Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2)  * Copyright (C) 2003 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3)  * Copyright 2003 PathScale, Inc.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5)  * Licensed under the GPL
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8) #include <linux/sched.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9) #include <linux/sched/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/syscalls.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/uaccess.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <asm/prctl.h> /* XXX This should get the constants from libc */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <os.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <registers.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) long arch_prctl(struct task_struct *task, int option,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) 		unsigned long __user *arg2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) 	unsigned long *ptr = arg2, tmp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) 	long ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) 	int pid = task->mm->context.id.u.pid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) 	 * With ARCH_SET_FS (and ARCH_SET_GS is treated similarly to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) 	 * be safe), we need to call arch_prctl on the host because
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) 	 * setting %fs may result in something else happening (like a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) 	 * GDT or thread.fs being set instead).  So, we let the host
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) 	 * fiddle the registers and thread struct and restore the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) 	 * registers afterwards.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) 	 *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) 	 * So, the saved registers are stored to the process (this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) 	 * needed because a stub may have been the last thing to run),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) 	 * arch_prctl is run on the host, then the registers are read
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) 	 * back.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) 	switch (option) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) 	case ARCH_SET_FS:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) 	case ARCH_SET_GS:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) 		ret = restore_pid_registers(pid, &current->thread.regs.regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) 		if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) 			return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) 	case ARCH_GET_FS:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) 	case ARCH_GET_GS:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) 		/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) 		 * With these two, we read to a local pointer and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) 		 * put_user it to the userspace pointer that we were
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) 		 * given.  If addr isn't valid (because it hasn't been
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) 		 * faulted in or is just bogus), we want put_user to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) 		 * fault it in (or return -EFAULT) instead of having
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) 		 * the host return -EFAULT.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) 		ptr = &tmp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) 	ret = os_arch_prctl(pid, option, ptr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) 	if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) 		return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) 	switch (option) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) 	case ARCH_SET_FS:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) 		current->thread.arch.fs = (unsigned long) ptr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) 		ret = save_registers(pid, &current->thread.regs.regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) 	case ARCH_SET_GS:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) 		ret = save_registers(pid, &current->thread.regs.regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) 	case ARCH_GET_FS:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) 		ret = put_user(tmp, arg2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) 	case ARCH_GET_GS:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) 		ret = put_user(tmp, arg2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) 	return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) SYSCALL_DEFINE2(arch_prctl, int, option, unsigned long, arg2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) 	return arch_prctl(current, option, (unsigned long __user *) arg2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) void arch_switch_to(struct task_struct *to)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) 	if ((to->thread.arch.fs == 0) || (to->mm == NULL))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) 	arch_prctl(to, ARCH_SET_FS, (void __user *) to->thread.arch.fs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) }