linux_dsm_epyc7002/arch/unicore32/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

325 lines
7.4 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* linux/arch/unicore32/kernel/traps.c
*
* Code specific to PKUnity SoC and UniCore ISA
*
* Copyright (C) 2001-2010 GUAN Xue-tao
*
* 'traps.c' handles hardware exceptions after we have saved some state.
* Mostly a debugging aid, but will probably kill the offending process.
*/
#include <linux/module.h>
#include <linux/signal.h>
#include <linux/sched/signal.h>
#include <linux/sched/debug.h>
#include <linux/sched/task_stack.h>
#include <linux/spinlock.h>
#include <linux/personality.h>
#include <linux/kallsyms.h>
#include <linux/kdebug.h>
#include <linux/uaccess.h>
#include <linux/delay.h>
#include <linux/hardirq.h>
#include <linux/init.h>
#include <linux/atomic.h>
#include <linux/unistd.h>
#include <asm/cacheflush.h>
#include <asm/traps.h>
#include "setup.h"
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(KERN_DEFAULT "[<%08lx>] (%pS) from [<%08lx>] (%pS)\n",
where, (void *)where, from, (void *)from);
#else
printk(KERN_DEFAULT "Function entered at [<%08lx>] from [<%08lx>]\n",
where, from);
#endif
}
/*
* 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;
}
/*
* 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(KERN_DEFAULT "%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(KERN_DEFAULT "%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 width = 8;
mm_segment_t fs;
char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str;
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);
for (i = -4; i < 1; i++) {
unsigned int val, bad;
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(KERN_DEFAULT "%sCode: %s\n", lvl, str);
set_fs(fs);
}
static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
{
unsigned int fp, mode;
int ok = 1;
printk(KERN_DEFAULT "Backtrace: ");
if (!tsk)
tsk = current;
if (regs) {
fp = regs->UCreg_fp;
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) {
printk("no frame pointer");
ok = 0;
} else if (verify_stack(fp)) {
printk("invalid frame pointer 0x%08x", fp);
ok = 0;
} else if (fp < (unsigned long)end_of_stack(tsk))
printk("frame pointer underflow");
printk("\n");
if (ok)
c_backtrace(fp, mode);
}
void show_stack(struct task_struct *tsk, unsigned long *sp)
{
dump_backtrace(NULL, tsk);
barrier();
}
static int __die(const char *str, int err, struct thread_info *thread,
struct pt_regs *regs)
{
struct task_struct *tsk = thread->task;
static int die_counter;
int ret;
printk(KERN_EMERG "Internal error: %s: %x [#%d]\n",
str, err, ++die_counter);
/* trap and error numbers are mostly meaningless on UniCore */
ret = notify_die(DIE_OOPS, str, regs, err, tsk->thread.trap_no, \
SIGSEGV);
if (ret == NOTIFY_STOP)
return ret;
print_modules();
__show_regs(regs);
printk(KERN_EMERG "Process %.*s (pid: %d, stack limit = 0x%p)\n",
TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk), thread + 1);
if (!user_mode(regs) || in_interrupt()) {
dump_mem(KERN_EMERG, "Stack: ", regs->UCreg_sp,
THREAD_SIZE + (unsigned long)task_stack_page(tsk));
dump_backtrace(regs, tsk);
dump_instr(KERN_EMERG, regs);
}
return ret;
}
DEFINE_SPINLOCK(die_lock);
/*
* This function is protected against re-entrancy.
*/
void die(const char *str, struct pt_regs *regs, int err)
{
struct thread_info *thread = current_thread_info();
int ret;
oops_enter();
spin_lock_irq(&die_lock);
console_verbose();
bust_spinlocks(1);
ret = __die(str, err, thread, regs);
bust_spinlocks(0);
add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
spin_unlock_irq(&die_lock);
oops_exit();
if (in_interrupt())
panic("Fatal exception in interrupt");
if (panic_on_oops)
panic("Fatal exception");
if (ret != NOTIFY_STOP)
do_exit(SIGSEGV);
}
void uc32_notify_die(const char *str, struct pt_regs *regs,
int sig, int 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(sig, code, addr);
} else
die(str, regs, err);
}
/*
* 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, unsigned int reason)
{
console_verbose();
printk(KERN_CRIT "Bad mode detected with reason 0x%x\n", reason);
die("Oops - bad mode", regs, 0);
local_irq_disable();
panic("bad mode");
}
void __pte_error(const char *file, int line, unsigned long val)
{
printk(KERN_DEFAULT "%s:%d: bad pte %08lx.\n", file, line, val);
}
void __pmd_error(const char *file, int line, unsigned long val)
{
printk(KERN_DEFAULT "%s:%d: bad pmd %08lx.\n", file, line, val);
}
void __pgd_error(const char *file, int line, unsigned long val)
{
printk(KERN_DEFAULT "%s:%d: bad pgd %08lx.\n", file, line, val);
}
asmlinkage void __div0(void)
{
printk(KERN_DEFAULT "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;
}
void __init early_trap_init(void)
{
unsigned long vectors = VECTORS_BASE;
/*
* Copy the vectors, stubs (in entry-unicore.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 + 0x200,
__stubs_start,
__stubs_end - __stubs_start);
early_signal_init();
flush_icache_range(vectors, vectors + PAGE_SIZE);
}