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
283  	if (port_val != 0x53fc) {
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
284  		/* 'S' and out&input bits */
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
285  		pr_info("%s: not found\n", synth->long_name);
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
286  		synth_release_region(synth_port_control, SYNTH_IO_EXTENT);
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
287  		synth_port_control = 0;
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
288  		return -ENODEV;
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
289  	}
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
290  	pr_info("%s: %03x-%03x, driver version %s,\n", synth->long_name,
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
291  		synth_port_control, synth_port_control + SYNTH_IO_EXTENT - 1,
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
292  		synth->version);
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
293  	synth->alive = 1;
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
294  	return 0;
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
295  }
c6e3fd22cd5383 drivers/staging/speakup/speakup_acntpc.c William Hubbs       2010-10-07 
296  

:::::: The code at line 262 was first introduced by commit
:::::: c6e3fd22cd538365bfeb82997d5b89562e077d42 Staging: add speakup to the staging
directory

:::::: TO: William Hubbs <w.d.hubbs(a)gmail.com&gt;
:::::: CC: Greg Kroah-Hartman <gregkh(a)suse.de&gt;

---
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https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

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[kbuild-all] drivers/accessibility/speakup/speakup_acntpc.c:262:14: warning: performing pointer arithmetic on a null pointer has undefined behavior