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: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Acked-by: Greg Ungerer <gerg@linux-m68k.org>
Link: https://lore.kernel.org/r/20200113103040.23661-1-geert@linux-m68k.org
This commit is contained in:
Geert Uytterhoeven 2020-01-13 11:30:40 +01:00
parent bfc7931c40
commit 6aabc1facd
2 changed files with 23 additions and 9 deletions

View File

@ -14,6 +14,7 @@ config M68K
select HAVE_AOUT if MMU
select HAVE_ASM_MODVERSIONS
select HAVE_DEBUG_BUGVERBOSE
select HAVE_COPY_THREAD_TLS
select GENERIC_IRQ_SHOW
select GENERIC_ATOMIC64
select HAVE_UID16

View File

@ -108,16 +108,28 @@ void flush_thread(void)
* 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
* 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 *
* and extract arguments for do_fork() from there. Eventually we might
* go for calling do_fork() directly from the wrapper, but only after we
* are finished with do_fork() prototype conversion.
* _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
* go for calling _do_fork() directly from the wrapper, but only after we
* are finished with _do_fork() prototype conversion.
*/
asmlinkage int m68k_clone(struct pt_regs *regs)
{
/* regs will be equal to current_pt_regs() */
return do_fork(regs->d1, regs->d2, 0,
(int __user *)regs->d3, (int __user *)regs->d4);
struct kernel_clone_args args = {
.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);
}
int copy_thread(unsigned long clone_flags, unsigned long usp,
unsigned long arg, struct task_struct *p)
int copy_thread_tls(unsigned long clone_flags, unsigned long usp,
unsigned long arg, struct task_struct *p,
unsigned long tls)
{
struct fork_frame {
struct switch_stack sw;
@ -166,7 +179,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
p->thread.usp = usp ?: rdusp();
if (clone_flags & CLONE_SETTLS)
task_thread_info(p)->tp_value = frame->regs.d5;
task_thread_info(p)->tp_value = tls;
#ifdef CONFIG_FPU
if (!FPU_IS_EMU) {