From: Christophe Leroy <christophe.leroy@csgroup.eu>
To: Daniel Axtens <dja@axtens.net>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Michael Ellerman <mpe@ellerman.id.au>,
Andrew Morton <akpm@linux-foundation.org>,
"James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>,
Helge Deller <deller@gmx.de>, Arnd Bergmann <arnd@arndb.de>,
Kees Cook <keescook@chromium.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-arch@vger.kernel.org, linux-ia64@vger.kernel.org,
linux-parisc@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH v2 02/13] powerpc: Rename 'funcaddr' to 'addr' in 'struct ppc64_opd_entry'
Date: Fri, 15 Oct 2021 06:59:31 +0200 [thread overview]
Message-ID: <6f1c3624-eef4-fc6c-9f2f-d649d8c93cdf@csgroup.eu> (raw)
In-Reply-To: <877def46xc.fsf@dja-thinkpad.axtens.net>
Le 14/10/2021 à 23:45, Daniel Axtens a écrit :
> Christophe Leroy <christophe.leroy@csgroup.eu> writes:
>
>> There are three architectures with function descriptors, try to
>> have common names for the address they contain in order to
>> refactor some functions into generic functions later.
>>
>> powerpc has 'funcaddr'
>> ia64 has 'ip'
>> parisc has 'addr'
>>
>> Vote for 'addr' and update 'struct ppc64_opd_entry' accordingly.
>
> I would have picked 'funcaddr', but at least 'addr' is better than 'ip'!
> And I agree that consistency, and then making things generic is worthwhile.
It's a function descriptor, there is only one address field, I don't
think there is any ambiguïty here, and I prefer modifying the least
impacted architectures.
Changing addr to funcaddr in PARISC would result in the following
changes, on an architecture I know nothing about. It's more changes than
we have on powerpc.
arch/parisc/include/asm/elf.h | 4 ++--
arch/parisc/kernel/kexec.c | 2 +-
arch/parisc/kernel/module.c | 12 ++++++------
arch/parisc/kernel/process.c | 2 +-
arch/parisc/kernel/signal.c | 4 ++--
5 files changed, 12 insertions(+), 12 deletions(-)
>
> I grepped the latest powerpc/next for uses of 'funcaddr'. There were 5,
> your patch changes all 5.
>
> The series passes build tests and this patch has no checkpatch or other
> style concerns.
>
> On that basis:
> Reviewed-by: Daniel Axtens <dja@axtens.net>
>
> Kind regards,
> Daniel
>
>> Reviewed-by: Kees Cook <keescook@chromium.org>
>> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
>> ---
>> arch/powerpc/include/asm/elf.h | 2 +-
>> arch/powerpc/include/asm/sections.h | 2 +-
>> arch/powerpc/kernel/module_64.c | 6 +++---
>> 3 files changed, 5 insertions(+), 5 deletions(-)
>>
>> diff --git a/arch/powerpc/include/asm/elf.h b/arch/powerpc/include/asm/elf.h
>> index a4406714c060..bb0f278f9ed4 100644
>> --- a/arch/powerpc/include/asm/elf.h
>> +++ b/arch/powerpc/include/asm/elf.h
>> @@ -178,7 +178,7 @@ void relocate(unsigned long final_address);
>>
>> /* There's actually a third entry here, but it's unused */
>> struct ppc64_opd_entry {
>> - unsigned long funcaddr;
>> + unsigned long addr;
>> unsigned long r2;
>> };
>>
>> diff --git a/arch/powerpc/include/asm/sections.h b/arch/powerpc/include/asm/sections.h
>> index 6e4af4492a14..32e7035863ac 100644
>> --- a/arch/powerpc/include/asm/sections.h
>> +++ b/arch/powerpc/include/asm/sections.h
>> @@ -77,7 +77,7 @@ static inline void *dereference_function_descriptor(void *ptr)
>> struct ppc64_opd_entry *desc = ptr;
>> void *p;
>>
>> - if (!get_kernel_nofault(p, (void *)&desc->funcaddr))
>> + if (!get_kernel_nofault(p, (void *)&desc->addr))
>> ptr = p;
>> return ptr;
>> }
>> diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
>> index 6baa676e7cb6..82908c9be627 100644
>> --- a/arch/powerpc/kernel/module_64.c
>> +++ b/arch/powerpc/kernel/module_64.c
>> @@ -72,11 +72,11 @@ static func_desc_t func_desc(unsigned long addr)
>> }
>> static unsigned long func_addr(unsigned long addr)
>> {
>> - return func_desc(addr).funcaddr;
>> + return func_desc(addr).addr;
>> }
>> static unsigned long stub_func_addr(func_desc_t func)
>> {
>> - return func.funcaddr;
>> + return func.addr;
>> }
>> static unsigned int local_entry_offset(const Elf64_Sym *sym)
>> {
>> @@ -187,7 +187,7 @@ static int relacmp(const void *_x, const void *_y)
>> static unsigned long get_stubs_size(const Elf64_Ehdr *hdr,
>> const Elf64_Shdr *sechdrs)
>> {
>> - /* One extra reloc so it's always 0-funcaddr terminated */
>> + /* One extra reloc so it's always 0-addr terminated */
>> unsigned long relocs = 1;
>> unsigned i;
>>
>> --
>> 2.31.1
next prev parent reply other threads:[~2021-10-15 4:59 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-14 5:49 [PATCH v2 00/13] Fix LKDTM for PPC64/IA64/PARISC Christophe Leroy
2021-10-14 5:49 ` [PATCH v2 01/13] powerpc: Move 'struct ppc64_opd_entry' back into asm/elf.h Christophe Leroy
2021-10-14 21:26 ` Daniel Axtens
2021-10-15 5:57 ` Nicholas Piggin
2021-10-14 5:49 ` [PATCH v2 02/13] powerpc: Rename 'funcaddr' to 'addr' in 'struct ppc64_opd_entry' Christophe Leroy
2021-10-14 21:45 ` Daniel Axtens
2021-10-15 4:59 ` Christophe Leroy [this message]
2021-10-15 6:01 ` Nicholas Piggin
2021-10-14 5:49 ` [PATCH v2 03/13] powerpc: Remove func_descr_t Christophe Leroy
2021-10-14 22:17 ` Daniel Axtens
2021-10-15 5:19 ` Christophe Leroy
2021-10-15 6:11 ` Nicholas Piggin
2021-10-14 5:49 ` [PATCH v2 04/13] powerpc: Prepare func_desc_t for refactorisation Christophe Leroy
2021-10-14 5:49 ` [PATCH v2 05/13] ia64: Rename 'ip' to 'addr' in 'struct fdesc' Christophe Leroy
2021-10-14 5:49 ` [PATCH v2 06/13] asm-generic: Use HAVE_FUNCTION_DESCRIPTORS to define associated stubs Christophe Leroy
2021-10-15 6:16 ` Nicholas Piggin
2021-10-15 6:24 ` Christophe Leroy
2021-10-15 8:02 ` Nicholas Piggin
2021-10-15 11:52 ` Nicholas Piggin
2021-10-14 5:49 ` [PATCH v2 07/13] asm-generic: Define 'func_desc_t' to commonly describe function descriptors Christophe Leroy
2021-10-14 6:52 ` Arnd Bergmann
2021-10-14 5:49 ` [PATCH v2 08/13] asm-generic: Refactor dereference_[kernel]_function_descriptor() Christophe Leroy
2021-10-15 7:00 ` Nicholas Piggin
2021-10-14 5:49 ` [PATCH v2 09/13] lkdtm: Force do_nothing() out of line Christophe Leroy
2021-10-14 5:49 ` [PATCH v2 10/13] lkdtm: Really write into kernel text in WRITE_KERN Christophe Leroy
2021-10-14 5:50 ` [PATCH v2 11/13] lkdtm: Fix lkdtm_EXEC_RODATA() Christophe Leroy
2021-10-15 21:32 ` Kees Cook
2021-10-16 6:41 ` Christophe Leroy
2021-10-17 7:50 ` Christophe Leroy
2021-10-14 5:50 ` [PATCH v2 12/13] lkdtm: Fix execute_[user]_location() Christophe Leroy
2021-10-15 21:31 ` Kees Cook
2021-10-16 6:42 ` Christophe Leroy
2021-11-16 15:07 ` Christophe Leroy
2021-10-14 5:50 ` [PATCH v2 13/13] lkdtm: Add a test for function descriptors protection Christophe Leroy
2021-10-15 21:35 ` Kees Cook
2021-10-16 6:28 ` Christophe Leroy
2021-10-14 21:35 ` [PATCH v2 00/13] Fix LKDTM for PPC64/IA64/PARISC Daniel Axtens
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