linux-kernel - Re: Incorrect order of last two arguments of ptrace for requests PPC_PTRACE

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: <20061204215825.GB22514@krispykreme>
Date:	Tue, 5 Dec 2006 08:58:25 +1100
From:	Anton Blanchard <anton@...ba.org>
To:	David Woodhouse <dwmw2@...radead.org>
Cc:	supriya kannery <supriyak@...ibm.com>, linuxppc-dev@...abs.org,
	linux-kernel@...r.kernel.org
Subject: Re: Incorrect order of last two arguments of ptrace for requests PPC_PTRACE_GETREGS, SETREGS, GETFPREGS, SETFPREGS


Hi,

> > In ptrace, when request is PPC_PTRACE_GETREGS, SETREGS, GETFPREGS and 
> > SETFPREGS, order of the last two arguments is not correct.
> > 
> > General format of ptrace is ptrace (request, pid, addr, data).  For the 
> > above mentioned request ids in ppc64, if we use ptrace like
> > 
> >  long reg[32];
> >  ptrace (PPC_PTRACE_GETREGS, pid, 0, &reg[0]);
> > 
> > the return value is always -1.
> > 
> > If we exchange the last two arguments like,
> > 
> >  ptrace (PPC_PTRACE_GETREGS, pid, &reg[0], 0);
> > 
> > it works!
> > 
> > This is because PPC_PTRACE_GETREGS option for powerpc is implemented 
> > such that general purpose
> > registers of the child process get copied to the address variable 
> > instead of data variable. Same is
> > the case with other PPC request options PPC_PTRACE_SETREGS, GETFPREGS 
> > and SETFPREGS.
> > 
> > Prepared a patch for this problem and tested with 2.6.18-rc6 kernel. 
> > This patch can be applied directly to 2.6.19-rc3 kernel.

I looked at this a while ago and my decision at the time was to keep the
old implementation around for a while and create two new ones that match
the x86 numbering:

#define PTRACE_GETREGS            12
#define PTRACE_SETREGS            13
#define PTRACE_GETFPREGS          14
#define PTRACE_SETFPREGS          15

I hate gratuitous differences, each ptrace app ends up with a sea of
ifdefs.

Also I think it would be worth changing getregs/setregs to grab the
entire pt_regs structure. Otherwise most ops (gdb, strace etc) will just
have to make multiple ptrace calls to get the nia etc.

Anton
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/