Merge tag 'uml-for-linus-6.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux

Pull UML fixes from Richard Weinberger:

 - Align signal stack correctly

 - Convert to raw spinlocks where needed (irq and virtio)

 - FPU related fixes

* tag 'uml-for-linus-6.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux:
  um: convert irq_lock to raw spinlock
  um: virtio_uml: use raw spinlock
  um: virt-pci: don't use kmalloc()
  um: fix execve stub execution on old host OSs
  um: properly align signal stack on x86_64
  um: avoid copying FP state from init_task
  um: add back support for FXSAVE registers

1 files changed, 9 insertions, 1 deletions

diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c
index e5a2d4d897e0c..0cd6fad3d908d 100644
--- a/arch/um/kernel/process.c
+++ b/arch/um/kernel/process.c
@@ -191,7 +191,15 @@ void initial_thread_cb(void (*proc)(void *), void *arg)
 int arch_dup_task_struct(struct task_struct *dst,
 			 struct task_struct *src)
 {
-	memcpy(dst, src, arch_task_struct_size);
+	/* init_task is not dynamically sized (missing FPU state) */
+	if (unlikely(src == &init_task)) {
+		memcpy(dst, src, sizeof(init_task));
+		memset((void *)dst + sizeof(init_task), 0,
+		       arch_task_struct_size - sizeof(init_task));
+	} else {
+		memcpy(dst, src, arch_task_struct_size);
+	}
+
 	return 0;
 }