/* * PowerPC backend to the KGDB stub. * * 1998 (c) Michael AK Tesch (tesch@cs.wisc.edu) * Copyright (C) 2003 Timesys Corporation. * Copyright (C) 2004-2006 MontaVista Software, Inc. * PPC64 Mods (C) 2005 Frank Rowand (frowand@mvista.com) * PPC32 support restored by Vitaly Wool and * Sergei Shtylyov * Copyright (C) 2007-2008 Wind River Systems, Inc. * * This file is licensed under the terms of the GNU General Public License * version 2. This program as licensed "as is" without any warranty of any * kind, whether express or implied. */ #include #include #include #include #include #include #include #include #include /* * This table contains the mapping between PowerPC hardware trap types, and * signals, which are primarily what GDB understands. GDB and the kernel * don't always agree on values, so we use constants taken from gdb-6.2. */ static struct hard_trap_info { unsigned int tt; /* Trap type code for powerpc */ unsigned char signo; /* Signal that we map this trap into */ } hard_trap_info[] = { { 0x0100, 0x02 /* SIGINT */ }, /* system reset */ { 0x0200, 0x0b /* SIGSEGV */ }, /* machine check */ { 0x0300, 0x0b /* SIGSEGV */ }, /* data access */ { 0x0400, 0x0b /* SIGSEGV */ }, /* instruction access */ { 0x0500, 0x02 /* SIGINT */ }, /* external interrupt */ { 0x0600, 0x0a /* SIGBUS */ }, /* alignment */ { 0x0700, 0x05 /* SIGTRAP */ }, /* program check */ { 0x0800, 0x08 /* SIGFPE */ }, /* fp unavailable */ { 0x0900, 0x0e /* SIGALRM */ }, /* decrementer */ { 0x0c00, 0x14 /* SIGCHLD */ }, /* system call */ #if defined(CONFIG_40x) || defined(CONFIG_BOOKE) { 0x2002, 0x05 /* SIGTRAP */ }, /* debug */ #if defined(CONFIG_FSL_BOOKE) { 0x2010, 0x08 /* SIGFPE */ }, /* spe unavailable */ { 0x2020, 0x08 /* SIGFPE */ }, /* spe unavailable */ { 0x2030, 0x08 /* SIGFPE */ }, /* spe fp data */ { 0x2040, 0x08 /* SIGFPE */ }, /* spe fp data */ { 0x2050, 0x08 /* SIGFPE */ }, /* spe fp round */ { 0x2060, 0x0e /* SIGILL */ }, /* performace monitor */ { 0x2900, 0x08 /* SIGFPE */ }, /* apu unavailable */ { 0x3100, 0x0e /* SIGALRM */ }, /* fixed interval timer */ { 0x3200, 0x02 /* SIGINT */ }, /* watchdog */ #else /* ! CONFIG_FSL_BOOKE */ { 0x1000, 0x0e /* SIGALRM */ }, /* prog interval timer */ { 0x1010, 0x0e /* SIGALRM */ }, /* fixed interval timer */ { 0x1020, 0x02 /* SIGINT */ }, /* watchdog */ { 0x2010, 0x08 /* SIGFPE */ }, /* fp unavailable */ { 0x2020, 0x08 /* SIGFPE */ }, /* ap unavailable */ #endif #else /* ! (defined(CONFIG_40x) || defined(CONFIG_BOOKE)) */ { 0x0d00, 0x05 /* SIGTRAP */ }, /* single-step */ #if defined(CONFIG_8xx) { 0x1000, 0x04 /* SIGILL */ }, /* software emulation */ #else /* ! CONFIG_8xx */ { 0x0f00, 0x04 /* SIGILL */ }, /* performance monitor */ { 0x0f20, 0x08 /* SIGFPE */ }, /* altivec unavailable */ { 0x1300, 0x05 /* SIGTRAP */ }, /* instruction address break */ #if defined(CONFIG_PPC64) { 0x1200, 0x05 /* SIGILL */ }, /* system error */ { 0x1500, 0x04 /* SIGILL */ }, /* soft patch */ { 0x1600, 0x04 /* SIGILL */ }, /* maintenance */ { 0x1700, 0x08 /* SIGFPE */ }, /* altivec assist */ { 0x1800, 0x04 /* SIGILL */ }, /* thermal */ #else /* ! CONFIG_PPC64 */ { 0x1400, 0x02 /* SIGINT */ }, /* SMI */ { 0x1600, 0x08 /* SIGFPE */ }, /* altivec assist */ { 0x1700, 0x04 /* SIGILL */ }, /* TAU */ { 0x2000, 0x05 /* SIGTRAP */ }, /* run mode */ #endif #endif #endif { 0x0000, 0x00 } /* Must be last */ }; static int computeSignal(unsigned int tt) { struct hard_trap_info *ht; for (ht = hard_trap_info; ht->tt && ht->signo; ht++) if (ht->tt == tt) return ht->signo; return SIGHUP; /* default for things we don't know about */ } static int kgdb_call_nmi_hook(struct pt_regs *regs) { kgdb_nmicallback(raw_smp_processor_id(), regs); return 0; } #ifdef CONFIG_SMP void kgdb_roundup_cpus(unsigned long flags) { smp_send_debugger_break(MSG_ALL_BUT_SELF); } #endif /* KGDB functions to use existing PowerPC64 hooks. */ static int kgdb_debugger(struct pt_regs *regs) { return kgdb_handle_exception(0, computeSignal(TRAP(regs)), 0, regs); } static int kgdb_handle_breakpoint(struct pt_regs *regs) { if (user_mode(regs)) return 0; if (kgdb_handle_exception(0, SIGTRAP, 0, regs) != 0) return 0; if (*(u32 *) (regs->nip) == *(u32 *) (&arch_kgdb_ops.gdb_bpt_instr)) regs->nip += 4; return 1; } static int kgdb_singlestep(struct pt_regs *regs) { struct thread_info *thread_info, *exception_thread_info; if (user_mode(regs)) return 0; /* * On Book E and perhaps other processsors, singlestep is handled on * the critical exception stack. This causes current_thread_info() * to fail, since it it locates the thread_info by masking off * the low bits of the current stack pointer. We work around * this issue by copying the thread_info from the kernel stack * before calling kgdb_handle_exception, and copying it back * afterwards. On most processors the copy is avoided since * exception_thread_info == thread_info. */ thread_info = (struct thread_info *)(regs->gpr[1] & ~(THREAD_SIZE-1)); exception_thread_info = current_thread_info(); if (thread_info != exception_thread_info) memcpy(exception_thread_info, thread_info, sizeof *thread_info); kgdb_handle_exception(0, SIGTRAP, 0, regs); if (thread_info != exception_thread_info) memcpy(thread_info, exception_thread_info, sizeof *thread_info); return 1; } static int kgdb_iabr_match(struct pt_regs *regs) { if (user_mode(regs)) return 0; if (kgdb_handle_exception(0, computeSignal(TRAP(regs)), 0, regs) != 0) return 0; return 1; } static int kgdb_dabr_match(struct pt_regs *regs) { if (user_mode(regs)) return 0; if (kgdb_handle_exception(0, computeSignal(TRAP(regs)), 0, regs) != 0) return 0; return 1; } #define PACK64(ptr, src) do { *(ptr++) = (src); } while (0) #define PACK32(ptr, src) do { \ u32 *ptr32; \ ptr32 = (u32 *)ptr; \ *(ptr32++) = (src); \ ptr = (unsigned long *)ptr32; \ } while (0) void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs) { unsigned long *ptr = gdb_regs; int reg; memset(gdb_regs, 0, NUMREGBYTES); for (reg = 0; reg < 32; reg++) PACK64(ptr, regs->gpr[reg]); #ifdef CONFIG_FSL_BOOKE #ifdef CONFIG_SPE for (reg = 0; reg < 32; reg++) PACK64(ptr, current->thread.evr[reg]); #else ptr += 32; #endif #else /* fp registers not used by kernel, leave zero */ ptr += 32 * 8 / sizeof(long); #endif PACK64(ptr, regs->nip); PACK64(ptr, regs->msr); PACK32(ptr, regs->ccr); PACK64(ptr, regs->link); PACK64(ptr, regs->ctr); PACK32(ptr, regs->xer); BUG_ON((unsigned long)ptr > (unsigned long)(((void *)gdb_regs) + NUMREGBYTES)); } void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p) { struct pt_regs *regs = (struct pt_regs *)(p->thread.ksp + STACK_FRAME_OVERHEAD); unsigned long *ptr = gdb_regs; int reg; memset(gdb_regs, 0, NUMREGBYTES); /* Regs GPR0-2 */ for (reg = 0; reg < 3; reg++) PACK64(ptr, regs->gpr[reg]); /* Regs GPR3-13 are caller saved, not in regs->gpr[] */ ptr += 11; /* Regs GPR14-31 */ for (reg = 14; reg < 32; reg++) PACK64(ptr, regs->gpr[reg]); #ifdef CONFIG_FSL_BOOKE #ifdef CONFIG_SPE for (reg = 0; reg < 32; reg++) PACK64(ptr, p->thread.evr[reg]); #else ptr += 32; #endif #else /* fp registers not used by kernel, leave zero */ ptr += 32 * 8 / sizeof(long); #endif PACK64(ptr, regs->nip); PACK64(ptr, regs->msr); PACK32(ptr, regs->ccr); PACK64(ptr, regs->link); PACK64(ptr, regs->ctr); PACK32(ptr, regs->xer); BUG_ON((unsigned long)ptr > (unsigned long)(((void *)gdb_regs) + NUMREGBYTES)); } #define UNPACK64(dest, ptr) do { dest = *(ptr++); } while (0) #define UNPACK32(dest, ptr) do { \ u32 *ptr32; \ ptr32 = (u32 *)ptr; \ dest = *(ptr32++); \ ptr = (unsigned long *)ptr32; \ } while (0) void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs) { unsigned long *ptr = gdb_regs; int reg; #ifdef CONFIG_SPE union { u32 v32[2]; u64 v64; } acc; #endif for (reg = 0; reg < 32; reg++) UNPACK64(regs->gpr[reg], ptr); #ifdef CONFIG_FSL_BOOKE #ifdef CONFIG_SPE for (reg = 0; reg < 32; reg++) UNPACK64(current->thread.evr[reg], ptr); #else ptr += 32; #endif #else /* fp registers not used by kernel, leave zero */ ptr += 32 * 8 / sizeof(int); #endif UNPACK64(regs->nip, ptr); UNPACK64(regs->msr, ptr); UNPACK32(regs->ccr, ptr); UNPACK64(regs->link, ptr); UNPACK64(regs->ctr, ptr); UNPACK32(regs->xer, ptr); BUG_ON((unsigned long)ptr > (unsigned long)(((void *)gdb_regs) + NUMREGBYTES)); } /* * This function does PowerPC specific procesing for interfacing to gdb. */ int kgdb_arch_handle_exception(int vector, int signo, int err_code, char *remcom_in_buffer, char *remcom_out_buffer, struct pt_regs *linux_regs) { char *ptr = &remcom_in_buffer[1]; unsigned long addr; switch (remcom_in_buffer[0]) { /* * sAA..AA Step one instruction from AA..AA * This will return an error to gdb .. */ case 's': case 'c': /* handle the optional parameter */ if (kgdb_hex2long(&ptr, &addr)) linux_regs->nip = addr; atomic_set(&kgdb_cpu_doing_single_step, -1); /* set the trace bit if we're stepping */ if (remcom_in_buffer[0] == 's') { #if defined(CONFIG_40x) || defined(CONFIG_BOOKE) mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) | DBCR0_IC | DBCR0_IDM); linux_regs->msr |= MSR_DE; #else linux_regs->msr |= MSR_SE; #endif kgdb_single_step = 1; atomic_set(&kgdb_cpu_doing_single_step, raw_smp_processor_id()); } return 0; } return -1; } /* * Global data */ struct kgdb_arch arch_kgdb_ops = { .gdb_bpt_instr = {0x7d, 0x82, 0x10, 0x08}, }; static int kgdb_not_implemented(struct pt_regs *regs) { return 0; } static void *old__debugger_ipi; static void *old__debugger; static void *old__debugger_bpt; static void *old__debugger_sstep; static void *old__debugger_iabr_match; static void *old__debugger_dabr_match; static void *old__debugger_fault_handler; int kgdb_arch_init(void) { old__debugger_ipi = __debugger_ipi; old__debugger = __debugger; old__debugger_bpt = __debugger_bpt; old__debugger_sstep = __debugger_sstep; old__debugger_iabr_match = __debugger_iabr_match; old__debugger_dabr_match = __debugger_dabr_match; old__debugger_fault_handler = __debugger_fault_handler; __debugger_ipi = kgdb_call_nmi_hook; __debugger = kgdb_debugger; __debugger_bpt = kgdb_handle_breakpoint; __debugger_sstep = kgdb_singlestep; __debugger_iabr_match = kgdb_iabr_match; __debugger_dabr_match = kgdb_dabr_match; __debugger_fault_handler = kgdb_not_implemented; return 0; } void kgdb_arch_exit(void) { __debugger_ipi = old__debugger_ipi; __debugger = old__debugger; __debugger_bpt = old__debugger_bpt; __debugger_sstep = old__debugger_sstep; __debugger_iabr_match = old__debugger_iabr_match; __debugger_dabr_match = old__debugger_dabr_match; __debugger_fault_handler = old__debugger_fault_handler; }