Initial import

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..e77c3ccf8
--- /dev/null
+++ b/arch/powerpc/kernel/kgdb.c
@@ -0,0 +1,494 @@
+/*
+ * 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/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 <linux/slab.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 */  },		/* performance 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 */
+}
+
+/**
+ *
+ *	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_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();
+}
+#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) == *(u32 *) (&arch_kgdb_ops.gdb_bpt_instr))
+		regs->nip += BREAK_INSTR_SIZE;
+
+	return 1;
+}
+
+static DEFINE_PER_CPU(struct thread_info, kgdb_thread_info);
+static int kgdb_singlestep(struct pt_regs *regs)
+{
+	struct thread_info *thread_info, *exception_thread_info;
+	struct thread_info *backup_current_thread_info =
+		this_cpu_ptr(&kgdb_thread_info);
+
+	if (user_mode(regs))
+		return 0;
+
+	/*
+	 * On Book E and perhaps other processors, 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) {
+		/* Save the original current_thread_info. */
+		memcpy(backup_current_thread_info, exception_thread_info, sizeof *thread_info);
+		memcpy(exception_thread_info, thread_info, sizeof *thread_info);
+	}
+
+	kgdb_handle_exception(0, SIGTRAP, 0, regs);
+
+	if (thread_info != exception_thread_info)
+		/* Restore current_thread_info lastly. */
+		memcpy(exception_thread_info, backup_current_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_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_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 GDB_SIZEOF_REG sizeof(unsigned long)
+#define GDB_SIZEOF_REG_U32 sizeof(u32)
+
+#ifdef CONFIG_FSL_BOOKE
+#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_FSL_BOOKE) && defined(CONFIG_SPE)
+		if (current)
+			memcpy(mem, &current->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_FSL_BOOKE) && defined(CONFIG_SPE)
+		memcpy(&current->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->nip = pc;
+}
+
+/*
+ * 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') {
+#ifdef CONFIG_PPC_ADV_DEBUG_REGS
+			mtspr(SPRN_DBCR0,
+			      mfspr(SPRN_DBCR0) | DBCR0_IC | DBCR0_IDM);
+			linux_regs->msr |= MSR_DE;
+#else
+			linux_regs->msr |= MSR_SE;
+#endif
+			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_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_call_nmi_hook;
+	__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;
+}