Hi, This is version 6 of my attempt to get rid of a clang -Wnull-pointer-arithmetic warning for the use of PCI_IOBASE in asm-generic/io.h and fix the NULL pointer access it points out. This was originally found on s390 but should apply to all platforms leaving PCI_IOBASE undefined while making use of the inb() and friends helpers from asm-generic/io.h. This applies cleanly and was compile tested on top of v5.12 for the previously broken ARC, nds32, h8300 and risc-v architecture. It also applies cleanly on v5.13-rc1 for which I boot tested it on s390. I did boot test this only on x86_64 and s390x the former implements inb() et al itself while the latter would emit a WARN_ONCE() but no drivers use inb(). Thanks, Niklas Changes sinve v5: - memset() the buffer in insb()/insw()/insl() in the WARN_ONCE() case to prevent use of uninitialized data (Arnd) Changes since v4: - Added Link to patch 4 (Arnd) - Improved comment on RISC-V patch mentioning current brokeness (Arnd) Changes since v3: - Changed the subject of the last patch to better reflect the actual change i.e. the addition of WARN_ONCE() to the helpers not the silencing of the clang warning - Added asm/bug.h to asm-generic/io.h so it doesn't have to be included previously by all arches to be available for the WARN_ONCE() - Added patch for risc-v which defines PCI_IOBASE except when compiled for nommu Changes since v2: - Improved comment for SPARC PCI_IOBASE definition as suggested by David Laight - Added a patch for ARC which is missing the asm/bug.h include for WARN_ONCE() (kernel test robot) - Added ifdefs to ioport_map() and __pci_ioport_map() since apparently at least test configs enable CONFIG_HAS_IOPORT_MAP even on architectures which leave PCI_IOBASE unset (kernel test robot for nds32 and ARC). Changes since v1: - Added patch to explicitly set PCI_IOBASE to 0 on sparc as suggested by Arnd Bergmann - Instead of working around the warning with a uintptr_t PCI_IOBASE make inb() and friends explicitly WARN_ONCE() and return 0xff... (Arnd Bergmann) Niklas Schnelle (3): sparc: explicitly set PCI_IOBASE to 0 risc-v: Use generic io.h helpers for nommu asm-generic/io.h: warn in inb() and friends with undefined PCI_IOBASE arch/riscv/include/asm/io.h | 5 +-- arch/sparc/include/asm/io.h | 8 +++++ include/asm-generic/io.h | 68 ++++++++++++++++++++++++++++++++++--- 3 files changed, 75 insertions(+), 6 deletions(-) -- 2.25.1
