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

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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-and-Tested-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
This commit is contained in:
Al Viro 2012-10-13 17:35:21 -04:00 committed by Guan Xuetao
parent ddd2d384b0
commit 38e993535e
5 changed files with 23 additions and 99 deletions
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2
arch/unicore32/Kconfig
View File

@ -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

5
arch/unicore32/include/asm/processor.h
View File

@ -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)

15
arch/unicore32/kernel/entry.S
View File

@ -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
*-----------------------------------------------------------------------------

58
arch/unicore32/kernel/process.c
View File

@ -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;
thread->cpu_context.pc = (unsigned long)ret_from_fork;
if (clone_flags & CLONE_SETTLS)
childregs->UCreg_16 = regs->UCreg_03;
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;

42
arch/unicore32/kernel/sys.c
View File

@ -63,48 +63,6 @@ out:
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,