From 53197fc49549240f6c6a963b2713a4cd9517964b Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Fri, 2 Apr 2010 11:48:03 -0500 Subject: Separate the gdbstub from the debug core Split the former kernel/kgdb.c into debug_core.c which contains the kernel debugger exception logic and to the gdbstub.c which contains the logic for allowing gdb to talk to the debug core. This also created a private include file called debug_core.h which contains all the definitions to glue the debug_core to any other debugger connections. CC: Ingo Molnar Signed-off-by: Jason Wessel --- include/linux/kgdb.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h index 19ec41a183f5..4830142ec339 100644 --- a/include/linux/kgdb.h +++ b/include/linux/kgdb.h @@ -264,6 +264,7 @@ extern unsigned long __weak kgdb_arch_pc(int exception, struct pt_regs *regs); extern int kgdb_register_io_module(struct kgdb_io *local_kgdb_io_ops); extern void kgdb_unregister_io_module(struct kgdb_io *local_kgdb_io_ops); +extern struct kgdb_io *dbg_io_ops; extern int kgdb_hex2long(char **ptr, unsigned long *long_val); extern int kgdb_mem2hex(char *mem, char *buf, int count); -- cgit v1.2.3 From 5d5314d6795f3c1c0f415348ff8c51f7de042b77 Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Thu, 20 May 2010 21:04:20 -0500 Subject: kdb: core for kgdb back end (1 of 2) This patch contains only the kdb core. Because the change set was large, it was split. The next patch in the series includes the instrumentation into the core kernel which are mainly helper functions for kdb. This work is directly derived from kdb v4.4 found at: ftp://oss.sgi.com/projects/kdb/download/v4.4/ The kdb internals have been re-organized to make them mostly platform independent and to connect everything to the debug core which is used by gdbstub (which has long been known as kgdb). The original version of kdb was 58,000 lines worth of changes to support x86. From that implementation only the kdb shell, and basic commands for memory access, runcontrol, lsmod, and dmesg where carried forward. This is a generic implementation which aims to cover all the current architectures using the kgdb core: ppc, arm, x86, mips, sparc, sh and blackfin. More archictectures can be added by implementing the architecture specific kgdb functions. [mort@sgi.com: Compile fix with hugepages enabled] [mort@sgi.com: Clean breakpoint code renaming kdba_ -> kdb_] [mort@sgi.com: fix new line after printing registers] [mort@sgi.com: Remove the concept of global vs. local breakpoints] [mort@sgi.com: Rework kdb_si_swapinfo to use more generic name] [mort@sgi.com: fix the information dump macros, remove 'arch' from the names] [sfr@canb.auug.org.au: include fixup to include linux/slab.h] CC: linux-arch@vger.kernel.org Signed-off-by: Jason Wessel Signed-off-by: Martin Hicks --- include/linux/kdb.h | 113 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 113 insertions(+) create mode 100644 include/linux/kdb.h (limited to 'include/linux') diff --git a/include/linux/kdb.h b/include/linux/kdb.h new file mode 100644 index 000000000000..4d93790faec3 --- /dev/null +++ b/include/linux/kdb.h @@ -0,0 +1,113 @@ +#ifndef _KDB_H +#define _KDB_H + +/* + * Kernel Debugger Architecture Independent Global Headers + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (c) 2000-2007 Silicon Graphics, Inc. All Rights Reserved. + * Copyright (C) 2000 Stephane Eranian + * Copyright (C) 2009 Jason Wessel + */ + +#ifdef CONFIG_KGDB_KDB +#include +#include +#include + +#define KDB_POLL_FUNC_MAX 5 + +/* + * kdb_initial_cpu is initialized to -1, and is set to the cpu + * number whenever the kernel debugger is entered. + */ +extern int kdb_initial_cpu; +extern atomic_t kdb_event; + +/* + * kdb_diemsg + * + * Contains a pointer to the last string supplied to the + * kernel 'die' panic function. + */ +extern const char *kdb_diemsg; + +#define KDB_FLAG_EARLYKDB (1 << 0) /* set from boot parameter kdb=early */ +#define KDB_FLAG_CATASTROPHIC (1 << 1) /* A catastrophic event has occurred */ +#define KDB_FLAG_CMD_INTERRUPT (1 << 2) /* Previous command was interrupted */ +#define KDB_FLAG_NOIPI (1 << 3) /* Do not send IPIs */ +#define KDB_FLAG_ONLY_DO_DUMP (1 << 4) /* Only do a dump, used when + * kdb is off */ +#define KDB_FLAG_NO_CONSOLE (1 << 5) /* No console is available, + * kdb is disabled */ +#define KDB_FLAG_NO_VT_CONSOLE (1 << 6) /* No VT console is available, do + * not use keyboard */ +#define KDB_FLAG_NO_I8042 (1 << 7) /* No i8042 chip is available, do + * not use keyboard */ + +extern int kdb_flags; /* Global flags, see kdb_state for per cpu state */ + +extern void kdb_save_flags(void); +extern void kdb_restore_flags(void); + +#define KDB_FLAG(flag) (kdb_flags & KDB_FLAG_##flag) +#define KDB_FLAG_SET(flag) ((void)(kdb_flags |= KDB_FLAG_##flag)) +#define KDB_FLAG_CLEAR(flag) ((void)(kdb_flags &= ~KDB_FLAG_##flag)) + +/* + * External entry point for the kernel debugger. The pt_regs + * at the time of entry are supplied along with the reason for + * entry to the kernel debugger. + */ + +typedef enum { + KDB_REASON_ENTER = 1, /* KDB_ENTER() trap/fault - regs valid */ + KDB_REASON_ENTER_SLAVE, /* KDB_ENTER_SLAVE() trap/fault - regs valid */ + KDB_REASON_BREAK, /* Breakpoint inst. - regs valid */ + KDB_REASON_DEBUG, /* Debug Fault - regs valid */ + KDB_REASON_OOPS, /* Kernel Oops - regs valid */ + KDB_REASON_SWITCH, /* CPU switch - regs valid*/ + KDB_REASON_KEYBOARD, /* Keyboard entry - regs valid */ + KDB_REASON_NMI, /* Non-maskable interrupt; regs valid */ + KDB_REASON_RECURSE, /* Recursive entry to kdb; + * regs probably valid */ + KDB_REASON_SSTEP, /* Single Step trap. - regs valid */ +} kdb_reason_t; + +extern int kdb_printf(const char *, ...) + __attribute__ ((format (printf, 1, 2))); +typedef int (*kdb_printf_t)(const char *, ...) + __attribute__ ((format (printf, 1, 2))); + +extern void kdb_init(int level); + +/* Access to kdb specific polling devices */ +typedef int (*get_char_func)(void); +extern get_char_func kdb_poll_funcs[]; +extern int kdb_get_kbd_char(void); + +static inline +int kdb_process_cpu(const struct task_struct *p) +{ + unsigned int cpu = task_thread_info(p)->cpu; + if (cpu > num_possible_cpus()) + cpu = 0; + return cpu; +} + +/* kdb access to register set for stack dumping */ +extern struct pt_regs *kdb_current_regs; + +#else /* ! CONFIG_KGDB_KDB */ +#define kdb_printf(...) +#define kdb_init(x) +#endif /* CONFIG_KGDB_KDB */ +enum { + KDB_NOT_INITIALIZED, + KDB_INIT_EARLY, + KDB_INIT_FULL, +}; +#endif /* !_KDB_H */ -- cgit v1.2.3 From dcc7871128e99458ca86186b7bc8bf27ff0c47b5 Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Thu, 20 May 2010 21:04:21 -0500 Subject: kgdb: core changes to support kdb These are the minimum changes to the kgdb core in order to enable an API to connect a new front end (kdb) to the debug core. This patch introduces the dbg_kdb_mode variable controls where the user level I/O is routed. It will be routed to the gdbstub (kgdb) or to the kdb front end which is a simple shell available over the kgdboc connection. You can switch back and forth between kdb or the gdb stub mode of operation dynamically. From gdb stub mode you can blindly type "$3#33", or from the kdb mode you can enter "kgdb" to switch to the gdb stub. The logic in the debug core depends on kdb to look for the typical gdb connection sequences and return immediately with KGDB_PASS_EVENT if a gdb serial command sequence is detected. That should allow a reasonably seamless transition between kdb -> gdb without leaving the kernel exception state. The two gdb serial queries that kdb is responsible for detecting are the "?" and "qSupported" packets. CC: Ingo Molnar Signed-off-by: Jason Wessel Acked-by: Martin Hicks --- include/linux/kgdb.h | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h index 4830142ec339..5b37df00000d 100644 --- a/include/linux/kgdb.h +++ b/include/linux/kgdb.h @@ -16,10 +16,12 @@ #include #include #include - #include +#ifdef CONFIG_HAVE_ARCH_KGDB #include +#endif +#ifdef CONFIG_KGDB struct pt_regs; /** @@ -262,6 +264,7 @@ extern struct kgdb_arch arch_kgdb_ops; extern unsigned long __weak kgdb_arch_pc(int exception, struct pt_regs *regs); +extern void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc); extern int kgdb_register_io_module(struct kgdb_io *local_kgdb_io_ops); extern void kgdb_unregister_io_module(struct kgdb_io *local_kgdb_io_ops); extern struct kgdb_io *dbg_io_ops; @@ -279,5 +282,9 @@ extern int kgdb_nmicallback(int cpu, void *regs); extern int kgdb_single_step; extern atomic_t kgdb_active; - +#define in_dbg_master() \ + (raw_smp_processor_id() == atomic_read(&kgdb_active)) +#else /* ! CONFIG_KGDB */ +#define in_dbg_master() (0) +#endif /* ! CONFIG_KGDB */ #endif /* _KGDB_H_ */ -- cgit v1.2.3 From f5316b4aea024da9266d740322a5481657f6ce59 Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Thu, 20 May 2010 21:04:22 -0500 Subject: kgdb,8250,pl011: Return immediately from console poll The design of the kdb shell requires that every device that can provide input to kdb have a polling routine that exits immediately if there is no character available. This is required in order to get the page scrolling mechanism working. Changing the kernel debugger I/O API to require all polling character routines to exit immediately if there is no data allows the kernel debugger to process multiple input channels. NO_POLL_CHAR will be the return code to the polling routine when ever there is no character available. CC: linux-serial@vger.kernel.org Signed-off-by: Jason Wessel --- include/linux/kdb.h | 1 + include/linux/serial_core.h | 1 + 2 files changed, 2 insertions(+) (limited to 'include/linux') diff --git a/include/linux/kdb.h b/include/linux/kdb.h index 4d93790faec3..d72fa3908128 100644 --- a/include/linux/kdb.h +++ b/include/linux/kdb.h @@ -19,6 +19,7 @@ #include #define KDB_POLL_FUNC_MAX 5 +extern int kdb_poll_idx; /* * kdb_initial_cpu is initialized to -1, and is set to the cpu diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h index 78dd1e7120a9..ad839963fa68 100644 --- a/include/linux/serial_core.h +++ b/include/linux/serial_core.h @@ -246,6 +246,7 @@ struct uart_ops { #endif }; +#define NO_POLL_CHAR 0x00ff0000 #define UART_CONFIG_TYPE (1 << 0) #define UART_CONFIG_IRQ (1 << 1) -- cgit v1.2.3 From 84c08fd61e2d21702337e9fe366e97cdf09bf797 Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Thu, 20 May 2010 21:04:24 -0500 Subject: kgdb,docs: Update the kgdb docs to include kdb Update the kgdb docs to reflect the new directory structure and API. Merge in the kdb shell information. [Randy Dunlap : grammatical corrections] CC: Randy Dunlap Signed-off-by: Jason Wessel --- include/linux/kgdb.h | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h index 5b37df00000d..407edb1e0c4d 100644 --- a/include/linux/kgdb.h +++ b/include/linux/kgdb.h @@ -204,6 +204,17 @@ kgdb_arch_handle_exception(int vector, int signo, int err_code, */ extern void kgdb_roundup_cpus(unsigned long flags); +/** + * kgdb_arch_set_pc - Generic call back to the program counter + * @regs: Current &struct pt_regs. + * @pc: The new value for the program counter + * + * This function handles updating the program counter and requires an + * architecture specific implementation. + */ +extern void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc); + + /* Optional functions. */ extern int kgdb_validate_break_address(unsigned long addr); extern int kgdb_arch_set_breakpoint(unsigned long addr, char *saved_instr); @@ -264,7 +275,6 @@ extern struct kgdb_arch arch_kgdb_ops; extern unsigned long __weak kgdb_arch_pc(int exception, struct pt_regs *regs); -extern void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc); extern int kgdb_register_io_module(struct kgdb_io *local_kgdb_io_ops); extern void kgdb_unregister_io_module(struct kgdb_io *local_kgdb_io_ops); extern struct kgdb_io *dbg_io_ops; -- cgit v1.2.3 From 98ec1878cacb393975cba64f7392eece81716cb4 Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Mon, 27 Apr 2009 10:58:06 -0500 Subject: kgdb: remove post_primary_code references Remove all the references to the kgdb_post_primary_code. This function serves no useful purpose because you can obtain the same information from the "struct kgdb_state *ks" from with in the debugger, if for some reason you want the data. Also remove the unintentional duplicate assignment for ks->ex_vector. Signed-off-by: Jason Wessel --- include/linux/kgdb.h | 14 -------------- 1 file changed, 14 deletions(-) (limited to 'include/linux') diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h index 407edb1e0c4d..406f6f9286f3 100644 --- a/include/linux/kgdb.h +++ b/include/linux/kgdb.h @@ -35,20 +35,6 @@ struct pt_regs; */ extern int kgdb_skipexception(int exception, struct pt_regs *regs); -/** - * kgdb_post_primary_code - (optional) Save error vector/code numbers. - * @regs: Original pt_regs. - * @e_vector: Original error vector. - * @err_code: Original error code. - * - * This is usually needed on architectures which support SMP and - * KGDB. This function is called after all the secondary cpus have - * been put to a know spin state and the primary CPU has control over - * KGDB. - */ -extern void kgdb_post_primary_code(struct pt_regs *regs, int e_vector, - int err_code); - /** * kgdb_disable_hw_debug - (optional) Disable hardware debugging hook * @regs: Current &struct pt_regs. -- cgit v1.2.3 From f503b5ae53cb557ac351a668fcac1baab1cef0db Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Thu, 20 May 2010 21:04:25 -0500 Subject: x86,kgdb: Add low level debug hook The only way the debugger can handle a trap in inside rcu_lock, notify_die, or atomic_notifier_call_chain without a triple fault is to have a low level "first opportunity handler" in the int3 exception handler. Generally this will be something the vast majority of folks will not need, but for those who need it, it is added as a kernel .config option called KGDB_LOW_LEVEL_TRAP. CC: Ingo Molnar CC: Thomas Gleixner CC: H. Peter Anvin CC: x86@kernel.org Signed-off-by: Jason Wessel --- include/linux/kgdb.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h index 406f6f9286f3..19d1b29a2694 100644 --- a/include/linux/kgdb.h +++ b/include/linux/kgdb.h @@ -60,6 +60,7 @@ struct uart_port; void kgdb_breakpoint(void); extern int kgdb_connected; +extern int kgdb_io_module_registered; extern atomic_t kgdb_setting_breakpoint; extern atomic_t kgdb_cpu_doing_single_step; -- cgit v1.2.3 From 1cee5e35f15d0893be1ba944f1aec8676e43ab76 Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Wed, 3 Jun 2009 14:06:57 -0500 Subject: kgdb: Add the ability to schedule a breakpoint via a tasklet Some kgdb I/O modules require the ability to create a breakpoint tasklet, such as kgdboc and external modules such as kgdboe. The breakpoint tasklet is used as an asynchronous entry point into the debugger which will have a different function scope than the current execution path where it might not be safe to have an inline breakpoint. This is true of some of the kgdb I/O drivers which share code with kgdb and rest of the kernel users. Signed-off-by: Jason Wessel --- include/linux/kgdb.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h index 19d1b29a2694..ee007ea341b8 100644 --- a/include/linux/kgdb.h +++ b/include/linux/kgdb.h @@ -271,6 +271,7 @@ extern int kgdb_mem2hex(char *mem, char *buf, int count); extern int kgdb_hex2mem(char *buf, char *mem, int count); extern int kgdb_isremovedbreak(unsigned long addr); +extern void kgdb_schedule_breakpoint(void); extern int kgdb_handle_exception(int ex_vector, int signo, int err_code, -- cgit v1.2.3 From efe2f29e324fd20e0449bcd6dc6dbe4734c2ba94 Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Thu, 20 May 2010 21:04:26 -0500 Subject: kgdboc,kdb: Allow kdb to work on a non open console port If kdb is open on a serial port that is not actually a console make sure to call the poll routines to emit and receive characters. Signed-off-by: Jason Wessel Acked-by: Martin Hicks --- include/linux/kgdb.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux') diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h index ee007ea341b8..6c784ab6856a 100644 --- a/include/linux/kgdb.h +++ b/include/linux/kgdb.h @@ -247,6 +247,8 @@ struct kgdb_arch { * the I/O driver. * @post_exception: Pointer to a function that will do any cleanup work * for the I/O driver. + * @is_console: 1 if the end device is a console 0 if the I/O device is + * not a console */ struct kgdb_io { const char *name; @@ -256,6 +258,7 @@ struct kgdb_io { int (*init) (void); void (*pre_exception) (void); void (*post_exception) (void); + int is_console; }; extern struct kgdb_arch arch_kgdb_ops; -- cgit v1.2.3 From d37d39ae3b4a8f9a21114921fb344fe7cadb1abd Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Thu, 20 May 2010 21:04:27 -0500 Subject: printk,kdb: capture printk() when in kdb shell Certain calls from the kdb shell will call out to printk(), and any of these calls should get vectored back to the kdb_printf() so that the kdb pager and processing can be used, as well as to properly channel I/O to the polled I/O devices. CC: Randy Dunlap Signed-off-by: Jason Wessel Acked-by: Andrew Morton --- include/linux/kdb.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux') diff --git a/include/linux/kdb.h b/include/linux/kdb.h index d72fa3908128..ccb2b3ec0fe8 100644 --- a/include/linux/kdb.h +++ b/include/linux/kdb.h @@ -78,6 +78,9 @@ typedef enum { KDB_REASON_SSTEP, /* Single Step trap. - regs valid */ } kdb_reason_t; +extern int kdb_trap_printk; +extern int vkdb_printf(const char *fmt, va_list args) + __attribute__ ((format (printf, 1, 0))); extern int kdb_printf(const char *, ...) __attribute__ ((format (printf, 1, 2))); typedef int (*kdb_printf_t)(const char *, ...) -- cgit v1.2.3