m32r: switch to generic kernel_thread()/kernel_execve() (ea4a1da9) · Commits · e / devices / android_kernel_xiaomi_markw

arch/m32r/Kconfig

+2 −0

Original line number	Diff line number	Diff line
		@@ -15,6 +15,8 @@ config M32R
		select GENERIC_ATOMIC64
		select ARCH_USES_GETTIMEOFFSET
		select MODULES_USE_ELF_RELA
		select GENERIC_KERNEL_THREAD
		select GENERIC_KERNEL_EXECVE

		config SBUS
		bool

arch/m32r/include/asm/processor.h

+0 −5

Original line number	Diff line number	Diff line
		@@ -118,11 +118,6 @@ struct mm_struct;
		/* Free all resources held by a thread. */
		extern void release_thread(struct task_struct *);

		/*
		* create a kernel thread without removing it from tasklists
		*/
		extern int kernel_thread(int (fn)(void ), void * arg, unsigned long flags);

		/* Copy and release all segment info associated with a VM */
		extern void copy_segments(struct task_struct p, struct mm_struct mm);
		extern void release_segments(struct mm_struct * mm);

arch/m32r/kernel/entry.S

+9 −0

Original line number	Diff line number	Diff line
		@@ -125,6 +125,15 @@
		and \reg, sp
		.endm

		ENTRY(ret_from_kernel_thread)
		pop r0
		bl schedule_tail
		GET_THREAD_INFO(r8)
		ld r0, R0(r8)
		ld r1, R1(r8)
		jl r1
		bra syscall_exit

		ENTRY(ret_from_fork)
		pop r0
		bl schedule_tail

arch/m32r/kernel/process.c

+16 −44

Original line number	Diff line number	Diff line
		@@ -164,41 +164,6 @@ void show_regs(struct pt_regs * regs)
		#endif
		}

		/*
		* Create a kernel thread
		*/

		/*
		* This is the mechanism for creating a new kernel thread.
		*
		* NOTE! Only a kernel-only process(ie the swapper or direct descendants
		* who haven't done an "execve()") should use this: it will work within
		* a system call from a "real" process, but the process memory space will
		* not be free'd until both the parent and the child have exited.
		*/
		static void kernel_thread_helper(void nouse, int (fn)(void ), void arg)
		{
		fn(arg);
		do_exit(-1);
		}

		int kernel_thread(int (fn)(void ), void *arg, unsigned long flags)
		{
		struct pt_regs regs;

		memset(&regs, 0, sizeof (regs));
		regs.r1 = (unsigned long)fn;
		regs.r2 = (unsigned long)arg;

		regs.bpc = (unsigned long)kernel_thread_helper;

		regs.psw = M32R_PSW_BIE;

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

		/*
		* Free current thread data structures etc..
		*/
		@@ -227,19 +192,26 @@ int dump_fpu(struct pt_regs regs, elf_fpregset_t fpu)
		}

		int copy_thread(unsigned long clone_flags, unsigned long spu,
		unsigned long unused, struct task_struct tsk, struct pt_regs regs)
		unsigned long arg, struct task_struct tsk, struct pt_regs regs)
		{
		struct pt_regs *childregs = task_pt_regs(tsk);
		extern void ret_from_fork(void);

		extern void ret_from_kernel_thread(void);

		if (unlikely(tsk->flags & PF_KTHREAD)) {
		memset(childregs, 0, sizeof(struct pt_regs));
		childregs->psw = M32R_PSW_BIE;
		childregs->r1 = spu; /* fn */
		childregs->r0 = arg;
		tsk->thread.lr = (unsigned long)ret_from_kernel_thread;
		} else {
		/* Copy registers */
		childregs = regs;

		childregs->spu = spu;
		childregs->r0 = 0; /* Child gets zero as return value */
		regs->r0 = tsk->pid;
		tsk->thread.sp = (unsigned long)childregs;
		tsk->thread.lr = (unsigned long)ret_from_fork;
		}
		tsk->thread.sp = (unsigned long)childregs;

		return 0;
		}

arch/m32r/kernel/sys_m32r.c

+0 −21

Original line number	Diff line number	Diff line
		@@ -88,24 +88,3 @@ asmlinkage int sys_cachectl(char *addr, int nbytes, int op)
		/* Not implemented yet. */
		return -ENOSYS;
		}

		/*
		* Do a system call from kernel instead of calling sys_execve so we
		* end up with proper pt_regs.
		*/
		int kernel_execve(const char *filename,
		const char *const argv[],
		const char *const envp[])
		{
		register long __scno __asm__ ("r7") = __NR_execve;
		register long __arg3 __asm__ ("r2") = (long)(envp);
		register long __arg2 __asm__ ("r1") = (long)(argv);
		register long __res __asm__ ("r0") = (long)(filename);
		__asm__ __volatile__ (
		"trap #" SYSCALL_VECTOR "\|\| nop"
		: "=r" (__res)
		: "r" (__scno), "0" (__res), "r" (__arg2),
		"r" (__arg3)
		: "memory");
		return __res;
		}