Linux-Kernel Archive: [PATCH 4/7] fork: Generalize PF_IO_WORKER handling [PATCH 4/7] fork: Generalize PF_IO_WORKER handling From: Eric W. Biederman Date: Fri May 06 2022 - 10:15:58 EST Next message: Eric W. Biederman: "[PATCH 6/7] fork: Explicitly set PF_KTHREAD" Previous message: Eric W. Biederman: "[PATCH 3/7] fork: Explicity test for idle tasks in copy_thread" In reply to: Eric W. Biederman: "[PATCH 3/7] fork: Explicity test for idle tasks in copy_thread" Next in thread: Eric W. Biederman: "[PATCH 6/7] fork: Explicitly set PF_KTHREAD" Messages sorted by: [ date ] [ thread ] [ subject ] [ author ] Add fn and fn_arg members into struct kernel_clone_args and test for them in copy_thread (instead of testing for PF_KTHREAD | PF_IO_WORKER). This allows any task that wants to be a user space task that only runs in kernel mode to use this functionality. The code on x86 is an exception and still retains a PF_KTHREAD test because x86 unlikely everything else handles kthreads slightly differently than user space tasks that start with a function. The functions that created tasks that start with a function have been updated to set ".fn" and ".fn_arg" instead of ".stack" and ".stack_size". These functions are fork_idle(), create_io_thread(), kernel_thread(), and user_mode_thread(). Signed-off-by: "Eric W. Biederman" --- arch/alpha/kernel/process.c | 7 +++---- arch/arc/kernel/process.c | 7 +++---- arch/arm/kernel/process.c | 7 +++---- arch/arm64/kernel/process.c | 7 +++---- arch/csky/kernel/process.c | 7 +++---- arch/h8300/kernel/process.c | 7 +++---- arch/hexagon/kernel/process.c | 7 +++---- arch/ia64/kernel/process.c | 6 +++--- arch/m68k/kernel/process.c | 7 +++---- arch/microblaze/kernel/process.c | 7 +++---- arch/mips/kernel/process.c | 7 +++---- arch/nios2/kernel/process.c | 7 +++---- arch/openrisc/kernel/process.c | 7 +++---- arch/parisc/kernel/process.c | 11 +++++------ arch/powerpc/kernel/process.c | 9 ++++----- arch/riscv/kernel/process.c | 7 +++---- arch/s390/kernel/process.c | 7 +++---- arch/sh/kernel/process_32.c | 7 +++---- arch/sparc/kernel/process_32.c | 7 +++---- arch/sparc/kernel/process_64.c | 7 +++---- arch/um/kernel/process.c | 10 ++++------ arch/x86/include/asm/fpu/sched.h | 2 +- arch/x86/include/asm/switch_to.h | 8 ++++---- arch/x86/kernel/fpu/core.c | 4 ++-- arch/x86/kernel/process.c | 13 ++++++------- arch/xtensa/kernel/process.c | 11 +++++------ include/linux/sched/task.h | 2 ++ kernel/fork.c | 16 ++++++++-------- 28 files changed, 95 insertions(+), 116 deletions(-) diff --git a/arch/alpha/kernel/process.c b/arch/alpha/kernel/process.c index 732e39217c7f..6cbba7370b4e 100644 --- a/arch/alpha/kernel/process.c +++ b/arch/alpha/kernel/process.c @@ -237,7 +237,6 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) { unsigned long clone_flags = args->flags; unsigned long usp = args->stack; - unsigned long kthread_arg = args->stack_size; unsigned long tls = args->tls; extern void ret_from_fork(void); extern void ret_from_kernel_thread(void); @@ -251,13 +250,13 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) childti->pcb.ksp = (unsigned long) childstack; childti->pcb.flags = 1; /* set FEN, clear everything else */ - if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) { + if (unlikely(args->fn)) { /* kernel thread */ memset(childstack, 0, sizeof(struct switch_stack) + sizeof(struct pt_regs)); childstack->r26 = (unsigned long) ret_from_kernel_thread; - childstack->r9 = usp; /* function */ - childstack->r10 = kthread_arg; + childstack->r9 = (unsigned long) args->fn; + childstack->r10 = (unsigned long) args->fn_arg; childregs->hae = alpha_mv.hae_cache; childti->pcb.usp = 0; return 0; diff --git a/arch/arc/kernel/process.c b/arch/arc/kernel/process.c index caf948ba647c..3369f0700702 100644 --- a/arch/arc/kernel/process.c +++ b/arch/arc/kernel/process.c @@ -166,7 +166,6 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) { unsigned long clone_flags = args->flags; unsigned long usp = args->stack; - unsigned long kthread_arg = args->stack_size; unsigned long tls = args->tls; struct pt_regs *c_regs; /* child's pt_regs */ unsigned long *childksp; /* to unwind out of __switch_to() */ @@ -193,11 +192,11 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) childksp[0] = 0; /* fp */ childksp[1] = (unsigned long)ret_from_fork; /* blink */ - if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) { + if (unlikely(args->fn)) { memset(c_regs, 0, sizeof(struct pt_regs)); - c_callee->r13 = kthread_arg; - c_callee->r14 = usp; /* function */ + c_callee->r13 = (unsigned long)args->fn_arg; + c_callee->r14 = (unsigned long)args->fn; return 0; } diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c index 8e13b426dd26..3d9cace63884 100644 --- a/arch/arm/kernel/process.c +++ b/arch/arm/kernel/process.c @@ -242,7 +242,6 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) { unsigned long clone_flags = args->flags; unsigned long stack_start = args->stack; - unsigned long stk_sz = args->stack_size; unsigned long tls = args->tls; struct thread_info *thread = task_thread_info(p); struct pt_regs *childregs = task_pt_regs(p); @@ -259,15 +258,15 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) thread->cpu_domain = get_domain(); #endif - if (likely(!(p->flags & (PF_KTHREAD | PF_IO_WORKER)))) { + if (likely(!args->fn)) { *childregs = *current_pt_regs(); childregs->ARM_r0 = 0; if (stack_start) childregs->ARM_sp = stack_start; } else { memset(childregs, 0, sizeof(struct pt_regs)); - thread->cpu_context.r4 = stk_sz; - thread->cpu_context.r5 = stack_start; + thread->cpu_context.r4 = (unsigned long)args->fn_arg; + thread->cpu_context.r5 = (unsigned long)args->fn; childregs->ARM_cpsr = SVC_MODE; } thread->cpu_context.pc = (unsigned long)ret_from_fork; diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index e002f6681c8d..d0ef05c661b0 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -320,7 +320,6 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) { unsigned long clone_flags = args->flags; unsigned long stack_start = args->stack; - unsigned long stk_sz = args->stack_size; unsigned long tls = args->tls; struct pt_regs *childregs = task_pt_regs(p); @@ -337,7 +336,7 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) ptrauth_thread_init_kernel(p); - if (likely(!(p->flags & (PF_KTHREAD | PF_IO_WORKER)))) { + if (likely(!args->fn)) { *childregs = *current_pt_regs(); childregs->regs[0] = 0; @@ -371,8 +370,8 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) memset(childregs, 0, sizeof(struct pt_regs)); childregs->pstate = PSR_MODE_EL1h | PSR_IL_BIT; - p->thread.cpu_context.x19 = stack_start; - p->thread.cpu_context.x20 = stk_sz; + p->thread.cpu_context.x19 = (unsigned long)args->fn; + p->thread.cpu_context.x20 = (unsigned long)args->fn_arg; } p->thread.cpu_context.pc = (unsigned long)ret_from_fork; p->thread.cpu_context.sp = (unsigned long)childregs; diff --git a/arch/csky/kernel/process.c b/arch/csky/kernel/process.c index 7dba33d37e1a..9af49aea1c3b 100644 --- a/arch/csky/kernel/process.c +++ b/arch/csky/kernel/process.c @@ -34,7 +34,6 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) { unsigned long clone_flags = args->flags; unsigned long usp = args->stack; - unsigned long kthread_arg = args->stack_size; unsigned long tls = args->tls; struct switch_stack *childstack; struct pt_regs *childregs = task_pt_regs(p); @@ -49,11 +48,11 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) /* setup thread.sp for switch_to !!! */ p->thread.sp = (unsigned long)childstack; - if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) { + if (unlikely(args->fn)) { memset(childregs, 0, sizeof(struct pt_regs)); childstack->r15 = (unsigned long) ret_from_kernel_thread; - childstack->r10 = kthread_arg; - childstack->r9 = usp; + childstack->r10 = (unsigned long) args->fn_arg; + childstack->r9 = (unsigned long) args->fn; childregs->sr = mfcr("psr"); } else { *childregs = *(current_pt_regs()); diff --git a/arch/h8300/kernel/process.c b/arch/h8300/kernel/process.c index 296ff831446e..5bfe0f8f54bf 100644 --- a/arch/h8300/kernel/process.c +++ b/arch/h8300/kernel/process.c @@ -108,16 +108,15 @@ void flush_thread(void) int copy_thread(struct task_struct *p, const kernel_cloen_args *args) { unsigned long usp = args->stack; - unsigned long topstk = args->stack_size; struct pt_regs *childregs; childregs = (struct pt_regs *) (THREAD_SIZE + task_stack_page(p)) - 1; - if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) { + if (unlikely(args->fn)) { memset(childregs, 0, sizeof(struct pt_regs)); childregs->retpc = (unsigned long) ret_from_kernel_thread; - childregs->er4 = topstk; /* arg */ - childregs->er5 = usp; /* fn */ + childregs->er4 = (unsigned long) args->fn_arg; + childregs->er5 = (unsigned long) args->fn; } else { *childregs = *current_pt_regs(); childregs->er0 = 0; diff --git a/arch/hexagon/kernel/process.c b/arch/hexagon/kernel/process.c index f1c1f6f21941..f0552f98a7ba 100644 --- a/arch/hexagon/kernel/process.c +++ b/arch/hexagon/kernel/process.c @@ -54,7 +54,6 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) { unsigned long clone_flags = args->flags; unsigned long usp = args->stack; - unsigned long arg = args->stack_size; unsigned long tls = args->tls; struct thread_info *ti = task_thread_info(p); struct hexagon_switch_stack *ss; @@ -76,11 +75,11 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) sizeof(*ss)); ss->lr = (unsigned long)ret_from_fork; p->thread.switch_sp = ss; - if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) { + if (unlikely(args->fn)) { memset(childregs, 0, sizeof(struct pt_regs)); /* r24 <- fn, r25 <- arg */ - ss->r24 = usp; - ss->r25 = arg; + ss->r24 = (unsigned long)args->fn; + ss->r25 = (unsigned long)args->fn_arg; pt_set_kmode(childregs); return 0; } diff --git a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c index 8f010ae818bc..167b1765bea1 100644 --- a/arch/ia64/kernel/process.c +++ b/arch/ia64/kernel/process.c @@ -341,14 +341,14 @@ copy_thread(struct task_struct *p, const struct kernel_clone_args *args) ia64_drop_fpu(p); /* don't pick up stale state from a CPU's fph */ - if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) { + if (unlikely(args->fn)) { if (unlikely(args->idle)) { /* fork_idle() called us */ return 0; } memset(child_stack, 0, sizeof(*child_ptregs) + sizeof(*child_stack)); - child_stack->r4 = user_stack_base; /* payload */ - child_stack->r5 = user_stack_size; /* argument */ + child_stack->r4 = (unsigned long) args->fn; + child_stack->r5 = (unsigned long) args->fn_arg; /* * Preserve PSR bits, except for bits 32-34 and 37-45, * which we can't read. diff --git a/arch/m68k/kernel/process.c b/arch/m68k/kernel/process.c index 8ac575656fc4..221feb0269f1 100644 --- a/arch/m68k/kernel/process.c +++ b/arch/m68k/kernel/process.c @@ -142,7 +142,6 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) { unsigned long clone_flags = args->flags; unsigned long usp = args->stack; - unsigned long arg = args->stack_size; unsigned long tls = args->tls; struct fork_frame { struct switch_stack sw; @@ -160,12 +159,12 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) */ p->thread.fc = USER_DATA; - if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) { + if (unlikely(args->fn)) { /* kernel thread */ memset(frame, 0, sizeof(struct fork_frame)); frame->regs.sr = PS_S; - frame->sw.a3 = usp; /* function */ - frame->sw.d7 = arg; + frame->sw.a3 = (unsigned long)args->fn; + frame->sw.d7 = (unsigned long)args->fn_arg; frame->sw.retpc = (unsigned long)ret_from_kernel_thread; p->thread.usp = 0; return 0; diff --git a/arch/microblaze/kernel/process.c b/arch/microblaze/kernel/process.c index b5f549125c6a..3c6241bcaea8 100644 --- a/arch/microblaze/kernel/process.c +++ b/arch/microblaze/kernel/process.c @@ -56,19 +56,18 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) { unsigned long clone_flags = args->flags; unsigned long usp = args->stack; - unsigned long arg = args->stack_size; unsigned long tls = args->tls; struct pt_regs *childregs = task_pt_regs(p); struct thread_info *ti = task_thread_info(p); - if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) { + if (unlikely(args->fn)) { /* 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)); memset(&ti->cpu_context, 0, sizeof(struct cpu_context)); ti->cpu_context.r1 = (unsigned long)childregs; - ti->cpu_context.r20 = (unsigned long)usp; /* fn */ - ti->cpu_context.r19 = (unsigned long)arg; + ti->cpu_context.r20 = (unsigned long)args->fn; + ti->cpu_context.r19 = (unsigned long)args->fn_arg; childregs->pt_mode = 1; local_save_flags(childregs->msr); ti->cpu_context.msr = childregs->msr & ~MSR_IE; diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c index a572d097b16b..35b912bce429 100644 --- a/arch/mips/kernel/process.c +++ b/arch/mips/kernel/process.c @@ -109,7 +109,6 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) { unsigned long clone_flags = args->flags; unsigned long usp = args->stack; - unsigned long kthread_arg = args->stack_size; unsigned long tls = args->tls; struct thread_info *ti = task_thread_info(p); struct pt_regs *childregs, *regs = current_pt_regs(); @@ -122,12 +121,12 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) /* 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 | PF_IO_WORKER))) { + if (unlikely(args->fn)) { /* kernel thread */ unsigned long status = p->thread.cp0_status; memset(childregs, 0, sizeof(struct pt_regs)); - p->thread.reg16 = usp; /* fn */ - p->thread.reg17 = kthread_arg; + p->thread.reg16 = (unsigned long)args->fn; + p->thread.reg17 = (unsigned long)args->fn_arg; p->thread.reg29 = childksp; p->thread.reg31 = (unsigned long) ret_from_kernel_thread; #if defined(CONFIG_CPU_R3000) diff --git a/arch/nios2/kernel/process.c b/arch/nios2/kernel/process.c index 98c4bfe972e0..29593b98567d 100644 --- a/arch/nios2/kernel/process.c +++ b/arch/nios2/kernel/process.c @@ -104,7 +104,6 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) { unsigned long clone_flags = args->flags; unsigned long usp = args->stack; - unsigned long arg = args->stack_size; unsigned long tls = args->tls; struct pt_regs *childregs = task_pt_regs(p); struct pt_regs *regs; @@ -112,12 +111,12 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) struct switch_stack *childstack = ((struct switch_stack *)childregs) - 1; - if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) { + if (unlikely(args->fn)) { memset(childstack, 0, sizeof(struct switch_stack) + sizeof(struct pt_regs)); - childstack->r16 = usp; /* fn */ - childstack->r17 = arg; + childstack->r16 = (unsigned long) args->fn; + childstack->r17 = (unsigned long) args->fn_arg; childstack->ra = (unsigned long) ret_from_kernel_thread; childregs->estatus = STATUS_PIE; childregs->sp = (unsigned long) childstack; diff --git a/arch/openrisc/kernel/process.c b/arch/openrisc/kernel/process.c index 486e46dd5883..d9697cc9bc4d 100644 --- a/arch/openrisc/kernel/process.c +++ b/arch/openrisc/kernel/process.c @@ -156,7 +156,6 @@ copy_thread(struct task_struct *p, const struct kernel_clone_args *args) { unsigned long clone_flags = args->flags; unsigned long usp = args->stack; - unsigned long arg = args->stack_size; unsigned long tls = args->tls; struct pt_regs *userregs; struct pt_regs *kregs; @@ -175,10 +174,10 @@ copy_thread(struct task_struct *p, const struct kernel_clone_args *args) sp -= sizeof(struct pt_regs); kregs = (struct pt_regs *)sp; - if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) { + if (unlikely(args->fn)) { memset(kregs, 0, sizeof(struct pt_regs)); - kregs->gpr[20] = usp; /* fn, kernel thread */ - kregs->gpr[22] = arg; + kregs->gpr[20] = (unsigned long)args->fn; + kregs->gpr[22] = (unsigned long)args->fn_arg; } else { *userregs = *current_pt_regs(); diff --git a/arch/parisc/kernel/process.c b/arch/parisc/kernel/process.c index 30a5874ca845..a6a2a558fc5b 100644 --- a/arch/parisc/kernel/process.c +++ b/arch/parisc/kernel/process.c @@ -210,7 +210,6 @@ copy_thread(struct task_struct *p, const struct kernel_clone_args *args) { unsigned long clone_flags = args->flags; unsigned long usp = args->stack; - unsigned long kthread_arg = args->stack_size; unsigned long tls = args->tls; struct pt_regs *cregs = &(p->thread.regs); void *stack = task_stack_page(p); @@ -221,7 +220,7 @@ copy_thread(struct task_struct *p, const struct kernel_clone_args *args) extern void * const ret_from_kernel_thread; extern void * const child_return; - if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) { + if (unlikely(args->fn)) { /* kernel thread */ memset(cregs, 0, sizeof(struct pt_regs)); if (args->idle) /* idle thread */ @@ -236,12 +235,12 @@ copy_thread(struct task_struct *p, const struct kernel_clone_args *args) * ret_from_kernel_thread. */ #ifdef CONFIG_64BIT - cregs->gr[27] = ((unsigned long *)usp)[3]; - cregs->gr[26] = ((unsigned long *)usp)[2]; + cregs->gr[27] = ((unsigned long *)args->fn)[3]; + cregs->gr[26] = ((unsigned long *)args->fn)[2]; #else - cregs->gr[26] = usp; + cregs->gr[26] = (unsigned long) args->fn; #endif - cregs->gr[25] = kthread_arg; + cregs->gr[25] = (unsigned long) args->fn_arg; } else { /* user thread */ /* usp must be word aligned. This also prevents users from diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index 3fd67c861d54..4f367bb68906 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -1720,7 +1720,6 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) { unsigned long clone_flags = args->flags; unsigned long usp = args->stack; - unsigned long kthread_arg = args->stack_size; unsigned long tls = args->tls; struct pt_regs *childregs, *kregs; extern void ret_from_fork(void); @@ -1738,18 +1737,18 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) /* Copy registers */ sp -= sizeof(struct pt_regs); childregs = (struct pt_regs *) sp; - if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) { + if (unlikely(args->fn)) { /* kernel thread */ memset(childregs, 0, sizeof(struct pt_regs)); childregs->gpr[1] = sp + sizeof(struct pt_regs); /* function */ - if (usp) - childregs->gpr[14] = ppc_function_entry((void *)usp); + if (args->fn) + childregs->gpr[14] = ppc_function_entry((void *)args->fn); #ifdef CONFIG_PPC64 clear_tsk_thread_flag(p, TIF_32BIT); childregs->softe = IRQS_ENABLED; #endif - childregs->gpr[15] = kthread_arg; + childregs->gpr[15] = (unsigned long)args->fn_arg; p->thread.regs = NULL; /* no user register state */ ti->flags |= _TIF_RESTOREALL; f = ret_from_kernel_thread; diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c index 334382731725..24efabdbc551 100644 --- a/arch/riscv/kernel/process.c +++ b/arch/riscv/kernel/process.c @@ -124,12 +124,11 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) { unsigned long clone_flags = args->flags; unsigned long usp = args->stack; - unsigned long arg = args->stack_size; unsigned long tls = args->tls; struct pt_regs *childregs = task_pt_regs(p); /* p->thread holds context to be restored by __switch_to() */ - if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) { + if (unlikely(args->fn)) { /* Kernel thread */ memset(childregs, 0, sizeof(struct pt_regs)); childregs->gp = gp_in_global; @@ -137,8 +136,8 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) childregs->status = SR_PP | SR_PIE; p->thread.ra = (unsigned long)ret_from_kernel_thread; - p->thread.s[0] = usp; /* fn */ - p->thread.s[1] = arg; + p->thread.s[0] = (unsigned long)args->fn; + p->thread.s[1] = (unsigned long)args->fn_arg; } else { *childregs = *(current_pt_regs()); if (usp) /* User fork */ diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c index bb5daec39516..89949b9f3cf8 100644 --- a/arch/s390/kernel/process.c +++ b/arch/s390/kernel/process.c @@ -98,7 +98,6 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) { unsigned long clone_flags = args->flags; unsigned long new_stackp = args->stack; - unsigned long arg = args->stack_size; unsigned long tls = args->tls; struct fake_frame { @@ -133,15 +132,15 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) frame->sf.gprs[9] = (unsigned long)frame; /* Store access registers to kernel stack of new process. */ - if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) { + if (unlikely(args->fn)) { /* kernel thread */ memset(&frame->childregs, 0, sizeof(struct pt_regs)); frame->childregs.psw.mask = PSW_KERNEL_BITS | PSW_MASK_DAT | PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK; frame->childregs.psw.addr = (unsigned long)__ret_from_fork; - frame->childregs.gprs[9] = new_stackp; /* function */ - frame->childregs.gprs[10] = arg; + frame->childregs.gprs[9] = (unsigned long)args->fn; + frame->childregs.gprs[10] = (unsigned long)args->fn_arg; frame->childregs.orig_gpr2 = -1; frame->childregs.last_break = 1; return 0; diff --git a/arch/sh/kernel/process_32.c b/arch/sh/kernel/process_32.c index 6023399b1892..a808843375e7 100644 --- a/arch/sh/kernel/process_32.c +++ b/arch/sh/kernel/process_32.c @@ -96,7 +96,6 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) { unsigned long clone_flags = args->flags; unsigned long usp = args->stack; - unsigned long arg = args->stack_size; unsigned long tls = args->tls; struct thread_info *ti = task_thread_info(p); struct pt_regs *childregs; @@ -117,11 +116,11 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) childregs = task_pt_regs(p); p->thread.sp = (unsigned long) childregs; - if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) { + if (unlikely(args->fn)) { memset(childregs, 0, sizeof(struct pt_regs)); p->thread.pc = (unsigned long) ret_from_kernel_thread; - childregs->regs[4] = arg; - childregs->regs[5] = usp; + childregs->regs[4] = (unsigned long) args->fn_arg; + childregs->regs[5] = (unsigned long) args->fn; childregs->sr = SR_MD; #if defined(CONFIG_SH_FPU) childregs->sr |= SR_FD; diff --git a/arch/sparc/kernel/process_32.c b/arch/sparc/kernel/process_32.c index 80e6775e18c0..33b0215a4182 100644 --- a/arch/sparc/kernel/process_32.c +++ b/arch/sparc/kernel/process_32.c @@ -263,7 +263,6 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) { unsigned long clone_flags = args->flags; unsigned long sp = args->stack; - unsigned long arg = args->stack_size; unsigned long tls = args->tls; struct thread_info *ti = task_thread_info(p); struct pt_regs *childregs, *regs = current_pt_regs(); @@ -299,13 +298,13 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) ti->ksp = (unsigned long) new_stack; p->thread.kregs = childregs; - if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) { + if (unlikely(args->fn)) { extern int nwindows; unsigned long psr; memset(new_stack, 0, STACKFRAME_SZ + TRACEREG_SZ); ti->kpc = (((unsigned long) ret_from_kernel_thread) - 0x8); - childregs->u_regs[UREG_G1] = sp; /* function */ - childregs->u_regs[UREG_G2] = arg; + childregs->u_regs[UREG_G1] = (unsigned long) args->fn; + childregs->u_regs[UREG_G2] = (unsigned long) args->fn_arg; psr = childregs->psr = get_psr(); ti->kpsr = psr | PSR_PIL; ti->kwim = 1 << (((psr & PSR_CWP) + 1) % nwindows); diff --git a/arch/sparc/kernel/process_64.c b/arch/sparc/kernel/process_64.c index 38c46ca826d9..6335b698a4b4 100644 --- a/arch/sparc/kernel/process_64.c +++ b/arch/sparc/kernel/process_64.c @@ -568,7 +568,6 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) { unsigned long clone_flags = args->flags; unsigned long sp = args->stack; - unsigned long arg = args->stack_size; unsigned long tls = args->tls; struct thread_info *t = task_thread_info(p); struct pt_regs *regs = current_pt_regs(); @@ -587,12 +586,12 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) sizeof(struct sparc_stackf)); t->fpsaved[0] = 0; - if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) { + if (unlikely(args->fn)) { memset(child_trap_frame, 0, child_stack_sz); __thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP] = (current_pt_regs()->tstate + 1) & TSTATE_CWP; - t->kregs->u_regs[UREG_G1] = sp; /* function */ - t->kregs->u_regs[UREG_G2] = arg; + t->kregs->u_regs[UREG_G1] = (unsigned long) args->fn; + t->kregs->u_regs[UREG_G2] = (unsigned long) args->fn_arg; return 0; } diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c index fd2d2361484d..181cc9aafb25 100644 --- a/arch/um/kernel/process.c +++ b/arch/um/kernel/process.c @@ -158,15 +158,13 @@ int copy_thread(struct task_struct * p, const struct kernel_clone_args *args) { unsigned long clone_flags = args->flags; unsigned long sp = args->stack; - unsigned long arg = args->stack_size; unsigned long tls = args->tls; void (*handler)(void); - int kthread = current->flags & (PF_KTHREAD | PF_IO_WORKER); int ret = 0; p->thread = (struct thread_struct) INIT_THREAD; - if (!kthread) { + if (!args->fn) { memcpy(&p->thread.regs.regs, current_pt_regs(), sizeof(p->thread.regs.regs)); PT_REGS_SET_SYSCALL_RETURN(&p->thread.regs, 0); @@ -178,14 +176,14 @@ int copy_thread(struct task_struct * p, const struct kernel_clone_args *args) arch_copy_thread(¤t->thread.arch, &p->thread.arch); } else { get_safe_registers(p->thread.regs.regs.gp, p->thread.regs.regs.fp); - p->thread.request.u.thread.proc = (int (*)(void *))sp; - p->thread.request.u.thread.arg = (void *)arg; + p->thread.request.u.thread.proc = args->fn; + p->thread.request.u.thread.arg = args->fn_arg; handler = new_thread_handler; } new_thread(task_stack_page(p), &p->thread.switch_buf, handler); - if (!kthread) { + if (!args->fn) { clear_flushed_tls(p); /* diff --git a/arch/x86/include/asm/fpu/sched.h b/arch/x86/include/asm/fpu/sched.h index 99a8820e8cc4..b2486b2cbc6e 100644 --- a/arch/x86/include/asm/fpu/sched.h +++ b/arch/x86/include/asm/fpu/sched.h @@ -11,7 +11,7 @@ extern void save_fpregs_to_fpstate(struct fpu *fpu); extern void fpu__drop(struct fpu *fpu); -extern int fpu_clone(struct task_struct *dst, unsigned long clone_flags); +extern int fpu_clone(struct task_struct *dst, unsigned long clone_flags, bool minimal); extern void fpu_flush_thread(void); /* diff --git a/arch/x86/include/asm/switch_to.h b/arch/x86/include/asm/switch_to.h index b5f0d2ff47e4..c08eb0fdd11f 100644 --- a/arch/x86/include/asm/switch_to.h +++ b/arch/x86/include/asm/switch_to.h @@ -78,13 +78,13 @@ static inline void update_task_stack(struct task_struct *task) } static inline void kthread_frame_init(struct inactive_task_frame *frame, - unsigned long fun, unsigned long arg) + int (*fun)(void *), void *arg) { - frame->bx = fun; + frame->bx = (unsigned long)fun; #ifdef CONFIG_X86_32 - frame->di = arg; + frame->di = (unsigned long)arg; #else - frame->r12 = arg; + frame->r12 = (unsigned long)arg; #endif } diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index c049561f373a..fbade5a3975b 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -556,7 +556,7 @@ static inline void fpu_inherit_perms(struct fpu *dst_fpu) } /* Clone current's FPU state on fork */ -int fpu_clone(struct task_struct *dst, unsigned long clone_flags) +int fpu_clone(struct task_struct *dst, unsigned long clone_flags, bool minimal) { struct fpu *src_fpu = ¤t->thread.fpu; struct fpu *dst_fpu = &dst->thread.fpu; @@ -579,7 +579,7 @@ int fpu_clone(struct task_struct *dst, unsigned long clone_flags) * No FPU state inheritance for kernel threads and IO * worker threads. */ - if (dst->flags & (PF_KTHREAD | PF_IO_WORKER)) { + if (minimal) { /* Clear out the minimal state */ memcpy(&dst_fpu->fpstate->regs, &init_fpstate.regs, init_fpstate_copy_size()); diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 0fce52b10dc4..d20eaad52a85 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -134,7 +134,6 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) { unsigned long clone_flags = args->flags; unsigned long sp = args->stack; - unsigned long arg = args->stack_size; unsigned long tls = args->tls; struct inactive_task_frame *frame; struct fork_frame *fork_frame; @@ -172,13 +171,13 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) frame->flags = X86_EFLAGS_FIXED; #endif - fpu_clone(p, clone_flags); + fpu_clone(p, clone_flags, args->fn); /* Kernel thread ? */ if (unlikely(p->flags & PF_KTHREAD)) { p->thread.pkru = pkru_get_init_value(); memset(childregs, 0, sizeof(struct pt_regs)); - kthread_frame_init(frame, sp, arg); + kthread_frame_init(frame, args->fn, args->fn_arg); return 0; } @@ -198,10 +197,10 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) task_user_gs(p) = get_user_gs(current_pt_regs()); #endif - if (unlikely(p->flags & PF_IO_WORKER)) { + if (unlikely(args->fn)) { /* - * An IO thread is a user space thread, but it doesn't - * return to ret_after_fork(). + * 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. @@ -211,7 +210,7 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) */ childregs->sp = 0; childregs->ip = 0; - kthread_frame_init(frame, sp, arg); + kthread_frame_init(frame, args->fn, args->fn_arg); return 0; } diff --git a/arch/xtensa/kernel/process.c b/arch/xtensa/kernel/process.c index 15ce25073142..c3751cc88e5d 100644 --- a/arch/xtensa/kernel/process.c +++ b/arch/xtensa/kernel/process.c @@ -205,7 +205,6 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) { unsigned long clone_flags = args->flags; unsigned long usp_thread_fn = args->stack; - unsigned long thread_fn_arg = args->stack_size; unsigned long tls = args->tls; struct pt_regs *childregs = task_pt_regs(p); @@ -226,7 +225,7 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) #error Unsupported Xtensa ABI #endif - if (!(p->flags & (PF_KTHREAD | PF_IO_WORKER))) { + if (!args->fn) { struct pt_regs *regs = current_pt_regs(); unsigned long usp = usp_thread_fn ? usp_thread_fn : regs->areg[1]; @@ -278,15 +277,15 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) * Window underflow will load registers from the * spill slots on the stack on return from _switch_to. */ - SPILL_SLOT(childregs, 2) = usp_thread_fn; - SPILL_SLOT(childregs, 3) = thread_fn_arg; + SPILL_SLOT(childregs, 2) = (unsigned long)args->fn; + SPILL_SLOT(childregs, 3) = (unsigned long)args->fn_arg; #elif defined(__XTENSA_CALL0_ABI__) /* * a12 = thread_fn, a13 = thread_fn arg. * _switch_to epilogue will load registers from the stack. */ - ((unsigned long *)p->thread.sp)[0] = usp_thread_fn; - ((unsigned long *)p->thread.sp)[1] = thread_fn_arg; + ((unsigned long *)p->thread.sp)[0] = (unsigned long)args->fn; + ((unsigned long *)p->thread.sp)[1] = (unsigned long)args->fn_arg; #else #error Unsupported Xtensa ABI #endif diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h index 3d6b99ce5408..505aaf9fe477 100644 --- a/include/linux/sched/task.h +++ b/include/linux/sched/task.h @@ -34,6 +34,8 @@ struct kernel_clone_args { int io_thread; int kthread; int idle; + int (*fn)(void *); + void *fn_arg; struct cgroup *cgrp; struct css_set *cset; }; diff --git a/kernel/fork.c b/kernel/fork.c index 93d77ee921ff..8e17c3fbce42 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -2555,8 +2555,8 @@ struct task_struct * __init fork_idle(int cpu) struct task_struct *task; struct kernel_clone_args args = { .flags = CLONE_VM, - .stack = (unsigned long)&idle_dummy, - .stack_size = (unsigned long)NULL, + .fn = &idle_dummy, + .fn_arg = NULL, .kthread = 1, .idle = 1, }; @@ -2589,8 +2589,8 @@ struct task_struct *create_io_thread(int (*fn)(void *), void *arg, int node) .flags = ((lower_32_bits(flags) | CLONE_VM | CLONE_UNTRACED) & ~CSIGNAL), .exit_signal = (lower_32_bits(flags) & CSIGNAL), - .stack = (unsigned long)fn, - .stack_size = (unsigned long)arg, + .fn = fn, + .fn_arg = arg, .io_thread = 1, }; @@ -2694,8 +2694,8 @@ pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) .flags = ((lower_32_bits(flags) | CLONE_VM | CLONE_UNTRACED) & ~CSIGNAL), .exit_signal = (lower_32_bits(flags) & CSIGNAL), - .stack = (unsigned long)fn, - .stack_size = (unsigned long)arg, + .fn = fn, + .fn_arg = arg, .kthread = 1, }; @@ -2711,8 +2711,8 @@ pid_t user_mode_thread(int (*fn)(void *), void *arg, unsigned long flags) .flags = ((lower_32_bits(flags) | CLONE_VM | CLONE_UNTRACED) & ~CSIGNAL), .exit_signal = (lower_32_bits(flags) & CSIGNAL), - .stack = (unsigned long)fn, - .stack_size = (unsigned long)arg, + .fn = fn, + .fn_arg = arg, }; return kernel_clone(&args); -- 2.35.3 Next message: Eric W. 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