summaryrefslogtreecommitdiff
path: root/arch/powerpc/kernel/kgdb.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/powerpc/kernel/kgdb.c')
-rw-r--r--arch/powerpc/kernel/kgdb.c410
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;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-16 05:14:15 +0000