diff options
Diffstat (limited to 'arch/arm64/kernel/process.c')
| -rw-r--r-- | arch/arm64/kernel/process.c | 77 |
1 files changed, 24 insertions, 53 deletions
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index f22965ea1cf..bf615e212c6 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -240,27 +240,35 @@ int copy_thread(unsigned long clone_flags, unsigned long stack_start, struct pt_regs *childregs = task_pt_regs(p); unsigned long tls = p->thread.tp_value; - *childregs = *regs; - childregs->regs[0] = 0; + memset(&p->thread.cpu_context, 0, sizeof(struct cpu_context)); - if (is_compat_thread(task_thread_info(p))) - childregs->compat_sp = stack_start; - else { + if (likely(regs)) { + *childregs = *regs; + childregs->regs[0] = 0; + if (is_compat_thread(task_thread_info(p))) { + childregs->compat_sp = stack_start; + } else { + /* + * Read the current TLS pointer from tpidr_el0 as it may be + * out-of-sync with the saved value. + */ + asm("mrs %0, tpidr_el0" : "=r" (tls)); + childregs->sp = stack_start; + } /* - * Read the current TLS pointer from tpidr_el0 as it may be - * out-of-sync with the saved value. + * If a TLS pointer was passed to clone (4th argument), use it + * for the new thread. */ - asm("mrs %0, tpidr_el0" : "=r" (tls)); - childregs->sp = stack_start; + if (clone_flags & CLONE_SETTLS) + tls = regs->regs[3]; + } else { + memset(childregs, 0, sizeof(struct pt_regs)); + childregs->pstate = PSR_MODE_EL1h; + p->thread.cpu_context.x19 = stack_start; + p->thread.cpu_context.x20 = stk_sz; } - - memset(&p->thread.cpu_context, 0, sizeof(struct cpu_context)); - p->thread.cpu_context.sp = (unsigned long)childregs; p->thread.cpu_context.pc = (unsigned long)ret_from_fork; - - /* If a TLS pointer was passed to clone, use that for the new thread. */ - if (clone_flags & CLONE_SETTLS) - tls = regs->regs[3]; + p->thread.cpu_context.sp = (unsigned long)childregs; p->thread.tp_value = tls; ptrace_hw_copy_thread(p); @@ -327,43 +335,6 @@ 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. x1 is the thread argument, x2 is the pointer to - * the thread function, and x3 points to the exit function. - */ -extern void kernel_thread_helper(void); -asm( ".section .text\n" -" .align\n" -" .type kernel_thread_helper, #function\n" -"kernel_thread_helper:\n" -" mov x0, x1\n" -" mov x30, x3\n" -" br x2\n" -" .size kernel_thread_helper, . - kernel_thread_helper\n" -" .previous"); - -#define kernel_thread_exit do_exit - -/* - * 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.regs[1] = (unsigned long)arg; - regs.regs[2] = (unsigned long)fn; - regs.regs[3] = (unsigned long)kernel_thread_exit; - regs.pc = (unsigned long)kernel_thread_helper; - regs.pstate = PSR_MODE_EL1h; - - 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; |