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Diffstat (limited to 'arch/powerpc/kernel/kgdb.c')
| -rw-r--r-- | arch/powerpc/kernel/kgdb.c | 494 |
1 files changed, 494 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/kgdb.c b/arch/powerpc/kernel/kgdb.c new file mode 100644 index 000000000..ebe4d1645 --- /dev/null +++ b/arch/powerpc/kernel/kgdb.c @@ -0,0 +1,494 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * 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. + */ + +#include <linux/kernel.h> +#include <linux/kgdb.h> +#include <linux/smp.h> +#include <linux/signal.h> +#include <linux/ptrace.h> +#include <linux/kdebug.h> +#include <asm/current.h> +#include <asm/processor.h> +#include <asm/machdep.h> +#include <asm/debug.h> +#include <asm/code-patching.h> +#include <linux/slab.h> +#include <asm/inst.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 */ +#ifdef CONFIG_BOOKE_OR_40x + { 0x2002, 0x05 /* SIGTRAP */ }, /* debug */ +#if defined(CONFIG_PPC_85xx) + { 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 */ }, /* performance monitor */ + { 0x2900, 0x08 /* SIGFPE */ }, /* apu unavailable */ + { 0x3100, 0x0e /* SIGALRM */ }, /* fixed interval timer */ + { 0x3200, 0x02 /* SIGINT */ }, /* watchdog */ +#else /* ! CONFIG_PPC_85xx */ + { 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 /* !CONFIG_BOOKE_OR_40x */ + { 0x0d00, 0x05 /* SIGTRAP */ }, /* single-step */ +#if defined(CONFIG_PPC_8xx) + { 0x1000, 0x04 /* SIGILL */ }, /* software emulation */ +#else /* ! CONFIG_PPC_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 */ +} + +/** + * + * kgdb_skipexception - Bail out of KGDB when we've been triggered. + * @exception: Exception vector number + * @regs: Current &struct pt_regs. + * + * On some architectures we need to skip a breakpoint exception when + * it occurs after a breakpoint has been removed. + * + */ +int kgdb_skipexception(int exception, struct pt_regs *regs) +{ + return kgdb_isremovedbreak(regs->nip); +} + +static int kgdb_debugger_ipi(struct pt_regs *regs) +{ + kgdb_nmicallback(raw_smp_processor_id(), regs); + return 0; +} + +#ifdef CONFIG_SMP +void kgdb_roundup_cpus(void) +{ + smp_send_debugger_break(); +} +#endif + +/* KGDB functions to use existing PowerPC64 hooks. */ +static int kgdb_debugger(struct pt_regs *regs) +{ + return !kgdb_handle_exception(1, computeSignal(TRAP(regs)), + DIE_OOPS, regs); +} + +static int kgdb_handle_breakpoint(struct pt_regs *regs) +{ + if (user_mode(regs)) + return 0; + + if (kgdb_handle_exception(1, SIGTRAP, 0, regs) != 0) + return 0; + + if (*(u32 *)regs->nip == BREAK_INSTR) + regs_add_return_ip(regs, BREAK_INSTR_SIZE); + + return 1; +} + +static int kgdb_singlestep(struct pt_regs *regs) +{ + if (user_mode(regs)) + return 0; + + kgdb_handle_exception(0, SIGTRAP, 0, regs); + + 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_break_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 sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p) +{ + struct pt_regs *regs = (struct pt_regs *)(p->thread.ksp + + STACK_INT_FRAME_REGS); + 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_PPC_85xx +#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 GDB_SIZEOF_REG sizeof(unsigned long) +#define GDB_SIZEOF_REG_U32 sizeof(u32) + +#ifdef CONFIG_PPC_85xx +#define GDB_SIZEOF_FLOAT_REG sizeof(unsigned long) +#else +#define GDB_SIZEOF_FLOAT_REG sizeof(u64) +#endif + +struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] = +{ + { "r0", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[0]) }, + { "r1", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[1]) }, + { "r2", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[2]) }, + { "r3", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[3]) }, + { "r4", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[4]) }, + { "r5", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[5]) }, + { "r6", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[6]) }, + { "r7", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[7]) }, + { "r8", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[8]) }, + { "r9", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[9]) }, + { "r10", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[10]) }, + { "r11", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[11]) }, + { "r12", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[12]) }, + { "r13", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[13]) }, + { "r14", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[14]) }, + { "r15", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[15]) }, + { "r16", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[16]) }, + { "r17", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[17]) }, + { "r18", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[18]) }, + { "r19", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[19]) }, + { "r20", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[20]) }, + { "r21", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[21]) }, + { "r22", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[22]) }, + { "r23", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[23]) }, + { "r24", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[24]) }, + { "r25", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[25]) }, + { "r26", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[26]) }, + { "r27", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[27]) }, + { "r28", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[28]) }, + { "r29", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[29]) }, + { "r30", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[30]) }, + { "r31", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[31]) }, + + { "f0", GDB_SIZEOF_FLOAT_REG, 0 }, + { "f1", GDB_SIZEOF_FLOAT_REG, 1 }, + { "f2", GDB_SIZEOF_FLOAT_REG, 2 }, + { "f3", GDB_SIZEOF_FLOAT_REG, 3 }, + { "f4", GDB_SIZEOF_FLOAT_REG, 4 }, + { "f5", GDB_SIZEOF_FLOAT_REG, 5 }, + { "f6", GDB_SIZEOF_FLOAT_REG, 6 }, + { "f7", GDB_SIZEOF_FLOAT_REG, 7 }, + { "f8", GDB_SIZEOF_FLOAT_REG, 8 }, + { "f9", GDB_SIZEOF_FLOAT_REG, 9 }, + { "f10", GDB_SIZEOF_FLOAT_REG, 10 }, + { "f11", GDB_SIZEOF_FLOAT_REG, 11 }, + { "f12", GDB_SIZEOF_FLOAT_REG, 12 }, + { "f13", GDB_SIZEOF_FLOAT_REG, 13 }, + { "f14", GDB_SIZEOF_FLOAT_REG, 14 }, + { "f15", GDB_SIZEOF_FLOAT_REG, 15 }, + { "f16", GDB_SIZEOF_FLOAT_REG, 16 }, + { "f17", GDB_SIZEOF_FLOAT_REG, 17 }, + { "f18", GDB_SIZEOF_FLOAT_REG, 18 }, + { "f19", GDB_SIZEOF_FLOAT_REG, 19 }, + { "f20", GDB_SIZEOF_FLOAT_REG, 20 }, + { "f21", GDB_SIZEOF_FLOAT_REG, 21 }, + { "f22", GDB_SIZEOF_FLOAT_REG, 22 }, + { "f23", GDB_SIZEOF_FLOAT_REG, 23 }, + { "f24", GDB_SIZEOF_FLOAT_REG, 24 }, + { "f25", GDB_SIZEOF_FLOAT_REG, 25 }, + { "f26", GDB_SIZEOF_FLOAT_REG, 26 }, + { "f27", GDB_SIZEOF_FLOAT_REG, 27 }, + { "f28", GDB_SIZEOF_FLOAT_REG, 28 }, + { "f29", GDB_SIZEOF_FLOAT_REG, 29 }, + { "f30", GDB_SIZEOF_FLOAT_REG, 30 }, + { "f31", GDB_SIZEOF_FLOAT_REG, 31 }, + + { "pc", GDB_SIZEOF_REG, offsetof(struct pt_regs, nip) }, + { "msr", GDB_SIZEOF_REG, offsetof(struct pt_regs, msr) }, + { "cr", GDB_SIZEOF_REG_U32, offsetof(struct pt_regs, ccr) }, + { "lr", GDB_SIZEOF_REG, offsetof(struct pt_regs, link) }, + { "ctr", GDB_SIZEOF_REG_U32, offsetof(struct pt_regs, ctr) }, + { "xer", GDB_SIZEOF_REG, offsetof(struct pt_regs, xer) }, +}; + +char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs) +{ + if (regno >= DBG_MAX_REG_NUM || regno < 0) + return NULL; + + if (regno < 32 || regno >= 64) + /* First 0 -> 31 gpr registers*/ + /* pc, msr, ls... registers 64 -> 69 */ + memcpy(mem, (void *)regs + dbg_reg_def[regno].offset, + dbg_reg_def[regno].size); + + if (regno >= 32 && regno < 64) { + /* FP registers 32 -> 63 */ +#if defined(CONFIG_PPC_85xx) && defined(CONFIG_SPE) + if (current) + memcpy(mem, ¤t->thread.evr[regno-32], + dbg_reg_def[regno].size); +#else + /* fp registers not used by kernel, leave zero */ + memset(mem, 0, dbg_reg_def[regno].size); +#endif + } + + return dbg_reg_def[regno].name; +} + +int dbg_set_reg(int regno, void *mem, struct pt_regs *regs) +{ + if (regno >= DBG_MAX_REG_NUM || regno < 0) + return -EINVAL; + + if (regno < 32 || regno >= 64) + /* First 0 -> 31 gpr registers*/ + /* pc, msr, ls... registers 64 -> 69 */ + memcpy((void *)regs + dbg_reg_def[regno].offset, mem, + dbg_reg_def[regno].size); + + if (regno >= 32 && regno < 64) { + /* FP registers 32 -> 63 */ +#if defined(CONFIG_PPC_85xx) && defined(CONFIG_SPE) + memcpy(¤t->thread.evr[regno-32], mem, + dbg_reg_def[regno].size); +#else + /* fp registers not used by kernel, leave zero */ + return 0; +#endif + } + + return 0; +} + +void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc) +{ + regs_set_return_ip(regs, pc); +} + +/* + * This function does PowerPC specific processing 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)) + regs_set_return_ip(linux_regs, addr); + + atomic_set(&kgdb_cpu_doing_single_step, -1); + /* set the trace bit if we're stepping */ + if (remcom_in_buffer[0] == 's') { +#ifdef CONFIG_PPC_ADV_DEBUG_REGS + mtspr(SPRN_DBCR0, + mfspr(SPRN_DBCR0) | DBCR0_IC | DBCR0_IDM); + regs_set_return_msr(linux_regs, linux_regs->msr | MSR_DE); +#else + regs_set_return_msr(linux_regs, linux_regs->msr | MSR_SE); +#endif + atomic_set(&kgdb_cpu_doing_single_step, + raw_smp_processor_id()); + } + return 0; + } + + return -1; +} + +int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt) +{ + u32 instr, *addr = (u32 *)bpt->bpt_addr; + int err; + + err = get_kernel_nofault(instr, addr); + if (err) + return err; + + err = patch_instruction(addr, ppc_inst(BREAK_INSTR)); + if (err) + return -EFAULT; + + *(u32 *)bpt->saved_instr = instr; + + return 0; +} + +int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt) +{ + int err; + unsigned int instr = *(unsigned int *)bpt->saved_instr; + u32 *addr = (u32 *)bpt->bpt_addr; + + err = patch_instruction(addr, ppc_inst(instr)); + if (err) + return -EFAULT; + + return 0; +} + +/* + * Global data + */ +const struct kgdb_arch arch_kgdb_ops; + +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_break_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_break_match = __debugger_break_match; + old__debugger_fault_handler = __debugger_fault_handler; + + __debugger_ipi = kgdb_debugger_ipi; + __debugger = kgdb_debugger; + __debugger_bpt = kgdb_handle_breakpoint; + __debugger_sstep = kgdb_singlestep; + __debugger_iabr_match = kgdb_iabr_match; + __debugger_break_match = kgdb_break_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_break_match = old__debugger_break_match; + __debugger_fault_handler = old__debugger_fault_handler; +} |