Jens Axboe <axboe@xxxxxxxxx> writes:
> PF_IO_WORKER are kernel threads too, but they aren't PF_KTHREAD in the
> sense that we don't assign ->set_child_tid with our own structure. Just
> ensure that every arch sets up the PF_IO_WORKER threads like kthreads.
I think it is worth calling out that this is only for the arch
implementation of copy_thread.
This looks good for now. But I am wondering if eventually we want to
refactor the copy_thread interface to more cleanly handle the
difference between tasks that only run in the kernel and userspace
tasks.
Eric
> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
> ---
> arch/alpha/kernel/process.c | 2 +-
> arch/arc/kernel/process.c | 2 +-
> arch/arm/kernel/process.c | 2 +-
> arch/arm64/kernel/process.c | 2 +-
> arch/c6x/kernel/process.c | 2 +-
> arch/csky/kernel/process.c | 2 +-
> arch/h8300/kernel/process.c | 2 +-
> arch/hexagon/kernel/process.c | 2 +-
> arch/ia64/kernel/process.c | 2 +-
> arch/m68k/kernel/process.c | 2 +-
> arch/microblaze/kernel/process.c | 2 +-
> arch/mips/kernel/process.c | 2 +-
> arch/nds32/kernel/process.c | 2 +-
> arch/nios2/kernel/process.c | 2 +-
> arch/openrisc/kernel/process.c | 2 +-
> arch/riscv/kernel/process.c | 2 +-
> arch/s390/kernel/process.c | 2 +-
> arch/sh/kernel/process_32.c | 2 +-
> arch/sparc/kernel/process_32.c | 2 +-
> arch/sparc/kernel/process_64.c | 2 +-
> arch/um/kernel/process.c | 2 +-
> arch/x86/kernel/process.c | 2 +-
> arch/xtensa/kernel/process.c | 2 +-
> 23 files changed, 23 insertions(+), 23 deletions(-)
>
> diff --git a/arch/alpha/kernel/process.c b/arch/alpha/kernel/process.c
> index 6c71554206cc..5112ab996394 100644
> --- a/arch/alpha/kernel/process.c
> +++ b/arch/alpha/kernel/process.c
> @@ -249,7 +249,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
> childti->pcb.ksp = (unsigned long) childstack;
> childti->pcb.flags = 1; /* set FEN, clear everything else */
>
> - if (unlikely(p->flags & PF_KTHREAD)) {
> + if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) {
> /* kernel thread */
> memset(childstack, 0,
> sizeof(struct switch_stack) + sizeof(struct pt_regs));
> diff --git a/arch/arc/kernel/process.c b/arch/arc/kernel/process.c
> index 37f724ad5e39..d838d0d57696 100644
> --- a/arch/arc/kernel/process.c
> +++ b/arch/arc/kernel/process.c
> @@ -191,7 +191,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
> childksp[0] = 0; /* fp */
> childksp[1] = (unsigned long)ret_from_fork; /* blink */
>
> - if (unlikely(p->flags & PF_KTHREAD)) {
> + if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) {
> memset(c_regs, 0, sizeof(struct pt_regs));
>
> c_callee->r13 = kthread_arg;
> diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
> index ee3aee69e444..5199a2bb4111 100644
> --- a/arch/arm/kernel/process.c
> +++ b/arch/arm/kernel/process.c
> @@ -243,7 +243,7 @@ int copy_thread(unsigned long clone_flags, unsigned long stack_start,
> thread->cpu_domain = get_domain();
> #endif
>
> - if (likely(!(p->flags & PF_KTHREAD))) {
> + if (likely(!(p->flags & (PF_KTHREAD | PF_IO_WORKER)))) {
> *childregs = *current_pt_regs();
> childregs->ARM_r0 = 0;
> if (stack_start)
> diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
> index 6616486a58fe..05f001b401a5 100644
> --- a/arch/arm64/kernel/process.c
> +++ b/arch/arm64/kernel/process.c
> @@ -398,7 +398,7 @@ int copy_thread(unsigned long clone_flags, unsigned long stack_start,
>
> ptrauth_thread_init_kernel(p);
>
> - if (likely(!(p->flags & PF_KTHREAD))) {
> + if (likely(!(p->flags & (PF_KTHREAD | PF_IO_WORKER)))) {
> *childregs = *current_pt_regs();
> childregs->regs[0] = 0;
>
> diff --git a/arch/c6x/kernel/process.c b/arch/c6x/kernel/process.c
> index 9f4fd6a40a10..403ad4ce3db0 100644
> --- a/arch/c6x/kernel/process.c
> +++ b/arch/c6x/kernel/process.c
> @@ -112,7 +112,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
>
> childregs = task_pt_regs(p);
>
> - if (unlikely(p->flags & PF_KTHREAD)) {
> + if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) {
> /* case of __kernel_thread: we return to supervisor space */
> memset(childregs, 0, sizeof(struct pt_regs));
> childregs->sp = (unsigned long)(childregs + 1);
> diff --git a/arch/csky/kernel/process.c b/arch/csky/kernel/process.c
> index 69af6bc87e64..3d0ca22cd0e2 100644
> --- a/arch/csky/kernel/process.c
> +++ b/arch/csky/kernel/process.c
> @@ -49,7 +49,7 @@ int copy_thread(unsigned long clone_flags,
> /* setup thread.sp for switch_to !!! */
> p->thread.sp = (unsigned long)childstack;
>
> - if (unlikely(p->flags & PF_KTHREAD)) {
> + if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) {
> memset(childregs, 0, sizeof(struct pt_regs));
> childstack->r15 = (unsigned long) ret_from_kernel_thread;
> childstack->r10 = kthread_arg;
> diff --git a/arch/h8300/kernel/process.c b/arch/h8300/kernel/process.c
> index bc1364db58fe..46b1342ce515 100644
> --- a/arch/h8300/kernel/process.c
> +++ b/arch/h8300/kernel/process.c
> @@ -112,7 +112,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
>
> childregs = (struct pt_regs *) (THREAD_SIZE + task_stack_page(p)) - 1;
>
> - if (unlikely(p->flags & PF_KTHREAD)) {
> + if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) {
> memset(childregs, 0, sizeof(struct pt_regs));
> childregs->retpc = (unsigned long) ret_from_kernel_thread;
> childregs->er4 = topstk; /* arg */
> diff --git a/arch/hexagon/kernel/process.c b/arch/hexagon/kernel/process.c
> index 6a980cba7b29..c61165c99ae0 100644
> --- a/arch/hexagon/kernel/process.c
> +++ b/arch/hexagon/kernel/process.c
> @@ -73,7 +73,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg,
> sizeof(*ss));
> ss->lr = (unsigned long)ret_from_fork;
> p->thread.switch_sp = ss;
> - if (unlikely(p->flags & PF_KTHREAD)) {
> + if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) {
> memset(childregs, 0, sizeof(struct pt_regs));
> /* r24 <- fn, r25 <- arg */
> ss->r24 = usp;
> diff --git a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c
> index 4ebbfa076a26..7e1a1525e202 100644
> --- a/arch/ia64/kernel/process.c
> +++ b/arch/ia64/kernel/process.c
> @@ -338,7 +338,7 @@ copy_thread(unsigned long clone_flags, unsigned long user_stack_base,
>
> ia64_drop_fpu(p); /* don't pick up stale state from a CPU's fph */
>
> - if (unlikely(p->flags & PF_KTHREAD)) {
> + if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) {
> if (unlikely(!user_stack_base)) {
> /* fork_idle() called us */
> return 0;
> diff --git a/arch/m68k/kernel/process.c b/arch/m68k/kernel/process.c
> index 08359a6e058f..da83cc83e791 100644
> --- a/arch/m68k/kernel/process.c
> +++ b/arch/m68k/kernel/process.c
> @@ -157,7 +157,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg,
> */
> p->thread.fs = get_fs().seg;
>
> - if (unlikely(p->flags & PF_KTHREAD)) {
> + if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) {
> /* kernel thread */
> memset(frame, 0, sizeof(struct fork_frame));
> frame->regs.sr = PS_S;
> diff --git a/arch/microblaze/kernel/process.c b/arch/microblaze/kernel/process.c
> index 657c2beb665e..62aa237180b6 100644
> --- a/arch/microblaze/kernel/process.c
> +++ b/arch/microblaze/kernel/process.c
> @@ -59,7 +59,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg,
> struct pt_regs *childregs = task_pt_regs(p);
> struct thread_info *ti = task_thread_info(p);
>
> - if (unlikely(p->flags & PF_KTHREAD)) {
> + if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) {
> /* if we're creating a new kernel thread then just zeroing all
> * the registers. That's OK for a brand new thread.*/
> memset(childregs, 0, sizeof(struct pt_regs));
> diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c
> index d7e288f3a1e7..f69434015be7 100644
> --- a/arch/mips/kernel/process.c
> +++ b/arch/mips/kernel/process.c
> @@ -135,7 +135,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
> /* Put the stack after the struct pt_regs. */
> childksp = (unsigned long) childregs;
> p->thread.cp0_status = (read_c0_status() & ~(ST0_CU2|ST0_CU1)) | ST0_KERNEL_CUMASK;
> - if (unlikely(p->flags & PF_KTHREAD)) {
> + if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) {
> /* kernel thread */
> unsigned long status = p->thread.cp0_status;
> memset(childregs, 0, sizeof(struct pt_regs));
> diff --git a/arch/nds32/kernel/process.c b/arch/nds32/kernel/process.c
> index e01ad5d17224..c1327e552ec6 100644
> --- a/arch/nds32/kernel/process.c
> +++ b/arch/nds32/kernel/process.c
> @@ -156,7 +156,7 @@ int copy_thread(unsigned long clone_flags, unsigned long stack_start,
>
> memset(&p->thread.cpu_context, 0, sizeof(struct cpu_context));
>
> - if (unlikely(p->flags & PF_KTHREAD)) {
> + if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) {
> memset(childregs, 0, sizeof(struct pt_regs));
> /* kernel thread fn */
> p->thread.cpu_context.r6 = stack_start;
> diff --git a/arch/nios2/kernel/process.c b/arch/nios2/kernel/process.c
> index 50b4eb19a6cc..c5f916ca6845 100644
> --- a/arch/nios2/kernel/process.c
> +++ b/arch/nios2/kernel/process.c
> @@ -109,7 +109,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg,
> struct switch_stack *childstack =
> ((struct switch_stack *)childregs) - 1;
>
> - if (unlikely(p->flags & PF_KTHREAD)) {
> + if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) {
> memset(childstack, 0,
> sizeof(struct switch_stack) + sizeof(struct pt_regs));
>
> diff --git a/arch/openrisc/kernel/process.c b/arch/openrisc/kernel/process.c
> index 3c98728cce24..83fba4ee4453 100644
> --- a/arch/openrisc/kernel/process.c
> +++ b/arch/openrisc/kernel/process.c
> @@ -167,7 +167,7 @@ copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg,
> sp -= sizeof(struct pt_regs);
> kregs = (struct pt_regs *)sp;
>
> - if (unlikely(p->flags & PF_KTHREAD)) {
> + if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) {
> memset(kregs, 0, sizeof(struct pt_regs));
> kregs->gpr[20] = usp; /* fn, kernel thread */
> kregs->gpr[22] = arg;
> diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c
> index dd5f985b1f40..06d326caa7d8 100644
> --- a/arch/riscv/kernel/process.c
> +++ b/arch/riscv/kernel/process.c
> @@ -112,7 +112,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg,
> struct pt_regs *childregs = task_pt_regs(p);
>
> /* p->thread holds context to be restored by __switch_to() */
> - if (unlikely(p->flags & PF_KTHREAD)) {
> + if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) {
> /* Kernel thread */
> memset(childregs, 0, sizeof(struct pt_regs));
> childregs->gp = gp_in_global;
> diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
> index bc3ca54edfb4..ac7a06d5e230 100644
> --- a/arch/s390/kernel/process.c
> +++ b/arch/s390/kernel/process.c
> @@ -114,7 +114,7 @@ int copy_thread(unsigned long clone_flags, unsigned long new_stackp,
> frame->sf.gprs[9] = (unsigned long) frame;
>
> /* Store access registers to kernel stack of new process. */
> - if (unlikely(p->flags & PF_KTHREAD)) {
> + if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) {
> /* kernel thread */
> memset(&frame->childregs, 0, sizeof(struct pt_regs));
> frame->childregs.psw.mask = PSW_KERNEL_BITS | PSW_MASK_DAT |
> diff --git a/arch/sh/kernel/process_32.c b/arch/sh/kernel/process_32.c
> index 80a5d1c66a51..1aa508eb0823 100644
> --- a/arch/sh/kernel/process_32.c
> +++ b/arch/sh/kernel/process_32.c
> @@ -114,7 +114,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg,
>
> childregs = task_pt_regs(p);
> p->thread.sp = (unsigned long) childregs;
> - if (unlikely(p->flags & PF_KTHREAD)) {
> + if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) {
> memset(childregs, 0, sizeof(struct pt_regs));
> p->thread.pc = (unsigned long) ret_from_kernel_thread;
> childregs->regs[4] = arg;
> diff --git a/arch/sparc/kernel/process_32.c b/arch/sparc/kernel/process_32.c
> index a02363735915..0f9c606e1e78 100644
> --- a/arch/sparc/kernel/process_32.c
> +++ b/arch/sparc/kernel/process_32.c
> @@ -309,7 +309,7 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, unsigned long arg,
> ti->ksp = (unsigned long) new_stack;
> p->thread.kregs = childregs;
>
> - if (unlikely(p->flags & PF_KTHREAD)) {
> + if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) {
> extern int nwindows;
> unsigned long psr;
> memset(new_stack, 0, STACKFRAME_SZ + TRACEREG_SZ);
> diff --git a/arch/sparc/kernel/process_64.c b/arch/sparc/kernel/process_64.c
> index 6f8c7822fc06..7afd0a859a78 100644
> --- a/arch/sparc/kernel/process_64.c
> +++ b/arch/sparc/kernel/process_64.c
> @@ -597,7 +597,7 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, unsigned long arg,
> sizeof(struct sparc_stackf));
> t->fpsaved[0] = 0;
>
> - if (unlikely(p->flags & PF_KTHREAD)) {
> + if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) {
> memset(child_trap_frame, 0, child_stack_sz);
> __thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP] =
> (current_pt_regs()->tstate + 1) & TSTATE_CWP;
> diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c
> index 81d508daf67c..c5011064b5dd 100644
> --- a/arch/um/kernel/process.c
> +++ b/arch/um/kernel/process.c
> @@ -157,7 +157,7 @@ int copy_thread(unsigned long clone_flags, unsigned long sp,
> unsigned long arg, struct task_struct * p, unsigned long tls)
> {
> void (*handler)(void);
> - int kthread = current->flags & PF_KTHREAD;
> + int kthread = current->flags & (PF_KTHREAD | PF_IO_WORKER);
> int ret = 0;
>
> p->thread = (struct thread_struct) INIT_THREAD;
> diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
> index 145a7ac0c19a..9c214d7085a4 100644
> --- a/arch/x86/kernel/process.c
> +++ b/arch/x86/kernel/process.c
> @@ -161,7 +161,7 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, unsigned long arg,
> #endif
>
> /* Kernel thread ? */
> - if (unlikely(p->flags & PF_KTHREAD)) {
> + if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) {
> memset(childregs, 0, sizeof(struct pt_regs));
> kthread_frame_init(frame, sp, arg);
> return 0;
> diff --git a/arch/xtensa/kernel/process.c b/arch/xtensa/kernel/process.c
> index 397a7de56377..9534ef515d74 100644
> --- a/arch/xtensa/kernel/process.c
> +++ b/arch/xtensa/kernel/process.c
> @@ -217,7 +217,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp_thread_fn,
>
> p->thread.sp = (unsigned long)childregs;
>
> - if (!(p->flags & PF_KTHREAD)) {
> + if (!(p->flags & (PF_KTHREAD | PF_IO_WORKER))) {
> struct pt_regs *regs = current_pt_regs();
> unsigned long usp = usp_thread_fn ?
> usp_thread_fn : regs->areg[1];
