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Commit 38e99353 authored by Al Viro's avatar Al Viro Committed by Guan Xuetao
Browse files

unicore32: switch to generic kernel_thread()/kernel_execve() 



Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Acked-and-Tested-by: default avatarGuan Xuetao <gxt@mprc.pku.edu.cn>
parent ddd2d384

arch/unicore32/Kconfig

+2 −0
Original line number Diff line number Diff line
@@ -16,6 +16,8 @@ config UNICORE32 
	select ARCH_WANT_FRAME_POINTERS

	select GENERIC_IOMAP

	select MODULES_USE_ELF_REL

	select GENERIC_KERNEL_THREAD

	select GENERIC_KERNEL_EXECVE

	help

	  UniCore-32 is 32-bit Instruction Set Architecture,

	  including a series of low-power-consumption RISC chip

arch/unicore32/include/asm/processor.h

+0 −5
Original line number Diff line number Diff line
@@ -72,11 +72,6 @@ unsigned long get_wchan(struct task_struct *p); 


#define cpu_relax()			barrier()



/*

 * Create a new kernel thread

 */

extern int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);



#define task_pt_regs(p) \

	((struct pt_regs *)(THREAD_START_SP + task_stack_page(p)) - 1)

arch/unicore32/kernel/entry.S

+7 −8
Original line number Diff line number Diff line
@@ -573,17 +573,16 @@ ENDPROC(ret_to_user) 
 */

ENTRY(ret_from_fork)

	b.l	schedule_tail

	get_thread_info tsk

	ldw	r1, [tsk+], #TI_FLAGS		@ check for syscall tracing

	mov	why, #1

	cand.a	r1, #_TIF_SYSCALL_TRACE		@ are we tracing syscalls?

	beq	ret_slow_syscall

	mov	r1, sp

	mov	r0, #1				@ trace exit [IP = 1]

	b.l	syscall_trace

	b	ret_slow_syscall

ENDPROC(ret_from_fork)



ENTRY(ret_from_kernel_thread)

	b.l	schedule_tail

	mov	r0, r5

	adr	lr, ret_slow_syscall

	mov	pc, r4

ENDPROC(ret_from_kernel_thread)



/*=============================================================================

 * SWI handler

 *-----------------------------------------------------------------------------

arch/unicore32/kernel/process.c

+14 −44
Original line number Diff line number Diff line
@@ -258,6 +258,7 @@ void release_thread(struct task_struct *dead_task) 
}



asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");

asmlinkage void ret_from_kernel_thread(void) __asm__("ret_from_kernel_thread");



int

copy_thread(unsigned long clone_flags, unsigned long stack_start,
@@ -266,17 +267,22 @@ copy_thread(unsigned long clone_flags, unsigned long stack_start, 
	struct thread_info *thread = task_thread_info(p);

	struct pt_regs *childregs = task_pt_regs(p);



	*childregs = *regs;

	childregs->UCreg_00 = 0;

	childregs->UCreg_sp = stack_start;



	memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));

	thread->cpu_context.sp = (unsigned long)childregs;

	if (unlikely(!regs)) {

		thread->cpu_context.pc = (unsigned long)ret_from_kernel_thread;

		thread->cpu_context.r4 = stack_start;

		thread->cpu_context.r5 = stk_sz;

		memset(childregs, 0, sizeof(struct pt_regs));

	} else {

		thread->cpu_context.pc = (unsigned long)ret_from_fork;

		*childregs = *regs;

		childregs->UCreg_00 = 0;

		childregs->UCreg_sp = stack_start;



		if (clone_flags & CLONE_SETTLS)

			childregs->UCreg_16 = regs->UCreg_03;



	}

	return 0;

}
@@ -305,42 +311,6 @@ int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fp) 
}

EXPORT_SYMBOL(dump_fpu);



/*

 * Shuffle the argument into the correct register before calling the

 * thread function.  r1 is the thread argument, r2 is the pointer to

 * the thread function, and r3 points to the exit function.

 */

asm(".pushsection .text\n"

"	.align\n"

"	.type	kernel_thread_helper, #function\n"

"kernel_thread_helper:\n"

"	mov.a	asr, r7\n"

"	mov	r0, r4\n"

"	mov	lr, r6\n"

"	mov	pc, r5\n"

"	.size	kernel_thread_helper, . - kernel_thread_helper\n"

"	.popsection");



/*

 * Create a kernel thread.

 */

pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)

{

	struct pt_regs regs;



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



	regs.UCreg_04 = (unsigned long)arg;

	regs.UCreg_05 = (unsigned long)fn;

	regs.UCreg_06 = (unsigned long)do_exit;

	regs.UCreg_07 = PRIV_MODE;

	regs.UCreg_pc = (unsigned long)kernel_thread_helper;

	regs.UCreg_asr = regs.UCreg_07 | PSR_I_BIT;



	return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);

}

EXPORT_SYMBOL(kernel_thread);



unsigned long get_wchan(struct task_struct *p)

{

	struct stackframe frame;

arch/unicore32/kernel/sys.c

+0 −42
Original line number Diff line number Diff line
@@ -63,48 +63,6 @@ asmlinkage long __sys_execve(const char __user *filename, 
	return error;

}



int kernel_execve(const char *filename,

		  const char *const argv[],

		  const char *const envp[])

{

	struct pt_regs regs;

	int ret;



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

	ret = do_execve(filename,

			(const char __user *const __user *)argv,

			(const char __user *const __user *)envp, &regs);

	if (ret < 0)

		goto out;



	/*

	 * Save argc to the register structure for userspace.

	 */

	regs.UCreg_00 = ret;



	/*

	 * We were successful.  We won't be returning to our caller, but

	 * instead to user space by manipulating the kernel stack.

	 */

	asm("add	r0, %0, %1\n\t"

		"mov	r1, %2\n\t"

		"mov	r2, %3\n\t"

		"mov	r22, #0\n\t"	/* not a syscall */

		"mov	r23, %0\n\t"	/* thread structure */

		"b.l	memmove\n\t"	/* copy regs to top of stack */

		"mov	sp, r0\n\t"	/* reposition stack pointer */

		"b	ret_to_user"

		:

		: "r" (current_thread_info()),

		  "Ir" (THREAD_START_SP - sizeof(regs)),

		  "r" (&regs),

		  "Ir" (sizeof(regs))

		: "r0", "r1", "r2", "r3", "ip", "lr", "memory");



 out:

	return ret;

}



/* Note: used by the compat code even in 64-bit Linux. */

SYSCALL_DEFINE6(mmap2, unsigned long, addr, unsigned long, len,

		unsigned long, prot, unsigned long, flags,