From 457677c70c7672a4586b0b8abc396cc1ecdd376d Mon Sep 17 00:00:00 2001
From: Amanieu d'Antras <amanieu@gmail.com>
Date: Sat, 4 Jan 2020 13:39:30 +0100
Subject: um: Implement copy_thread_tls

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>
---
 arch/um/Kconfig                      | 1 +
 arch/um/include/asm/ptrace-generic.h | 2 +-
 arch/um/kernel/process.c             | 6 +++---
 3 files changed, 5 insertions(+), 4 deletions(-)

(limited to 'arch/um')

diff --git a/arch/um/Kconfig b/arch/um/Kconfig
index 2a6d04fcb3e9..6f0edd0c0220 100644
--- a/arch/um/Kconfig
+++ b/arch/um/Kconfig
@@ -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
diff --git a/arch/um/include/asm/ptrace-generic.h b/arch/um/include/asm/ptrace-generic.h
index 81c647ef9c6c..adf91ef553ae 100644
--- a/arch/um/include/asm/ptrace-generic.h
+++ b/arch/um/include/asm/ptrace-generic.h
@@ -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);
diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c
index 263a8f069133..17045e7211bf 100644
--- a/arch/um/kernel/process.c
+++ b/arch/um/kernel/process.c
@@ -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;
-- 
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