troubleshoot.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/proc_fs.h>
#include <linux/file.h>
#include <linux/sched/mm.h>
#include <linux/sched/debug.h>
#include <asm/arcregs.h>
#include <asm/irqflags.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 */
if (is_isa_arcv2() && start_num == 0)
reg_rev++;
else
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);
}
static void print_task_path_n_nm(struct task_struct *tsk, char *buf)
{
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_nm = file_path(exe_file, buf, 255);
fput(exe_file);
}
done:
pr_info("Path: %s\n", !IS_ERR(path_nm) ? path_nm : "?");
}
static void show_faulting_vma(unsigned long address, char *buf)
{
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
* non-inclusive vma
*/
down_read(&active_mm->mmap_sem);
vma = find_vma(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)) {
if (vma->vm_file) {
nm = file_path(vma->vm_file, buf, PAGE_SIZE - 1);
if (IS_ERR(nm))
nm = "?";
}
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");
up_read(&active_mm->mmap_sem);
}
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("Machine Check (%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");
#ifdef CONFIG_ISA_ARCV2
} else if (vec == ECR_V_MEM_ERR) {
if (cause_code == 0x00)
pr_cont("Bus Error from Insn Mem\n");
else if (cause_code == 0x10)
pr_cont("Bus Error from Data Mem\n");
else
pr_cont("Bus Error, check PRM\n");
#endif
} else if (vec == ECR_V_TRAP) {
if (regs->ecr_param == 5)
pr_cont("gcc generated __builtin_trap\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_KERNEL);
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" " : ""
#ifdef CONFIG_ISA_ARCOMPACT
pr_cont(" : %2s%2s%2s%2s%2s%2s%2s\n",
(regs->status32 & STATUS_U_MASK) ? "U " : "K ",
STS_BIT(regs, DE), STS_BIT(regs, AE),
STS_BIT(regs, A2), STS_BIT(regs, A1),
STS_BIT(regs, E2), STS_BIT(regs, E1));
#else
pr_cont(" : %2s%2s%2s%2s\n",
STS_BIT(regs, IE),
(regs->status32 & STATUS_U_MASK) ? "U " : "K ",
STS_BIT(regs, DE), STS_BIT(regs, AE));
#endif
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;
/* Show fault description */
pr_info("\n%s\n", str);
/* 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);
}
