1 /*
2 * HW exception handling
3 *
4 * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
5 * Copyright (C) 2008 PetaLogix
6 *
7 * This file is subject to the terms and conditions of the GNU General
8 * Public License. See the file COPYING in the main directory of this
9 * archive for more details.
10 */
11
12 /*
13 * This file handles the architecture-dependent parts of hardware exceptions
14 */
15
16 #include <linux/export.h>
17 #include <linux/kernel.h>
18 #include <linux/signal.h>
19 #include <linux/sched.h>
20 #include <linux/sched/debug.h>
21 #include <linux/kallsyms.h>
22
23 #include <asm/exceptions.h>
24 #include <asm/entry.h> /* For KM CPU var */
25 #include <linux/uaccess.h>
26 #include <linux/errno.h>
27 #include <linux/ptrace.h>
28 #include <asm/current.h>
29 #include <asm/cacheflush.h>
30
31 #define MICROBLAZE_ILL_OPCODE_EXCEPTION 0x02
32 #define MICROBLAZE_IBUS_EXCEPTION 0x03
33 #define MICROBLAZE_DBUS_EXCEPTION 0x04
34 #define MICROBLAZE_DIV_ZERO_EXCEPTION 0x05
35 #define MICROBLAZE_FPU_EXCEPTION 0x06
36 #define MICROBLAZE_PRIVILEGED_EXCEPTION 0x07
37
38 static DEFINE_SPINLOCK(die_lock);
39
die(const char * str,struct pt_regs * fp,long err)40 void die(const char *str, struct pt_regs *fp, long err)
41 {
42 console_verbose();
43 spin_lock_irq(&die_lock);
44 pr_warn("Oops: %s, sig: %ld\n", str, err);
45 show_regs(fp);
46 spin_unlock_irq(&die_lock);
47 /* make_task_dead() should take care of panic'ing from an interrupt
48 * context so we don't handle it here
49 */
50 make_task_dead(err);
51 }
52
53 /* for user application debugging */
sw_exception(struct pt_regs * regs)54 asmlinkage void sw_exception(struct pt_regs *regs)
55 {
56 _exception(SIGTRAP, regs, TRAP_BRKPT, regs->r16);
57 flush_dcache_range(regs->r16, regs->r16 + 0x4);
58 flush_icache_range(regs->r16, regs->r16 + 0x4);
59 }
60
_exception(int signr,struct pt_regs * regs,int code,unsigned long addr)61 void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
62 {
63 if (kernel_mode(regs))
64 die("Exception in kernel mode", regs, signr);
65
66 force_sig_fault(signr, code, (void __user *)addr);
67 }
68
full_exception(struct pt_regs * regs,unsigned int type,int fsr,int addr)69 asmlinkage void full_exception(struct pt_regs *regs, unsigned int type,
70 int fsr, int addr)
71 {
72 addr = regs->pc;
73
74 #if 0
75 pr_warn("Exception %02x in %s mode, FSR=%08x PC=%08x ESR=%08x\n",
76 type, user_mode(regs) ? "user" : "kernel", fsr,
77 (unsigned int) regs->pc, (unsigned int) regs->esr);
78 #endif
79
80 switch (type & 0x1F) {
81 case MICROBLAZE_ILL_OPCODE_EXCEPTION:
82 if (user_mode(regs)) {
83 pr_debug("Illegal opcode exception in user mode\n");
84 _exception(SIGILL, regs, ILL_ILLOPC, addr);
85 return;
86 }
87 pr_warn("Illegal opcode exception in kernel mode.\n");
88 die("opcode exception", regs, SIGBUS);
89 break;
90 case MICROBLAZE_IBUS_EXCEPTION:
91 if (user_mode(regs)) {
92 pr_debug("Instruction bus error exception in user mode\n");
93 _exception(SIGBUS, regs, BUS_ADRERR, addr);
94 return;
95 }
96 pr_warn("Instruction bus error exception in kernel mode.\n");
97 die("bus exception", regs, SIGBUS);
98 break;
99 case MICROBLAZE_DBUS_EXCEPTION:
100 if (user_mode(regs)) {
101 pr_debug("Data bus error exception in user mode\n");
102 _exception(SIGBUS, regs, BUS_ADRERR, addr);
103 return;
104 }
105 pr_warn("Data bus error exception in kernel mode.\n");
106 die("bus exception", regs, SIGBUS);
107 break;
108 case MICROBLAZE_DIV_ZERO_EXCEPTION:
109 if (user_mode(regs)) {
110 pr_debug("Divide by zero exception in user mode\n");
111 _exception(SIGFPE, regs, FPE_INTDIV, addr);
112 return;
113 }
114 pr_warn("Divide by zero exception in kernel mode.\n");
115 die("Divide by zero exception", regs, SIGBUS);
116 break;
117 case MICROBLAZE_FPU_EXCEPTION:
118 pr_debug("FPU exception\n");
119 /* IEEE FP exception */
120 /* I removed fsr variable and use code var for storing fsr */
121 if (fsr & FSR_IO)
122 fsr = FPE_FLTINV;
123 else if (fsr & FSR_OF)
124 fsr = FPE_FLTOVF;
125 else if (fsr & FSR_UF)
126 fsr = FPE_FLTUND;
127 else if (fsr & FSR_DZ)
128 fsr = FPE_FLTDIV;
129 else if (fsr & FSR_DO)
130 fsr = FPE_FLTRES;
131 _exception(SIGFPE, regs, fsr, addr);
132 break;
133 case MICROBLAZE_PRIVILEGED_EXCEPTION:
134 pr_debug("Privileged exception\n");
135 _exception(SIGILL, regs, ILL_PRVOPC, addr);
136 break;
137 default:
138 /* FIXME what to do in unexpected exception */
139 pr_warn("Unexpected exception %02x PC=%08x in %s mode\n",
140 type, (unsigned int) addr,
141 kernel_mode(regs) ? "kernel" : "user");
142 }
143 return;
144 }
145