Commit d195ce46 authored by Nicholas Piggin's avatar Nicholas Piggin Committed by Michael Ellerman
Browse files

powerpc: copy_thread don't set _TIF_RESTOREALL 



In the kernel user thread path, don't set _TIF_RESTOREALL because
the thread is required to call kernel_execve() before it returns,
which will set _TIF_RESTOREALL if necessary via start_thread().

Signed-off-by: default avatarNicholas Piggin <npiggin@gmail.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230325122904.2375060-8-npiggin@gmail.com
parent b504b6aa

arch/powerpc/kernel/interrupt_64.S

+5 −0
Original line number Diff line number Diff line
@@ -748,6 +748,11 @@ _GLOBAL(ret_from_kernel_user_thread) 
#endif

	bctrl

	li	r3,0

	/*

	 * It does not matter whether this returns via the scv or sc path

	 * because it returns as execve() and therefore has no calling ABI

	 * (i.e., it sets registers according to the exec()ed entry point).

	 */

	b	.Lsyscall_exit



_GLOBAL(start_kernel_thread)

arch/powerpc/kernel/process.c

+0 −2
Original line number Diff line number Diff line
@@ -1745,7 +1745,6 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) 
	extern void start_kernel_thread(void);

	void (*f)(void);

	unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;

	struct thread_info *ti = task_thread_info(p);

#ifdef CONFIG_HAVE_HW_BREAKPOINT

	int i;

#endif
@@ -1784,7 +1783,6 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) 
#ifdef CONFIG_PPC64

			childregs->softe = IRQS_ENABLED;

#endif

			ti->flags |= _TIF_RESTOREALL;

			f = ret_from_kernel_user_thread;

		} else {

			struct pt_regs *regs = current_pt_regs();