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Diffstat (limited to 'arch/i386/kernel/traps.c')
-rw-r--r--arch/i386/kernel/traps.c82
1 files changed, 57 insertions, 25 deletions
diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c
index 83c579e82a81..cd2d5d5514fe 100644
--- a/arch/i386/kernel/traps.c
+++ b/arch/i386/kernel/traps.c
@@ -27,6 +27,7 @@
#include <linux/ptrace.h>
#include <linux/utsname.h>
#include <linux/kprobes.h>
+#include <linux/kexec.h>
#ifdef CONFIG_EISA
#include <linux/ioport.h>
@@ -104,6 +105,7 @@ int register_die_notifier(struct notifier_block *nb)
spin_unlock_irqrestore(&die_notifier_lock, flags);
return err;
}
+EXPORT_SYMBOL(register_die_notifier);
static inline int valid_stack_ptr(struct thread_info *tinfo, void *p)
{
@@ -209,7 +211,7 @@ void show_registers(struct pt_regs *regs)
esp = (unsigned long) (&regs->esp);
ss = __KERNEL_DS;
- if (regs->xcs & 3) {
+ if (user_mode(regs)) {
in_kernel = 0;
esp = regs->esp;
ss = regs->xss & 0xffff;
@@ -233,22 +235,22 @@ void show_registers(struct pt_regs *regs)
* time of the fault..
*/
if (in_kernel) {
- u8 *eip;
+ u8 __user *eip;
printk("\nStack: ");
show_stack(NULL, (unsigned long*)esp);
printk("Code: ");
- eip = (u8 *)regs->eip - 43;
+ eip = (u8 __user *)regs->eip - 43;
for (i = 0; i < 64; i++, eip++) {
unsigned char c;
- if (eip < (u8 *)PAGE_OFFSET || __get_user(c, eip)) {
+ if (eip < (u8 __user *)PAGE_OFFSET || __get_user(c, eip)) {
printk(" Bad EIP value.");
break;
}
- if (eip == (u8 *)regs->eip)
+ if (eip == (u8 __user *)regs->eip)
printk("<%02x> ", c);
else
printk("%02x ", c);
@@ -265,20 +267,20 @@ static void handle_BUG(struct pt_regs *regs)
char c;
unsigned long eip;
- if (regs->xcs & 3)
+ if (user_mode(regs))
goto no_bug; /* Not in kernel */
eip = regs->eip;
if (eip < PAGE_OFFSET)
goto no_bug;
- if (__get_user(ud2, (unsigned short *)eip))
+ if (__get_user(ud2, (unsigned short __user *)eip))
goto no_bug;
if (ud2 != 0x0b0f)
goto no_bug;
- if (__get_user(line, (unsigned short *)(eip + 2)))
+ if (__get_user(line, (unsigned short __user *)(eip + 2)))
goto bug;
- if (__get_user(file, (char **)(eip + 4)) ||
+ if (__get_user(file, (char * __user *)(eip + 4)) ||
(unsigned long)file < PAGE_OFFSET || __get_user(c, file))
file = "<bad filename>";
@@ -293,6 +295,9 @@ bug:
printk("Kernel BUG\n");
}
+/* This is gone through when something in the kernel
+ * has done something bad and is about to be terminated.
+*/
void die(const char * str, struct pt_regs * regs, long err)
{
static struct {
@@ -340,6 +345,10 @@ void die(const char * str, struct pt_regs * regs, long err)
bust_spinlocks(0);
die.lock_owner = -1;
spin_unlock_irq(&die.lock);
+
+ if (kexec_should_crash(current))
+ crash_kexec(regs);
+
if (in_interrupt())
panic("Fatal exception in interrupt");
@@ -353,26 +362,27 @@ void die(const char * str, struct pt_regs * regs, long err)
static inline void die_if_kernel(const char * str, struct pt_regs * regs, long err)
{
- if (!(regs->eflags & VM_MASK) && !(3 & regs->xcs))
+ if (!user_mode_vm(regs))
die(str, regs, err);
}
static void do_trap(int trapnr, int signr, char *str, int vm86,
struct pt_regs * regs, long error_code, siginfo_t *info)
{
+ struct task_struct *tsk = current;
+ tsk->thread.error_code = error_code;
+ tsk->thread.trap_no = trapnr;
+
if (regs->eflags & VM_MASK) {
if (vm86)
goto vm86_trap;
goto trap_signal;
}
- if (!(regs->xcs & 3))
+ if (!user_mode(regs))
goto kernel_trap;
trap_signal: {
- struct task_struct *tsk = current;
- tsk->thread.error_code = error_code;
- tsk->thread.trap_no = trapnr;
if (info)
force_sig_info(signr, info, tsk);
else
@@ -485,10 +495,13 @@ fastcall void do_general_protection(struct pt_regs * regs, long error_code)
}
put_cpu();
+ current->thread.error_code = error_code;
+ current->thread.trap_no = 13;
+
if (regs->eflags & VM_MASK)
goto gp_in_vm86;
- if (!(regs->xcs & 3))
+ if (!user_mode(regs))
goto gp_in_kernel;
current->thread.error_code = error_code;
@@ -569,6 +582,15 @@ void die_nmi (struct pt_regs *regs, const char *msg)
console_silent();
spin_unlock(&nmi_print_lock);
bust_spinlocks(0);
+
+ /* If we are in kernel we are probably nested up pretty bad
+ * and might aswell get out now while we still can.
+ */
+ if (!user_mode(regs)) {
+ current->thread.trap_no = 2;
+ crash_kexec(regs);
+ }
+
do_exit(SIGSEGV);
}
@@ -624,6 +646,14 @@ fastcall void do_nmi(struct pt_regs * regs, long error_code)
nmi_enter();
cpu = smp_processor_id();
+
+#ifdef CONFIG_HOTPLUG_CPU
+ if (!cpu_online(cpu)) {
+ nmi_exit();
+ return;
+ }
+#endif
+
++nmi_count(cpu);
if (!nmi_callback(regs, cpu))
@@ -636,11 +666,13 @@ void set_nmi_callback(nmi_callback_t callback)
{
nmi_callback = callback;
}
+EXPORT_SYMBOL_GPL(set_nmi_callback);
void unset_nmi_callback(void)
{
nmi_callback = dummy_nmi_callback;
}
+EXPORT_SYMBOL_GPL(unset_nmi_callback);
#ifdef CONFIG_KPROBES
fastcall void do_int3(struct pt_regs *regs, long error_code)
@@ -682,7 +714,7 @@ fastcall void do_debug(struct pt_regs * regs, long error_code)
unsigned int condition;
struct task_struct *tsk = current;
- __asm__ __volatile__("movl %%db6,%0" : "=r" (condition));
+ get_debugreg(condition, 6);
if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code,
SIGTRAP) == NOTIFY_STOP)
@@ -713,7 +745,7 @@ fastcall void do_debug(struct pt_regs * regs, long error_code)
* check for kernel mode by just checking the CPL
* of CS.
*/
- if ((regs->xcs & 3) == 0)
+ if (!user_mode(regs))
goto clear_TF_reenable;
}
@@ -724,9 +756,7 @@ fastcall void do_debug(struct pt_regs * regs, long error_code)
* the signal is delivered.
*/
clear_dr7:
- __asm__("movl %0,%%db7"
- : /* no output */
- : "r" (0));
+ set_debugreg(0, 7);
return;
debug_vm86:
@@ -773,15 +803,17 @@ void math_error(void __user *eip)
*/
cwd = get_fpu_cwd(task);
swd = get_fpu_swd(task);
- switch (((~cwd) & swd & 0x3f) | (swd & 0x240)) {
+ switch (swd & ~cwd & 0x3f) {
case 0x000:
default:
break;
case 0x001: /* Invalid Op */
- case 0x041: /* Stack Fault */
- case 0x241: /* Stack Fault | Direction */
+ /*
+ * swd & 0x240 == 0x040: Stack Underflow
+ * swd & 0x240 == 0x240: Stack Overflow
+ * User must clear the SF bit (0x40) if set
+ */
info.si_code = FPE_FLTINV;
- /* Should we clear the SF or let user space do it ???? */
break;
case 0x002: /* Denormalize */
case 0x010: /* Underflow */
@@ -871,9 +903,9 @@ fastcall void do_simd_coprocessor_error(struct pt_regs * regs,
error_code);
return;
}
- die_if_kernel("cache flush denied", regs, error_code);
current->thread.trap_no = 19;
current->thread.error_code = error_code;
+ die_if_kernel("cache flush denied", regs, error_code);
force_sig(SIGSEGV, current);
}
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-25 00:24:30 +0100