Commit 6aabc1fa authored by Geert Uytterhoeven's avatar Geert Uytterhoeven
Browse files

m68k: Implement copy_thread_tls() 



This is required for clone3(), which passes the TLS value through a
struct rather than a register.

As do_fork() is only available if CONFIG_HAVE_COPY_THREAD_TLS is set,
m68k_clone() must be changed to call _do_fork() directly.

Signed-off-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
Acked-by: default avatarChristian Brauner <christian.brauner@ubuntu.com>
Acked-by: default avatarGreg Ungerer <gerg@linux-m68k.org>
Link: https://lore.kernel.org/r/20200113103040.23661-1-geert@linux-m68k.org
parent bfc7931c

arch/m68k/Kconfig

+1 −0
Original line number Original line Diff line number Diff line
@@ -14,6 +14,7 @@ config M68K 
	select HAVE_AOUT if MMU

	select HAVE_AOUT if MMU

	select HAVE_ASM_MODVERSIONS

	select HAVE_ASM_MODVERSIONS

	select HAVE_DEBUG_BUGVERBOSE

	select HAVE_DEBUG_BUGVERBOSE

	select HAVE_COPY_THREAD_TLS

	select GENERIC_IRQ_SHOW

	select GENERIC_IRQ_SHOW

	select GENERIC_ATOMIC64

	select GENERIC_ATOMIC64

	select HAVE_UID16

	select HAVE_UID16

arch/m68k/kernel/process.c

+22 −9
Original line number Original line Diff line number Diff line
@@ -108,16 +108,28 @@ void flush_thread(void) 
 * on top of pt_regs, which means that sys_clone() arguments would be

 * on top of pt_regs, which means that sys_clone() arguments would be

 * buried.  We could, of course, copy them, but it's too costly for no

 * buried.  We could, of course, copy them, but it's too costly for no

 * good reason - generic clone() would have to copy them *again* for

 * good reason - generic clone() would have to copy them *again* for

 * do_fork() anyway.  So in this case it's actually better to pass pt_regs *

 * _do_fork() anyway.  So in this case it's actually better to pass pt_regs *

 * and extract arguments for do_fork() from there.  Eventually we might

 * and extract arguments for _do_fork() from there.  Eventually we might

 * go for calling do_fork() directly from the wrapper, but only after we

 * go for calling _do_fork() directly from the wrapper, but only after we

 * are finished with do_fork() prototype conversion.

 * are finished with _do_fork() prototype conversion.

 */

 */

asmlinkage int m68k_clone(struct pt_regs *regs)

asmlinkage int m68k_clone(struct pt_regs *regs)

{

{

	/* regs will be equal to current_pt_regs() */

	/* regs will be equal to current_pt_regs() */

	return do_fork(regs->d1, regs->d2, 0,

	struct kernel_clone_args args = {

		       (int __user *)regs->d3, (int __user *)regs->d4);

		.flags		= regs->d1 & ~CSIGNAL,

		.pidfd		= (int __user *)regs->d3,

		.child_tid	= (int __user *)regs->d4,

		.parent_tid	= (int __user *)regs->d3,

		.exit_signal	= regs->d1 & CSIGNAL,

		.stack		= regs->d2,

		.tls		= regs->d5,

	};



	if (!legacy_clone_args_valid(&args))

		return -EINVAL;



	return _do_fork(&args);

}

}





/*

/*
@@ -130,8 +142,9 @@ asmlinkage int m68k_clone3(struct pt_regs *regs) 
	return sys_clone3((struct clone_args __user *)regs->d1, regs->d2);

	return sys_clone3((struct clone_args __user *)regs->d1, regs->d2);

}

}





int copy_thread(unsigned long clone_flags, unsigned long usp,

int copy_thread_tls(unsigned long clone_flags, unsigned long usp,

		 unsigned long arg, struct task_struct *p)

		    unsigned long arg, struct task_struct *p,

		    unsigned long tls)

{

{

	struct fork_frame {

	struct fork_frame {

		struct switch_stack sw;

		struct switch_stack sw;
@@ -166,7 +179,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp, 
	p->thread.usp = usp ?: rdusp();

	p->thread.usp = usp ?: rdusp();





	if (clone_flags & CLONE_SETTLS)

	if (clone_flags & CLONE_SETTLS)

		task_thread_info(p)->tp_value = frame->regs.d5;

		task_thread_info(p)->tp_value = tls;





#ifdef CONFIG_FPU

#ifdef CONFIG_FPU

	if (!FPU_IS_EMU) {

	if (!FPU_IS_EMU) {

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