um: Implement copy_thread_tls

commit 457677c70c7672a4586b0b8abc396cc1ecdd376d upstream.

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

Signed-off-by: Amanieu d'Antras <[email protected]>
Cc: [email protected]
Cc: <[email protected]> # 5.3.x
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Christian Brauner <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
This commit is contained in:
Amanieu d'Antras 2020-01-04 13:39:30 +01:00 • committed by Greg Kroah-Hartman
commit 8c9ff5c7dd
5 changed files with 10 additions and 12 deletions

View file

@ -14,6 +14,7 @@ config UML
select HAVE_FUTEX_CMPXCHG if FUTEX
select HAVE_DEBUG_KMEMLEAK
select HAVE_DEBUG_BUGVERBOSE
select HAVE_COPY_THREAD_TLS
select GENERIC_IRQ_SHOW
select GENERIC_CPU_DEVICES
select GENERIC_CLOCKEVENTS

View file

@ -36,7 +36,7 @@ extern long subarch_ptrace(struct task_struct *child, long request,
extern unsigned long getreg(struct task_struct *child, int regno);
extern int putreg(struct task_struct *child, int regno, unsigned long value);
extern int arch_copy_tls(struct task_struct *new);
extern int arch_set_tls(struct task_struct *new, unsigned long tls);
extern void clear_flushed_tls(struct task_struct *task);
extern int syscall_trace_enter(struct pt_regs *regs);
extern void syscall_trace_leave(struct pt_regs *regs);

View file

@ -153,8 +153,8 @@ void fork_handler(void)
userspace(&current->thread.regs.regs, current_thread_info()->aux_fp_regs);
}
int copy_thread(unsigned long clone_flags, unsigned long sp,
unsigned long arg, struct task_struct * p)
int copy_thread_tls(unsigned long clone_flags, unsigned long sp,
unsigned long arg, struct task_struct * p, unsigned long tls)
{
void (*handler)(void);
int kthread = current->flags & PF_KTHREAD;
@ -188,7 +188,7 @@ int copy_thread(unsigned long clone_flags, unsigned long sp,
* Set a new TLS for the child thread?
*/
if (clone_flags & CLONE_SETTLS)
ret = arch_copy_tls(p);
ret = arch_set_tls(p, tls);
}
return ret;