From: Michael Ellerman <mpe@ellerman.id.au>
To: Arnd Bergmann <arnd@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>,
Naresh Kamboju <naresh.kamboju@linaro.org>,
linux-kernel@vger.kernel.org,
linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
"Aneesh Kumar K . V" <aneesh.kumar@kernel.org>,
Anders Roxell <anders.roxell@linaro.org>,
Kees Cook <keescook@chromium.org>,
Niklas Schnelle <schnelle@linux.ibm.com>,
clang-built-linux <llvm@lists.linux.dev>,
Nick Desaulniers <ndesaulniers@google.com>,
Nathan Chancellor <nathan@kernel.org>,
Jeff Xu <jeffxu@chromium.org>,
"Naveen N . Rao" <naveen.n.rao@linux.ibm.com>,
Dan Carpenter <dan.carpenter@linaro.org>,
Nicholas Piggin <npiggin@gmail.com>,
Christophe Leroy <christophe.leroy@csgroup.eu>,
Bill Wendling <morbo@google.com>,
Justin Stitt <justinstitt@google.com>,
Baoquan He <bhe@redhat.com>,
"Mike Rapoport (IBM)" <rppt@kernel.org>
Subject: Re: [PATCH] powerpc: drop port I/O helpers for CONFIG_HAS_IOPORT=n
Date: Thu, 18 Apr 2024 16:33:04 +1000 [thread overview]
Message-ID: <875xwfb2ov.fsf@mail.lhotse> (raw)
In-Reply-To: <878r1bb2zj.fsf@mail.lhotse>
Michael Ellerman <mpe@ellerman.id.au> writes:
> Arnd Bergmann <arnd@kernel.org> writes:
>> From: Arnd Bergmann <arnd@arndb.de>
>>
>> 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 <arnd@arndb.de>
>> Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
>> --
>
> This needs a small fixup:
Well, only because my tree doesn't have f0a816fb12da ("/dev/port: don't compile file operations without CONFIG_DEVPORT").
cheers
WARNING: multiple messages have this Message-ID (diff)
From: Michael Ellerman <mpe@ellerman.id.au>
To: Arnd Bergmann <arnd@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>,
Anders Roxell <anders.roxell@linaro.org>,
Kees Cook <keescook@chromium.org>, Arnd Bergmann <arnd@arndb.de>,
Niklas Schnelle <schnelle@linux.ibm.com>,
Naresh Kamboju <naresh.kamboju@linaro.org>,
clang-built-linux <llvm@lists.linux.dev>,
Nick Desaulniers <ndesaulniers@google.com>,
linux-kernel@vger.kernel.org, Nicholas Piggin <npiggin@gmail.com>,
"Aneesh Kumar K . V" <aneesh.kumar@kernel.org>,
Jeff Xu <jeffxu@chromium.org>, Baoquan He <bhe@redhat.com>,
"Mike Rapoport \(IBM\)" <rppt@kernel.org>,
Justin Stitt <justinstitt@google.com>,
"Naveen N . Rao" <naveen.n.rao@linux.ibm.com>,
linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
Dan Carpenter <dan.carpenter@linaro.org>,
Bill Wendling <morbo@google.com>
Subject: Re: [PATCH] powerpc: drop port I/O helpers for CONFIG_HAS_IOPORT=n
Date: Thu, 18 Apr 2024 16:33:04 +1000 [thread overview]
Message-ID: <875xwfb2ov.fsf@mail.lhotse> (raw)
In-Reply-To: <878r1bb2zj.fsf@mail.lhotse>
Michael Ellerman <mpe@ellerman.id.au> writes:
> Arnd Bergmann <arnd@kernel.org> writes:
>> From: Arnd Bergmann <arnd@arndb.de>
>>
>> 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 <arnd@arndb.de>
>> Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
>> --
>
> This needs a small fixup:
Well, only because my tree doesn't have f0a816fb12da ("/dev/port: don't compile file operations without CONFIG_DEVPORT").
cheers
next prev parent reply other threads:[~2024-04-18 6:33 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-16 15:33 [PATCH] powerpc: drop port I/O helpers for CONFIG_HAS_IOPORT=n Arnd Bergmann
2024-04-16 15:33 ` Arnd Bergmann
2024-04-18 6:26 ` Michael Ellerman
2024-04-18 6:26 ` Michael Ellerman
2024-04-18 6:33 ` Michael Ellerman [this message]
2024-04-18 6:33 ` Michael Ellerman
2024-04-18 6:59 ` Arnd Bergmann
2024-04-18 6:59 ` Arnd Bergmann
2024-04-18 13:01 ` Michael Ellerman
2024-04-18 13:01 ` Michael Ellerman
2024-04-19 5:12 ` Michael Ellerman
2024-04-19 5:12 ` Michael Ellerman
2024-04-19 5:58 ` Arnd Bergmann
2024-04-19 5:58 ` Arnd Bergmann
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