cris: switch to generic kernel_thread() (69b58a67) · Commits · e / devices / android_kernel_xiaomi_markw

arch/cris/Kconfig

+1 −0

Original line number	Diff line number	Diff line
		@@ -49,6 +49,7 @@ config CRIS
		select GENERIC_SMP_IDLE_THREAD if ETRAX_ARCH_V32
		select GENERIC_CMOS_UPDATE
		select MODULES_USE_ELF_RELA
		select GENERIC_KERNEL_THREAD

		config HZ
		int

arch/cris/arch-v10/kernel/entry.S

+9 −1

Original line number	Diff line number	Diff line
		@@ -35,6 +35,7 @@
		.globl system_call
		.globl ret_from_intr
		.globl ret_from_fork
		.globl ret_from_kernel_thread
		.globl resume
		.globl multiple_interrupt
		.globl hwbreakpoint
		@@ -82,6 +83,13 @@ ret_from_fork:
		ba ret_from_sys_call
		nop

		ret_from_kernel_thread:
		jsr schedule_tail
		move.d $r2, $r10 ; argument is here
		jsr $r1 ; call the payload
		moveq 0, $r10
		jsr sys_exit ; never returns

		ret_from_intr:
		;; check for resched if preemptive kernel or if we're going back to user-mode
		;; this test matches the user_regs(regs) macro

arch/cris/arch-v10/kernel/process.c

+24 −59

Original line number	Diff line number	Diff line
		@@ -17,6 +17,7 @@
		#include <arch/svinto.h>
		#include <linux/init.h>
		#include <arch/system.h>
		#include <asm/ptrace.h>

		#ifdef CONFIG_ETRAX_GPIO
		void etrax_gpio_wake_up_check(void); /* drivers/gpio.c */
		@@ -81,31 +82,6 @@ unsigned long thread_saved_pc(struct task_struct *t)
		return task_pt_regs(t)->irp;
		}

		static void kernel_thread_helper(void* dummy, int (fn)(void ), void * arg)
		{
		fn(arg);
		do_exit(-1); /* Should never be called, return bad exit value */
		}

		/*
		* Create a kernel thread
		*/
		int kernel_thread(int (fn)(void ), void * arg, unsigned long flags)
		{
		struct pt_regs regs;

		memset(&regs, 0, sizeof(regs));

		/* Don't use r10 since that is set to 0 in copy_thread */
		regs.r11 = (unsigned long)fn;
		regs.r12 = (unsigned long)arg;
		regs.irp = (unsigned long)kernel_thread_helper;
		regs.dccr = 1 << I_DCCR_BITNR;

		/* Ok, create the new process.. */
		return do_fork(flags \| CLONE_VM \| CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
		}

		/* setup the child's kernel stack with a pt_regs and switch_stack on it.
		* it will be un-nested during _resume and _ret_from_sys_call when the
		* new thread is scheduled.
		@@ -115,30 +91,36 @@ int kernel_thread(int (fn)(void ), void * arg, unsigned long flags)
		*
		*/
		asmlinkage void ret_from_fork(void);
		asmlinkage void ret_from_kernel_thread(void);

		int copy_thread(unsigned long clone_flags, unsigned long usp,
		unsigned long unused,
		unsigned long arg,
		struct task_struct p, struct pt_regs regs)
		{
		struct pt_regs * childregs;
		struct switch_stack *swstack;
		struct pt_regs *childregs = task_pt_regs(p);
		struct switch_stack swstack = ((struct switch_stack )childregs) - 1;

		/* put the pt_regs structure at the end of the new kernel stack page and fix it up
		* remember that the task_struct doubles as the kernel stack for the task
		*/

		childregs = task_pt_regs(p);

		if (unlikely(p->flags & PF_KTHREAD)) {
		memset(swstack, 0,
		sizeof(struct switch_stack) + sizeof(struct pt_regs));
		swstack->r1 = usp;
		swstack->r2 = arg;
		childregs->dccr = 1 << I_DCCR_BITNR;
		swstack->return_ip = (unsigned long) ret_from_kernel_thread;
		p->thread.ksp = (unsigned long) swstack;
		p->thread.usp = 0;
		return 0;
		}
		childregs = regs; /* struct copy of pt_regs */

		p->set_child_tid = p->clear_child_tid = NULL;

		childregs->r10 = 0; /* child returns 0 after a fork/clone */

		/* put the switch stack right below the pt_regs */

		swstack = ((struct switch_stack *)childregs) - 1;

		swstack->r9 = 0; /* parameter to ret_from_sys_call, 0 == dont restart the syscall */

		/* we want to return into ret_from_sys_call after the _resume */
		@@ -161,45 +143,28 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
		return 0;
		}

		/*
		* Be aware of the "magic" 7th argument in the four system-calls below.
		* They need the latest stackframe, which is put as the 7th argument by
		* entry.S. The previous arguments are dummies or actually used, but need
		* to be defined to reach the 7th argument.
		*
		* N.B.: Another method to get the stackframe is to use current_regs(). But
		* it returns the latest stack-frame stacked when going from _user mode_ and
		* some of these (at least sys_clone) are called from kernel-mode sometimes
		* (for example during kernel_thread, above) and thus cannot use it. Thus,
		* to be sure not to get any surprises, we use the method for the other calls
		* as well.
		*/

		asmlinkage int sys_fork(long r10, long r11, long r12, long r13, long mof, long srp,
		struct pt_regs *regs)
		asmlinkage int sys_fork(void)
		{
		return do_fork(SIGCHLD, rdusp(), regs, 0, NULL, NULL);
		return do_fork(SIGCHLD, rdusp(), current_pt_regs(), 0, NULL, NULL);
		}

		/* if newusp is 0, we just grab the old usp */
		/* FIXME: Is parent_tid/child_tid really third/fourth argument? Update lib? */
		asmlinkage int sys_clone(unsigned long newusp, unsigned long flags,
		int* parent_tid, int* child_tid, long mof, long srp,
		struct pt_regs *regs)
		int* parent_tid, int* child_tid)
		{
		if (!newusp)
		newusp = rdusp();
		return do_fork(flags, newusp, regs, 0, parent_tid, child_tid);
		return do_fork(flags, newusp, current_pt_regs(), 0, parent_tid, child_tid);
		}

		/* vfork is a system call in i386 because of register-pressure - maybe
		* we can remove it and handle it in libc but we put it here until then.
		*/

		asmlinkage int sys_vfork(long r10, long r11, long r12, long r13, long mof, long srp,
		struct pt_regs *regs)
		asmlinkage int sys_vfork(void)
		{
		return do_fork(CLONE_VFORK \| CLONE_VM \| SIGCHLD, rdusp(), regs, 0, NULL, NULL);
		return do_fork(CLONE_VFORK \| CLONE_VM \| SIGCHLD, rdusp(), current_pt_regs(), 0, NULL, NULL);
		}

		/*

arch/cris/arch-v32/kernel/entry.S

+13 −0

Original line number	Diff line number	Diff line
		@@ -31,6 +31,7 @@
		.globl system_call
		.globl ret_from_intr
		.globl ret_from_fork
		.globl ret_from_kernel_thread
		.globl resume
		.globl multiple_interrupt
		.globl nmi_interrupt
		@@ -84,6 +85,18 @@ ret_from_fork:
		nop
		.size ret_from_fork, . - ret_from_fork

		.type ret_from_kernel_thread,@function
		ret_from_kernel_thread:
		jsr schedule_tail
		nop
		move.d $r2, $r10
		jsr $r1
		nop
		moveq 0, $r10
		jsr sys_exit
		nop
		.size ret_from_kernel_thread, . - ret_from_kernel_thread

		.type ret_from_intr,@function
		ret_from_intr:
		;; Check for resched if preemptive kernel, or if we're going back to

arch/cris/arch-v32/kernel/process.c

+22 −52

Original line number	Diff line number	Diff line
		@@ -16,6 +16,7 @@
		#include <hwregs/reg_map.h>
		#include <hwregs/timer_defs.h>
		#include <hwregs/intr_vect_defs.h>
		#include <asm/ptrace.h>

		extern void stop_watchdog(void);

		@@ -94,31 +95,6 @@ unsigned long thread_saved_pc(struct task_struct *t)
		return task_pt_regs(t)->erp;
		}

		static void
		kernel_thread_helper(void* dummy, int (fn)(void ), void * arg)
		{
		fn(arg);
		do_exit(-1); /* Should never be called, return bad exit value. */
		}

		/* Create a kernel thread. */
		int
		kernel_thread(int (fn)(void ), void * arg, unsigned long flags)
		{
		struct pt_regs regs;

		memset(&regs, 0, sizeof(regs));

		/* Don't use r10 since that is set to 0 in copy_thread. */
		regs.r11 = (unsigned long) fn;
		regs.r12 = (unsigned long) arg;
		regs.erp = (unsigned long) kernel_thread_helper;
		regs.ccs = 1 << (I_CCS_BITNR + CCS_SHIFT);

		/* Create the new process. */
		return do_fork(flags \| CLONE_VM \| CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
		}

		/*
		* Setup the child's kernel stack with a pt_regs and call switch_stack() on it.
		* It will be unnested during _resume and _ret_from_sys_call when the new thread
		@@ -129,23 +105,33 @@ kernel_thread(int (fn)(void ), void * arg, unsigned long flags)
		*/

		extern asmlinkage void ret_from_fork(void);
		extern asmlinkage void ret_from_kernel_thread(void);

		int
		copy_thread(unsigned long clone_flags, unsigned long usp,
		unsigned long unused,
		unsigned long arg,
		struct task_struct p, struct pt_regs regs)
		{
		struct pt_regs *childregs;
		struct switch_stack *swstack;
		struct pt_regs *childregs = task_pt_regs(p);
		struct switch_stack swstack = ((struct switch_stack ) childregs) - 1;

		/*
		* Put the pt_regs structure at the end of the new kernel stack page and
		* fix it up. Note: the task_struct doubles as the kernel stack for the
		* task.
		*/
		childregs = task_pt_regs(p);
		if (unlikely(p->flags & PF_KTHREAD)) {
		memset(swstack, 0,
		sizeof(struct switch_stack) + sizeof(struct pt_regs));
		swstack->r1 = usp;
		swstack->r2 = arg;
		childregs->ccs = 1 << (I_CCS_BITNR + CCS_SHIFT);
		swstack->return_ip = (unsigned long) ret_from_kernel_thread;
		p->thread.ksp = (unsigned long) swstack;
		p->thread.usp = 0;
		return 0;
		}
		childregs = regs; /* Struct copy of pt_regs. */
		p->set_child_tid = p->clear_child_tid = NULL;
		childregs->r10 = 0; /* Child returns 0 after a fork/clone. */

		/* Set a new TLS ?
		@@ -156,7 +142,6 @@ copy_thread(unsigned long clone_flags, unsigned long usp,
		}

		/* Put the switch stack right below the pt_regs. */
		swstack = ((struct switch_stack *) childregs) - 1;

		/* Parameter to ret_from_sys_call. 0 is don't restart the syscall. */
		swstack->r9 = 0;
		@@ -174,35 +159,21 @@ copy_thread(unsigned long clone_flags, unsigned long usp,
		return 0;
		}

		/*
		* Be aware of the "magic" 7th argument in the four system-calls below.
		* They need the latest stackframe, which is put as the 7th argument by
		* entry.S. The previous arguments are dummies or actually used, but need
		* to be defined to reach the 7th argument.
		*
		* N.B.: Another method to get the stackframe is to use current_regs(). But
		* it returns the latest stack-frame stacked when going from _user mode_ and
		* some of these (at least sys_clone) are called from kernel-mode sometimes
		* (for example during kernel_thread, above) and thus cannot use it. Thus,
		* to be sure not to get any surprises, we use the method for the other calls
		* as well.
		*/
		asmlinkage int
		sys_fork(long r10, long r11, long r12, long r13, long mof, long srp,
		struct pt_regs *regs)
		sys_fork(void)
		{
		return do_fork(SIGCHLD, rdusp(), regs, 0, NULL, NULL);
		return do_fork(SIGCHLD, rdusp(), current_pt_regs(), 0, NULL, NULL);
		}

		/* FIXME: Is parent_tid/child_tid really third/fourth argument? Update lib? */
		asmlinkage int
		sys_clone(unsigned long newusp, unsigned long flags, int parent_tid, int child_tid,
		unsigned long tls, long srp, struct pt_regs *regs)
		unsigned long tls)
		{
		if (!newusp)
		newusp = rdusp();

		return do_fork(flags, newusp, regs, 0, parent_tid, child_tid);
		return do_fork(flags, newusp, current_pt_regs(), 0, parent_tid, child_tid);
		}

		/*
		@@ -210,10 +181,9 @@ sys_clone(unsigned long newusp, unsigned long flags, int parent_tid, int child
		* we can remove it and handle it in libc but we put it here until then.
		*/
		asmlinkage int
		sys_vfork(long r10, long r11, long r12, long r13, long mof, long srp,
		struct pt_regs *regs)
		sys_vfork(void)
		{
		return do_fork(CLONE_VFORK \| CLONE_VM \| SIGCHLD, rdusp(), regs, 0, NULL, NULL);
		return do_fork(CLONE_VFORK \| CLONE_VM \| SIGCHLD, rdusp(), current_pt_regs(), 0, NULL, NULL);
		}

		/* sys_execve() executes a new program. */