| /* |
| * Main exception handling logic. |
| * |
| * Copyright 2004-2010 Analog Devices Inc. |
| * |
| * Licensed under the GPL-2 or later |
| */ |
| |
| #include <linux/bug.h> |
| #include <linux/uaccess.h> |
| #include <linux/module.h> |
| #include <asm/traps.h> |
| #include <asm/cplb.h> |
| #include <asm/blackfin.h> |
| #include <asm/irq_handler.h> |
| #include <linux/irq.h> |
| #include <asm/trace.h> |
| #include <asm/fixed_code.h> |
| #include <asm/pseudo_instructions.h> |
| |
| #ifdef CONFIG_KGDB |
| # include <linux/kgdb.h> |
| |
| # define CHK_DEBUGGER_TRAP() \ |
| do { \ |
| kgdb_handle_exception(trapnr, sig, info.si_code, fp); \ |
| } while (0) |
| # define CHK_DEBUGGER_TRAP_MAYBE() \ |
| do { \ |
| if (kgdb_connected) \ |
| CHK_DEBUGGER_TRAP(); \ |
| } while (0) |
| #else |
| # define CHK_DEBUGGER_TRAP() do { } while (0) |
| # define CHK_DEBUGGER_TRAP_MAYBE() do { } while (0) |
| #endif |
| |
| |
| #ifdef CONFIG_DEBUG_VERBOSE |
| #define verbose_printk(fmt, arg...) \ |
| printk(fmt, ##arg) |
| #else |
| #define verbose_printk(fmt, arg...) \ |
| ({ if (0) printk(fmt, ##arg); 0; }) |
| #endif |
| |
| #if defined(CONFIG_DEBUG_MMRS) || defined(CONFIG_DEBUG_MMRS_MODULE) |
| u32 last_seqstat; |
| #ifdef CONFIG_DEBUG_MMRS_MODULE |
| EXPORT_SYMBOL(last_seqstat); |
| #endif |
| #endif |
| |
| /* Initiate the event table handler */ |
| void __init trap_init(void) |
| { |
| CSYNC(); |
| bfin_write_EVT3(trap); |
| CSYNC(); |
| } |
| |
| static int kernel_mode_regs(struct pt_regs *regs) |
| { |
| return regs->ipend & 0xffc0; |
| } |
| |
| asmlinkage notrace void trap_c(struct pt_regs *fp) |
| { |
| #ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON |
| int j; |
| #endif |
| #ifdef CONFIG_BFIN_PSEUDODBG_INSNS |
| int opcode; |
| #endif |
| unsigned int cpu = raw_smp_processor_id(); |
| const char *strerror = NULL; |
| int sig = 0; |
| siginfo_t info; |
| unsigned long trapnr = fp->seqstat & SEQSTAT_EXCAUSE; |
| |
| trace_buffer_save(j); |
| #if defined(CONFIG_DEBUG_MMRS) || defined(CONFIG_DEBUG_MMRS_MODULE) |
| last_seqstat = (u32)fp->seqstat; |
| #endif |
| |
| /* Important - be very careful dereferncing pointers - will lead to |
| * double faults if the stack has become corrupt |
| */ |
| |
| /* trap_c() will be called for exceptions. During exceptions |
| * processing, the pc value should be set with retx value. |
| * With this change we can cleanup some code in signal.c- TODO |
| */ |
| fp->orig_pc = fp->retx; |
| /* printk("exception: 0x%x, ipend=%x, reti=%x, retx=%x\n", |
| trapnr, fp->ipend, fp->pc, fp->retx); */ |
| |
| /* send the appropriate signal to the user program */ |
| switch (trapnr) { |
| |
| /* This table works in conjuction with the one in ./mach-common/entry.S |
| * Some exceptions are handled there (in assembly, in exception space) |
| * Some are handled here, (in C, in interrupt space) |
| * Some, like CPLB, are handled in both, where the normal path is |
| * handled in assembly/exception space, and the error path is handled |
| * here |
| */ |
| |
| /* 0x00 - Linux Syscall, getting here is an error */ |
| /* 0x01 - userspace gdb breakpoint, handled here */ |
| case VEC_EXCPT01: |
| info.si_code = TRAP_ILLTRAP; |
| sig = SIGTRAP; |
| CHK_DEBUGGER_TRAP_MAYBE(); |
| /* Check if this is a breakpoint in kernel space */ |
| if (kernel_mode_regs(fp)) |
| goto traps_done; |
| else |
| break; |
| /* 0x03 - User Defined, userspace stack overflow */ |
| case VEC_EXCPT03: |
| info.si_code = SEGV_STACKFLOW; |
| sig = SIGSEGV; |
| strerror = KERN_NOTICE EXC_0x03(KERN_NOTICE); |
| CHK_DEBUGGER_TRAP_MAYBE(); |
| break; |
| /* 0x02 - KGDB initial connection and break signal trap */ |
| case VEC_EXCPT02: |
| #ifdef CONFIG_KGDB |
| info.si_code = TRAP_ILLTRAP; |
| sig = SIGTRAP; |
| CHK_DEBUGGER_TRAP(); |
| goto traps_done; |
| #endif |
| /* 0x04 - User Defined */ |
| /* 0x05 - User Defined */ |
| /* 0x06 - User Defined */ |
| /* 0x07 - User Defined */ |
| /* 0x08 - User Defined */ |
| /* 0x09 - User Defined */ |
| /* 0x0A - User Defined */ |
| /* 0x0B - User Defined */ |
| /* 0x0C - User Defined */ |
| /* 0x0D - User Defined */ |
| /* 0x0E - User Defined */ |
| /* 0x0F - User Defined */ |
| /* If we got here, it is most likely that someone was trying to use a |
| * custom exception handler, and it is not actually installed properly |
| */ |
| case VEC_EXCPT04 ... VEC_EXCPT15: |
| info.si_code = ILL_ILLPARAOP; |
| sig = SIGILL; |
| strerror = KERN_NOTICE EXC_0x04(KERN_NOTICE); |
| CHK_DEBUGGER_TRAP_MAYBE(); |
| break; |
| /* 0x10 HW Single step, handled here */ |
| case VEC_STEP: |
| info.si_code = TRAP_STEP; |
| sig = SIGTRAP; |
| CHK_DEBUGGER_TRAP_MAYBE(); |
| /* Check if this is a single step in kernel space */ |
| if (kernel_mode_regs(fp)) |
| goto traps_done; |
| else |
| break; |
| /* 0x11 - Trace Buffer Full, handled here */ |
| case VEC_OVFLOW: |
| info.si_code = TRAP_TRACEFLOW; |
| sig = SIGTRAP; |
| strerror = KERN_NOTICE EXC_0x11(KERN_NOTICE); |
| CHK_DEBUGGER_TRAP_MAYBE(); |
| break; |
| /* 0x12 - Reserved, Caught by default */ |
| /* 0x13 - Reserved, Caught by default */ |
| /* 0x14 - Reserved, Caught by default */ |
| /* 0x15 - Reserved, Caught by default */ |
| /* 0x16 - Reserved, Caught by default */ |
| /* 0x17 - Reserved, Caught by default */ |
| /* 0x18 - Reserved, Caught by default */ |
| /* 0x19 - Reserved, Caught by default */ |
| /* 0x1A - Reserved, Caught by default */ |
| /* 0x1B - Reserved, Caught by default */ |
| /* 0x1C - Reserved, Caught by default */ |
| /* 0x1D - Reserved, Caught by default */ |
| /* 0x1E - Reserved, Caught by default */ |
| /* 0x1F - Reserved, Caught by default */ |
| /* 0x20 - Reserved, Caught by default */ |
| /* 0x21 - Undefined Instruction, handled here */ |
| case VEC_UNDEF_I: |
| #ifdef CONFIG_BUG |
| if (kernel_mode_regs(fp)) { |
| switch (report_bug(fp->pc, fp)) { |
| case BUG_TRAP_TYPE_NONE: |
| break; |
| case BUG_TRAP_TYPE_WARN: |
| dump_bfin_trace_buffer(); |
| fp->pc += 2; |
| goto traps_done; |
| case BUG_TRAP_TYPE_BUG: |
| /* call to panic() will dump trace, and it is |
| * off at this point, so it won't be clobbered |
| */ |
| panic("BUG()"); |
| } |
| } |
| #endif |
| #ifdef CONFIG_BFIN_PSEUDODBG_INSNS |
| /* |
| * Support for the fake instructions, if the instruction fails, |
| * then just execute a illegal opcode failure (like normal). |
| * Don't support these instructions inside the kernel |
| */ |
| if (!kernel_mode_regs(fp) && get_instruction(&opcode, (unsigned short *)fp->pc)) { |
| if (execute_pseudodbg_assert(fp, opcode)) |
| goto traps_done; |
| } |
| #endif |
| info.si_code = ILL_ILLOPC; |
| sig = SIGILL; |
| strerror = KERN_NOTICE EXC_0x21(KERN_NOTICE); |
| CHK_DEBUGGER_TRAP_MAYBE(); |
| break; |
| /* 0x22 - Illegal Instruction Combination, handled here */ |
| case VEC_ILGAL_I: |
| info.si_code = ILL_ILLPARAOP; |
| sig = SIGILL; |
| strerror = KERN_NOTICE EXC_0x22(KERN_NOTICE); |
| CHK_DEBUGGER_TRAP_MAYBE(); |
| break; |
| /* 0x23 - Data CPLB protection violation, handled here */ |
| case VEC_CPLB_VL: |
| info.si_code = ILL_CPLB_VI; |
| sig = SIGSEGV; |
| strerror = KERN_NOTICE EXC_0x23(KERN_NOTICE); |
| CHK_DEBUGGER_TRAP_MAYBE(); |
| break; |
| /* 0x24 - Data access misaligned, handled here */ |
| case VEC_MISALI_D: |
| info.si_code = BUS_ADRALN; |
| sig = SIGBUS; |
| strerror = KERN_NOTICE EXC_0x24(KERN_NOTICE); |
| CHK_DEBUGGER_TRAP_MAYBE(); |
| break; |
| /* 0x25 - Unrecoverable Event, handled here */ |
| case VEC_UNCOV: |
| info.si_code = ILL_ILLEXCPT; |
| sig = SIGILL; |
| strerror = KERN_NOTICE EXC_0x25(KERN_NOTICE); |
| CHK_DEBUGGER_TRAP_MAYBE(); |
| break; |
| /* 0x26 - Data CPLB Miss, normal case is handled in _cplb_hdr, |
| error case is handled here */ |
| case VEC_CPLB_M: |
| info.si_code = BUS_ADRALN; |
| sig = SIGBUS; |
| strerror = KERN_NOTICE EXC_0x26(KERN_NOTICE); |
| break; |
| /* 0x27 - Data CPLB Multiple Hits - Linux Trap Zero, handled here */ |
| case VEC_CPLB_MHIT: |
| info.si_code = ILL_CPLB_MULHIT; |
| sig = SIGSEGV; |
| #ifdef CONFIG_DEBUG_HUNT_FOR_ZERO |
| if (cpu_pda[cpu].dcplb_fault_addr < FIXED_CODE_START) |
| strerror = KERN_NOTICE "NULL pointer access\n"; |
| else |
| #endif |
| strerror = KERN_NOTICE EXC_0x27(KERN_NOTICE); |
| CHK_DEBUGGER_TRAP_MAYBE(); |
| break; |
| /* 0x28 - Emulation Watchpoint, handled here */ |
| case VEC_WATCH: |
| info.si_code = TRAP_WATCHPT; |
| sig = SIGTRAP; |
| pr_debug(EXC_0x28(KERN_DEBUG)); |
| CHK_DEBUGGER_TRAP_MAYBE(); |
| /* Check if this is a watchpoint in kernel space */ |
| if (kernel_mode_regs(fp)) |
| goto traps_done; |
| else |
| break; |
| #ifdef CONFIG_BF535 |
| /* 0x29 - Instruction fetch access error (535 only) */ |
| case VEC_ISTRU_VL: /* ADSP-BF535 only (MH) */ |
| info.si_code = BUS_OPFETCH; |
| sig = SIGBUS; |
| strerror = KERN_NOTICE "BF535: VEC_ISTRU_VL\n"; |
| CHK_DEBUGGER_TRAP_MAYBE(); |
| break; |
| #else |
| /* 0x29 - Reserved, Caught by default */ |
| #endif |
| /* 0x2A - Instruction fetch misaligned, handled here */ |
| case VEC_MISALI_I: |
| info.si_code = BUS_ADRALN; |
| sig = SIGBUS; |
| strerror = KERN_NOTICE EXC_0x2A(KERN_NOTICE); |
| CHK_DEBUGGER_TRAP_MAYBE(); |
| break; |
| /* 0x2B - Instruction CPLB protection violation, handled here */ |
| case VEC_CPLB_I_VL: |
| info.si_code = ILL_CPLB_VI; |
| sig = SIGBUS; |
| strerror = KERN_NOTICE EXC_0x2B(KERN_NOTICE); |
| CHK_DEBUGGER_TRAP_MAYBE(); |
| break; |
| /* 0x2C - Instruction CPLB miss, handled in _cplb_hdr */ |
| case VEC_CPLB_I_M: |
| info.si_code = ILL_CPLB_MISS; |
| sig = SIGBUS; |
| strerror = KERN_NOTICE EXC_0x2C(KERN_NOTICE); |
| break; |
| /* 0x2D - Instruction CPLB Multiple Hits, handled here */ |
| case VEC_CPLB_I_MHIT: |
| info.si_code = ILL_CPLB_MULHIT; |
| sig = SIGSEGV; |
| #ifdef CONFIG_DEBUG_HUNT_FOR_ZERO |
| if (cpu_pda[cpu].icplb_fault_addr < FIXED_CODE_START) |
| strerror = KERN_NOTICE "Jump to NULL address\n"; |
| else |
| #endif |
| strerror = KERN_NOTICE EXC_0x2D(KERN_NOTICE); |
| CHK_DEBUGGER_TRAP_MAYBE(); |
| break; |
| /* 0x2E - Illegal use of Supervisor Resource, handled here */ |
| case VEC_ILL_RES: |
| info.si_code = ILL_PRVOPC; |
| sig = SIGILL; |
| strerror = KERN_NOTICE EXC_0x2E(KERN_NOTICE); |
| CHK_DEBUGGER_TRAP_MAYBE(); |
| break; |
| /* 0x2F - Reserved, Caught by default */ |
| /* 0x30 - Reserved, Caught by default */ |
| /* 0x31 - Reserved, Caught by default */ |
| /* 0x32 - Reserved, Caught by default */ |
| /* 0x33 - Reserved, Caught by default */ |
| /* 0x34 - Reserved, Caught by default */ |
| /* 0x35 - Reserved, Caught by default */ |
| /* 0x36 - Reserved, Caught by default */ |
| /* 0x37 - Reserved, Caught by default */ |
| /* 0x38 - Reserved, Caught by default */ |
| /* 0x39 - Reserved, Caught by default */ |
| /* 0x3A - Reserved, Caught by default */ |
| /* 0x3B - Reserved, Caught by default */ |
| /* 0x3C - Reserved, Caught by default */ |
| /* 0x3D - Reserved, Caught by default */ |
| /* 0x3E - Reserved, Caught by default */ |
| /* 0x3F - Reserved, Caught by default */ |
| case VEC_HWERR: |
| info.si_code = BUS_ADRALN; |
| sig = SIGBUS; |
| switch (fp->seqstat & SEQSTAT_HWERRCAUSE) { |
| /* System MMR Error */ |
| case (SEQSTAT_HWERRCAUSE_SYSTEM_MMR): |
| info.si_code = BUS_ADRALN; |
| sig = SIGBUS; |
| strerror = KERN_NOTICE HWC_x2(KERN_NOTICE); |
| break; |
| /* External Memory Addressing Error */ |
| case (SEQSTAT_HWERRCAUSE_EXTERN_ADDR): |
| if (ANOMALY_05000310) { |
| static unsigned long anomaly_rets; |
| |
| if ((fp->pc >= (L1_CODE_START + L1_CODE_LENGTH - 512)) && |
| (fp->pc < (L1_CODE_START + L1_CODE_LENGTH))) { |
| /* |
| * A false hardware error will happen while fetching at |
| * the L1 instruction SRAM boundary. Ignore it. |
| */ |
| anomaly_rets = fp->rets; |
| goto traps_done; |
| } else if (fp->rets == anomaly_rets) { |
| /* |
| * While boundary code returns to a function, at the ret |
| * point, a new false hardware error might occur too based |
| * on tests. Ignore it too. |
| */ |
| goto traps_done; |
| } else if ((fp->rets >= (L1_CODE_START + L1_CODE_LENGTH - 512)) && |
| (fp->rets < (L1_CODE_START + L1_CODE_LENGTH))) { |
| /* |
| * If boundary code calls a function, at the entry point, |
| * a new false hardware error maybe happen based on tests. |
| * Ignore it too. |
| */ |
| goto traps_done; |
| } else |
| anomaly_rets = 0; |
| } |
| |
| info.si_code = BUS_ADRERR; |
| sig = SIGBUS; |
| strerror = KERN_NOTICE HWC_x3(KERN_NOTICE); |
| break; |
| /* Performance Monitor Overflow */ |
| case (SEQSTAT_HWERRCAUSE_PERF_FLOW): |
| strerror = KERN_NOTICE HWC_x12(KERN_NOTICE); |
| break; |
| /* RAISE 5 instruction */ |
| case (SEQSTAT_HWERRCAUSE_RAISE_5): |
| printk(KERN_NOTICE HWC_x18(KERN_NOTICE)); |
| break; |
| default: /* Reserved */ |
| printk(KERN_NOTICE HWC_default(KERN_NOTICE)); |
| break; |
| } |
| CHK_DEBUGGER_TRAP_MAYBE(); |
| break; |
| /* |
| * We should be handling all known exception types above, |
| * if we get here we hit a reserved one, so panic |
| */ |
| default: |
| info.si_code = ILL_ILLPARAOP; |
| sig = SIGILL; |
| verbose_printk(KERN_EMERG "Caught Unhandled Exception, code = %08lx\n", |
| (fp->seqstat & SEQSTAT_EXCAUSE)); |
| CHK_DEBUGGER_TRAP_MAYBE(); |
| break; |
| } |
| |
| BUG_ON(sig == 0); |
| |
| /* If the fault was caused by a kernel thread, or interrupt handler |
| * we will kernel panic, so the system reboots. |
| */ |
| if (kernel_mode_regs(fp) || (current && !current->mm)) { |
| console_verbose(); |
| oops_in_progress = 1; |
| } |
| |
| if (sig != SIGTRAP) { |
| if (strerror) |
| verbose_printk(strerror); |
| |
| dump_bfin_process(fp); |
| dump_bfin_mem(fp); |
| show_regs(fp); |
| |
| /* Print out the trace buffer if it makes sense */ |
| #ifndef CONFIG_DEBUG_BFIN_NO_KERN_HWTRACE |
| if (trapnr == VEC_CPLB_I_M || trapnr == VEC_CPLB_M) |
| verbose_printk(KERN_NOTICE "No trace since you do not have " |
| "CONFIG_DEBUG_BFIN_NO_KERN_HWTRACE enabled\n\n"); |
| else |
| #endif |
| dump_bfin_trace_buffer(); |
| |
| if (oops_in_progress) { |
| /* Dump the current kernel stack */ |
| verbose_printk(KERN_NOTICE "Kernel Stack\n"); |
| show_stack(current, NULL); |
| print_modules(); |
| #ifndef CONFIG_ACCESS_CHECK |
| verbose_printk(KERN_EMERG "Please turn on " |
| "CONFIG_ACCESS_CHECK\n"); |
| #endif |
| panic("Kernel exception"); |
| } else { |
| #ifdef CONFIG_DEBUG_VERBOSE |
| unsigned long *stack; |
| /* Dump the user space stack */ |
| stack = (unsigned long *)rdusp(); |
| verbose_printk(KERN_NOTICE "Userspace Stack\n"); |
| show_stack(NULL, stack); |
| #endif |
| } |
| } |
| |
| #ifdef CONFIG_IPIPE |
| if (!ipipe_trap_notify(fp->seqstat & 0x3f, fp)) |
| #endif |
| { |
| info.si_signo = sig; |
| info.si_errno = 0; |
| switch (trapnr) { |
| case VEC_CPLB_VL: |
| case VEC_MISALI_D: |
| case VEC_CPLB_M: |
| case VEC_CPLB_MHIT: |
| info.si_addr = (void __user *)cpu_pda[cpu].dcplb_fault_addr; |
| break; |
| default: |
| info.si_addr = (void __user *)fp->pc; |
| break; |
| } |
| force_sig_info(sig, &info, current); |
| } |
| |
| if ((ANOMALY_05000461 && trapnr == VEC_HWERR && !access_ok(VERIFY_READ, fp->pc, 8)) || |
| (ANOMALY_05000281 && trapnr == VEC_HWERR) || |
| (ANOMALY_05000189 && (trapnr == VEC_CPLB_I_VL || trapnr == VEC_CPLB_VL))) |
| fp->pc = SAFE_USER_INSTRUCTION; |
| |
| traps_done: |
| trace_buffer_restore(j); |
| } |
| |
| asmlinkage void double_fault_c(struct pt_regs *fp) |
| { |
| #ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON |
| int j; |
| trace_buffer_save(j); |
| #endif |
| |
| console_verbose(); |
| oops_in_progress = 1; |
| #ifdef CONFIG_DEBUG_VERBOSE |
| printk(KERN_EMERG "Double Fault\n"); |
| #ifdef CONFIG_DEBUG_DOUBLEFAULT_PRINT |
| if (((long)fp->seqstat & SEQSTAT_EXCAUSE) == VEC_UNCOV) { |
| unsigned int cpu = raw_smp_processor_id(); |
| char buf[150]; |
| decode_address(buf, cpu_pda[cpu].retx_doublefault); |
| printk(KERN_EMERG "While handling exception (EXCAUSE = 0x%x) at %s:\n", |
| (unsigned int)cpu_pda[cpu].seqstat_doublefault & SEQSTAT_EXCAUSE, buf); |
| decode_address(buf, cpu_pda[cpu].dcplb_doublefault_addr); |
| printk(KERN_NOTICE " DCPLB_FAULT_ADDR: %s\n", buf); |
| decode_address(buf, cpu_pda[cpu].icplb_doublefault_addr); |
| printk(KERN_NOTICE " ICPLB_FAULT_ADDR: %s\n", buf); |
| |
| decode_address(buf, fp->retx); |
| printk(KERN_NOTICE "The instruction at %s caused a double exception\n", buf); |
| } else |
| #endif |
| { |
| dump_bfin_process(fp); |
| dump_bfin_mem(fp); |
| show_regs(fp); |
| dump_bfin_trace_buffer(); |
| } |
| #endif |
| panic("Double Fault - unrecoverable event"); |
| |
| } |
| |
| |
| void panic_cplb_error(int cplb_panic, struct pt_regs *fp) |
| { |
| switch (cplb_panic) { |
| case CPLB_NO_UNLOCKED: |
| printk(KERN_EMERG "All CPLBs are locked\n"); |
| break; |
| case CPLB_PROT_VIOL: |
| return; |
| case CPLB_NO_ADDR_MATCH: |
| return; |
| case CPLB_UNKNOWN_ERR: |
| printk(KERN_EMERG "Unknown CPLB Exception\n"); |
| break; |
| } |
| |
| oops_in_progress = 1; |
| |
| dump_bfin_process(fp); |
| dump_bfin_mem(fp); |
| show_regs(fp); |
| dump_stack(); |
| panic("Unrecoverable event"); |
| } |
| |
| #ifdef CONFIG_BUG |
| int is_valid_bugaddr(unsigned long addr) |
| { |
| unsigned int opcode; |
| |
| if (!get_instruction(&opcode, (unsigned short *)addr)) |
| return 0; |
| |
| return opcode == BFIN_BUG_OPCODE; |
| } |
| #endif |
| |
| /* stub this out */ |
| #ifndef CONFIG_DEBUG_VERBOSE |
| void show_regs(struct pt_regs *fp) |
| { |
| |
| } |
| #endif |