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Diffstat (limited to 'arch/arm/kernel/traps.c')
-rw-r--r--arch/arm/kernel/traps.c99
1 files changed, 62 insertions, 37 deletions
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 3647170e9a1..b0179b89a04 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -233,9 +233,9 @@ void show_stack(struct task_struct *tsk, unsigned long *sp)
#define S_ISA " ARM"
#endif
-static int __die(const char *str, int err, struct thread_info *thread, struct pt_regs *regs)
+static int __die(const char *str, int err, struct pt_regs *regs)
{
- struct task_struct *tsk = thread->task;
+ struct task_struct *tsk = current;
static int die_counter;
int ret;
@@ -245,12 +245,12 @@ static int __die(const char *str, int err, struct thread_info *thread, struct pt
/* 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 ret;
+ return 1;
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);
+ 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,
@@ -259,45 +259,77 @@ static int __die(const char *str, int err, struct thread_info *thread, struct pt
dump_instr(KERN_EMERG, regs);
}
- return ret;
+ return 0;
}
-static DEFINE_RAW_SPINLOCK(die_lock);
+static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED;
+static int die_owner = -1;
+static unsigned int die_nest_count;
-/*
- * This function is protected against re-entrancy.
- */
-void die(const char *str, struct pt_regs *regs, int err)
+static unsigned long oops_begin(void)
{
- struct thread_info *thread = current_thread_info();
- int ret;
- enum bug_trap_type bug_type = BUG_TRAP_TYPE_NONE;
+ int cpu;
+ unsigned long flags;
oops_enter();
- raw_spin_lock_irq(&die_lock);
+ /* 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);
- if (!user_mode(regs))
- bug_type = report_bug(regs->ARM_pc, regs);
- if (bug_type != BUG_TRAP_TYPE_NONE)
- str = "Oops - BUG";
- ret = __die(str, err, thread, regs);
+ return flags;
+}
- if (regs && kexec_should_crash(thread->task))
+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);
- raw_spin_unlock_irq(&die_lock);
+ 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 (ret != NOTIFY_STOP)
- do_exit(SIGSEGV);
+ 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,
@@ -370,18 +402,10 @@ static int call_undef_hook(struct pt_regs *regs, unsigned int instr)
asmlinkage void __exception do_undefinstr(struct pt_regs *regs)
{
- unsigned int correction = thumb_mode(regs) ? 2 : 4;
unsigned int instr;
siginfo_t info;
void __user *pc;
- /*
- * According to the ARM ARM, PC is 2 or 4 bytes ahead,
- * depending whether we're in Thumb mode or not.
- * Correct this offset.
- */
- regs->ARM_pc -= correction;
-
pc = (void __user *)instruction_pointer(regs);
if (processor_mode(regs) == SVC_MODE) {
@@ -396,20 +420,23 @@ asmlinkage void __exception do_undefinstr(struct pt_regs *regs)
#endif
instr = *(u32 *) pc;
} else if (thumb_mode(regs)) {
- get_user(instr, (u16 __user *)pc);
+ if (get_user(instr, (u16 __user *)pc))
+ goto die_sig;
if (is_wide_instruction(instr)) {
unsigned int instr2;
- get_user(instr2, (u16 __user *)pc+1);
+ if (get_user(instr2, (u16 __user *)pc+1))
+ goto die_sig;
instr <<= 16;
instr |= instr2;
}
- } else {
- get_user(instr, (u32 __user *)pc);
+ } else if (get_user(instr, (u32 __user *)pc)) {
+ goto die_sig;
}
if (call_undef_hook(regs, instr) == 0)
return;
+die_sig:
#ifdef CONFIG_DEBUG_USER
if (user_debug & UDBG_UNDEFINED) {
printk(KERN_INFO "%s (%d): undefined instruction: pc=%p\n",
@@ -820,8 +847,6 @@ void __init early_trap_init(void *vectors_base)
*/
memcpy((void *)(vectors + KERN_SIGRETURN_CODE - CONFIG_VECTORS_BASE),
sigreturn_codes, sizeof(sigreturn_codes));
- memcpy((void *)(vectors + KERN_RESTART_CODE - CONFIG_VECTORS_BASE),
- syscall_restart_code, sizeof(syscall_restart_code));
flush_icache_range(vectors, vectors + PAGE_SIZE);
modify_domain(DOMAIN_USER, DOMAIN_CLIENT);