From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eugene Syromyatnikov Subject: [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 06:54:41 +0300 Message-ID: <20161212035441.GA29133@obsidian> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline Sender: linux-man-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: mtk.manpages-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org Cc: linux-man-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-man@vger.kernel.org --- man2/prctl.2 | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) 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/ -- 2.10.2 -- 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