On Wed, 17 Oct 2018, Tim Chen wrote: > Add arch_set_dumpable for setting architecture specific security > modifications on processes according to its dumpable properties. > Non dumpable processes are security sensitive and they can be modified > to gain architecture specific security defenses via arch_set_dumpable.
You love that sentence, right? But it's still wrong. arch_set_dumpable() does arch specific extra modifications depending on 'value'. It's not a one way street. It can tighten or relax. > Signed-off-by: Tim Chen <[email protected]> > --- > fs/exec.c | 6 ++++++ And this is related to the subsystem in $subject (x86/process) in which way? > 1 file changed, 6 insertions(+) > > diff --git a/fs/exec.c b/fs/exec.c > index e204830..6f329fc 100644 > --- a/fs/exec.c > +++ b/fs/exec.c > @@ -1940,6 +1940,11 @@ void set_binfmt(struct linux_binfmt *new) > } > EXPORT_SYMBOL(set_binfmt); > > +void __weak arch_set_dumpable(struct task_struct *tsk, unsigned int value) > +{ > + return; > +} > + > /* > * set_dumpable stores three-value SUID_DUMP_* into mm->flags. > */ > @@ -1956,6 +1961,7 @@ void set_dumpable(struct task_struct *tsk, unsigned int > value) > old = READ_ONCE(tsk->mm->flags); > new = (old & ~MMF_DUMPABLE_MASK) | value; > } while (cmpxchg(&tsk->mm->flags, old, new) != old); > + arch_set_dumpable(tsk, value); So now the obvious question. set_dumpable() operates on tsk->mm. i.e. it's a process wide operation. But arch_set_dumpable() operates on the task itself. What about the other tasks of that process? Thanks, tglx
