diff options
Diffstat (limited to 'arch/arm/kernel/process.c')
| -rw-r--r-- | arch/arm/kernel/process.c | 74 |
1 files changed, 12 insertions, 62 deletions
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c index 04eea22d795..90084a6de35 100644 --- a/arch/arm/kernel/process.c +++ b/arch/arm/kernel/process.c @@ -381,13 +381,20 @@ 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->ARM_r0 = 0; - childregs->ARM_sp = stack_start; - memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save)); - thread->cpu_context.sp = (unsigned long)childregs; + + if (likely(regs)) { + *childregs = *regs; + childregs->ARM_r0 = 0; + childregs->ARM_sp = stack_start; + } else { + memset(childregs, 0, sizeof(struct pt_regs)); + thread->cpu_context.r4 = stk_sz; + thread->cpu_context.r5 = stack_start; + childregs->ARM_cpsr = SVC_MODE; + } thread->cpu_context.pc = (unsigned long)ret_from_fork; + thread->cpu_context.sp = (unsigned long)childregs; clear_ptrace_hw_breakpoint(p); @@ -423,63 +430,6 @@ int dump_fpu (struct pt_regs *regs, struct user_fp *fp) } EXPORT_SYMBOL(dump_fpu); -/* - * Shuffle the argument into the correct register before calling the - * thread function. r4 is the thread argument, r5 is the pointer to - * the thread function, and r6 points to the exit function. - */ -extern void kernel_thread_helper(void); -asm( ".pushsection .text\n" -" .align\n" -" .type kernel_thread_helper, #function\n" -"kernel_thread_helper:\n" -#ifdef CONFIG_TRACE_IRQFLAGS -" bl trace_hardirqs_on\n" -#endif -" msr cpsr_c, r7\n" -" mov r0, r4\n" -" mov lr, r6\n" -" mov pc, r5\n" -" .size kernel_thread_helper, . - kernel_thread_helper\n" -" .popsection"); - -#ifdef CONFIG_ARM_UNWIND -extern void kernel_thread_exit(long code); -asm( ".pushsection .text\n" -" .align\n" -" .type kernel_thread_exit, #function\n" -"kernel_thread_exit:\n" -" .fnstart\n" -" .cantunwind\n" -" bl do_exit\n" -" nop\n" -" .fnend\n" -" .size kernel_thread_exit, . - kernel_thread_exit\n" -" .popsection"); -#else -#define kernel_thread_exit do_exit -#endif - -/* - * Create a kernel thread. - */ -pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) -{ - struct pt_regs regs; - - memset(®s, 0, sizeof(regs)); - - regs.ARM_r4 = (unsigned long)arg; - regs.ARM_r5 = (unsigned long)fn; - regs.ARM_r6 = (unsigned long)kernel_thread_exit; - regs.ARM_r7 = SVC_MODE | PSR_ENDSTATE | PSR_ISETSTATE; - regs.ARM_pc = (unsigned long)kernel_thread_helper; - regs.ARM_cpsr = regs.ARM_r7 | PSR_I_BIT; - - return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, ®s, 0, NULL, NULL); -} -EXPORT_SYMBOL(kernel_thread); - unsigned long get_wchan(struct task_struct *p) { struct stackframe frame; |