linux-stable/arch/arc/kernel/troubleshoot.c
Linus Torvalds 76d3f4c27d ARC changes for 3.11
Highlights of changes:
 
 -Continuation of ARC MM changes from 3.10 including
    zero page optimization;
    Setting pagecache pages dirty by default;
    Non executable stack by default;
    Reducing dcache flushes for aliasing VIPT config
 
 -Long overdue rework of pt_regs machinery - removing the unused word gutters
  and adding ECR register to baseline (helps cleanup lot of low level code)
 
 -Support for ARC gcc 4.8
 
 -Few other preventive fixes, cosmetics, usage of Kconfig helper..
 
 The diffstat is larger than normal primarily because of arcregs.h header split
 as well as beautification of macros in entry.h
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Merge tag 'arc-v3.11-rc1-part1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

Pull first batch of ARC changes from Vineet Gupta:
 "There's a second bunch to follow next week - which depends on commits
  on other trees (irq/net).  I'd have preferred the accompanying ARC
  change via respective trees, but it didn't workout somehow.

  Highlights of changes:

   - Continuation of ARC MM changes from 3.10 including

       zero page optimization
       Setting pagecache pages dirty by default
       Non executable stack by default
       Reducing dcache flushes for aliasing VIPT config

   - Long overdue rework of pt_regs machinery - removing the unused word
     gutters and adding ECR register to baseline (helps cleanup lot of
     low level code)

   - Support for ARC gcc 4.8

   - Few other preventive fixes, cosmetics, usage of Kconfig helper..

  The diffstat is larger than normal primarily because of arcregs.h
  header split as well as beautification of macros in entry.h"

* tag 'arc-v3.11-rc1-part1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc: (32 commits)
  ARC: warn on improper stack unwind FDE entries
  arc: delete __cpuinit usage from all arc files
  ARC: [tlb-miss] Fix bug with CONFIG_ARC_DBG_TLB_MISS_COUNT
  ARC: [tlb-miss] Extraneous PTE bit testing/setting
  ARC: Adjustments for gcc 4.8
  ARC: Setup Vector Table Base in early boot
  ARC: Remove explicit passing around of ECR
  ARC: pt_regs update #5: Use real ECR for pt_regs->event vs. synth values
  ARC: stop using pt_regs->orig_r8
  ARC: pt_regs update #4: r25 saved/restored unconditionally
  ARC: K/U SP saved from one location in stack switching macro
  ARC: Entry Handler tweaks: Simplify branch for in-kernel preemption
  ARC: Entry Handler tweaks: Avoid hardcoded LIMMS for ECR values
  ARC: Increase readability of entry handlers
  ARC: pt_regs update #3: Remove unused gutter at start of callee_regs
  ARC: pt_regs update #2: Remove unused gutter at start of pt_regs
  ARC: pt_regs update #1: Align pt_regs end with end of kernel stack page
  ARC: pt_regs update #0: remove kernel stack canary
  ARC: [mm] Remove @write argument to do_page_fault()
  ARC: [mm] Make stack/heap Non-executable by default
  ...
2013-07-03 11:09:27 -07:00

332 lines
8.4 KiB
C

/*
* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
*/
#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);
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");
/* because pt_regs has regs reversed: r12..r0, r25..r13 */
reg_rev--;
}
if (start_num != 0)
n += scnprintf(buf + n, len - n, "\n\n");
/* To continue printing callee regs on same line as scratch regs */
if (start_num == 0)
pr_info("%s", buf);
else
pr_cont("%s\n", 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("Path: %s\n", path_nm);
}
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;
/* can't use print_vma_addr() yet as it doesn't check for
* non-inclusive vma
*/
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 = file_inode(vma->vm_file);
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",
vma->vm_start < TASK_UNMAPPED_BASE ?
address : 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;
unsigned long address;
pr_info("\n[ECR ]: 0x%08lx => ", regs->event);
/* For Data fault, this is data address not instruction addr */
address = current->thread.fault_address;
vec = regs->ecr_vec;
cause_code = regs->ecr_cause;
/* 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" :
((cause_code == 0x02) ? "Write" : "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_MISALIG_DATA)
pr_cont("Misaligned r/w from 0x%08lx\n", address);
else
pr_cont("%s access not allowed on page\n",
(cause_code == 0x01) ? "Read" :
((cause_code == 0x02) ? "Write" : "EX"));
} 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);
show_regs_print_info(KERN_INFO);
show_ecr_verbose(regs);
pr_info("[EFA ]: 0x%08lx\n[BLINK ]: %pS\n[ERET ]: %pS\n",
current->thread.fault_address,
(void *)regs->blink, (void *)regs->ret);
if (user_mode(regs))
show_faulting_vma(regs->ret, buf); /* faulting code, not data */
pr_info("[STAT32]: 0x%08lx", regs->status32);
#define STS_BIT(r, bit) r->status32 & STATUS_##bit##_MASK ? #bit : ""
if (!user_mode(regs))
pr_cont(" : %2s %2s %2s %2s %2s\n",
STS_BIT(regs, AE), STS_BIT(regs, A2), STS_BIT(regs, A1),
STS_BIT(regs, E2), STS_BIT(regs, E1));
pr_info("BTA: 0x%08lx\t SP: 0x%08lx\t FP: 0x%08lx\n",
regs->bta, regs->sp, regs->fp);
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)
{
current->thread.fault_address = address;
/* 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