Merge tag 'v4.4.46' into linux-linaro-lsk-v4.4

[firefly-linux-kernel-4.4.55.git] / arch / arm64 / kernel / traps.c

diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index ca7f0ac5f70807ca2770ba646770e7cb82f235af..a036ff290d69d4687477bfd5f4c42f385474bac2 100644 (file)
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -146,17 +146,24 @@ static void dump_instr(const char *lvl, struct pt_regs *regs)
 static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
 {
        struct stackframe frame;
+       unsigned long irq_stack_ptr;
+       int skip;
+
+       /*
+        * Switching between stacks is valid when tracing current and in
+        * non-preemptible context.
+        */
+       if (tsk == current && !preemptible())
+               irq_stack_ptr = IRQ_STACK_PTR(smp_processor_id());
+       else
+               irq_stack_ptr = 0;
 
        pr_debug("%s(regs = %p tsk = %p)\n", __func__, regs, tsk);
 
        if (!tsk)
                tsk = current;
 
-       if (regs) {
-               frame.fp = regs->regs[29];
-               frame.sp = regs->sp;
-               frame.pc = regs->pc;
-       } else if (tsk == current) {
+       if (tsk == current) {
                frame.fp = (unsigned long)__builtin_frame_address(0);
                frame.sp = current_stack_pointer;
                frame.pc = (unsigned long)dump_backtrace;
@@ -168,21 +175,49 @@ static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
                frame.sp = thread_saved_sp(tsk);
                frame.pc = thread_saved_pc(tsk);
        }
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+       frame.graph = tsk->curr_ret_stack;
+#endif
 
-       pr_emerg("Call trace:\n");
+       skip = !!regs;
+       printk("Call trace:\n");
        while (1) {
                unsigned long where = frame.pc;
                unsigned long stack;
                int ret;
 
-               dump_backtrace_entry(where);
-               ret = unwind_frame(&frame);
+               /* skip until specified stack frame */
+               if (!skip) {
+                       dump_backtrace_entry(where);
+               } else if (frame.fp == regs->regs[29]) {
+                       skip = 0;
+                       /*
+                        * Mostly, this is the case where this function is
+                        * called in panic/abort. As exception handler's
+                        * stack frame does not contain the corresponding pc
+                        * at which an exception has taken place, use regs->pc
+                        * instead.
+                        */
+                       dump_backtrace_entry(regs->pc);
+               }
+               ret = unwind_frame(tsk, &frame);
                if (ret < 0)
                        break;
                stack = frame.sp;
-               if (in_exception_text(where))
+               if (in_exception_text(where)) {
+                       /*
+                        * If we switched to the irq_stack before calling this
+                        * exception handler, then the pt_regs will be on the
+                        * task stack. The easiest way to tell is if the large
+                        * pt_regs would overlap with the end of the irq_stack.
+                        */
+                       if (stack < irq_stack_ptr &&
+                           (stack + sizeof(struct pt_regs)) > irq_stack_ptr)
+                               stack = IRQ_STACK_TO_TASK_STACK(irq_stack_ptr);
+
                        dump_mem("", "Exception stack", stack,
                                 stack + sizeof(struct pt_regs), false);
+               }
        }
 }
 
@@ -476,22 +511,22 @@ asmlinkage void bad_el0_sync(struct pt_regs *regs, int reason, unsigned int esr)
 
 void __pte_error(const char *file, int line, unsigned long val)
 {
-       pr_crit("%s:%d: bad pte %016lx.\n", file, line, val);
+       pr_err("%s:%d: bad pte %016lx.\n", file, line, val);
 }
 
 void __pmd_error(const char *file, int line, unsigned long val)
 {
-       pr_crit("%s:%d: bad pmd %016lx.\n", file, line, val);
+       pr_err("%s:%d: bad pmd %016lx.\n", file, line, val);
 }
 
 void __pud_error(const char *file, int line, unsigned long val)
 {
-       pr_crit("%s:%d: bad pud %016lx.\n", file, line, val);
+       pr_err("%s:%d: bad pud %016lx.\n", file, line, val);
 }
 
 void __pgd_error(const char *file, int line, unsigned long val)
 {
-       pr_crit("%s:%d: bad pgd %016lx.\n", file, line, val);
+       pr_err("%s:%d: bad pgd %016lx.\n", file, line, val);
 }
 
 /* GENERIC_BUG traps */