x86/vm86: Set thread.vm86 to NULL on fork/clone

amluto · KAGA-KOKO · commit 2459ee8651dc · 2015-10-31T09:50:25.000+01:00
thread.vm86 points to per-task information -- the pointer should not be copied on clone. Fixes: d4ce0f2 ("x86/vm86: Move fields from 'struct kernel_vm86_struct' to 'struct vm86'") Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Stas Sergeev <stsp@list.ru> Link: http://lkml.kernel.org/r/71c5d6985d70ec8197c8d72f003823c81b7dcf99.1446270067.git.luto@kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
@@ -84,6 +84,9 @@ EXPORT_SYMBOL_GPL(idle_notifier_unregister);
 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
 {
 	memcpy(dst, src, arch_task_struct_size);
+#ifdef CONFIG_VM86
+	dst->thread.vm86 = NULL;
+#endif
 
 	return fpu__copy(&dst->thread.fpu, &src->thread.fpu);
 }

Original file line number	Diff line number	Diff line change
`@@ -84,6 +84,9 @@ EXPORT_SYMBOL_GPL(idle_notifier_unregister);`
`84`	`84`	`int arch_dup_task_struct(struct task_struct dst, struct task_struct src)`
`85`	`85`	`{`
`86`	`86`	`memcpy(dst, src, arch_task_struct_size);`
	`87`	`+#ifdef CONFIG_VM86`
	`88`	`+ dst->thread.vm86 = NULL;`
	`89`	`+#endif`
`87`	`90`
`88`	`91`	`return fpu__copy(&dst->thread.fpu, &src->thread.fpu);`
`89`	`92`	`}`