--- /dev/null
+/*
+ * arch/arm/kernel/kgdb.c
+ *
+ * ARM KGDB support
+ *
+ * Copyright (c) 2002-2004 MontaVista Software, Inc
+ * Copyright (c) 2008 Wind River Systems, Inc.
+ *
+ * Authors: George Davis <davis_g@mvista.com>
+ * Deepak Saxena <dsaxena@plexity.net>
+ */
+#include <linux/kgdb.h>
+#include <asm/traps.h>
+
+/* Make a local copy of the registers passed into the handler (bletch) */
+void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *kernel_regs)
+{
+ int regno;
+
+ /* Initialize all to zero. */
+ for (regno = 0; regno < GDB_MAX_REGS; regno++)
+ gdb_regs[regno] = 0;
+
+ gdb_regs[_R0] = kernel_regs->ARM_r0;
+ gdb_regs[_R1] = kernel_regs->ARM_r1;
+ gdb_regs[_R2] = kernel_regs->ARM_r2;
+ gdb_regs[_R3] = kernel_regs->ARM_r3;
+ gdb_regs[_R4] = kernel_regs->ARM_r4;
+ gdb_regs[_R5] = kernel_regs->ARM_r5;
+ gdb_regs[_R6] = kernel_regs->ARM_r6;
+ gdb_regs[_R7] = kernel_regs->ARM_r7;
+ gdb_regs[_R8] = kernel_regs->ARM_r8;
+ gdb_regs[_R9] = kernel_regs->ARM_r9;
+ gdb_regs[_R10] = kernel_regs->ARM_r10;
+ gdb_regs[_FP] = kernel_regs->ARM_fp;
+ gdb_regs[_IP] = kernel_regs->ARM_ip;
+ gdb_regs[_SPT] = kernel_regs->ARM_sp;
+ gdb_regs[_LR] = kernel_regs->ARM_lr;
+ gdb_regs[_PC] = kernel_regs->ARM_pc;
+ gdb_regs[_CPSR] = kernel_regs->ARM_cpsr;
+}
+
+/* Copy local gdb registers back to kgdb regs, for later copy to kernel */
+void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *kernel_regs)
+{
+ kernel_regs->ARM_r0 = gdb_regs[_R0];
+ kernel_regs->ARM_r1 = gdb_regs[_R1];
+ kernel_regs->ARM_r2 = gdb_regs[_R2];
+ kernel_regs->ARM_r3 = gdb_regs[_R3];
+ kernel_regs->ARM_r4 = gdb_regs[_R4];
+ kernel_regs->ARM_r5 = gdb_regs[_R5];
+ kernel_regs->ARM_r6 = gdb_regs[_R6];
+ kernel_regs->ARM_r7 = gdb_regs[_R7];
+ kernel_regs->ARM_r8 = gdb_regs[_R8];
+ kernel_regs->ARM_r9 = gdb_regs[_R9];
+ kernel_regs->ARM_r10 = gdb_regs[_R10];
+ kernel_regs->ARM_fp = gdb_regs[_FP];
+ kernel_regs->ARM_ip = gdb_regs[_IP];
+ kernel_regs->ARM_sp = gdb_regs[_SPT];
+ kernel_regs->ARM_lr = gdb_regs[_LR];
+ kernel_regs->ARM_pc = gdb_regs[_PC];
+ kernel_regs->ARM_cpsr = gdb_regs[_CPSR];
+}
+
+void
+sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *task)
+{
+ struct pt_regs *thread_regs;
+ int regno;
+
+ /* Just making sure... */
+ if (task == NULL)
+ return;
+
+ /* Initialize to zero */
+ for (regno = 0; regno < GDB_MAX_REGS; regno++)
+ gdb_regs[regno] = 0;
+
+ /* Otherwise, we have only some registers from switch_to() */
+ thread_regs = task_pt_regs(task);
+ gdb_regs[_R0] = thread_regs->ARM_r0;
+ gdb_regs[_R1] = thread_regs->ARM_r1;
+ gdb_regs[_R2] = thread_regs->ARM_r2;
+ gdb_regs[_R3] = thread_regs->ARM_r3;
+ gdb_regs[_R4] = thread_regs->ARM_r4;
+ gdb_regs[_R5] = thread_regs->ARM_r5;
+ gdb_regs[_R6] = thread_regs->ARM_r6;
+ gdb_regs[_R7] = thread_regs->ARM_r7;
+ gdb_regs[_R8] = thread_regs->ARM_r8;
+ gdb_regs[_R9] = thread_regs->ARM_r9;
+ gdb_regs[_R10] = thread_regs->ARM_r10;
+ gdb_regs[_FP] = thread_regs->ARM_fp;
+ gdb_regs[_IP] = thread_regs->ARM_ip;
+ gdb_regs[_SPT] = thread_regs->ARM_sp;
+ gdb_regs[_LR] = thread_regs->ARM_lr;
+ gdb_regs[_PC] = thread_regs->ARM_pc;
+ gdb_regs[_CPSR] = thread_regs->ARM_cpsr;
+}
+
+static int compiled_break;
+
+int kgdb_arch_handle_exception(int exception_vector, int signo,
+ int err_code, char *remcom_in_buffer,
+ char *remcom_out_buffer,
+ struct pt_regs *linux_regs)
+{
+ unsigned long addr;
+ char *ptr;
+
+ switch (remcom_in_buffer[0]) {
+ case 'D':
+ case 'k':
+ case 'c':
+ kgdb_contthread = NULL;
+
+ /*
+ * Try to read optional parameter, pc unchanged if no parm.
+ * If this was a compiled breakpoint, we need to move
+ * to the next instruction or we will just breakpoint
+ * over and over again.
+ */
+ ptr = &remcom_in_buffer[1];
+ if (kgdb_hex2long(&ptr, &addr))
+ linux_regs->ARM_pc = addr;
+ else if (compiled_break == 1)
+ linux_regs->ARM_pc += 4;
+
+ compiled_break = 0;
+
+ return 0;
+ }
+
+ return -1;
+}
+
+static int kgdb_brk_fn(struct pt_regs *regs, unsigned int instr)
+{
+ kgdb_handle_exception(1, SIGTRAP, 0, regs);
+
+ return 0;
+}
+
+static int kgdb_compiled_brk_fn(struct pt_regs *regs, unsigned int instr)
+{
+ compiled_break = 1;
+ kgdb_handle_exception(1, SIGTRAP, 0, regs);
+
+ return 0;
+}
+
+static struct undef_hook kgdb_brkpt_hook = {
+ .instr_mask = 0xffffffff,
+ .instr_val = KGDB_BREAKINST,
+ .fn = kgdb_brk_fn
+};
+
+static struct undef_hook kgdb_compiled_brkpt_hook = {
+ .instr_mask = 0xffffffff,
+ .instr_val = KGDB_COMPILED_BREAK,
+ .fn = kgdb_compiled_brk_fn
+};
+
+/**
+ * kgdb_arch_init - Perform any architecture specific initalization.
+ *
+ * This function will handle the initalization of any architecture
+ * specific callbacks.
+ */
+int kgdb_arch_init(void)
+{
+ register_undef_hook(&kgdb_brkpt_hook);
+ register_undef_hook(&kgdb_compiled_brkpt_hook);
+
+ return 0;
+}
+
+/**
+ * kgdb_arch_exit - Perform any architecture specific uninitalization.
+ *
+ * This function will handle the uninitalization of any architecture
+ * specific callbacks, for dynamic registration and unregistration.
+ */
+void kgdb_arch_exit(void)
+{
+ unregister_undef_hook(&kgdb_brkpt_hook);
+ unregister_undef_hook(&kgdb_compiled_brkpt_hook);
+}
+
+/*
+ * Register our undef instruction hooks with ARM undef core.
+ * We regsiter a hook specifically looking for the KGB break inst
+ * and we handle the normal undef case within the do_undefinstr
+ * handler.
+ */
+struct kgdb_arch arch_kgdb_ops = {
+#ifndef __ARMEB__
+ .gdb_bpt_instr = {0xfe, 0xde, 0xff, 0xe7}
+#else /* ! __ARMEB__ */
+ .gdb_bpt_instr = {0xe7, 0xff, 0xde, 0xfe}
+#endif
+};
--- /dev/null
+/*
+ * ARM KGDB support
+ *
+ * Author: Deepak Saxena <dsaxena@mvista.com>
+ *
+ * Copyright (C) 2002 MontaVista Software Inc.
+ *
+ */
+
+#ifndef __ARM_KGDB_H__
+#define __ARM_KGDB_H__
+
+#include <linux/ptrace.h>
+
+/*
+ * GDB assumes that we're a user process being debugged, so
+ * it will send us an SWI command to write into memory as the
+ * debug trap. When an SWI occurs, the next instruction addr is
+ * placed into R14_svc before jumping to the vector trap.
+ * This doesn't work for kernel debugging as we are already in SVC
+ * we would loose the kernel's LR, which is a bad thing. This
+ * is bad thing.
+ *
+ * By doing this as an undefined instruction trap, we force a mode
+ * switch from SVC to UND mode, allowing us to save full kernel state.
+ *
+ * We also define a KGDB_COMPILED_BREAK which can be used to compile
+ * in breakpoints. This is important for things like sysrq-G and for
+ * the initial breakpoint from trap_init().
+ *
+ * Note to ARM HW designers: Add real trap support like SH && PPC to
+ * make our lives much much simpler. :)
+ */
+#define BREAK_INSTR_SIZE 4
+#define GDB_BREAKINST 0xef9f0001
+#define KGDB_BREAKINST 0xe7ffdefe
+#define KGDB_COMPILED_BREAK 0xe7ffdeff
+#define CACHE_FLUSH_IS_SAFE 1
+
+#ifndef __ASSEMBLY__
+
+static inline void arch_kgdb_breakpoint(void)
+{
+ asm(".word 0xe7ffdeff");
+}
+
+extern void kgdb_handle_bus_error(void);
+extern int kgdb_fault_expected;
+
+#endif /* !__ASSEMBLY__ */
+
+/*
+ * From Kevin Hilman:
+ *
+ * gdb is expecting the following registers layout.
+ *
+ * r0-r15: 1 long word each
+ * f0-f7: unused, 3 long words each !!
+ * fps: unused, 1 long word
+ * cpsr: 1 long word
+ *
+ * Even though f0-f7 and fps are not used, they need to be
+ * present in the registers sent for correct processing in
+ * the host-side gdb.
+ *
+ * In particular, it is crucial that CPSR is in the right place,
+ * otherwise gdb will not be able to correctly interpret stepping over
+ * conditional branches.
+ */
+#define _GP_REGS 16
+#define _FP_REGS 8
+#define _EXTRA_REGS 2
+#define GDB_MAX_REGS (_GP_REGS + (_FP_REGS * 3) + _EXTRA_REGS)
+
+#define KGDB_MAX_NO_CPUS 1
+#define BUFMAX 400
+#define NUMREGBYTES (GDB_MAX_REGS << 2)
+#define NUMCRITREGBYTES (32 << 2)
+
+#define _R0 0
+#define _R1 1
+#define _R2 2
+#define _R3 3
+#define _R4 4
+#define _R5 5
+#define _R6 6
+#define _R7 7
+#define _R8 8
+#define _R9 9
+#define _R10 10
+#define _FP 11
+#define _IP 12
+#define _SPT 13
+#define _LR 14
+#define _PC 15
+#define _CPSR (GDB_MAX_REGS - 1)
+
+/*
+ * So that we can denote the end of a frame for tracing,
+ * in the simple case:
+ */
+#define CFI_END_FRAME(func) __CFI_END_FRAME(_PC, _SPT, func)
+
+#endif /* __ASM_KGDB_H__ */
git.samba.org / sfrench / cifs-2.6.git / commitdiff