diff options
Diffstat (limited to 'arch/blackfin/kernel/traps.c')
| -rw-r--r-- | arch/blackfin/kernel/traps.c | 582 |
1 files changed, 582 insertions, 0 deletions
diff --git a/arch/blackfin/kernel/traps.c b/arch/blackfin/kernel/traps.c new file mode 100644 index 00000000000..de5c2c3ebd9 --- /dev/null +++ b/arch/blackfin/kernel/traps.c @@ -0,0 +1,582 @@ +/* + * 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> +#include <asm/pda.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 conjunction 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; + if (execute_pseudodbg(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 |