linux-kernel - Re: [PATCH v3] MIPS: Fix MAX_REG

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

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAAhV-H5A_xFMXOXPJFz6FyD_FixDW2msGM1fRe-FdDSq=anS8w@mail.gmail.com>
Date: Sun, 27 Apr 2025 21:30:42 +0800
From: Huacai Chen <chenhuacai@...nel.org>
To: Thomas Bogendoerfer <tsbogend@...ha.franken.de>
Cc: Thorsten Blum <thorsten.blum@...ux.dev>, Oleg Nesterov <oleg@...hat.com>, 
	"Maciej W. Rozycki" <macro@...am.me.uk>, linux-mips@...r.kernel.org, 
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3] MIPS: Fix MAX_REG_OFFSET

On Sun, Apr 27, 2025 at 8:52 PM Thomas Bogendoerfer
<tsbogend@...ha.franken.de> wrote:
>
> On Sun, Apr 27, 2025 at 08:32:05PM +0800, Huacai Chen wrote:
> > Hi, Thorsten,
> >
> > On Sun, Apr 27, 2025 at 7:35 PM Thorsten Blum <thorsten.blum@...ux.dev> wrote:
> > >
> > > Fix MAX_REG_OFFSET to point to the last register in 'pt_regs' and not to
> > > the marker itself, which could allow regs_get_register() to return an
> > > invalid offset.
> > >
> > > Fixes: 40e084a506eb ("MIPS: Add uprobes support.")
> > > Signed-off-by: Thorsten Blum <thorsten.blum@...ux.dev>
> > > ---
> > > Compile-tested only.
> > >
> > > Changes in v2:
> > > - Fix MAX_REG_OFFSET as suggested by Maciej (thanks!)
> > > - Link to v1: https://lore.kernel.org/lkml/20250411090032.7844-1-thorsten.blum@linux.dev/
> > >
> > > Changes in v3:
> > > - Keep the marker and avoid using #ifdef by adjusting MAX_REG_OFFSET as
> > >   suggested by Thomas and Maciej
> > > - Link to v2: https://lore.kernel.org/lkml/20250417174712.69292-2-thorsten.blum@linux.dev/
> > > ---
> > >  arch/mips/include/asm/ptrace.h | 3 ++-
> > >  1 file changed, 2 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/arch/mips/include/asm/ptrace.h b/arch/mips/include/asm/ptrace.h
> > > index 85fa9962266a..ef72c46b5568 100644
> > > --- a/arch/mips/include/asm/ptrace.h
> > > +++ b/arch/mips/include/asm/ptrace.h
> > > @@ -65,7 +65,8 @@ static inline void instruction_pointer_set(struct pt_regs *regs,
> > >
> > >  /* Query offset/name of register from its name/offset */
> > >  extern int regs_query_register_offset(const char *name);
> > > -#define MAX_REG_OFFSET (offsetof(struct pt_regs, __last))
> > > +#define MAX_REG_OFFSET \
> > > +       (offsetof(struct pt_regs, __last) - sizeof(unsigned long))
> > There is no 80 columns limit now, so no new line needed here.
>
> but not forbidden to care about it. I still prefer this limit.
Of course you are free to choose. But in my opinion "force to long
lines" and "force to short lines" are both bad, code readability is
the first thing to be considered.

Huacai

>
> Thomas.
>
> --
> Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
> good idea.                                                [ RFC1925, 2.3 ]