^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) * arch/xtensa/kernel/process.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) * Xtensa Processor version.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) * This file is subject to the terms and conditions of the GNU General Public
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * License. See the file "COPYING" in the main directory of this archive
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) * for more details.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) * Copyright (C) 2001 - 2005 Tensilica Inc.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) * Joe Taylor <joe@tensilica.com, joetylr@yahoo.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) * Chris Zankel <chris@zankel.net>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) * Marc Gauthier <marc@tensilica.com, marc@alumni.uwaterloo.ca>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) * Kevin Chea
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include <linux/errno.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include <linux/sched.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #include <linux/sched/debug.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) #include <linux/sched/task.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) #include <linux/sched/task_stack.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) #include <linux/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) #include <linux/smp.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) #include <linux/stddef.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) #include <linux/unistd.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) #include <linux/ptrace.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) #include <linux/elf.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) #include <linux/hw_breakpoint.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) #include <linux/prctl.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) #include <linux/init_task.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) #include <linux/mqueue.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) #include <linux/fs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) #include <linux/rcupdate.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) #include <linux/uaccess.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) #include <asm/io.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) #include <asm/processor.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) #include <asm/platform.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) #include <asm/mmu.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) #include <asm/irq.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) #include <linux/atomic.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) #include <asm/asm-offsets.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) #include <asm/regs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) #include <asm/hw_breakpoint.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) extern void ret_from_fork(void);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) extern void ret_from_kernel_thread(void);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) void (*pm_power_off)(void) = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) EXPORT_SYMBOL(pm_power_off);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) #ifdef CONFIG_STACKPROTECTOR
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) #include <linux/stackprotector.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) unsigned long __stack_chk_guard __read_mostly;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) EXPORT_SYMBOL(__stack_chk_guard);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) #if XTENSA_HAVE_COPROCESSORS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) void coprocessor_release_all(struct thread_info *ti)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) unsigned long cpenable;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) /* Make sure we don't switch tasks during this operation. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) preempt_disable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) /* Walk through all cp owners and release it for the requested one. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) cpenable = ti->cpenable;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) for (i = 0; i < XCHAL_CP_MAX; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) if (coprocessor_owner[i] == ti) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) coprocessor_owner[i] = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) cpenable &= ~(1 << i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) ti->cpenable = cpenable;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) if (ti == current_thread_info())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) xtensa_set_sr(0, cpenable);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) preempt_enable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) void coprocessor_flush_all(struct thread_info *ti)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) unsigned long cpenable, old_cpenable;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) preempt_disable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) old_cpenable = xtensa_get_sr(cpenable);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) cpenable = ti->cpenable;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) xtensa_set_sr(cpenable, cpenable);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) for (i = 0; i < XCHAL_CP_MAX; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) if ((cpenable & 1) != 0 && coprocessor_owner[i] == ti)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) coprocessor_flush(ti, i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) cpenable >>= 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) xtensa_set_sr(old_cpenable, cpenable);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) preempt_enable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) * Powermanagement idle function, if any is provided by the platform.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) void arch_cpu_idle(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) platform_idle();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) * This is called when the thread calls exit().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) void exit_thread(struct task_struct *tsk)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) #if XTENSA_HAVE_COPROCESSORS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) coprocessor_release_all(task_thread_info(tsk));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) * Flush thread state. This is called when a thread does an execve()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) * Note that we flush coprocessor registers for the case execve fails.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) void flush_thread(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) #if XTENSA_HAVE_COPROCESSORS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) struct thread_info *ti = current_thread_info();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) coprocessor_flush_all(ti);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) coprocessor_release_all(ti);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) flush_ptrace_hw_breakpoint(current);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) * this gets called so that we can store coprocessor state into memory and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) * copy the current task into the new thread.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) #if XTENSA_HAVE_COPROCESSORS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) coprocessor_flush_all(task_thread_info(src));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) *dst = *src;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) * Copy thread.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) * There are two modes in which this function is called:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) * 1) Userspace thread creation,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) * regs != NULL, usp_thread_fn is userspace stack pointer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) * It is expected to copy parent regs (in case CLONE_VM is not set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) * in the clone_flags) and set up passed usp in the childregs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) * 2) Kernel thread creation,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) * regs == NULL, usp_thread_fn is the function to run in the new thread
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) * and thread_fn_arg is its parameter.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) * childregs are not used for the kernel threads.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) * The stack layout for the new thread looks like this:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) * +------------------------+
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) * | childregs |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) * +------------------------+ <- thread.sp = sp in dummy-frame
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) * | dummy-frame | (saved in dummy-frame spill-area)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) * +------------------------+
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) * We create a dummy frame to return to either ret_from_fork or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) * ret_from_kernel_thread:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) * a0 points to ret_from_fork/ret_from_kernel_thread (simulating a call4)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) * sp points to itself (thread.sp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) * a2, a3 are unused for userspace threads,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) * a2 points to thread_fn, a3 holds thread_fn arg for kernel threads.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) * Note: This is a pristine frame, so we don't need any spill region on top of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) * childregs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) * The fun part: if we're keeping the same VM (i.e. cloning a thread,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) * not an entire process), we're normally given a new usp, and we CANNOT share
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) * any live address register windows. If we just copy those live frames over,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) * the two threads (parent and child) will overflow the same frames onto the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) * parent stack at different times, likely corrupting the parent stack (esp.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) * if the parent returns from functions that called clone() and calls new
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) * ones, before the child overflows its now old copies of its parent windows).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) * One solution is to spill windows to the parent stack, but that's fairly
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) * involved. Much simpler to just not copy those live frames across.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) int copy_thread(unsigned long clone_flags, unsigned long usp_thread_fn,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) unsigned long thread_fn_arg, struct task_struct *p,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) unsigned long tls)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) struct pt_regs *childregs = task_pt_regs(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) #if (XTENSA_HAVE_COPROCESSORS || XTENSA_HAVE_IO_PORTS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) struct thread_info *ti;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) /* Create a call4 dummy-frame: a0 = 0, a1 = childregs. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) SPILL_SLOT(childregs, 1) = (unsigned long)childregs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) SPILL_SLOT(childregs, 0) = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) p->thread.sp = (unsigned long)childregs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) if (!(p->flags & PF_KTHREAD)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) struct pt_regs *regs = current_pt_regs();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) unsigned long usp = usp_thread_fn ?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) usp_thread_fn : regs->areg[1];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) p->thread.ra = MAKE_RA_FOR_CALL(
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) (unsigned long)ret_from_fork, 0x1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) /* This does not copy all the regs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) * In a bout of brilliance or madness,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) * ARs beyond a0-a15 exist past the end of the struct.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) *childregs = *regs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) childregs->areg[1] = usp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) childregs->areg[2] = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) /* When sharing memory with the parent thread, the child
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) usually starts on a pristine stack, so we have to reset
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) windowbase, windowstart and wmask.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) (Note that such a new thread is required to always create
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) an initial call4 frame)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) The exception is vfork, where the new thread continues to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) run on the parent's stack until it calls execve. This could
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) be a call8 or call12, which requires a legal stack frame
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) of the previous caller for the overflow handlers to work.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) (Note that it's always legal to overflow live registers).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) In this case, ensure to spill at least the stack pointer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) of that frame. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) if (clone_flags & CLONE_VM) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) /* check that caller window is live and same stack */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) int len = childregs->wmask & ~0xf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) if (regs->areg[1] == usp && len != 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) int callinc = (regs->areg[0] >> 30) & 3;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) int caller_ars = XCHAL_NUM_AREGS - callinc * 4;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) put_user(regs->areg[caller_ars+1],
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) (unsigned __user*)(usp - 12));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) childregs->wmask = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) childregs->windowstart = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) childregs->windowbase = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) int len = childregs->wmask & ~0xf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) memcpy(&childregs->areg[XCHAL_NUM_AREGS - len/4],
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) ®s->areg[XCHAL_NUM_AREGS - len/4], len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) childregs->syscall = regs->syscall;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) if (clone_flags & CLONE_SETTLS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) childregs->threadptr = tls;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) p->thread.ra = MAKE_RA_FOR_CALL(
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) (unsigned long)ret_from_kernel_thread, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) /* pass parameters to ret_from_kernel_thread:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) * a2 = thread_fn, a3 = thread_fn arg
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) SPILL_SLOT(childregs, 3) = thread_fn_arg;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) SPILL_SLOT(childregs, 2) = usp_thread_fn;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) /* Childregs are only used when we're going to userspace
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) * in which case start_thread will set them up.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) #if (XTENSA_HAVE_COPROCESSORS || XTENSA_HAVE_IO_PORTS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) ti = task_thread_info(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) ti->cpenable = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) clear_ptrace_hw_breakpoint(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) * These bracket the sleeping functions..
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) unsigned long get_wchan(struct task_struct *p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) unsigned long sp, pc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) unsigned long stack_page = (unsigned long) task_stack_page(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) int count = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) if (!p || p == current || p->state == TASK_RUNNING)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) sp = p->thread.sp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) pc = MAKE_PC_FROM_RA(p->thread.ra, p->thread.sp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) if (sp < stack_page + sizeof(struct task_struct) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) sp >= (stack_page + THREAD_SIZE) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) pc == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) if (!in_sched_functions(pc))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) return pc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) /* Stack layout: sp-4: ra, sp-3: sp' */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) pc = MAKE_PC_FROM_RA(SPILL_SLOT(sp, 0), sp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) sp = SPILL_SLOT(sp, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) } while (count++ < 16);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) }
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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