| Message ID | 20190129003422.9328-5-rick.p.edgecombe@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Merge text_poke fixes and executable lockdowns | expand |
On Mon, Jan 28, 2019 at 04:34:06PM -0800, Rick Edgecombe wrote: > From: Nadav Amit <namit@vmware.com> > > Provide a function for copying init_mm. This function will be later used > for setting a temporary mm. > > Cc: Andy Lutomirski <luto@kernel.org> > Cc: Kees Cook <keescook@chromium.org> > Cc: Dave Hansen <dave.hansen@intel.com> > Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> > Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> > Tested-by: Masami Hiramatsu <mhiramat@kernel.org> > Signed-off-by: Nadav Amit <namit@vmware.com> > Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> > --- > include/linux/sched/task.h | 1 + > kernel/fork.c | 24 ++++++++++++++++++------ > 2 files changed, 19 insertions(+), 6 deletions(-) > > diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h > index 44c6f15800ff..c5a00a7b3beb 100644 > --- a/include/linux/sched/task.h > +++ b/include/linux/sched/task.h > @@ -76,6 +76,7 @@ extern void exit_itimers(struct signal_struct *); > extern long _do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *, unsigned long); > extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *); > struct task_struct *fork_idle(int); > +struct mm_struct *copy_init_mm(void); > extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags); > extern long kernel_wait4(pid_t, int __user *, int, struct rusage *); > > diff --git a/kernel/fork.c b/kernel/fork.c > index b69248e6f0e0..d7b156c49f29 100644 > --- a/kernel/fork.c > +++ b/kernel/fork.c > @@ -1299,13 +1299,20 @@ void mm_release(struct task_struct *tsk, struct mm_struct *mm) > complete_vfork_done(tsk); > } > > -/* > - * Allocate a new mm structure and copy contents from the > - * mm structure of the passed in task structure. > +/** > + * dup_mm() - duplicates an existing mm structure > + * @tsk: the task_struct with which the new mm will be associated. > + * @oldmm: the mm to duplicate. > + * > + * Allocates a new mm structure and copy contents from the provided s/copy/copies/
> On Feb 5, 2019, at 12:53 AM, Borislav Petkov <bp@alien8.de> wrote: > > On Mon, Jan 28, 2019 at 04:34:06PM -0800, Rick Edgecombe wrote: >> From: Nadav Amit <namit@vmware.com> >> >> - * Allocate a new mm structure and copy contents from the >> - * mm structure of the passed in task structure. >> +/** >> + * dup_mm() - duplicates an existing mm structure >> + * @tsk: the task_struct with which the new mm will be associated. >> + * @oldmm: the mm to duplicate. >> + * >> + * Allocates a new mm structure and copy contents from the provided > > s/copy/copies/ Thanks, applied (I revised this sentence a bit).
diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h index 44c6f15800ff..c5a00a7b3beb 100644 --- a/include/linux/sched/task.h +++ b/include/linux/sched/task.h @@ -76,6 +76,7 @@ extern void exit_itimers(struct signal_struct *); extern long _do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *, unsigned long); extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *); struct task_struct *fork_idle(int); +struct mm_struct *copy_init_mm(void); extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags); extern long kernel_wait4(pid_t, int __user *, int, struct rusage *); diff --git a/kernel/fork.c b/kernel/fork.c index b69248e6f0e0..d7b156c49f29 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1299,13 +1299,20 @@ void mm_release(struct task_struct *tsk, struct mm_struct *mm) complete_vfork_done(tsk); } -/* - * Allocate a new mm structure and copy contents from the - * mm structure of the passed in task structure. +/** + * dup_mm() - duplicates an existing mm structure + * @tsk: the task_struct with which the new mm will be associated. + * @oldmm: the mm to duplicate. + * + * Allocates a new mm structure and copy contents from the provided + * @oldmm structure. + * + * Return: the duplicated mm or NULL on failure. */ -static struct mm_struct *dup_mm(struct task_struct *tsk) +static struct mm_struct *dup_mm(struct task_struct *tsk, + struct mm_struct *oldmm) { - struct mm_struct *mm, *oldmm = current->mm; + struct mm_struct *mm; int err; mm = allocate_mm(); @@ -1372,7 +1379,7 @@ static int copy_mm(unsigned long clone_flags, struct task_struct *tsk) } retval = -ENOMEM; - mm = dup_mm(tsk); + mm = dup_mm(tsk, current->mm); if (!mm) goto fail_nomem; @@ -2187,6 +2194,11 @@ struct task_struct *fork_idle(int cpu) return task; } +struct mm_struct *copy_init_mm(void) +{ + return dup_mm(NULL, &init_mm); +} + /* * Ok, this is the main fork-routine. *