From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael Kerrisk (man-pages)" Subject: Re: [PATCH] prctl.2: Add note regarding the size of the output user space buffer for PR_GET_TID_ADDRESS operation on x32/n32 Date: Mon, 12 Dec 2016 07:22:52 +0100 Message-ID: <92c16e2d-d6d3-85c4-2f55-521e54e1ed4b@gmail.com> References: <20161212035441.GA29133@obsidian> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20161212035441.GA29133@obsidian> Sender: linux-man-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Eugene Syromyatnikov Cc: mtk.manpages-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, linux-man-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-man@vger.kernel.org On 12/12/2016 04:54 AM, Eugene Syromyatnikov wrote: > --- > man2/prctl.2 | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) Thanks, Eugene. Applied. (And fantastic to get patches with this level of detail!) Cheers, Michael > diff --git a/man2/prctl.2 b/man2/prctl.2 > index 5f84bb7..39b3e9a 100644 > --- a/man2/prctl.2 > +++ b/man2/prctl.2 > @@ -988,7 +988,10 @@ flag, in the location pointed to by > .IR "(int\ **)\ arg2" . > This feature is available only if the kernel is built with the > .BR CONFIG_CHECKPOINT_RESTORE > -option enabled. > +option enabled. Note that since the prctl() syscall does not have compat > +implementation for AMD64 x32 and MIPS n32 ABIs, and the kernel writes out > +pointer of kernel's pointer size, this operation expects a user space buffer > +of 8 (not 4) bytes on these ABIs. > .TP > .BR PR_SET_TIMERSLACK " (since Linux 2.6.28)" > .\" See https://lwn.net/Articles/369549/ > -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/ -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html