Re: [PATCH] ptrace RSE bug

Petr Tesarik
2007-10-17T19:55:45Z

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