376 lines
9.2 KiB
C
376 lines
9.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Author: Huacai Chen <chenhuacai@loongson.cn>
|
|
* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
|
|
*
|
|
* Derived from MIPS:
|
|
* Copyright (C) 1994 - 1999, 2000 by Ralf Baechle and others.
|
|
* Copyright (C) 2005, 2006 by Ralf Baechle (ralf@linux-mips.org)
|
|
* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
|
|
* Copyright (C) 2004 Thiemo Seufer
|
|
* Copyright (C) 2013 Imagination Technologies Ltd.
|
|
*/
|
|
#include <linux/cpu.h>
|
|
#include <linux/init.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/sched/debug.h>
|
|
#include <linux/sched/task.h>
|
|
#include <linux/sched/task_stack.h>
|
|
#include <linux/hw_breakpoint.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/stddef.h>
|
|
#include <linux/unistd.h>
|
|
#include <linux/export.h>
|
|
#include <linux/ptrace.h>
|
|
#include <linux/mman.h>
|
|
#include <linux/personality.h>
|
|
#include <linux/sys.h>
|
|
#include <linux/completion.h>
|
|
#include <linux/kallsyms.h>
|
|
#include <linux/random.h>
|
|
#include <linux/prctl.h>
|
|
#include <linux/nmi.h>
|
|
|
|
#include <asm/asm.h>
|
|
#include <asm/bootinfo.h>
|
|
#include <asm/cpu.h>
|
|
#include <asm/elf.h>
|
|
#include <asm/exec.h>
|
|
#include <asm/fpu.h>
|
|
#include <asm/lbt.h>
|
|
#include <asm/io.h>
|
|
#include <asm/irq.h>
|
|
#include <asm/irq_regs.h>
|
|
#include <asm/loongarch.h>
|
|
#include <asm/pgtable.h>
|
|
#include <asm/processor.h>
|
|
#include <asm/reg.h>
|
|
#include <asm/unwind.h>
|
|
#include <asm/vdso.h>
|
|
|
|
#ifdef CONFIG_STACKPROTECTOR
|
|
#include <linux/stackprotector.h>
|
|
unsigned long __stack_chk_guard __read_mostly;
|
|
EXPORT_SYMBOL(__stack_chk_guard);
|
|
#endif
|
|
|
|
/*
|
|
* Idle related variables and functions
|
|
*/
|
|
|
|
unsigned long boot_option_idle_override = IDLE_NO_OVERRIDE;
|
|
EXPORT_SYMBOL(boot_option_idle_override);
|
|
|
|
asmlinkage void ret_from_fork(void);
|
|
asmlinkage void ret_from_kernel_thread(void);
|
|
|
|
void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long sp)
|
|
{
|
|
unsigned long crmd;
|
|
unsigned long prmd;
|
|
unsigned long euen;
|
|
|
|
/* New thread loses kernel privileges. */
|
|
crmd = regs->csr_crmd & ~(PLV_MASK);
|
|
crmd |= PLV_USER;
|
|
regs->csr_crmd = crmd;
|
|
|
|
prmd = regs->csr_prmd & ~(PLV_MASK);
|
|
prmd |= PLV_USER;
|
|
regs->csr_prmd = prmd;
|
|
|
|
euen = regs->csr_euen & ~(CSR_EUEN_FPEN);
|
|
regs->csr_euen = euen;
|
|
lose_fpu(0);
|
|
lose_lbt(0);
|
|
current->thread.fpu.fcsr = boot_cpu_data.fpu_csr0;
|
|
|
|
clear_thread_flag(TIF_LSX_CTX_LIVE);
|
|
clear_thread_flag(TIF_LASX_CTX_LIVE);
|
|
clear_thread_flag(TIF_LBT_CTX_LIVE);
|
|
clear_used_math();
|
|
regs->csr_era = pc;
|
|
regs->regs[3] = sp;
|
|
}
|
|
|
|
void flush_thread(void)
|
|
{
|
|
flush_ptrace_hw_breakpoint(current);
|
|
}
|
|
|
|
void exit_thread(struct task_struct *tsk)
|
|
{
|
|
}
|
|
|
|
int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
|
|
{
|
|
/*
|
|
* Save any process state which is live in hardware registers to the
|
|
* parent context prior to duplication. This prevents the new child
|
|
* state becoming stale if the parent is preempted before copy_thread()
|
|
* gets a chance to save the parent's live hardware registers to the
|
|
* child context.
|
|
*/
|
|
preempt_disable();
|
|
|
|
if (is_fpu_owner()) {
|
|
if (is_lasx_enabled())
|
|
save_lasx(current);
|
|
else if (is_lsx_enabled())
|
|
save_lsx(current);
|
|
else
|
|
save_fp(current);
|
|
}
|
|
|
|
preempt_enable();
|
|
|
|
if (!used_math())
|
|
memcpy(dst, src, offsetof(struct task_struct, thread.fpu.fpr));
|
|
else
|
|
memcpy(dst, src, offsetof(struct task_struct, thread.lbt.scr0));
|
|
|
|
#ifdef CONFIG_CPU_HAS_LBT
|
|
memcpy(&dst->thread.lbt, &src->thread.lbt, sizeof(struct loongarch_lbt));
|
|
#endif
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Copy architecture-specific thread state
|
|
*/
|
|
int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
|
|
{
|
|
unsigned long childksp;
|
|
unsigned long tls = args->tls;
|
|
unsigned long usp = args->stack;
|
|
unsigned long clone_flags = args->flags;
|
|
struct pt_regs *childregs, *regs = current_pt_regs();
|
|
|
|
childksp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
|
|
|
|
/* set up new TSS. */
|
|
childregs = (struct pt_regs *) childksp - 1;
|
|
/* Put the stack after the struct pt_regs. */
|
|
childksp = (unsigned long) childregs;
|
|
p->thread.sched_cfa = 0;
|
|
p->thread.csr_euen = 0;
|
|
p->thread.csr_crmd = csr_read32(LOONGARCH_CSR_CRMD);
|
|
p->thread.csr_prmd = csr_read32(LOONGARCH_CSR_PRMD);
|
|
p->thread.csr_ecfg = csr_read32(LOONGARCH_CSR_ECFG);
|
|
if (unlikely(args->fn)) {
|
|
/* kernel thread */
|
|
p->thread.reg03 = childksp;
|
|
p->thread.reg23 = (unsigned long)args->fn;
|
|
p->thread.reg24 = (unsigned long)args->fn_arg;
|
|
p->thread.reg01 = (unsigned long)ret_from_kernel_thread;
|
|
p->thread.sched_ra = (unsigned long)ret_from_kernel_thread;
|
|
memset(childregs, 0, sizeof(struct pt_regs));
|
|
childregs->csr_euen = p->thread.csr_euen;
|
|
childregs->csr_crmd = p->thread.csr_crmd;
|
|
childregs->csr_prmd = p->thread.csr_prmd;
|
|
childregs->csr_ecfg = p->thread.csr_ecfg;
|
|
goto out;
|
|
}
|
|
|
|
/* user thread */
|
|
*childregs = *regs;
|
|
childregs->regs[4] = 0; /* Child gets zero as return value */
|
|
if (usp)
|
|
childregs->regs[3] = usp;
|
|
|
|
p->thread.reg03 = (unsigned long) childregs;
|
|
p->thread.reg01 = (unsigned long) ret_from_fork;
|
|
p->thread.sched_ra = (unsigned long) ret_from_fork;
|
|
|
|
/*
|
|
* New tasks lose permission to use the fpu. This accelerates context
|
|
* switching for most programs since they don't use the fpu.
|
|
*/
|
|
childregs->csr_euen = 0;
|
|
|
|
if (clone_flags & CLONE_SETTLS)
|
|
childregs->regs[2] = tls;
|
|
|
|
out:
|
|
ptrace_hw_copy_thread(p);
|
|
clear_tsk_thread_flag(p, TIF_USEDFPU);
|
|
clear_tsk_thread_flag(p, TIF_USEDSIMD);
|
|
clear_tsk_thread_flag(p, TIF_USEDLBT);
|
|
clear_tsk_thread_flag(p, TIF_LSX_CTX_LIVE);
|
|
clear_tsk_thread_flag(p, TIF_LASX_CTX_LIVE);
|
|
clear_tsk_thread_flag(p, TIF_LBT_CTX_LIVE);
|
|
|
|
return 0;
|
|
}
|
|
|
|
unsigned long __get_wchan(struct task_struct *task)
|
|
{
|
|
unsigned long pc = 0;
|
|
struct unwind_state state;
|
|
|
|
if (!try_get_task_stack(task))
|
|
return 0;
|
|
|
|
for (unwind_start(&state, task, NULL);
|
|
!unwind_done(&state); unwind_next_frame(&state)) {
|
|
pc = unwind_get_return_address(&state);
|
|
if (!pc)
|
|
break;
|
|
if (in_sched_functions(pc))
|
|
continue;
|
|
break;
|
|
}
|
|
|
|
put_task_stack(task);
|
|
|
|
return pc;
|
|
}
|
|
|
|
bool in_irq_stack(unsigned long stack, struct stack_info *info)
|
|
{
|
|
unsigned long nextsp;
|
|
unsigned long begin = (unsigned long)this_cpu_read(irq_stack);
|
|
unsigned long end = begin + IRQ_STACK_START;
|
|
|
|
if (stack < begin || stack >= end)
|
|
return false;
|
|
|
|
nextsp = *(unsigned long *)end;
|
|
if (nextsp & (SZREG - 1))
|
|
return false;
|
|
|
|
info->begin = begin;
|
|
info->end = end;
|
|
info->next_sp = nextsp;
|
|
info->type = STACK_TYPE_IRQ;
|
|
|
|
return true;
|
|
}
|
|
|
|
bool in_task_stack(unsigned long stack, struct task_struct *task,
|
|
struct stack_info *info)
|
|
{
|
|
unsigned long begin = (unsigned long)task_stack_page(task);
|
|
unsigned long end = begin + THREAD_SIZE;
|
|
|
|
if (stack < begin || stack >= end)
|
|
return false;
|
|
|
|
info->begin = begin;
|
|
info->end = end;
|
|
info->next_sp = 0;
|
|
info->type = STACK_TYPE_TASK;
|
|
|
|
return true;
|
|
}
|
|
|
|
int get_stack_info(unsigned long stack, struct task_struct *task,
|
|
struct stack_info *info)
|
|
{
|
|
task = task ? : current;
|
|
|
|
if (!stack || stack & (SZREG - 1))
|
|
goto unknown;
|
|
|
|
if (in_task_stack(stack, task, info))
|
|
return 0;
|
|
|
|
if (task != current)
|
|
goto unknown;
|
|
|
|
if (in_irq_stack(stack, info))
|
|
return 0;
|
|
|
|
unknown:
|
|
info->type = STACK_TYPE_UNKNOWN;
|
|
return -EINVAL;
|
|
}
|
|
|
|
unsigned long stack_top(void)
|
|
{
|
|
unsigned long top = TASK_SIZE & PAGE_MASK;
|
|
|
|
/* Space for the VDSO & data page */
|
|
top -= PAGE_ALIGN(current->thread.vdso->size);
|
|
top -= VVAR_SIZE;
|
|
|
|
/* Space to randomize the VDSO base */
|
|
if (current->flags & PF_RANDOMIZE)
|
|
top -= VDSO_RANDOMIZE_SIZE;
|
|
|
|
return top;
|
|
}
|
|
|
|
/*
|
|
* Don't forget that the stack pointer must be aligned on a 8 bytes
|
|
* boundary for 32-bits ABI and 16 bytes for 64-bits ABI.
|
|
*/
|
|
unsigned long arch_align_stack(unsigned long sp)
|
|
{
|
|
if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
|
|
sp -= get_random_u32_below(PAGE_SIZE);
|
|
|
|
return sp & STACK_ALIGN;
|
|
}
|
|
|
|
static DEFINE_PER_CPU(call_single_data_t, backtrace_csd);
|
|
static struct cpumask backtrace_csd_busy;
|
|
|
|
static void handle_backtrace(void *info)
|
|
{
|
|
nmi_cpu_backtrace(get_irq_regs());
|
|
cpumask_clear_cpu(smp_processor_id(), &backtrace_csd_busy);
|
|
}
|
|
|
|
static void raise_backtrace(cpumask_t *mask)
|
|
{
|
|
call_single_data_t *csd;
|
|
int cpu;
|
|
|
|
for_each_cpu(cpu, mask) {
|
|
/*
|
|
* If we previously sent an IPI to the target CPU & it hasn't
|
|
* cleared its bit in the busy cpumask then it didn't handle
|
|
* our previous IPI & it's not safe for us to reuse the
|
|
* call_single_data_t.
|
|
*/
|
|
if (cpumask_test_and_set_cpu(cpu, &backtrace_csd_busy)) {
|
|
pr_warn("Unable to send backtrace IPI to CPU%u - perhaps it hung?\n",
|
|
cpu);
|
|
continue;
|
|
}
|
|
|
|
csd = &per_cpu(backtrace_csd, cpu);
|
|
csd->func = handle_backtrace;
|
|
smp_call_function_single_async(cpu, csd);
|
|
}
|
|
}
|
|
|
|
void arch_trigger_cpumask_backtrace(const cpumask_t *mask, int exclude_cpu)
|
|
{
|
|
nmi_trigger_cpumask_backtrace(mask, exclude_cpu, raise_backtrace);
|
|
}
|
|
|
|
#ifdef CONFIG_64BIT
|
|
void loongarch_dump_regs64(u64 *uregs, const struct pt_regs *regs)
|
|
{
|
|
unsigned int i;
|
|
|
|
for (i = LOONGARCH_EF_R1; i <= LOONGARCH_EF_R31; i++) {
|
|
uregs[i] = regs->regs[i - LOONGARCH_EF_R0];
|
|
}
|
|
|
|
uregs[LOONGARCH_EF_ORIG_A0] = regs->orig_a0;
|
|
uregs[LOONGARCH_EF_CSR_ERA] = regs->csr_era;
|
|
uregs[LOONGARCH_EF_CSR_BADV] = regs->csr_badvaddr;
|
|
uregs[LOONGARCH_EF_CSR_CRMD] = regs->csr_crmd;
|
|
uregs[LOONGARCH_EF_CSR_PRMD] = regs->csr_prmd;
|
|
uregs[LOONGARCH_EF_CSR_EUEN] = regs->csr_euen;
|
|
uregs[LOONGARCH_EF_CSR_ECFG] = regs->csr_ecfg;
|
|
uregs[LOONGARCH_EF_CSR_ESTAT] = regs->csr_estat;
|
|
}
|
|
#endif /* CONFIG_64BIT */
|