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Diffstat (limited to 'arch/powerpc/kernel/kgdb.c')
| -rw-r--r-- | arch/powerpc/kernel/kgdb.c | 410 |
1 files changed, 410 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/kgdb.c b/arch/powerpc/kernel/kgdb.c new file mode 100644 index 000000000000..b4fdf2f2743c --- /dev/null +++ b/arch/powerpc/kernel/kgdb.c @@ -0,0 +1,410 @@ +/* + * 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 <vwool@ru.mvista.com> and + * Sergei Shtylyov <sshtylyov@ru.mvista.com> + * 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 <linux/kernel.h> +#include <linux/init.h> +#include <linux/kgdb.h> +#include <linux/smp.h> +#include <linux/signal.h> +#include <linux/ptrace.h> +#include <asm/current.h> +#include <asm/processor.h> +#include <asm/machdep.h> + +/* + * 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; + if (kgdb_contthread) + 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; +} |