diff options
| -rw-r--r-- | arch/arm/Kconfig | 1 | ||||
| -rw-r--r-- | arch/arm/kernel/Makefile | 1 | ||||
| -rw-r--r-- | arch/arm/kernel/kgdb.c | 201 | ||||
| -rw-r--r-- | arch/arm/kernel/setup.c | 2 | ||||
| -rw-r--r-- | arch/arm/kernel/traps.c | 5 | ||||
| -rw-r--r-- | include/asm-arm/kgdb.h | 104 | ||||
| -rw-r--r-- | include/asm-arm/traps.h | 2 |
7 files changed, 316 insertions, 0 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index c7ad324ddf2..d048f6887d0 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -12,6 +12,7 @@ config ARM select RTC_LIB select SYS_SUPPORTS_APM_EMULATION select HAVE_OPROFILE + select HAVE_ARCH_KGDB select HAVE_KPROBES if (!XIP_KERNEL) select HAVE_KRETPROBES if (HAVE_KPROBES) select HAVE_FTRACE if (!XIP_KERNEL) diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile index eb9092ca800..1d296fc8494 100644 --- a/arch/arm/kernel/Makefile +++ b/arch/arm/kernel/Makefile @@ -28,6 +28,7 @@ obj-$(CONFIG_KPROBES) += kprobes.o kprobes-decode.o obj-$(CONFIG_ATAGS_PROC) += atags.o obj-$(CONFIG_OABI_COMPAT) += sys_oabi-compat.o obj-$(CONFIG_ARM_THUMBEE) += thumbee.o +obj-$(CONFIG_KGDB) += kgdb.o obj-$(CONFIG_CRUNCH) += crunch.o crunch-bits.o AFLAGS_crunch-bits.o := -Wa,-mcpu=ep9312 diff --git a/arch/arm/kernel/kgdb.c b/arch/arm/kernel/kgdb.c new file mode 100644 index 00000000000..aaffaecffcd --- /dev/null +++ b/arch/arm/kernel/kgdb.c @@ -0,0 +1,201 @@ +/* + * 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 +}; diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c index b7b0720bc1b..38f0e7940a1 100644 --- a/arch/arm/kernel/setup.c +++ b/arch/arm/kernel/setup.c @@ -36,6 +36,7 @@ #include <asm/mach/arch.h> #include <asm/mach/irq.h> #include <asm/mach/time.h> +#include <asm/traps.h> #include "compat.h" #include "atags.h" @@ -853,6 +854,7 @@ void __init setup_arch(char **cmdline_p) conswitchp = &dummy_con; #endif #endif + early_trap_init(); } diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c index 5595fdd75e8..7277aef8309 100644 --- a/arch/arm/kernel/traps.c +++ b/arch/arm/kernel/traps.c @@ -708,6 +708,11 @@ EXPORT_SYMBOL(abort); void __init trap_init(void) { + return; +} + +void __init early_trap_init(void) +{ unsigned long vectors = CONFIG_VECTORS_BASE; extern char __stubs_start[], __stubs_end[]; extern char __vectors_start[], __vectors_end[]; diff --git a/include/asm-arm/kgdb.h b/include/asm-arm/kgdb.h new file mode 100644 index 00000000000..67af4b84198 --- /dev/null +++ b/include/asm-arm/kgdb.h @@ -0,0 +1,104 @@ +/* + * 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__ */ diff --git a/include/asm-arm/traps.h b/include/asm-arm/traps.h index f1541afcf85..aa399aec568 100644 --- a/include/asm-arm/traps.h +++ b/include/asm-arm/traps.h @@ -24,4 +24,6 @@ static inline int in_exception_text(unsigned long ptr) ptr < (unsigned long)&__exception_text_end; } +extern void __init early_trap_init(void); + #endif |