The following commit has been merged into the core/core branch of tip: Commit-ID: 546c42b2c5c161619736dd730d3df709181999d0 Gitweb: https://git.kernel.org/tip/546c42b2c5c161619736dd730d3df709181999d0 Author: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> AuthorDate: Thu, 17 Feb 2022 11:24:00 +01:00 Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx> CommitterDate: Tue, 22 Feb 2022 22:25:01 +01:00 fork: Duplicate task_struct before stack allocation alloc_thread_stack_node() already populates the task_struct::stack member except on IA64. The stack pointer is saved and populated again because IA64 needs it and arch_dup_task_struct() overwrites it. Allocate thread's stack after task_struct has been duplicated as a preparation for further changes. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Acked-by: Andy Lutomirski <luto@xxxxxxxxxx> Link: https://lore.kernel.org/r/20220217102406.3697941-3-bigeasy@xxxxxxxxxxxxx --- kernel/fork.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/kernel/fork.c b/kernel/fork.c index f5cc101..30c01ce 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -888,6 +888,10 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node) if (!tsk) return NULL; + err = arch_dup_task_struct(tsk, orig); + if (err) + goto free_tsk; + stack = alloc_thread_stack_node(tsk, node); if (!stack) goto free_tsk; @@ -897,8 +901,6 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node) stack_vm_area = task_stack_vm_area(tsk); - err = arch_dup_task_struct(tsk, orig); - /* * arch_dup_task_struct() clobbers the stack-related fields. Make * sure they're properly initialized before using any stack-related @@ -912,9 +914,6 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node) refcount_set(&tsk->stack_refcount, 1); #endif - if (err) - goto free_stack; - err = scs_prepare(tsk, node); if (err) goto free_stack;