1 files changed, 18 insertions, 12 deletions

diff --git a/arch/arc/kernel/troubleshoot.c b/arch/arc/kernel/troubleshoot.c
index e8d9fb452346..215f515442e0 100644
--- a/arch/arc/kernel/troubleshoot.c
+++ b/arch/arc/kernel/troubleshoot.c
@@ -18,6 +18,8 @@
 #include <asm/arcregs.h>
 #include <asm/irqflags.h>
 
+#define ARC_PATH_MAX    256
+
 /*
  * Common routine to print scratch regs (r0-r12) or callee regs (r13-r25)
  *   -Prints 3 regs per line and a CR.
@@ -58,11 +60,12 @@ static void show_callee_regs(struct callee_regs *cregs)
         print_reg_file(&(cregs->r13), 13);
 }
 
-static void print_task_path_n_nm(struct task_struct *tsk, char *buf)
+static void print_task_path_n_nm(struct task_struct *tsk)
 {
         char *path_nm = NULL;
         struct mm_struct *mm;
         struct file *exe_file;
+        char buf[ARC_PATH_MAX];
 
         mm = get_task_mm(tsk);
         if (!mm)
@@ -72,7 +75,7 @@ static void print_task_path_n_nm(struct task_struct *tsk, char *buf)
         mmput(mm);
 
         if (exe_file) {
-                path_nm = file_path(exe_file, buf, 255);
+                path_nm = file_path(exe_file, buf, ARC_PATH_MAX-1);
                 fput(exe_file);
         }
 
@@ -80,10 +83,9 @@ done:
         pr_info("Path: %s\n", !IS_ERR(path_nm) ? path_nm : "?");
 }
 
-static void show_faulting_vma(unsigned long address, char *buf)
+static void show_faulting_vma(unsigned long address)
 {
         struct vm_area_struct *vma;
-        char *nm = buf;
         struct mm_struct *active_mm = current->active_mm;
 
         /* can't use print_vma_addr() yet as it doesn't check for
@@ -96,8 +98,11 @@ static void show_faulting_vma(unsigned long address, char *buf)
          * if the container VMA is not found
          */
         if (vma && (vma->vm_start <= address)) {
+                char buf[ARC_PATH_MAX];
+                char *nm = "?";
+
                 if (vma->vm_file) {
-                        nm = file_path(vma->vm_file, buf, PAGE_SIZE - 1);
+                        nm = file_path(vma->vm_file, buf, ARC_PATH_MAX-1);
                         if (IS_ERR(nm))
                                 nm = "?";
                 }
@@ -173,13 +178,14 @@ void show_regs(struct pt_regs *regs)
 {
         struct task_struct *tsk = current;
         struct callee_regs *cregs;
-        char *buf;
 
-        buf = (char *)__get_free_page(GFP_KERNEL);
-        if (!buf)
-                return;
+        /*
+         * generic code calls us with preemption disabled, but some calls
+         * here could sleep, so re-enable to avoid lockdep splat
+         */
+        preempt_enable();
 
-        print_task_path_n_nm(tsk, buf);
+        print_task_path_n_nm(tsk);
         show_regs_print_info(KERN_INFO);
 
         show_ecr_verbose(regs);
@@ -189,7 +195,7 @@ void show_regs(struct pt_regs *regs)
                 (void *)regs->blink, (void *)regs->ret);
 
         if (user_mode(regs))
-                show_faulting_vma(regs->ret, buf); /* faulting code, not data */
+                show_faulting_vma(regs->ret); /* faulting code, not data */
 
         pr_info("[STAT32]: 0x%08lx", regs->status32);
 
@@ -222,7 +228,7 @@ void show_regs(struct pt_regs *regs)
         if (cregs)
                 show_callee_regs(cregs);
 
-        free_page((unsigned long)buf);
+        preempt_disable();
 }
 
 void show_kernel_fault_diag(const char *str, struct pt_regs *regs,