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Filename Latest commit message Latest commit date
Michael Ellerman be601edecf powerpc/io: Avoid clang null pointer arithmetic warnings
[ Upstream commit 03c0f2c2b2220fc9cf8785cd7b61d3e71e24a366 ]

With -Wextra clang warns about pointer arithmetic using a null pointer.
When building with CONFIG_PCI=n, that triggers a warning in the IO
accessors, eg:

  In file included from linux/arch/powerpc/include/asm/io.h:672:
  linux/arch/powerpc/include/asm/io-defs.h:23:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     23 | DEF_PCI_AC_RET(inb, u8, (unsigned long port), (port), pio, port)
        | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  ...
  linux/arch/powerpc/include/asm/io.h:591:53: note: expanded from macro '__do_inb'
    591 | #define __do_inb(port)          readb((PCI_IO_ADDR)_IO_BASE + port);
        |                                       ~~~~~~~~~~~~~~~~~~~~~ ^

That is because when CONFIG_PCI=n, _IO_BASE is defined as 0.

Although _IO_BASE is defined as plain 0, the cast (PCI_IO_ADDR) converts
it to void * before the addition with port happens.

Instead the addition can be done first, and then the cast. The resulting
value will be the same, but avoids the warning, and also avoids void
pointer arithmetic which is apparently non-standard.

Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Closes: https://lore.kernel.org/all/CA+G9fYtEh8zmq8k8wE-8RZwW-Qr927RLTn+KqGnq1F=ptaaNsA@mail.gmail.com
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240503075619.394467-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-05 09:08:21 +02:00
arch powerpc/io: Avoid clang null pointer arithmetic warnings 2024-07-05 09:08:21 +02:00
block block: prevent division by zero in blk_rq_stat_sum() 2024-04-13 12:51:38 +02:00
certs
crypto crypto: ecrdsa - Fix module auto-load on add_key 2024-06-16 13:28:51 +02:00
Documentation ASoC: dt-bindings: rt5645: add cbj sleeve gpio property 2024-06-16 13:28:31 +02:00
drivers Bluetooth: ath3k: Fix multiple issues reported by checkpatch.pl 2024-07-05 09:08:21 +02:00
fs nilfs2: fix potential kernel bug due to lack of writeback flag waiting 2024-07-05 09:08:19 +02:00
include hugetlb_encode.h: fix undefined behaviour (34 << 26) 2024-07-05 09:08:20 +02:00
init init: open /initrd.image with O_LARGEFILE 2024-04-13 12:51:36 +02:00
ipc ipc/sem: Fix dangling sem_array access in semtimedop race 2022-12-08 11:23:06 +01:00
kernel rcutorture: Fix rcu_torture_one_read() pipe_count overflow comment 2024-07-05 09:08:20 +02:00
lib dyndbg: fix old BUG_ON in >control parser 2024-05-17 11:43:55 +02:00
LICENSES
mm x86/mm/pat: fix VM_PAT handling in COW mappings 2024-04-13 12:51:40 +02:00
net drop_monitor: replace spin_lock by raw_spin_lock 2024-07-05 09:08:21 +02:00
samples media: rename VFL_TYPE_GRABBER to _VIDEO 2024-03-26 18:22:22 -04:00
scripts kconfig: fix comparison to constant symbols, 'm', 'n' 2024-06-16 13:28:47 +02:00
security smack: Handle SMACK64TRANSMUTE in smack_inode_setsecurity() 2024-04-13 12:51:22 +02:00
sound ASoC: ti: davinci-mcasp: Fix race condition during probe 2024-07-05 09:08:13 +02:00
tools selftests/bpf: Prevent client connect before server bind in test_tc_tunnel.sh 2024-07-05 09:08:20 +02:00
usr
virt KVM: async_pf: Cleanup kvm_setup_async_pf() 2024-05-02 16:18:32 +02:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS iio: stx104: Move to addac subdirectory 2023-08-30 16:27:12 +02:00
Makefile Linux 5.4.278 2024-06-16 13:28:53 +02:00
README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.