From mboxrd@z Thu Jan 1 00:00:00 1970 From: Petr Tesarik Date: Wed, 17 Oct 2007 19:55:45 +0000 Subject: Re: [PATCH] ptrace RSE bug Message-Id: <471668C1.7000706@suse.cz> List-Id: References: <1188357710.22637.7.camel@sli10-conroe.sh.intel.com> In-Reply-To: <1188357710.22637.7.camel@sli10-conroe.sh.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org Petr Tesarik wrote: >[...] > 2. You must couple it with the (planned) changes to ptrace, > because otherwise PTRACE_{PEEK,POKE}{TEXT,DATA} still access the kernel > RBS, but it gets later overwritten back from userspace when it is synced. I have verified that failing to do so breaks "strace -f", because strace relies on intercepting the clone() system call and setting the CLONE_PTRACE bit in the flags argument. Of course, if the bit is only set in the kernel RBS, which is overwritten with the (old) value from the user RBS on a PTRACE_CONT, the new process is not traced. Regards, Petr Tesarik