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um: Implement copy_thread_tls

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

Signed-off-by: Amanieu d'Antras <amanieu@gmail.com>
Cc: linux-um@lists.infradead.org
Cc: <stable@vger.kernel.org> # 5.3.x
Link: https://lore.kernel.org/r/20200104123928.1048822-1-amanieu@gmail.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
This commit is contained in:
Amanieu d'Antras
2020-01-04 13:39:30 +01:00
committed by Christian Brauner
parent dd499f7a7e
commit 457677c70c
5 changed files with 10 additions and 12 deletions
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1
arch/um/Kconfig
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

2
arch/um/include/asm/ptrace-generic.h
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@@ -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);

6
arch/um/kernel/process.c
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;

6
arch/x86/um/tls_32.c
View File

@@ -215,14 +215,12 @@ static int set_tls_entry(struct task_struct* task, struct user_desc *info,
return 0;
}
int arch_copy_tls(struct task_struct *new)
int arch_set_tls(struct task_struct *new, unsigned long tls)
{
struct user_desc info;
int idx, ret = -EFAULT;
if (copy_from_user(&info,
(void __user *) UPT_SI(&new->thread.regs.regs),
sizeof(info)))
if (copy_from_user(&info, (void __user *) tls, sizeof(info)))
goto out;
ret = -EINVAL;

7
arch/x86/um/tls_64.c
View File

@@ -6,14 +6,13 @@ void clear_flushed_tls(struct task_struct *task)
{
}
int arch_copy_tls(struct task_struct *t)
int arch_set_tls(struct task_struct *t, unsigned long tls)
{
/*
* If CLONE_SETTLS is set, we need to save the thread id
* (which is argument 5, child_tid, of clone) so it can be set
* during context switches.
* so it can be set during context switches.
*/
t->thread.arch.fs = t->thread.regs.regs.gp[R8 / sizeof(long)];
t->thread.arch.fs = tls;
return 0;
}