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/x86/um/tls_32.c | 6 ++----
 arch/x86/um/tls_64.c | 7 +++----
 2 files changed, 5 insertions(+), 8 deletions(-)

(limited to 'arch/x86/um')

diff --git a/arch/x86/um/tls_32.c b/arch/x86/um/tls_32.c
index 5bd949da7a4a..ac8eee093f9c 100644
--- a/arch/x86/um/tls_32.c
+++ b/arch/x86/um/tls_32.c
@@ -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;
diff --git a/arch/x86/um/tls_64.c b/arch/x86/um/tls_64.c
index 3a621e0d3925..ebd3855d9b13 100644
--- a/arch/x86/um/tls_64.c
+++ b/arch/x86/um/tls_64.c
@@ -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;
 }
-- 
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