mm: fix exec activate_mm vs TLB shootdown and lazy tlb switching race
[linux/fpc-iii.git] / arch / arc / kernel / troubleshoot.c
blob7d8c1d6c2f60f918e95f2cafc81c90c028684b9a
1 /*
2 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 */
8 #include <linux/ptrace.h>
9 #include <linux/module.h>
10 #include <linux/mm.h>
11 #include <linux/fs.h>
12 #include <linux/kdev_t.h>
13 #include <linux/fs_struct.h>
14 #include <linux/proc_fs.h>
15 #include <linux/file.h>
16 #include <linux/sched/mm.h>
17 #include <linux/sched/debug.h>
19 #include <asm/arcregs.h>
20 #include <asm/irqflags.h>
23 * Common routine to print scratch regs (r0-r12) or callee regs (r13-r25)
24 * -Prints 3 regs per line and a CR.
25 * -To continue, callee regs right after scratch, special handling of CR
27 static noinline void print_reg_file(long *reg_rev, int start_num)
29 unsigned int i;
30 char buf[512];
31 int n = 0, len = sizeof(buf);
33 for (i = start_num; i < start_num + 13; i++) {
34 n += scnprintf(buf + n, len - n, "r%02u: 0x%08lx\t",
35 i, (unsigned long)*reg_rev);
37 if (((i + 1) % 3) == 0)
38 n += scnprintf(buf + n, len - n, "\n");
40 /* because pt_regs has regs reversed: r12..r0, r25..r13 */
41 if (is_isa_arcv2() && start_num == 0)
42 reg_rev++;
43 else
44 reg_rev--;
47 if (start_num != 0)
48 n += scnprintf(buf + n, len - n, "\n\n");
50 /* To continue printing callee regs on same line as scratch regs */
51 if (start_num == 0)
52 pr_info("%s", buf);
53 else
54 pr_cont("%s\n", buf);
57 static void show_callee_regs(struct callee_regs *cregs)
59 print_reg_file(&(cregs->r13), 13);
62 static void print_task_path_n_nm(struct task_struct *tsk, char *buf)
64 char *path_nm = NULL;
65 struct mm_struct *mm;
66 struct file *exe_file;
68 mm = get_task_mm(tsk);
69 if (!mm)
70 goto done;
72 exe_file = get_mm_exe_file(mm);
73 mmput(mm);
75 if (exe_file) {
76 path_nm = file_path(exe_file, buf, 255);
77 fput(exe_file);
80 done:
81 pr_info("Path: %s\n", !IS_ERR(path_nm) ? path_nm : "?");
84 static void show_faulting_vma(unsigned long address, char *buf)
86 struct vm_area_struct *vma;
87 struct inode *inode;
88 unsigned long ino = 0;
89 dev_t dev = 0;
90 char *nm = buf;
91 struct mm_struct *active_mm = current->active_mm;
93 /* can't use print_vma_addr() yet as it doesn't check for
94 * non-inclusive vma
96 down_read(&active_mm->mmap_sem);
97 vma = find_vma(active_mm, address);
99 /* check against the find_vma( ) behaviour which returns the next VMA
100 * if the container VMA is not found
102 if (vma && (vma->vm_start <= address)) {
103 struct file *file = vma->vm_file;
104 if (file) {
105 nm = file_path(file, buf, PAGE_SIZE - 1);
106 inode = file_inode(vma->vm_file);
107 dev = inode->i_sb->s_dev;
108 ino = inode->i_ino;
110 pr_info(" @off 0x%lx in [%s]\n"
111 " VMA: 0x%08lx to 0x%08lx\n",
112 vma->vm_start < TASK_UNMAPPED_BASE ?
113 address : address - vma->vm_start,
114 nm, vma->vm_start, vma->vm_end);
115 } else
116 pr_info(" @No matching VMA found\n");
118 up_read(&active_mm->mmap_sem);
121 static void show_ecr_verbose(struct pt_regs *regs)
123 unsigned int vec, cause_code;
124 unsigned long address;
126 pr_info("\n[ECR ]: 0x%08lx => ", regs->event);
128 /* For Data fault, this is data address not instruction addr */
129 address = current->thread.fault_address;
131 vec = regs->ecr_vec;
132 cause_code = regs->ecr_cause;
134 /* For DTLB Miss or ProtV, display the memory involved too */
135 if (vec == ECR_V_DTLB_MISS) {
136 pr_cont("Invalid %s @ 0x%08lx by insn @ 0x%08lx\n",
137 (cause_code == 0x01) ? "Read" :
138 ((cause_code == 0x02) ? "Write" : "EX"),
139 address, regs->ret);
140 } else if (vec == ECR_V_ITLB_MISS) {
141 pr_cont("Insn could not be fetched\n");
142 } else if (vec == ECR_V_MACH_CHK) {
143 pr_cont("Machine Check (%s)\n", (cause_code == 0x0) ?
144 "Double Fault" : "Other Fatal Err");
146 } else if (vec == ECR_V_PROTV) {
147 if (cause_code == ECR_C_PROTV_INST_FETCH)
148 pr_cont("Execute from Non-exec Page\n");
149 else if (cause_code == ECR_C_PROTV_MISALIG_DATA)
150 pr_cont("Misaligned r/w from 0x%08lx\n", address);
151 else
152 pr_cont("%s access not allowed on page\n",
153 (cause_code == 0x01) ? "Read" :
154 ((cause_code == 0x02) ? "Write" : "EX"));
155 } else if (vec == ECR_V_INSN_ERR) {
156 pr_cont("Illegal Insn\n");
157 #ifdef CONFIG_ISA_ARCV2
158 } else if (vec == ECR_V_MEM_ERR) {
159 if (cause_code == 0x00)
160 pr_cont("Bus Error from Insn Mem\n");
161 else if (cause_code == 0x10)
162 pr_cont("Bus Error from Data Mem\n");
163 else
164 pr_cont("Bus Error, check PRM\n");
165 #endif
166 } else {
167 pr_cont("Check Programmer's Manual\n");
171 /************************************************************************
172 * API called by rest of kernel
173 ***********************************************************************/
175 void show_regs(struct pt_regs *regs)
177 struct task_struct *tsk = current;
178 struct callee_regs *cregs;
179 char *buf;
181 buf = (char *)__get_free_page(GFP_KERNEL);
182 if (!buf)
183 return;
185 print_task_path_n_nm(tsk, buf);
186 show_regs_print_info(KERN_INFO);
188 show_ecr_verbose(regs);
190 pr_info("[EFA ]: 0x%08lx\n[BLINK ]: %pS\n[ERET ]: %pS\n",
191 current->thread.fault_address,
192 (void *)regs->blink, (void *)regs->ret);
194 if (user_mode(regs))
195 show_faulting_vma(regs->ret, buf); /* faulting code, not data */
197 pr_info("[STAT32]: 0x%08lx", regs->status32);
199 #define STS_BIT(r, bit) r->status32 & STATUS_##bit##_MASK ? #bit" " : ""
201 #ifdef CONFIG_ISA_ARCOMPACT
202 pr_cont(" : %2s%2s%2s%2s%2s%2s%2s\n",
203 (regs->status32 & STATUS_U_MASK) ? "U " : "K ",
204 STS_BIT(regs, DE), STS_BIT(regs, AE),
205 STS_BIT(regs, A2), STS_BIT(regs, A1),
206 STS_BIT(regs, E2), STS_BIT(regs, E1));
207 #else
208 pr_cont(" : %2s%2s%2s%2s\n",
209 STS_BIT(regs, IE),
210 (regs->status32 & STATUS_U_MASK) ? "U " : "K ",
211 STS_BIT(regs, DE), STS_BIT(regs, AE));
212 #endif
213 pr_info("BTA: 0x%08lx\t SP: 0x%08lx\t FP: 0x%08lx\n",
214 regs->bta, regs->sp, regs->fp);
215 pr_info("LPS: 0x%08lx\tLPE: 0x%08lx\tLPC: 0x%08lx\n",
216 regs->lp_start, regs->lp_end, regs->lp_count);
218 /* print regs->r0 thru regs->r12
219 * Sequential printing was generating horrible code
221 print_reg_file(&(regs->r0), 0);
223 /* If Callee regs were saved, display them too */
224 cregs = (struct callee_regs *)current->thread.callee_reg;
225 if (cregs)
226 show_callee_regs(cregs);
228 free_page((unsigned long)buf);
231 void show_kernel_fault_diag(const char *str, struct pt_regs *regs,
232 unsigned long address)
234 current->thread.fault_address = address;
236 /* Show fault description */
237 pr_info("\n%s\n", str);
239 /* Caller and Callee regs */
240 show_regs(regs);
242 /* Show stack trace if this Fatality happened in kernel mode */
243 if (!user_mode(regs))
244 show_stacktrace(current, regs);