kernel_optimize_test/arch/arm/kernel/traps.c
Linus Torvalds 5ad18b2e60 Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull force_sig() argument change from Eric Biederman:
 "A source of error over the years has been that force_sig has taken a
  task parameter when it is only safe to use force_sig with the current
  task.

  The force_sig function is built for delivering synchronous signals
  such as SIGSEGV where the userspace application caused a synchronous
  fault (such as a page fault) and the kernel responded with a signal.

  Because the name force_sig does not make this clear, and because the
  force_sig takes a task parameter the function force_sig has been
  abused for sending other kinds of signals over the years. Slowly those
  have been fixed when the oopses have been tracked down.

  This set of changes fixes the remaining abusers of force_sig and
  carefully rips out the task parameter from force_sig and friends
  making this kind of error almost impossible in the future"

* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (27 commits)
  signal/x86: Move tsk inside of CONFIG_MEMORY_FAILURE in do_sigbus
  signal: Remove the signal number and task parameters from force_sig_info
  signal: Factor force_sig_info_to_task out of force_sig_info
  signal: Generate the siginfo in force_sig
  signal: Move the computation of force into send_signal and correct it.
  signal: Properly set TRACE_SIGNAL_LOSE_INFO in __send_signal
  signal: Remove the task parameter from force_sig_fault
  signal: Use force_sig_fault_to_task for the two calls that don't deliver to current
  signal: Explicitly call force_sig_fault on current
  signal/unicore32: Remove tsk parameter from __do_user_fault
  signal/arm: Remove tsk parameter from __do_user_fault
  signal/arm: Remove tsk parameter from ptrace_break
  signal/nds32: Remove tsk parameter from send_sigtrap
  signal/riscv: Remove tsk parameter from do_trap
  signal/sh: Remove tsk parameter from force_sig_info_fault
  signal/um: Remove task parameter from send_sigtrap
  signal/x86: Remove task parameter from send_sigtrap
  signal: Remove task parameter from force_sig_mceerr
  signal: Remove task parameter from force_sig
  signal: Remove task parameter from force_sigsegv
  ...
2019-07-08 21:48:15 -07:00

838 lines
20 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* linux/arch/arm/kernel/traps.c
*
* Copyright (C) 1995-2009 Russell King
* Fragments that appear the same as linux/arch/i386/kernel/traps.c (C) Linus Torvalds
*
* 'traps.c' handles hardware exceptions after we have saved some state in
* 'linux/arch/arm/lib/traps.S'. Mostly a debugging aid, but will probably
* kill the offending process.
*/
#include <linux/signal.h>
#include <linux/personality.h>
#include <linux/kallsyms.h>
#include <linux/spinlock.h>
#include <linux/uaccess.h>
#include <linux/hardirq.h>
#include <linux/kdebug.h>
#include <linux/kprobes.h>
#include <linux/module.h>
#include <linux/kexec.h>
#include <linux/bug.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/sched/signal.h>
#include <linux/sched/debug.h>
#include <linux/sched/task_stack.h>
#include <linux/irq.h>
#include <linux/atomic.h>
#include <asm/cacheflush.h>
#include <asm/exception.h>
#include <asm/unistd.h>
#include <asm/traps.h>
#include <asm/ptrace.h>
#include <asm/unwind.h>
#include <asm/tls.h>
#include <asm/system_misc.h>
#include <asm/opcodes.h>
static const char *handler[]= {
"prefetch abort",
"data abort",
"address exception",
"interrupt",
"undefined instruction",
};
void *vectors_page;
#ifdef CONFIG_DEBUG_USER
unsigned int user_debug;
static int __init user_debug_setup(char *str)
{
get_option(&str, &user_debug);
return 1;
}
__setup("user_debug=", user_debug_setup);
#endif
static void dump_mem(const char *, const char *, unsigned long, unsigned long);
void dump_backtrace_entry(unsigned long where, unsigned long from, unsigned long frame)
{
#ifdef CONFIG_KALLSYMS
printk("[<%08lx>] (%ps) from [<%08lx>] (%pS)\n", where, (void *)where, from, (void *)from);
#else
printk("Function entered at [<%08lx>] from [<%08lx>]\n", where, from);
#endif
if (in_entry_text(from))
dump_mem("", "Exception stack", frame + 4, frame + 4 + sizeof(struct pt_regs));
}
void dump_backtrace_stm(u32 *stack, u32 instruction)
{
char str[80], *p;
unsigned int x;
int reg;
for (reg = 10, x = 0, p = str; reg >= 0; reg--) {
if (instruction & BIT(reg)) {
p += sprintf(p, " r%d:%08x", reg, *stack--);
if (++x == 6) {
x = 0;
p = str;
printk("%s\n", str);
}
}
}
if (p != str)
printk("%s\n", str);
}
#ifndef CONFIG_ARM_UNWIND
/*
* Stack pointers should always be within the kernels view of
* physical memory. If it is not there, then we can't dump
* out any information relating to the stack.
*/
static int verify_stack(unsigned long sp)
{
if (sp < PAGE_OFFSET ||
(sp > (unsigned long)high_memory && high_memory != NULL))
return -EFAULT;
return 0;
}
#endif
/*
* Dump out the contents of some memory nicely...
*/
static void dump_mem(const char *lvl, const char *str, unsigned long bottom,
unsigned long top)
{
unsigned long first;
mm_segment_t fs;
int i;
/*
* We need to switch to kernel mode so that we can use __get_user
* to safely read from kernel space. Note that we now dump the
* code first, just in case the backtrace kills us.
*/
fs = get_fs();
set_fs(KERNEL_DS);
printk("%s%s(0x%08lx to 0x%08lx)\n", lvl, str, bottom, top);
for (first = bottom & ~31; first < top; first += 32) {
unsigned long p;
char str[sizeof(" 12345678") * 8 + 1];
memset(str, ' ', sizeof(str));
str[sizeof(str) - 1] = '\0';
for (p = first, i = 0; i < 8 && p < top; i++, p += 4) {
if (p >= bottom && p < top) {
unsigned long val;
if (__get_user(val, (unsigned long *)p) == 0)
sprintf(str + i * 9, " %08lx", val);
else
sprintf(str + i * 9, " ????????");
}
}
printk("%s%04lx:%s\n", lvl, first & 0xffff, str);
}
set_fs(fs);
}
static void __dump_instr(const char *lvl, struct pt_regs *regs)
{
unsigned long addr = instruction_pointer(regs);
const int thumb = thumb_mode(regs);
const int width = thumb ? 4 : 8;
char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str;
int i;
/*
* Note that we now dump the code first, just in case the backtrace
* kills us.
*/
for (i = -4; i < 1 + !!thumb; i++) {
unsigned int val, bad;
if (thumb)
bad = get_user(val, &((u16 *)addr)[i]);
else
bad = get_user(val, &((u32 *)addr)[i]);
if (!bad)
p += sprintf(p, i == 0 ? "(%0*x) " : "%0*x ",
width, val);
else {
p += sprintf(p, "bad PC value");
break;
}
}
printk("%sCode: %s\n", lvl, str);
}
static void dump_instr(const char *lvl, struct pt_regs *regs)
{
mm_segment_t fs;
if (!user_mode(regs)) {
fs = get_fs();
set_fs(KERNEL_DS);
__dump_instr(lvl, regs);
set_fs(fs);
} else {
__dump_instr(lvl, regs);
}
}
#ifdef CONFIG_ARM_UNWIND
static inline void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
{
unwind_backtrace(regs, tsk);
}
#else
static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
{
unsigned int fp, mode;
int ok = 1;
printk("Backtrace: ");
if (!tsk)
tsk = current;
if (regs) {
fp = frame_pointer(regs);
mode = processor_mode(regs);
} else if (tsk != current) {
fp = thread_saved_fp(tsk);
mode = 0x10;
} else {
asm("mov %0, fp" : "=r" (fp) : : "cc");
mode = 0x10;
}
if (!fp) {
pr_cont("no frame pointer");
ok = 0;
} else if (verify_stack(fp)) {
pr_cont("invalid frame pointer 0x%08x", fp);
ok = 0;
} else if (fp < (unsigned long)end_of_stack(tsk))
pr_cont("frame pointer underflow");
pr_cont("\n");
if (ok)
c_backtrace(fp, mode);
}
#endif
void show_stack(struct task_struct *tsk, unsigned long *sp)
{
dump_backtrace(NULL, tsk);
barrier();
}
#ifdef CONFIG_PREEMPT
#define S_PREEMPT " PREEMPT"
#else
#define S_PREEMPT ""
#endif
#ifdef CONFIG_SMP
#define S_SMP " SMP"
#else
#define S_SMP ""
#endif
#ifdef CONFIG_THUMB2_KERNEL
#define S_ISA " THUMB2"
#else
#define S_ISA " ARM"
#endif
static int __die(const char *str, int err, struct pt_regs *regs)
{
struct task_struct *tsk = current;
static int die_counter;
int ret;
pr_emerg("Internal error: %s: %x [#%d]" S_PREEMPT S_SMP S_ISA "\n",
str, err, ++die_counter);
/* trap and error numbers are mostly meaningless on ARM */
ret = notify_die(DIE_OOPS, str, regs, err, tsk->thread.trap_no, SIGSEGV);
if (ret == NOTIFY_STOP)
return 1;
print_modules();
__show_regs(regs);
pr_emerg("Process %.*s (pid: %d, stack limit = 0x%p)\n",
TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk), end_of_stack(tsk));
if (!user_mode(regs) || in_interrupt()) {
dump_mem(KERN_EMERG, "Stack: ", regs->ARM_sp,
THREAD_SIZE + (unsigned long)task_stack_page(tsk));
dump_backtrace(regs, tsk);
dump_instr(KERN_EMERG, regs);
}
return 0;
}
static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED;
static int die_owner = -1;
static unsigned int die_nest_count;
static unsigned long oops_begin(void)
{
int cpu;
unsigned long flags;
oops_enter();
/* racy, but better than risking deadlock. */
raw_local_irq_save(flags);
cpu = smp_processor_id();
if (!arch_spin_trylock(&die_lock)) {
if (cpu == die_owner)
/* nested oops. should stop eventually */;
else
arch_spin_lock(&die_lock);
}
die_nest_count++;
die_owner = cpu;
console_verbose();
bust_spinlocks(1);
return flags;
}
static void oops_end(unsigned long flags, struct pt_regs *regs, int signr)
{
if (regs && kexec_should_crash(current))
crash_kexec(regs);
bust_spinlocks(0);
die_owner = -1;
add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
die_nest_count--;
if (!die_nest_count)
/* Nest count reaches zero, release the lock. */
arch_spin_unlock(&die_lock);
raw_local_irq_restore(flags);
oops_exit();
if (in_interrupt())
panic("Fatal exception in interrupt");
if (panic_on_oops)
panic("Fatal exception");
if (signr)
do_exit(signr);
}
/*
* This function is protected against re-entrancy.
*/
void die(const char *str, struct pt_regs *regs, int err)
{
enum bug_trap_type bug_type = BUG_TRAP_TYPE_NONE;
unsigned long flags = oops_begin();
int sig = SIGSEGV;
if (!user_mode(regs))
bug_type = report_bug(regs->ARM_pc, regs);
if (bug_type != BUG_TRAP_TYPE_NONE)
str = "Oops - BUG";
if (__die(str, err, regs))
sig = 0;
oops_end(flags, regs, sig);
}
void arm_notify_die(const char *str, struct pt_regs *regs,
int signo, int si_code, void __user *addr,
unsigned long err, unsigned long trap)
{
if (user_mode(regs)) {
current->thread.error_code = err;
current->thread.trap_no = trap;
force_sig_fault(signo, si_code, addr);
} else {
die(str, regs, err);
}
}
#ifdef CONFIG_GENERIC_BUG
int is_valid_bugaddr(unsigned long pc)
{
#ifdef CONFIG_THUMB2_KERNEL
u16 bkpt;
u16 insn = __opcode_to_mem_thumb16(BUG_INSTR_VALUE);
#else
u32 bkpt;
u32 insn = __opcode_to_mem_arm(BUG_INSTR_VALUE);
#endif
if (probe_kernel_address((unsigned *)pc, bkpt))
return 0;
return bkpt == insn;
}
#endif
static LIST_HEAD(undef_hook);
static DEFINE_RAW_SPINLOCK(undef_lock);
void register_undef_hook(struct undef_hook *hook)
{
unsigned long flags;
raw_spin_lock_irqsave(&undef_lock, flags);
list_add(&hook->node, &undef_hook);
raw_spin_unlock_irqrestore(&undef_lock, flags);
}
void unregister_undef_hook(struct undef_hook *hook)
{
unsigned long flags;
raw_spin_lock_irqsave(&undef_lock, flags);
list_del(&hook->node);
raw_spin_unlock_irqrestore(&undef_lock, flags);
}
static nokprobe_inline
int call_undef_hook(struct pt_regs *regs, unsigned int instr)
{
struct undef_hook *hook;
unsigned long flags;
int (*fn)(struct pt_regs *regs, unsigned int instr) = NULL;
raw_spin_lock_irqsave(&undef_lock, flags);
list_for_each_entry(hook, &undef_hook, node)
if ((instr & hook->instr_mask) == hook->instr_val &&
(regs->ARM_cpsr & hook->cpsr_mask) == hook->cpsr_val)
fn = hook->fn;
raw_spin_unlock_irqrestore(&undef_lock, flags);
return fn ? fn(regs, instr) : 1;
}
asmlinkage void do_undefinstr(struct pt_regs *regs)
{
unsigned int instr;
void __user *pc;
pc = (void __user *)instruction_pointer(regs);
if (processor_mode(regs) == SVC_MODE) {
#ifdef CONFIG_THUMB2_KERNEL
if (thumb_mode(regs)) {
instr = __mem_to_opcode_thumb16(((u16 *)pc)[0]);
if (is_wide_instruction(instr)) {
u16 inst2;
inst2 = __mem_to_opcode_thumb16(((u16 *)pc)[1]);
instr = __opcode_thumb32_compose(instr, inst2);
}
} else
#endif
instr = __mem_to_opcode_arm(*(u32 *) pc);
} else if (thumb_mode(regs)) {
if (get_user(instr, (u16 __user *)pc))
goto die_sig;
instr = __mem_to_opcode_thumb16(instr);
if (is_wide_instruction(instr)) {
unsigned int instr2;
if (get_user(instr2, (u16 __user *)pc+1))
goto die_sig;
instr2 = __mem_to_opcode_thumb16(instr2);
instr = __opcode_thumb32_compose(instr, instr2);
}
} else {
if (get_user(instr, (u32 __user *)pc))
goto die_sig;
instr = __mem_to_opcode_arm(instr);
}
if (call_undef_hook(regs, instr) == 0)
return;
die_sig:
#ifdef CONFIG_DEBUG_USER
if (user_debug & UDBG_UNDEFINED) {
pr_info("%s (%d): undefined instruction: pc=%p\n",
current->comm, task_pid_nr(current), pc);
__show_regs(regs);
dump_instr(KERN_INFO, regs);
}
#endif
arm_notify_die("Oops - undefined instruction", regs,
SIGILL, ILL_ILLOPC, pc, 0, 6);
}
NOKPROBE_SYMBOL(do_undefinstr)
/*
* Handle FIQ similarly to NMI on x86 systems.
*
* The runtime environment for NMIs is extremely restrictive
* (NMIs can pre-empt critical sections meaning almost all locking is
* forbidden) meaning this default FIQ handling must only be used in
* circumstances where non-maskability improves robustness, such as
* watchdog or debug logic.
*
* This handler is not appropriate for general purpose use in drivers
* platform code and can be overrideen using set_fiq_handler.
*/
asmlinkage void __exception_irq_entry handle_fiq_as_nmi(struct pt_regs *regs)
{
struct pt_regs *old_regs = set_irq_regs(regs);
nmi_enter();
/* nop. FIQ handlers for special arch/arm features can be added here. */
nmi_exit();
set_irq_regs(old_regs);
}
/*
* bad_mode handles the impossible case in the vectors. If you see one of
* these, then it's extremely serious, and could mean you have buggy hardware.
* It never returns, and never tries to sync. We hope that we can at least
* dump out some state information...
*/
asmlinkage void bad_mode(struct pt_regs *regs, int reason)
{
console_verbose();
pr_crit("Bad mode in %s handler detected\n", handler[reason]);
die("Oops - bad mode", regs, 0);
local_irq_disable();
panic("bad mode");
}
static int bad_syscall(int n, struct pt_regs *regs)
{
if ((current->personality & PER_MASK) != PER_LINUX) {
send_sig(SIGSEGV, current, 1);
return regs->ARM_r0;
}
#ifdef CONFIG_DEBUG_USER
if (user_debug & UDBG_SYSCALL) {
pr_err("[%d] %s: obsolete system call %08x.\n",
task_pid_nr(current), current->comm, n);
dump_instr(KERN_ERR, regs);
}
#endif
arm_notify_die("Oops - bad syscall", regs, SIGILL, ILL_ILLTRP,
(void __user *)instruction_pointer(regs) -
(thumb_mode(regs) ? 2 : 4),
n, 0);
return regs->ARM_r0;
}
static inline int
__do_cache_op(unsigned long start, unsigned long end)
{
int ret;
do {
unsigned long chunk = min(PAGE_SIZE, end - start);
if (fatal_signal_pending(current))
return 0;
ret = flush_cache_user_range(start, start + chunk);
if (ret)
return ret;
cond_resched();
start += chunk;
} while (start < end);
return 0;
}
static inline int
do_cache_op(unsigned long start, unsigned long end, int flags)
{
if (end < start || flags)
return -EINVAL;
if (!access_ok(start, end - start))
return -EFAULT;
return __do_cache_op(start, end);
}
/*
* Handle all unrecognised system calls.
* 0x9f0000 - 0x9fffff are some more esoteric system calls
*/
#define NR(x) ((__ARM_NR_##x) - __ARM_NR_BASE)
asmlinkage int arm_syscall(int no, struct pt_regs *regs)
{
if ((no >> 16) != (__ARM_NR_BASE>> 16))
return bad_syscall(no, regs);
switch (no & 0xffff) {
case 0: /* branch through 0 */
arm_notify_die("branch through zero", regs,
SIGSEGV, SEGV_MAPERR, NULL, 0, 0);
return 0;
case NR(breakpoint): /* SWI BREAK_POINT */
regs->ARM_pc -= thumb_mode(regs) ? 2 : 4;
ptrace_break(regs);
return regs->ARM_r0;
/*
* Flush a region from virtual address 'r0' to virtual address 'r1'
* _exclusive_. There is no alignment requirement on either address;
* user space does not need to know the hardware cache layout.
*
* r2 contains flags. It should ALWAYS be passed as ZERO until it
* is defined to be something else. For now we ignore it, but may
* the fires of hell burn in your belly if you break this rule. ;)
*
* (at a later date, we may want to allow this call to not flush
* various aspects of the cache. Passing '0' will guarantee that
* everything necessary gets flushed to maintain consistency in
* the specified region).
*/
case NR(cacheflush):
return do_cache_op(regs->ARM_r0, regs->ARM_r1, regs->ARM_r2);
case NR(usr26):
if (!(elf_hwcap & HWCAP_26BIT))
break;
regs->ARM_cpsr &= ~MODE32_BIT;
return regs->ARM_r0;
case NR(usr32):
if (!(elf_hwcap & HWCAP_26BIT))
break;
regs->ARM_cpsr |= MODE32_BIT;
return regs->ARM_r0;
case NR(set_tls):
set_tls(regs->ARM_r0);
return 0;
case NR(get_tls):
return current_thread_info()->tp_value[0];
default:
/* Calls 9f00xx..9f07ff are defined to return -ENOSYS
if not implemented, rather than raising SIGILL. This
way the calling program can gracefully determine whether
a feature is supported. */
if ((no & 0xffff) <= 0x7ff)
return -ENOSYS;
break;
}
#ifdef CONFIG_DEBUG_USER
/*
* experience shows that these seem to indicate that
* something catastrophic has happened
*/
if (user_debug & UDBG_SYSCALL) {
pr_err("[%d] %s: arm syscall %d\n",
task_pid_nr(current), current->comm, no);
dump_instr("", regs);
if (user_mode(regs)) {
__show_regs(regs);
c_backtrace(frame_pointer(regs), processor_mode(regs));
}
}
#endif
arm_notify_die("Oops - bad syscall(2)", regs, SIGILL, ILL_ILLTRP,
(void __user *)instruction_pointer(regs) -
(thumb_mode(regs) ? 2 : 4),
no, 0);
return 0;
}
#ifdef CONFIG_TLS_REG_EMUL
/*
* We might be running on an ARMv6+ processor which should have the TLS
* register but for some reason we can't use it, or maybe an SMP system
* using a pre-ARMv6 processor (there are apparently a few prototypes like
* that in existence) and therefore access to that register must be
* emulated.
*/
static int get_tp_trap(struct pt_regs *regs, unsigned int instr)
{
int reg = (instr >> 12) & 15;
if (reg == 15)
return 1;
regs->uregs[reg] = current_thread_info()->tp_value[0];
regs->ARM_pc += 4;
return 0;
}
static struct undef_hook arm_mrc_hook = {
.instr_mask = 0x0fff0fff,
.instr_val = 0x0e1d0f70,
.cpsr_mask = PSR_T_BIT,
.cpsr_val = 0,
.fn = get_tp_trap,
};
static int __init arm_mrc_hook_init(void)
{
register_undef_hook(&arm_mrc_hook);
return 0;
}
late_initcall(arm_mrc_hook_init);
#endif
/*
* A data abort trap was taken, but we did not handle the instruction.
* Try to abort the user program, or panic if it was the kernel.
*/
asmlinkage void
baddataabort(int code, unsigned long instr, struct pt_regs *regs)
{
unsigned long addr = instruction_pointer(regs);
#ifdef CONFIG_DEBUG_USER
if (user_debug & UDBG_BADABORT) {
pr_err("8<--- cut here ---\n");
pr_err("[%d] %s: bad data abort: code %d instr 0x%08lx\n",
task_pid_nr(current), current->comm, code, instr);
dump_instr(KERN_ERR, regs);
show_pte(KERN_ERR, current->mm, addr);
}
#endif
arm_notify_die("unknown data abort code", regs,
SIGILL, ILL_ILLOPC, (void __user *)addr, instr, 0);
}
void __readwrite_bug(const char *fn)
{
pr_err("%s called, but not implemented\n", fn);
BUG();
}
EXPORT_SYMBOL(__readwrite_bug);
void __pte_error(const char *file, int line, pte_t pte)
{
pr_err("%s:%d: bad pte %08llx.\n", file, line, (long long)pte_val(pte));
}
void __pmd_error(const char *file, int line, pmd_t pmd)
{
pr_err("%s:%d: bad pmd %08llx.\n", file, line, (long long)pmd_val(pmd));
}
void __pgd_error(const char *file, int line, pgd_t pgd)
{
pr_err("%s:%d: bad pgd %08llx.\n", file, line, (long long)pgd_val(pgd));
}
asmlinkage void __div0(void)
{
pr_err("Division by zero in kernel.\n");
dump_stack();
}
EXPORT_SYMBOL(__div0);
void abort(void)
{
BUG();
/* if that doesn't kill us, halt */
panic("Oops failed to kill thread");
}
void __init trap_init(void)
{
return;
}
#ifdef CONFIG_KUSER_HELPERS
static void __init kuser_init(void *vectors)
{
extern char __kuser_helper_start[], __kuser_helper_end[];
int kuser_sz = __kuser_helper_end - __kuser_helper_start;
memcpy(vectors + 0x1000 - kuser_sz, __kuser_helper_start, kuser_sz);
/*
* vectors + 0xfe0 = __kuser_get_tls
* vectors + 0xfe8 = hardware TLS instruction at 0xffff0fe8
*/
if (tls_emu || has_tls_reg)
memcpy(vectors + 0xfe0, vectors + 0xfe8, 4);
}
#else
static inline void __init kuser_init(void *vectors)
{
}
#endif
void __init early_trap_init(void *vectors_base)
{
#ifndef CONFIG_CPU_V7M
unsigned long vectors = (unsigned long)vectors_base;
extern char __stubs_start[], __stubs_end[];
extern char __vectors_start[], __vectors_end[];
unsigned i;
vectors_page = vectors_base;
/*
* Poison the vectors page with an undefined instruction. This
* instruction is chosen to be undefined for both ARM and Thumb
* ISAs. The Thumb version is an undefined instruction with a
* branch back to the undefined instruction.
*/
for (i = 0; i < PAGE_SIZE / sizeof(u32); i++)
((u32 *)vectors_base)[i] = 0xe7fddef1;
/*
* Copy the vectors, stubs and kuser helpers (in entry-armv.S)
* into the vector page, mapped at 0xffff0000, and ensure these
* are visible to the instruction stream.
*/
memcpy((void *)vectors, __vectors_start, __vectors_end - __vectors_start);
memcpy((void *)vectors + 0x1000, __stubs_start, __stubs_end - __stubs_start);
kuser_init(vectors_base);
flush_icache_range(vectors, vectors + PAGE_SIZE * 2);
#else /* ifndef CONFIG_CPU_V7M */
/*
* on V7-M there is no need to copy the vector table to a dedicated
* memory area. The address is configurable and so a table in the kernel
* image can be used.
*/
#endif
}