Contributors: 46
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Paul Burton |
845 |
22.23% |
17 |
13.71% |
| Ralf Baechle |
331 |
8.71% |
11 |
8.87% |
| Franck Bui-Huu |
321 |
8.45% |
9 |
7.26% |
| Atsushi Nemoto |
318 |
8.37% |
4 |
3.23% |
| Matt Redfearn |
290 |
7.63% |
8 |
6.45% |
| Marcin Nowakowski |
263 |
6.92% |
2 |
1.61% |
| Linus Torvalds (pre-git) |
257 |
6.76% |
15 |
12.10% |
| Jinyang He |
211 |
5.55% |
4 |
3.23% |
| Leonid Yegoshin |
187 |
4.92% |
1 |
0.81% |
| Tony Wu |
141 |
3.71% |
2 |
1.61% |
| Al Viro |
115 |
3.03% |
4 |
3.23% |
| Huacai Chen |
111 |
2.92% |
2 |
1.61% |
| Maciej W. Rozycki |
80 |
2.10% |
3 |
2.42% |
| James Hogan |
46 |
1.21% |
3 |
2.42% |
| Eric W. Biedermann |
38 |
1.00% |
2 |
1.61% |
| Eunbong Song 송은봉 |
29 |
0.76% |
1 |
0.81% |
| Daniel Kalmar |
28 |
0.74% |
1 |
0.81% |
| Corey Minyard |
28 |
0.74% |
1 |
0.81% |
| Yousong Zhou |
19 |
0.50% |
1 |
0.81% |
| Gregory Fong |
17 |
0.45% |
1 |
0.81% |
| Alex Smith |
13 |
0.34% |
2 |
1.61% |
| Thiemo Seufer |
11 |
0.29% |
1 |
0.81% |
| Markos Chandras |
11 |
0.29% |
1 |
0.81% |
| Andrew Morton |
10 |
0.26% |
1 |
0.81% |
| David Daney |
10 |
0.26% |
1 |
0.81% |
| Chris Metcalf |
9 |
0.24% |
1 |
0.81% |
| Peter Zijlstra |
8 |
0.21% |
1 |
0.81% |
| Thomas Bogendoerfer |
7 |
0.18% |
1 |
0.81% |
| Thomas Gleixner |
7 |
0.18% |
1 |
0.81% |
| Linus Torvalds |
6 |
0.16% |
4 |
3.23% |
| Ingo Molnar |
4 |
0.11% |
2 |
1.61% |
| Jason A. Donenfeld |
4 |
0.11% |
2 |
1.61% |
| James Cowgill |
3 |
0.08% |
1 |
0.81% |
| Alex Dowad |
3 |
0.08% |
1 |
0.81% |
| Kees Cook |
3 |
0.08% |
1 |
0.81% |
| Doug Anderson |
3 |
0.08% |
1 |
0.81% |
| Chris Dearman |
2 |
0.05% |
1 |
0.81% |
| Prem Karat |
2 |
0.05% |
1 |
0.81% |
| Pujin Shi |
2 |
0.05% |
1 |
0.81% |
| Sebastian Andrzej Siewior |
2 |
0.05% |
1 |
0.81% |
| Lucas De Marchi |
1 |
0.03% |
1 |
0.81% |
| Christian Brauner |
1 |
0.03% |
1 |
0.81% |
| Josh Poimboeuf |
1 |
0.03% |
1 |
0.81% |
| Tobias Klauser |
1 |
0.03% |
1 |
0.81% |
| Steven Cole |
1 |
0.03% |
1 |
0.81% |
| Andrea Gelmini |
1 |
0.03% |
1 |
0.81% |
| Total |
3801 |
|
124 |
|
/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* 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/errno.h>
#include <linux/init.h>
#include <linux/kallsyms.h>
#include <linux/kernel.h>
#include <linux/nmi.h>
#include <linux/personality.h>
#include <linux/prctl.h>
#include <linux/random.h>
#include <linux/sched.h>
#include <linux/sched/debug.h>
#include <linux/sched/task_stack.h>
#include <asm/abi.h>
#include <asm/asm.h>
#include <asm/dsemul.h>
#include <asm/dsp.h>
#include <asm/exec.h>
#include <asm/fpu.h>
#include <asm/inst.h>
#include <asm/irq.h>
#include <asm/irq_regs.h>
#include <asm/isadep.h>
#include <asm/msa.h>
#include <asm/mips-cps.h>
#include <asm/mipsregs.h>
#include <asm/processor.h>
#include <asm/reg.h>
#include <asm/stacktrace.h>
#ifdef CONFIG_HOTPLUG_CPU
void __noreturn arch_cpu_idle_dead(void)
{
play_dead();
}
#endif
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 status;
/* New thread loses kernel privileges. */
status = regs->cp0_status & ~(ST0_CU0|ST0_CU1|ST0_CU2|ST0_FR|KU_MASK);
status |= KU_USER;
regs->cp0_status = status;
lose_fpu(0);
clear_thread_flag(TIF_MSA_CTX_LIVE);
clear_used_math();
#ifdef CONFIG_MIPS_FP_SUPPORT
atomic_set(¤t->thread.bd_emu_frame, BD_EMUFRAME_NONE);
#endif
init_dsp();
regs->cp0_epc = pc;
regs->regs[29] = sp;
}
void exit_thread(struct task_struct *tsk)
{
/*
* User threads may have allocated a delay slot emulation frame.
* If so, clean up that allocation.
*/
if (!(current->flags & PF_KTHREAD))
dsemul_thread_cleanup(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_msa_enabled())
save_msa(current);
else if (is_fpu_owner())
_save_fp(current);
save_dsp(current);
preempt_enable();
*dst = *src;
return 0;
}
/*
* Copy architecture-specific thread state
*/
int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
{
unsigned long clone_flags = args->flags;
unsigned long usp = args->stack;
unsigned long tls = args->tls;
struct thread_info *ti = task_thread_info(p);
struct pt_regs *childregs, *regs = current_pt_regs();
unsigned long childksp;
childksp = (unsigned long)task_stack_page(p) + THREAD_SIZE - 32;
/* set up new TSS. */
childregs = (struct pt_regs *) childksp - 1;
/* Put the stack after the struct pt_regs. */
childksp = (unsigned long) childregs;
p->thread.cp0_status = (read_c0_status() & ~(ST0_CU2|ST0_CU1)) | ST0_KERNEL_CUMASK;
/*
* New tasks lose permission to use the fpu. This accelerates context
* switching for most programs since they don't use the fpu.
*/
clear_tsk_thread_flag(p, TIF_USEDFPU);
clear_tsk_thread_flag(p, TIF_USEDMSA);
clear_tsk_thread_flag(p, TIF_MSA_CTX_LIVE);
#ifdef CONFIG_MIPS_MT_FPAFF
clear_tsk_thread_flag(p, TIF_FPUBOUND);
#endif /* CONFIG_MIPS_MT_FPAFF */
if (unlikely(args->fn)) {
/* kernel thread */
unsigned long status = p->thread.cp0_status;
memset(childregs, 0, sizeof(struct pt_regs));
p->thread.reg16 = (unsigned long)args->fn;
p->thread.reg17 = (unsigned long)args->fn_arg;
p->thread.reg29 = childksp;
p->thread.reg31 = (unsigned long) ret_from_kernel_thread;
#if defined(CONFIG_CPU_R3000)
status = (status & ~(ST0_KUP | ST0_IEP | ST0_IEC)) |
((status & (ST0_KUC | ST0_IEC)) << 2);
#else
status |= ST0_EXL;
#endif
childregs->cp0_status = status;
return 0;
}
/* user thread */
*childregs = *regs;
childregs->regs[7] = 0; /* Clear error flag */
childregs->regs[2] = 0; /* Child gets zero as return value */
if (usp)
childregs->regs[29] = usp;
p->thread.reg29 = (unsigned long) childregs;
p->thread.reg31 = (unsigned long) ret_from_fork;
childregs->cp0_status &= ~(ST0_CU2|ST0_CU1);
#ifdef CONFIG_MIPS_FP_SUPPORT
atomic_set(&p->thread.bd_emu_frame, BD_EMUFRAME_NONE);
#endif
if (clone_flags & CLONE_SETTLS)
ti->tp_value = tls;
return 0;
}
#ifdef CONFIG_STACKPROTECTOR
#include <linux/stackprotector.h>
unsigned long __stack_chk_guard __read_mostly;
EXPORT_SYMBOL(__stack_chk_guard);
#endif
struct mips_frame_info {
void *func;
unsigned long func_size;
int frame_size;
int pc_offset;
};
#define J_TARGET(pc,target) \
(((unsigned long)(pc) & 0xf0000000) | ((target) << 2))
static inline int is_jr_ra_ins(union mips_instruction *ip)
{
#ifdef CONFIG_CPU_MICROMIPS
/*
* jr16 ra
* jr ra
*/
if (mm_insn_16bit(ip->word >> 16)) {
if (ip->mm16_r5_format.opcode == mm_pool16c_op &&
ip->mm16_r5_format.rt == mm_jr16_op &&
ip->mm16_r5_format.imm == 31)
return 1;
return 0;
}
if (ip->r_format.opcode == mm_pool32a_op &&
ip->r_format.func == mm_pool32axf_op &&
((ip->u_format.uimmediate >> 6) & GENMASK(9, 0)) == mm_jalr_op &&
ip->r_format.rt == 31)
return 1;
return 0;
#else
if (ip->r_format.opcode == spec_op &&
ip->r_format.func == jr_op &&
ip->r_format.rs == 31)
return 1;
return 0;
#endif
}
static inline int is_ra_save_ins(union mips_instruction *ip, int *poff)
{
#ifdef CONFIG_CPU_MICROMIPS
/*
* swsp ra,offset
* swm16 reglist,offset(sp)
* swm32 reglist,offset(sp)
* sw32 ra,offset(sp)
* jradiussp - NOT SUPPORTED
*
* microMIPS is way more fun...
*/
if (mm_insn_16bit(ip->word >> 16)) {
switch (ip->mm16_r5_format.opcode) {
case mm_swsp16_op:
if (ip->mm16_r5_format.rt != 31)
return 0;
*poff = ip->mm16_r5_format.imm;
*poff = (*poff << 2) / sizeof(ulong);
return 1;
case mm_pool16c_op:
switch (ip->mm16_m_format.func) {
case mm_swm16_op:
*poff = ip->mm16_m_format.imm;
*poff += 1 + ip->mm16_m_format.rlist;
*poff = (*poff << 2) / sizeof(ulong);
return 1;
default:
return 0;
}
default:
return 0;
}
}
switch (ip->i_format.opcode) {
case mm_sw32_op:
if (ip->i_format.rs != 29)
return 0;
if (ip->i_format.rt != 31)
return 0;
*poff = ip->i_format.simmediate / sizeof(ulong);
return 1;
case mm_pool32b_op:
switch (ip->mm_m_format.func) {
case mm_swm32_func:
if (ip->mm_m_format.rd < 0x10)
return 0;
if (ip->mm_m_format.base != 29)
return 0;
*poff = ip->mm_m_format.simmediate;
*poff += (ip->mm_m_format.rd & 0xf) * sizeof(u32);
*poff /= sizeof(ulong);
return 1;
default:
return 0;
}
default:
return 0;
}
#else
/* sw / sd $ra, offset($sp) */
if ((ip->i_format.opcode == sw_op || ip->i_format.opcode == sd_op) &&
ip->i_format.rs == 29 && ip->i_format.rt == 31) {
*poff = ip->i_format.simmediate / sizeof(ulong);
return 1;
}
#ifdef CONFIG_CPU_LOONGSON64
if ((ip->loongson3_lswc2_format.opcode == swc2_op) &&
(ip->loongson3_lswc2_format.ls == 1) &&
(ip->loongson3_lswc2_format.fr == 0) &&
(ip->loongson3_lswc2_format.base == 29)) {
if (ip->loongson3_lswc2_format.rt == 31) {
*poff = ip->loongson3_lswc2_format.offset << 1;
return 1;
}
if (ip->loongson3_lswc2_format.rq == 31) {
*poff = (ip->loongson3_lswc2_format.offset << 1) + 1;
return 1;
}
}
#endif
return 0;
#endif
}
static inline int is_jump_ins(union mips_instruction *ip)
{
#ifdef CONFIG_CPU_MICROMIPS
/*
* jr16,jrc,jalr16,jalr16
* jal
* jalr/jr,jalr.hb/jr.hb,jalrs,jalrs.hb
* jraddiusp - NOT SUPPORTED
*
* microMIPS is kind of more fun...
*/
if (mm_insn_16bit(ip->word >> 16)) {
if ((ip->mm16_r5_format.opcode == mm_pool16c_op &&
(ip->mm16_r5_format.rt & mm_jr16_op) == mm_jr16_op))
return 1;
return 0;
}
if (ip->j_format.opcode == mm_j32_op)
return 1;
if (ip->j_format.opcode == mm_jal32_op)
return 1;
if (ip->r_format.opcode != mm_pool32a_op ||
ip->r_format.func != mm_pool32axf_op)
return 0;
return ((ip->u_format.uimmediate >> 6) & mm_jalr_op) == mm_jalr_op;
#else
if (ip->j_format.opcode == j_op)
return 1;
if (ip->j_format.opcode == jal_op)
return 1;
if (ip->r_format.opcode != spec_op)
return 0;
return ip->r_format.func == jalr_op || ip->r_format.func == jr_op;
#endif
}
static inline int is_sp_move_ins(union mips_instruction *ip, int *frame_size)
{
#ifdef CONFIG_CPU_MICROMIPS
unsigned short tmp;
/*
* addiusp -imm
* addius5 sp,-imm
* addiu32 sp,sp,-imm
* jradiussp - NOT SUPPORTED
*
* microMIPS is not more fun...
*/
if (mm_insn_16bit(ip->word >> 16)) {
if (ip->mm16_r3_format.opcode == mm_pool16d_op &&
ip->mm16_r3_format.simmediate & mm_addiusp_func) {
tmp = ip->mm_b0_format.simmediate >> 1;
tmp = ((tmp & 0x1ff) ^ 0x100) - 0x100;
if ((tmp + 2) < 4) /* 0x0,0x1,0x1fe,0x1ff are special */
tmp ^= 0x100;
*frame_size = -(signed short)(tmp << 2);
return 1;
}
if (ip->mm16_r5_format.opcode == mm_pool16d_op &&
ip->mm16_r5_format.rt == 29) {
tmp = ip->mm16_r5_format.imm >> 1;
*frame_size = -(signed short)(tmp & 0xf);
return 1;
}
return 0;
}
if (ip->mm_i_format.opcode == mm_addiu32_op &&
ip->mm_i_format.rt == 29 && ip->mm_i_format.rs == 29) {
*frame_size = -ip->i_format.simmediate;
return 1;
}
#else
/* addiu/daddiu sp,sp,-imm */
if (ip->i_format.rs != 29 || ip->i_format.rt != 29)
return 0;
if (ip->i_format.opcode == addiu_op ||
ip->i_format.opcode == daddiu_op) {
*frame_size = -ip->i_format.simmediate;
return 1;
}
#endif
return 0;
}
static int get_frame_info(struct mips_frame_info *info)
{
bool is_mmips = IS_ENABLED(CONFIG_CPU_MICROMIPS);
union mips_instruction insn, *ip, *ip_end;
unsigned int last_insn_size = 0;
bool saw_jump = false;
info->pc_offset = -1;
info->frame_size = 0;
ip = (void *)msk_isa16_mode((ulong)info->func);
if (!ip)
goto err;
ip_end = (void *)ip + (info->func_size ? info->func_size : 512);
while (ip < ip_end) {
ip = (void *)ip + last_insn_size;
if (is_mmips && mm_insn_16bit(ip->halfword[0])) {
insn.word = ip->halfword[0] << 16;
last_insn_size = 2;
} else if (is_mmips) {
insn.word = ip->halfword[0] << 16 | ip->halfword[1];
last_insn_size = 4;
} else {
insn.word = ip->word;
last_insn_size = 4;
}
if (is_jr_ra_ins(ip)) {
break;
} else if (!info->frame_size) {
is_sp_move_ins(&insn, &info->frame_size);
continue;
} else if (!saw_jump && is_jump_ins(ip)) {
/*
* If we see a jump instruction, we are finished
* with the frame save.
*
* Some functions can have a shortcut return at
* the beginning of the function, so don't start
* looking for jump instruction until we see the
* frame setup.
*
* The RA save instruction can get put into the
* delay slot of the jump instruction, so look
* at the next instruction, too.
*/
saw_jump = true;
continue;
}
if (info->pc_offset == -1 &&
is_ra_save_ins(&insn, &info->pc_offset))
break;
if (saw_jump)
break;
}
if (info->frame_size && info->pc_offset >= 0) /* nested */
return 0;
if (info->pc_offset < 0) /* leaf */
return 1;
/* prologue seems bogus... */
err:
return -1;
}
static struct mips_frame_info schedule_mfi __read_mostly;
#ifdef CONFIG_KALLSYMS
static unsigned long get___schedule_addr(void)
{
return kallsyms_lookup_name("__schedule");
}
#else
static unsigned long get___schedule_addr(void)
{
union mips_instruction *ip = (void *)schedule;
int max_insns = 8;
int i;
for (i = 0; i < max_insns; i++, ip++) {
if (ip->j_format.opcode == j_op)
return J_TARGET(ip, ip->j_format.target);
}
return 0;
}
#endif
static int __init frame_info_init(void)
{
unsigned long size = 0;
#ifdef CONFIG_KALLSYMS
unsigned long ofs;
#endif
unsigned long addr;
addr = get___schedule_addr();
if (!addr)
addr = (unsigned long)schedule;
#ifdef CONFIG_KALLSYMS
kallsyms_lookup_size_offset(addr, &size, &ofs);
#endif
schedule_mfi.func = (void *)addr;
schedule_mfi.func_size = size;
get_frame_info(&schedule_mfi);
/*
* Without schedule() frame info, result given by
* thread_saved_pc() and __get_wchan() are not reliable.
*/
if (schedule_mfi.pc_offset < 0)
printk("Can't analyze schedule() prologue at %p\n", schedule);
return 0;
}
arch_initcall(frame_info_init);
/*
* Return saved PC of a blocked thread.
*/
static unsigned long thread_saved_pc(struct task_struct *tsk)
{
struct thread_struct *t = &tsk->thread;
/* New born processes are a special case */
if (t->reg31 == (unsigned long) ret_from_fork)
return t->reg31;
if (schedule_mfi.pc_offset < 0)
return 0;
return ((unsigned long *)t->reg29)[schedule_mfi.pc_offset];
}
#ifdef CONFIG_KALLSYMS
/* generic stack unwinding function */
unsigned long notrace unwind_stack_by_address(unsigned long stack_page,
unsigned long *sp,
unsigned long pc,
unsigned long *ra)
{
unsigned long low, high, irq_stack_high;
struct mips_frame_info info;
unsigned long size, ofs;
struct pt_regs *regs;
int leaf;
if (!stack_page)
return 0;
/*
* IRQ stacks start at IRQ_STACK_START
* task stacks at THREAD_SIZE - 32
*/
low = stack_page;
if (!preemptible() && on_irq_stack(raw_smp_processor_id(), *sp)) {
high = stack_page + IRQ_STACK_START;
irq_stack_high = high;
} else {
high = stack_page + THREAD_SIZE - 32;
irq_stack_high = 0;
}
/*
* If we reached the top of the interrupt stack, start unwinding
* the interrupted task stack.
*/
if (unlikely(*sp == irq_stack_high)) {
unsigned long task_sp = *(unsigned long *)*sp;
/*
* Check that the pointer saved in the IRQ stack head points to
* something within the stack of the current task
*/
if (!object_is_on_stack((void *)task_sp))
return 0;
/*
* Follow pointer to tasks kernel stack frame where interrupted
* state was saved.
*/
regs = (struct pt_regs *)task_sp;
pc = regs->cp0_epc;
if (!user_mode(regs) && __kernel_text_address(pc)) {
*sp = regs->regs[29];
*ra = regs->regs[31];
return pc;
}
return 0;
}
if (!kallsyms_lookup_size_offset(pc, &size, &ofs))
return 0;
/*
* Return ra if an exception occurred at the first instruction
*/
if (unlikely(ofs == 0)) {
pc = *ra;
*ra = 0;
return pc;
}
info.func = (void *)(pc - ofs);
info.func_size = ofs; /* analyze from start to ofs */
leaf = get_frame_info(&info);
if (leaf < 0)
return 0;
if (*sp < low || *sp + info.frame_size > high)
return 0;
if (leaf)
/*
* For some extreme cases, get_frame_info() can
* consider wrongly a nested function as a leaf
* one. In that cases avoid to return always the
* same value.
*/
pc = pc != *ra ? *ra : 0;
else
pc = ((unsigned long *)(*sp))[info.pc_offset];
*sp += info.frame_size;
*ra = 0;
return __kernel_text_address(pc) ? pc : 0;
}
EXPORT_SYMBOL(unwind_stack_by_address);
/* used by show_backtrace() */
unsigned long unwind_stack(struct task_struct *task, unsigned long *sp,
unsigned long pc, unsigned long *ra)
{
unsigned long stack_page = 0;
int cpu;
for_each_possible_cpu(cpu) {
if (on_irq_stack(cpu, *sp)) {
stack_page = (unsigned long)irq_stack[cpu];
break;
}
}
if (!stack_page)
stack_page = (unsigned long)task_stack_page(task);
return unwind_stack_by_address(stack_page, sp, pc, ra);
}
#endif
/*
* __get_wchan - a maintenance nightmare^W^Wpain in the ass ...
*/
unsigned long __get_wchan(struct task_struct *task)
{
unsigned long pc = 0;
#ifdef CONFIG_KALLSYMS
unsigned long sp;
unsigned long ra = 0;
#endif
if (!task_stack_page(task))
goto out;
pc = thread_saved_pc(task);
#ifdef CONFIG_KALLSYMS
sp = task->thread.reg29 + schedule_mfi.frame_size;
while (in_sched_functions(pc))
pc = unwind_stack(task, &sp, pc, &ra);
#endif
out:
return pc;
}
unsigned long mips_stack_top(void)
{
unsigned long top = TASK_SIZE & PAGE_MASK;
if (IS_ENABLED(CONFIG_MIPS_FP_SUPPORT)) {
/* One page for branch delay slot "emulation" */
top -= PAGE_SIZE;
}
/* Space for the VDSO, data page & GIC user page */
top -= PAGE_ALIGN(current->thread.abi->vdso->size);
top -= PAGE_SIZE;
top -= mips_gic_present() ? PAGE_SIZE : 0;
/* Space for cache colour alignment */
if (cpu_has_dc_aliases)
top -= shm_align_mask + 1;
/* 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 & ALMASK;
}
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 DEFINE_PER_CPU(call_single_data_t, backtrace_csd) =
CSD_INIT(handle_backtrace, NULL);
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);
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);
}
int mips_get_process_fp_mode(struct task_struct *task)
{
int value = 0;
if (!test_tsk_thread_flag(task, TIF_32BIT_FPREGS))
value |= PR_FP_MODE_FR;
if (test_tsk_thread_flag(task, TIF_HYBRID_FPREGS))
value |= PR_FP_MODE_FRE;
return value;
}
static long prepare_for_fp_mode_switch(void *unused)
{
/*
* This is icky, but we use this to simply ensure that all CPUs have
* context switched, regardless of whether they were previously running
* kernel or user code. This ensures that no CPU that a mode-switching
* program may execute on keeps its FPU enabled (& in the old mode)
* throughout the mode switch.
*/
return 0;
}
int mips_set_process_fp_mode(struct task_struct *task, unsigned int value)
{
const unsigned int known_bits = PR_FP_MODE_FR | PR_FP_MODE_FRE;
struct task_struct *t;
struct cpumask process_cpus;
int cpu;
/* If nothing to change, return right away, successfully. */
if (value == mips_get_process_fp_mode(task))
return 0;
/* Only accept a mode change if 64-bit FP enabled for o32. */
if (!IS_ENABLED(CONFIG_MIPS_O32_FP64_SUPPORT))
return -EOPNOTSUPP;
/* And only for o32 tasks. */
if (IS_ENABLED(CONFIG_64BIT) && !test_thread_flag(TIF_32BIT_REGS))
return -EOPNOTSUPP;
/* Check the value is valid */
if (value & ~known_bits)
return -EOPNOTSUPP;
/* Setting FRE without FR is not supported. */
if ((value & (PR_FP_MODE_FR | PR_FP_MODE_FRE)) == PR_FP_MODE_FRE)
return -EOPNOTSUPP;
/* Avoid inadvertently triggering emulation */
if ((value & PR_FP_MODE_FR) && raw_cpu_has_fpu &&
!(raw_current_cpu_data.fpu_id & MIPS_FPIR_F64))
return -EOPNOTSUPP;
if ((value & PR_FP_MODE_FRE) && raw_cpu_has_fpu && !cpu_has_fre)
return -EOPNOTSUPP;
/* FR = 0 not supported in MIPS R6 */
if (!(value & PR_FP_MODE_FR) && raw_cpu_has_fpu && cpu_has_mips_r6)
return -EOPNOTSUPP;
/* Indicate the new FP mode in each thread */
for_each_thread(task, t) {
/* Update desired FP register width */
if (value & PR_FP_MODE_FR) {
clear_tsk_thread_flag(t, TIF_32BIT_FPREGS);
} else {
set_tsk_thread_flag(t, TIF_32BIT_FPREGS);
clear_tsk_thread_flag(t, TIF_MSA_CTX_LIVE);
}
/* Update desired FP single layout */
if (value & PR_FP_MODE_FRE)
set_tsk_thread_flag(t, TIF_HYBRID_FPREGS);
else
clear_tsk_thread_flag(t, TIF_HYBRID_FPREGS);
}
/*
* We need to ensure that all threads in the process have switched mode
* before returning, in order to allow userland to not worry about
* races. We can do this by forcing all CPUs that any thread in the
* process may be running on to schedule something else - in this case
* prepare_for_fp_mode_switch().
*
* We begin by generating a mask of all CPUs that any thread in the
* process may be running on.
*/
cpumask_clear(&process_cpus);
for_each_thread(task, t)
cpumask_set_cpu(task_cpu(t), &process_cpus);
/*
* Now we schedule prepare_for_fp_mode_switch() on each of those CPUs.
*
* The CPUs may have rescheduled already since we switched mode or
* generated the cpumask, but that doesn't matter. If the task in this
* process is scheduled out then our scheduling
* prepare_for_fp_mode_switch() will simply be redundant. If it's
* scheduled in then it will already have picked up the new FP mode
* whilst doing so.
*/
cpus_read_lock();
for_each_cpu_and(cpu, &process_cpus, cpu_online_mask)
work_on_cpu(cpu, prepare_for_fp_mode_switch, NULL);
cpus_read_unlock();
return 0;
}
#if defined(CONFIG_32BIT) || defined(CONFIG_MIPS32_O32)
void mips_dump_regs32(u32 *uregs, const struct pt_regs *regs)
{
unsigned int i;
for (i = MIPS32_EF_R1; i <= MIPS32_EF_R31; i++) {
/* k0/k1 are copied as zero. */
if (i == MIPS32_EF_R26 || i == MIPS32_EF_R27)
uregs[i] = 0;
else
uregs[i] = regs->regs[i - MIPS32_EF_R0];
}
uregs[MIPS32_EF_LO] = regs->lo;
uregs[MIPS32_EF_HI] = regs->hi;
uregs[MIPS32_EF_CP0_EPC] = regs->cp0_epc;
uregs[MIPS32_EF_CP0_BADVADDR] = regs->cp0_badvaddr;
uregs[MIPS32_EF_CP0_STATUS] = regs->cp0_status;
uregs[MIPS32_EF_CP0_CAUSE] = regs->cp0_cause;
}
#endif /* CONFIG_32BIT || CONFIG_MIPS32_O32 */
#ifdef CONFIG_64BIT
void mips_dump_regs64(u64 *uregs, const struct pt_regs *regs)
{
unsigned int i;
for (i = MIPS64_EF_R1; i <= MIPS64_EF_R31; i++) {
/* k0/k1 are copied as zero. */
if (i == MIPS64_EF_R26 || i == MIPS64_EF_R27)
uregs[i] = 0;
else
uregs[i] = regs->regs[i - MIPS64_EF_R0];
}
uregs[MIPS64_EF_LO] = regs->lo;
uregs[MIPS64_EF_HI] = regs->hi;
uregs[MIPS64_EF_CP0_EPC] = regs->cp0_epc;
uregs[MIPS64_EF_CP0_BADVADDR] = regs->cp0_badvaddr;
uregs[MIPS64_EF_CP0_STATUS] = regs->cp0_status;
uregs[MIPS64_EF_CP0_CAUSE] = regs->cp0_cause;
}
#endif /* CONFIG_64BIT */