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