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Diffstat (limited to 'arch/x86_64/kernel/traps.c')
-rw-r--r--arch/x86_64/kernel/traps.c95
1 files changed, 52 insertions, 43 deletions
diff --git a/arch/x86_64/kernel/traps.c b/arch/x86_64/kernel/traps.c
index 7819022a8db..b54ccc07f37 100644
--- a/arch/x86_64/kernel/traps.c
+++ b/arch/x86_64/kernel/traps.c
@@ -30,9 +30,10 @@
#include <linux/kprobes.h>
#include <linux/kexec.h>
#include <linux/unwind.h>
+#include <linux/uaccess.h>
+#include <linux/bug.h>
#include <asm/system.h>
-#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/atomic.h>
#include <asm/debugreg.h>
@@ -108,7 +109,7 @@ static inline void preempt_conditional_cli(struct pt_regs *regs)
preempt_enable_no_resched();
}
-static int kstack_depth_to_print = 12;
+int kstack_depth_to_print = 12;
#ifdef CONFIG_STACK_UNWIND
static int call_trace = 1;
#else
@@ -225,16 +226,25 @@ static int dump_trace_unwind(struct unwind_frame_info *info, void *context)
{
struct ops_and_data *oad = (struct ops_and_data *)context;
int n = 0;
+ unsigned long sp = UNW_SP(info);
+ if (arch_unw_user_mode(info))
+ return -1;
while (unwind(info) == 0 && UNW_PC(info)) {
n++;
oad->ops->address(oad->data, UNW_PC(info));
if (arch_unw_user_mode(info))
break;
+ if ((sp & ~(PAGE_SIZE - 1)) == (UNW_SP(info) & ~(PAGE_SIZE - 1))
+ && sp > UNW_SP(info))
+ break;
+ sp = UNW_SP(info);
}
return n;
}
+#define MSG(txt) ops->warning(data, txt)
+
/*
* x86-64 can have upto three kernel stacks:
* process stack
@@ -242,12 +252,20 @@ static int dump_trace_unwind(struct unwind_frame_info *info, void *context)
* severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
*/
-void dump_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long * stack,
+static inline int valid_stack_ptr(struct thread_info *tinfo, void *p)
+{
+ void *t = (void *)tinfo;
+ return p > t && p < t + THREAD_SIZE - 3;
+}
+
+void dump_trace(struct task_struct *tsk, struct pt_regs *regs,
+ unsigned long *stack,
struct stacktrace_ops *ops, void *data)
{
- const unsigned cpu = smp_processor_id();
- unsigned long *irqstack_end = (unsigned long *)cpu_pda(cpu)->irqstackptr;
+ const unsigned cpu = get_cpu();
+ unsigned long *irqstack_end = (unsigned long*)cpu_pda(cpu)->irqstackptr;
unsigned used = 0;
+ struct thread_info *tinfo;
if (!tsk)
tsk = current;
@@ -261,28 +279,30 @@ void dump_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long * s
if (unwind_init_frame_info(&info, tsk, regs) == 0)
unw_ret = dump_trace_unwind(&info, &oad);
} else if (tsk == current)
- unw_ret = unwind_init_running(&info, dump_trace_unwind, &oad);
+ unw_ret = unwind_init_running(&info, dump_trace_unwind,
+ &oad);
else {
if (unwind_init_blocked(&info, tsk) == 0)
unw_ret = dump_trace_unwind(&info, &oad);
}
if (unw_ret > 0) {
if (call_trace == 1 && !arch_unw_user_mode(&info)) {
- ops->warning_symbol(data, "DWARF2 unwinder stuck at %s\n",
+ ops->warning_symbol(data,
+ "DWARF2 unwinder stuck at %s",
UNW_PC(&info));
if ((long)UNW_SP(&info) < 0) {
- ops->warning(data, "Leftover inexact backtrace:\n");
+ MSG("Leftover inexact backtrace:");
stack = (unsigned long *)UNW_SP(&info);
if (!stack)
- return;
+ goto out;
} else
- ops->warning(data, "Full inexact backtrace again:\n");
+ MSG("Full inexact backtrace again:");
} else if (call_trace >= 1)
- return;
+ goto out;
else
- ops->warning(data, "Full inexact backtrace again:\n");
+ MSG("Full inexact backtrace again:");
} else
- ops->warning(data, "Inexact backtrace:\n");
+ MSG("Inexact backtrace:");
}
if (!stack) {
unsigned long dummy;
@@ -299,9 +319,9 @@ void dump_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long * s
#define HANDLE_STACK(cond) \
do while (cond) { \
unsigned long addr = *stack++; \
- if (oops_in_progress ? \
- __kernel_text_address(addr) : \
- kernel_text_address(addr)) { \
+ /* Use unlocked access here because except for NMIs \
+ we should be already protected against module unloads */ \
+ if (__kernel_text_address(addr)) { \
/* \
* If the address is either in the text segment of the \
* kernel, or in the region which contains vmalloc'ed \
@@ -364,8 +384,11 @@ void dump_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long * s
/*
* This handles the process stack:
*/
- HANDLE_STACK (((long) stack & (THREAD_SIZE-1)) != 0);
+ tinfo = current_thread_info();
+ HANDLE_STACK (valid_stack_ptr(tinfo, stack));
#undef HANDLE_STACK
+out:
+ put_cpu();
}
EXPORT_SYMBOL(dump_trace);
@@ -502,30 +525,15 @@ bad:
printk("\n");
}
-void handle_BUG(struct pt_regs *regs)
-{
- struct bug_frame f;
- long len;
- const char *prefix = "";
+int is_valid_bugaddr(unsigned long rip)
+{
+ unsigned short ud2;
- if (user_mode(regs))
- return;
- if (__copy_from_user(&f, (const void __user *) regs->rip,
- sizeof(struct bug_frame)))
- return;
- if (f.filename >= 0 ||
- f.ud2[0] != 0x0f || f.ud2[1] != 0x0b)
- return;
- len = __strnlen_user((char *)(long)f.filename, PATH_MAX) - 1;
- if (len < 0 || len >= PATH_MAX)
- f.filename = (int)(long)"unmapped filename";
- else if (len > 50) {
- f.filename += len - 50;
- prefix = "...";
- }
- printk("----------- [cut here ] --------- [please bite here ] ---------\n");
- printk(KERN_ALERT "Kernel BUG at %s%.50s:%d\n", prefix, (char *)(long)f.filename, f.line);
-}
+ if (__copy_from_user(&ud2, (const void __user *) rip, sizeof(ud2)))
+ return 0;
+
+ return ud2 == 0x0b0f;
+}
#ifdef CONFIG_BUG
void out_of_line_bug(void)
@@ -605,7 +613,9 @@ void die(const char * str, struct pt_regs * regs, long err)
{
unsigned long flags = oops_begin();
- handle_BUG(regs);
+ if (!user_mode(regs))
+ report_bug(regs->rip);
+
__die(str, regs, err);
oops_end(flags);
do_exit(SIGSEGV);
@@ -772,8 +782,7 @@ mem_parity_error(unsigned char reason, struct pt_regs * regs)
{
printk(KERN_EMERG "Uhhuh. NMI received for unknown reason %02x.\n",
reason);
- printk(KERN_EMERG "You probably have a hardware problem with your "
- "RAM chips\n");
+ printk(KERN_EMERG "You have some hardware problem, likely on the PCI bus.\n");
if (panic_on_unrecovered_nmi)
panic("NMI: Not continuing");
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-24 02:05:23 +0000