| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Thu, 9 Nov 2023 10:49:05 +0000
From: Christophe Leroy <christophe.leroy@...roup.eu>
To: Michael Ellerman <mpe@...erman.id.au>, Arnd Bergmann <arnd@...db.de>, Arnd
Bergmann <arnd@...nel.org>, Andrew Morton <akpm@...ux-foundation.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>, Masahiro
Yamada <masahiroy@...nel.org>, "linux-kbuild@...r.kernel.org"
<linux-kbuild@...r.kernel.org>
CC: Matt Turner <mattst88@...il.com>, Vineet Gupta <vgupta@...nel.org>,
Russell King <linux@...linux.org.uk>, Catalin Marinas
<catalin.marinas@....com>, Will Deacon <will@...nel.org>, Steven Rostedt
<rostedt@...dmis.org>, Masami Hiramatsu <mhiramat@...nel.org>, Mark Rutland
<mark.rutland@....com>, guoren <guoren@...nel.org>, Peter Zijlstra
<peterz@...radead.org>, Ard Biesheuvel <ardb@...nel.org>, Huacai Chen
<chenhuacai@...nel.org>, Greg Ungerer <gerg@...ux-m68k.org>, Michal Simek
<monstr@...str.eu>, Thomas Bogendoerfer <tsbogend@...ha.franken.de>, Dinh
Nguyen <dinguyen@...nel.org>, Nicholas Piggin <npiggin@...il.com>, Geoff
Levand <geoff@...radead.org>, Palmer Dabbelt <palmer@...belt.com>, Heiko
Carstens <hca@...ux.ibm.com>, John Paul Adrian Glaubitz
<glaubitz@...sik.fu-berlin.de>, "David S . Miller" <davem@...emloft.net>,
Andy Lutomirski <luto@...nel.org>, Thomas Gleixner <tglx@...utronix.de>, Ingo
Molnar <mingo@...hat.com>, "x86@...nel.org" <x86@...nel.org>, Helge Deller
<deller@....de>, Sudip Mukherjee <sudipm.mukherjee@...il.com>, Greg
Kroah-Hartman <gregkh@...uxfoundation.org>, Timur Tabi <timur@...nel.org>,
Kent Overstreet <kent.overstreet@...ux.dev>, David Woodhouse
<dwmw2@...radead.org>, "Naveen N. Rao" <naveen.n.rao@...ux.ibm.com>, Anil S
Keshavamurthy <anil.s.keshavamurthy@...el.com>, Kees Cook
<keescook@...omium.org>, Vincenzo Frascino <vincenzo.frascino@....com>, Juri
Lelli <juri.lelli@...hat.com>, Vincent Guittot <vincent.guittot@...aro.org>,
Nathan Chancellor <nathan@...nel.org>, Nick Desaulniers
<ndesaulniers@...gle.com>, Nicolas Schier <nicolas@...sle.eu>, Alexander Viro
<viro@...iv.linux.org.uk>, Uwe Kleine-König
<u.kleine-koenig@...gutronix.de>, "linux-alpha@...r.kernel.org"
<linux-alpha@...r.kernel.org>, "linux-snps-arc@...ts.infradead.org"
<linux-snps-arc@...ts.infradead.org>, "linux-arm-kernel@...ts.infradead.org"
<linux-arm-kernel@...ts.infradead.org>, "linux-trace-kernel@...r.kernel.org"
<linux-trace-kernel@...r.kernel.org>, "linux-csky@...r.kernel.org"
<linux-csky@...r.kernel.org>, "loongarch@...ts.linux.dev"
<loongarch@...ts.linux.dev>, "linux-m68k@...ts.linux-m68k.org"
<linux-m68k@...ts.linux-m68k.org>, "linux-mips@...r.kernel.org"
<linux-mips@...r.kernel.org>, "linuxppc-dev@...ts.ozlabs.org"
<linuxppc-dev@...ts.ozlabs.org>, "linux-riscv@...ts.infradead.org"
<linux-riscv@...ts.infradead.org>, "linux-s390@...r.kernel.org"
<linux-s390@...r.kernel.org>, "linux-sh@...r.kernel.org"
<linux-sh@...r.kernel.org>, "sparclinux@...r.kernel.org"
<sparclinux@...r.kernel.org>, Netdev <netdev@...r.kernel.org>,
"linux-parisc@...r.kernel.org" <linux-parisc@...r.kernel.org>,
"linux-usb@...r.kernel.org" <linux-usb@...r.kernel.org>,
"linux-fbdev@...r.kernel.org" <linux-fbdev@...r.kernel.org>,
"dri-devel@...ts.freedesktop.org" <dri-devel@...ts.freedesktop.org>,
"linux-bcachefs@...r.kernel.org" <linux-bcachefs@...r.kernel.org>,
"linux-mtd@...ts.infradead.org" <linux-mtd@...ts.infradead.org>
Subject: Re: [PATCH 15/22] arch: vdso: consolidate gettime prototypes
Le 09/11/2023 à 11:18, Michael Ellerman a écrit :
> "Arnd Bergmann" <arnd@...db.de> writes:
>> On Wed, Nov 8, 2023, at 19:31, Christophe Leroy wrote:
>>> Le 08/11/2023 à 13:58, Arnd Bergmann a écrit :
>>
>>> powerpc has functions doing more or less the same, they are called
>>> __c_kernel_clock_gettime() and alike with their prototypes siting in
>>> arch/powerpc/include/asm/vdso/gettimeofday.h
>>>
>>> Should those prototypes be moved to include/vdso/gettime.h too and
>>> eventually renamed, or are they considered too powerpc specific ?
>>
>> I don't actually know, my initial interpretation was that
>> these function names are part of the user ABI for the vdso,
>> but I never looked closely enough at how vdso works to
>> be sure what the actual ABI is.
>
> AFAIK the ABI is just the symbols we export, as defined in the linker
> script:
>
> /*
> * This controls what symbols we export from the DSO.
> */
> VERSION
> {
> VDSO_VERSION_STRING {
> global:
> __kernel_get_syscall_map;
> __kernel_gettimeofday;
> __kernel_clock_gettime;
> __kernel_clock_getres;
> __kernel_get_tbfreq;
> __kernel_sync_dicache;
> __kernel_sigtramp_rt64;
> __kernel_getcpu;
> __kernel_time;
>
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/powerpc/kernel/vdso/vdso64.lds.S?h=v6.6&#n117
>
>> If __c_kernel_clock_gettime() etc are not part of the user-facing
>> ABI, I think renaming them for consistency with the other
>> architectures would be best.
>
> The __c symbols are not part of the ABI, so we could rename them.
>
> At the moment though they don't have the same prototype as the generic
> versions, because we find the VDSO data in asm and pass it to the C
> functions, eg:
>
> int __c_kernel_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz,
> const struct vdso_data *vd);
>
> I think we can rework that though, by implementing
> __arch_get_vdso_data() and getting the vdso_data in C. Then we'd be able
> to share the prototypes.
I think it would not a been good idea, it would be less performant, for
explanation see commit
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e876f0b69dc993e86ca7795e63e98385aa9a7ef3
Christophe
Powered by blists - more mailing lists