ARC: Diagnostics: show_regs() etc
authorVineet Gupta <vgupta@synopsys.com>
Fri, 18 Jan 2013 09:42:23 +0000 (15:12 +0530)
committerVineet Gupta <vgupta@synopsys.com>
Fri, 15 Feb 2013 17:46:02 +0000 (23:16 +0530)
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
arch/arc/kernel/troubleshoot.c
arch/arc/mm/tlbex.S

index 80bfe2a..7c10873 100644 (file)
  */
 
 #include <linux/ptrace.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/fs.h>
+#include <linux/kdev_t.h>
+#include <linux/fs_struct.h>
+#include <linux/proc_fs.h>
+#include <linux/file.h>
+#include <asm/arcregs.h>
+
+/*
+ * Common routine to print scratch regs (r0-r12) or callee regs (r13-r25)
+ *   -Prints 3 regs per line and a CR.
+ *   -To continue, callee regs right after scratch, special handling of CR
+ */
+static noinline void print_reg_file(long *reg_rev, int start_num)
+{
+       unsigned int i;
+       char buf[512];
+       int n = 0, len = sizeof(buf);
+
+       /* weird loop because pt_regs regs rev r12..r0, r25..r13 */
+       for (i = start_num; i < start_num + 13; i++) {
+               n += scnprintf(buf + n, len - n, "r%02u: 0x%08lx\t",
+                              i, (unsigned long)*reg_rev);
+
+               if (((i + 1) % 3) == 0)
+                       n += scnprintf(buf + n, len - n, "\n");
+
+               reg_rev--;
+       }
+
+       if (start_num != 0)
+               n += scnprintf(buf + n, len - n, "\n\n");
+
+       pr_info("%s", buf);
+}
+
+static void show_callee_regs(struct callee_regs *cregs)
+{
+       print_reg_file(&(cregs->r13), 13);
+}
+
+void print_task_path_n_nm(struct task_struct *tsk, char *buf)
+{
+       struct path path;
+       char *path_nm = NULL;
+       struct mm_struct *mm;
+       struct file *exe_file;
+
+       mm = get_task_mm(tsk);
+       if (!mm)
+               goto done;
+
+       exe_file = get_mm_exe_file(mm);
+       mmput(mm);
+
+       if (exe_file) {
+               path = exe_file->f_path;
+               path_get(&exe_file->f_path);
+               fput(exe_file);
+               path_nm = d_path(&path, buf, 255);
+               path_put(&path);
+       }
+
+done:
+       pr_info("%s, TGID %u\n", path_nm, tsk->tgid);
+}
+EXPORT_SYMBOL(print_task_path_n_nm);
+
+static void show_faulting_vma(unsigned long address, char *buf)
+{
+       struct vm_area_struct *vma;
+       struct inode *inode;
+       unsigned long ino = 0;
+       dev_t dev = 0;
+       char *nm = buf;
+
+       vma = find_vma(current->active_mm, address);
+
+       /* check against the find_vma( ) behaviour which returns the next VMA
+        * if the container VMA is not found
+        */
+       if (vma && (vma->vm_start <= address)) {
+               struct file *file = vma->vm_file;
+               if (file) {
+                       struct path *path = &file->f_path;
+                       nm = d_path(path, buf, PAGE_SIZE - 1);
+                       inode = vma->vm_file->f_path.dentry->d_inode;
+                       dev = inode->i_sb->s_dev;
+                       ino = inode->i_ino;
+               }
+               pr_info("    @off 0x%lx in [%s]\n"
+                       "    VMA: 0x%08lx to 0x%08lx\n\n",
+                      address - vma->vm_start, nm, vma->vm_start, vma->vm_end);
+       } else
+               pr_info("    @No matching VMA found\n");
+}
+
+static void show_ecr_verbose(struct pt_regs *regs)
+{
+       unsigned int vec, cause_code, cause_reg;
+       unsigned long address;
+
+       cause_reg = current->thread.cause_code;
+       pr_info("\n[ECR]: 0x%08x => ", cause_reg);
+
+       /* For Data fault, this is data address not instruction addr */
+       address = current->thread.fault_address;
+
+       vec = cause_reg >> 16;
+       cause_code = (cause_reg >> 8) & 0xFF;
+
+       /* For DTLB Miss or ProtV, display the memory involved too */
+       if (vec == ECR_V_DTLB_MISS) {
+               pr_cont("Invalid (%s) @ 0x%08lx by insn @ 0x%08lx\n",
+                      (cause_code == 0x01) ? "Read From" :
+                      ((cause_code == 0x02) ? "Write to" : "EX"),
+                      address, regs->ret);
+       } else if (vec == ECR_V_ITLB_MISS) {
+               pr_cont("Insn could not be fetched\n");
+       } else if (vec == ECR_V_MACH_CHK) {
+               pr_cont("%s\n", (cause_code == 0x0) ?
+                                       "Double Fault" : "Other Fatal Err");
+
+       } else if (vec == ECR_V_PROTV) {
+               if (cause_code == ECR_C_PROTV_INST_FETCH)
+                       pr_cont("Execute from Non-exec Page\n");
+               else if (cause_code == ECR_C_PROTV_LOAD)
+                       pr_cont("Read from Non-readable Page\n");
+               else if (cause_code == ECR_C_PROTV_STORE)
+                       pr_cont("Write to Non-writable Page\n");
+               else if (cause_code == ECR_C_PROTV_XCHG)
+                       pr_cont("Data exchange protection violation\n");
+               else if (cause_code == ECR_C_PROTV_MISALIG_DATA)
+                       pr_cont("Misaligned r/w from 0x%08lx\n", address);
+       } else if (vec == ECR_V_INSN_ERR) {
+               pr_cont("Illegal Insn\n");
+       } else {
+               pr_cont("Check Programmer's Manual\n");
+       }
+}
+
+/************************************************************************
+ *  API called by rest of kernel
+ ***********************************************************************/
 
 void show_regs(struct pt_regs *regs)
 {
+       struct task_struct *tsk = current;
+       struct callee_regs *cregs;
+       char *buf;
+
+       buf = (char *)__get_free_page(GFP_TEMPORARY);
+       if (!buf)
+               return;
+
+       print_task_path_n_nm(tsk, buf);
+
+       if (current->thread.cause_code)
+               show_ecr_verbose(regs);
+
+       pr_info("[EFA]: 0x%08lx\n", current->thread.fault_address);
+       pr_info("[ERET]: 0x%08lx (PC of Faulting Instr)\n", regs->ret);
+
+       show_faulting_vma(regs->ret, buf);      /* faulting code, not data */
+
+       /* can't use print_vma_addr() yet as it doesn't check for
+        * non-inclusive vma
+        */
+
+       /* print special regs */
+       pr_info("status32: 0x%08lx\n", regs->status32);
+       pr_info(" SP: 0x%08lx\tFP: 0x%08lx\n", regs->sp, regs->fp);
+       pr_info("BTA: 0x%08lx\tBLINK: 0x%08lx\n",
+               regs->bta, regs->blink);
+       pr_info("LPS: 0x%08lx\tLPE: 0x%08lx\tLPC: 0x%08lx\n",
+              regs->lp_start, regs->lp_end, regs->lp_count);
+
+       /* print regs->r0 thru regs->r12
+        * Sequential printing was generating horrible code
+        */
+       print_reg_file(&(regs->r0), 0);
+
+       /* If Callee regs were saved, display them too */
+       cregs = (struct callee_regs *)current->thread.callee_reg;
+       if (cregs)
+               show_callee_regs(cregs);
+
+       free_page((unsigned long)buf);
 }
 
 void show_kernel_fault_diag(const char *str, struct pt_regs *regs,
                            unsigned long address, unsigned long cause_reg)
 {
+       current->thread.fault_address = address;
+       current->thread.cause_code = cause_reg;
+
+       /* Caller and Callee regs */
+       show_regs(regs);
+
+       /* Show stack trace if this Fatality happened in kernel mode */
+       if (!user_mode(regs))
+               show_stacktrace(current, regs);
 }
+
+#ifdef CONFIG_DEBUG_FS
+
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/mount.h>
+#include <linux/pagemap.h>
+#include <linux/init.h>
+#include <linux/namei.h>
+#include <linux/debugfs.h>
+
+static struct dentry *test_dentry;
+static struct dentry *test_dir;
+static struct dentry *test_u32_dentry;
+
+static u32 clr_on_read = 1;
+
+#ifdef CONFIG_ARC_DBG_TLB_MISS_COUNT
+u32 numitlb, numdtlb, num_pte_not_present;
+
+static int fill_display_data(char *kbuf)
+{
+       size_t num = 0;
+       num += sprintf(kbuf + num, "I-TLB Miss %x\n", numitlb);
+       num += sprintf(kbuf + num, "D-TLB Miss %x\n", numdtlb);
+       num += sprintf(kbuf + num, "PTE not present %x\n", num_pte_not_present);
+
+       if (clr_on_read)
+               numitlb = numdtlb = num_pte_not_present = 0;
+
+       return num;
+}
+
+static int tlb_stats_open(struct inode *inode, struct file *file)
+{
+       file->private_data = (void *)__get_free_page(GFP_KERNEL);
+       return 0;
+}
+
+/* called on user read(): display the couters */
+static ssize_t tlb_stats_output(struct file *file,     /* file descriptor */
+                               char __user *user_buf,  /* user buffer */
+                               size_t len,             /* length of buffer */
+                               loff_t *offset)         /* offset in the file */
+{
+       size_t num;
+       char *kbuf = (char *)file->private_data;
+
+       /* All of the data can he shoved in one iteration */
+       if (*offset != 0)
+               return 0;
+
+       num = fill_display_data(kbuf);
+
+       /* simple_read_from_buffer() is helper for copy to user space
+          It copies up to @2 (num) bytes from kernel buffer @4 (kbuf) at offset
+          @3 (offset) into the user space address starting at @1 (user_buf).
+          @5 (len) is max size of user buffer
+        */
+       return simple_read_from_buffer(user_buf, num, offset, kbuf, len);
+}
+
+/* called on user write : clears the counters */
+static ssize_t tlb_stats_clear(struct file *file, const char __user *user_buf,
+                              size_t length, loff_t *offset)
+{
+       numitlb = numdtlb = num_pte_not_present = 0;
+       return length;
+}
+
+static int tlb_stats_close(struct inode *inode, struct file *file)
+{
+       free_page((unsigned long)(file->private_data));
+       return 0;
+}
+
+static const struct file_operations tlb_stats_file_ops = {
+       .read = tlb_stats_output,
+       .write = tlb_stats_clear,
+       .open = tlb_stats_open,
+       .release = tlb_stats_close
+};
+#endif
+
+static int __init arc_debugfs_init(void)
+{
+       test_dir = debugfs_create_dir("arc", NULL);
+
+#ifdef CONFIG_ARC_DBG_TLB_MISS_COUNT
+       test_dentry = debugfs_create_file("tlb_stats", 0444, test_dir, NULL,
+                                         &tlb_stats_file_ops);
+#endif
+
+       test_u32_dentry =
+           debugfs_create_u32("clr_on_read", 0444, test_dir, &clr_on_read);
+
+       return 0;
+}
+
+module_init(arc_debugfs_init);
+
+static void __exit arc_debugfs_exit(void)
+{
+       debugfs_remove(test_u32_dentry);
+       debugfs_remove(test_dentry);
+       debugfs_remove(test_dir);
+}
+module_exit(arc_debugfs_exit);
+
+#endif
index fc5b971..164b021 100644 (file)
@@ -133,6 +133,14 @@ ex_saved_reg1:
        lsr     r0, r2, (PAGE_SHIFT - 2)
        and     r0, r0, ( (PTRS_PER_PTE - 1) << 2)
        ld.aw   r0, [r1, r0]            ; get PTE and PTE ptr for fault addr
+#ifdef CONFIG_ARC_DBG_TLB_MISS_COUNT
+       and.f 0, r0, _PAGE_PRESENT
+       bz   1f
+       ld   r2, [num_pte_not_present]
+       add  r2, r2, 1
+       st   r2, [num_pte_not_present]
+1:
+#endif
 
 .endm
 
@@ -219,6 +227,12 @@ ARC_ENTRY EV_TLBMissI
 
        TLBMISS_FREEUP_REGS
 
+#ifdef CONFIG_ARC_DBG_TLB_MISS_COUNT
+       ld  r0, [@numitlb]
+       add r0, r0, 1
+       st  r0, [@numitlb]
+#endif
+
        ;----------------------------------------------------------------
        ; Get the PTE corresponding to V-addr accessed
        LOAD_FAULT_PTE
@@ -252,6 +266,12 @@ ARC_ENTRY EV_TLBMissD
 
        TLBMISS_FREEUP_REGS
 
+#ifdef CONFIG_ARC_DBG_TLB_MISS_COUNT
+       ld  r0, [@numdtlb]
+       add r0, r0, 1
+       st  r0, [@numdtlb]
+#endif
+
        ;----------------------------------------------------------------
        ; Get the PTE corresponding to V-addr accessed
        ; If PTE exists, it will setup, r0 = PTE, r1 = Ptr to PTE