diff options
Diffstat (limited to 'arch/x86/kernel/process.c')
| -rw-r--r-- | arch/x86/kernel/process.c | 28 |
1 files changed, 20 insertions, 8 deletions
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 9c214d7085a4..5e1f38179f49 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -63,14 +63,9 @@ __visible DEFINE_PER_CPU_PAGE_ALIGNED(struct tss_struct, cpu_tss_rw) = { */ .sp0 = (1UL << (BITS_PER_LONG-1)) + 1, - /* - * .sp1 is cpu_current_top_of_stack. The init task never - * runs user code, but cpu_current_top_of_stack should still - * be well defined before the first context switch. - */ +#ifdef CONFIG_X86_32 .sp1 = TOP_OF_INIT_STACK, -#ifdef CONFIG_X86_32 .ss0 = __KERNEL_DS, .ss1 = __KERNEL_CS, #endif @@ -161,7 +156,7 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, unsigned long arg, #endif /* Kernel thread ? */ - if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) { + if (unlikely(p->flags & PF_KTHREAD)) { memset(childregs, 0, sizeof(struct pt_regs)); kthread_frame_init(frame, sp, arg); return 0; @@ -177,6 +172,23 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, unsigned long arg, task_user_gs(p) = get_user_gs(current_pt_regs()); #endif + if (unlikely(p->flags & PF_IO_WORKER)) { + /* + * An IO thread is a user space thread, but it doesn't + * return to ret_after_fork(). + * + * In order to indicate that to tools like gdb, + * we reset the stack and instruction pointers. + * + * It does the same kernel frame setup to return to a kernel + * function that a kernel thread does. + */ + childregs->sp = 0; + childregs->ip = 0; + kthread_frame_init(frame, sp, arg); + return 0; + } + /* Set a new TLS for the child thread? */ if (clone_flags & CLONE_SETTLS) ret = set_new_tls(p, tls); @@ -451,7 +463,7 @@ void speculative_store_bypass_ht_init(void) * First HT sibling to come up on the core. Link shared state of * the first HT sibling to itself. The siblings on the same core * which come up later will see the shared state pointer and link - * themself to the state of this CPU. + * themselves to the state of this CPU. */ st->shared_state = st; } |