Re: [PATCH -mm] Don't truncate /proc/PID/environ at 4096 characters

Hugh Dickins
2007-09-19T19:30:39Z

On Wed, 19 Sep 2007, Mikael Pettersson wrote:
> H. Peter Anvin writes:
> > Mikael Pettersson wrote:
> > > Does /proc/PID/mem even work? If I do `strace cat /proc/PID/mem > /dev/null'
> > > for a known good PID, the first read() from /proc/PID/mem fails with ESRCH,
> >
> > Of course it does. Address zero isn't typically mapped.
>
> Indeed. My bad :-(

No, not quite. Peter explains why "cat /proc/self/mem" gets EIO,
but you were seeing "cat /proc/other/mem" get ESRCH: that's from
the stringent !MAY_PTRACE || !ptrace_may_attach checks.

Hugh