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m32r: switch to generic kernel_thread()/kernel_execve()

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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2012-10-15 16:26:03 -04:00
parent ddffeb8c4d
commit ea4a1da9b2
5 changed files with 26 additions and 69 deletions
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2
arch/m32r/Kconfig
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@ -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

5
arch/m32r/include/asm/processor.h
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@ -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);

9
arch/m32r/kernel/entry.S
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@ -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

58
arch/m32r/kernel/process.c
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@ -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);
/* Copy registers */
*childregs = *regs;
childregs->spu = spu;
childregs->r0 = 0; /* Child gets zero as return value */
regs->r0 = tsk->pid;
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 */
tsk->thread.lr = (unsigned long)ret_from_fork;
}
tsk->thread.sp = (unsigned long)childregs;
tsk->thread.lr = (unsigned long)ret_from_fork;
return 0;
}

21
arch/m32r/kernel/sys_m32r.c
View File

@ -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;
}