forked from luck/tmp_suning_uos_patched
5946d1f5b3
In kgdb context, calling console handlers aren't safe due to locks used in those handlers which could in turn lead to a deadlock. Although, using oops_in_progress increases the chance to bypass locks in most console handlers but it might not be sufficient enough in case a console uses more locks (VT/TTY is good example). Currently when a driver provides both polling I/O and a console then kdb will output using the console. We can increase robustness by using the currently active polling I/O driver (which should be lockless) instead of the corresponding console. For several common cases (e.g. an embedded system with a single serial port that is used both for console output and debugger I/O) this will result in no console handler being used. In order to achieve this we need to reverse the order of preference to use dbg_io_ops (uses polling I/O mode) over console APIs. So we just store "struct console" that represents debugger I/O in dbg_io_ops and while emitting kdb messages, skip console that matches dbg_io_ops console in order to avoid duplicate messages. After this change, "is_console" param becomes redundant and hence removed. Suggested-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Sumit Garg <sumit.garg@linaro.org> Link: https://lore.kernel.org/r/1591264879-25920-5-git-send-email-sumit.garg@linaro.org Reviewed-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
339 lines
11 KiB
C
339 lines
11 KiB
C
/*
|
|
* This provides the callbacks and functions that KGDB needs to share between
|
|
* the core, I/O and arch-specific portions.
|
|
*
|
|
* Author: Amit Kale <amitkale@linsyssoft.com> and
|
|
* Tom Rini <trini@kernel.crashing.org>
|
|
*
|
|
* 2001-2004 (c) Amit S. Kale and 2003-2005 (c) MontaVista Software, Inc.
|
|
* This file is licensed under the terms of the GNU General Public License
|
|
* version 2. This program is licensed "as is" without any warranty of any
|
|
* kind, whether express or implied.
|
|
*/
|
|
#ifndef _KGDB_H_
|
|
#define _KGDB_H_
|
|
|
|
#include <linux/linkage.h>
|
|
#include <linux/init.h>
|
|
#include <linux/atomic.h>
|
|
#ifdef CONFIG_HAVE_ARCH_KGDB
|
|
#include <asm/kgdb.h>
|
|
#endif
|
|
|
|
#ifdef CONFIG_KGDB
|
|
struct pt_regs;
|
|
|
|
/**
|
|
* kgdb_skipexception - (optional) exit kgdb_handle_exception early
|
|
* @exception: Exception vector number
|
|
* @regs: Current &struct pt_regs.
|
|
*
|
|
* On some architectures it is required to skip a breakpoint
|
|
* exception when it occurs after a breakpoint has been removed.
|
|
* This can be implemented in the architecture specific portion of kgdb.
|
|
*/
|
|
extern int kgdb_skipexception(int exception, struct pt_regs *regs);
|
|
|
|
struct tasklet_struct;
|
|
struct task_struct;
|
|
struct uart_port;
|
|
|
|
/**
|
|
* kgdb_breakpoint - compiled in breakpoint
|
|
*
|
|
* This will be implemented as a static inline per architecture. This
|
|
* function is called by the kgdb core to execute an architecture
|
|
* specific trap to cause kgdb to enter the exception processing.
|
|
*
|
|
*/
|
|
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;
|
|
|
|
extern struct task_struct *kgdb_usethread;
|
|
extern struct task_struct *kgdb_contthread;
|
|
|
|
enum kgdb_bptype {
|
|
BP_BREAKPOINT = 0,
|
|
BP_HARDWARE_BREAKPOINT,
|
|
BP_WRITE_WATCHPOINT,
|
|
BP_READ_WATCHPOINT,
|
|
BP_ACCESS_WATCHPOINT,
|
|
BP_POKE_BREAKPOINT,
|
|
};
|
|
|
|
enum kgdb_bpstate {
|
|
BP_UNDEFINED = 0,
|
|
BP_REMOVED,
|
|
BP_SET,
|
|
BP_ACTIVE
|
|
};
|
|
|
|
struct kgdb_bkpt {
|
|
unsigned long bpt_addr;
|
|
unsigned char saved_instr[BREAK_INSTR_SIZE];
|
|
enum kgdb_bptype type;
|
|
enum kgdb_bpstate state;
|
|
};
|
|
|
|
struct dbg_reg_def_t {
|
|
char *name;
|
|
int size;
|
|
int offset;
|
|
};
|
|
|
|
#ifndef DBG_MAX_REG_NUM
|
|
#define DBG_MAX_REG_NUM 0
|
|
#else
|
|
extern struct dbg_reg_def_t dbg_reg_def[];
|
|
extern char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs);
|
|
extern int dbg_set_reg(int regno, void *mem, struct pt_regs *regs);
|
|
#endif
|
|
#ifndef KGDB_MAX_BREAKPOINTS
|
|
# define KGDB_MAX_BREAKPOINTS 1000
|
|
#endif
|
|
|
|
#define KGDB_HW_BREAKPOINT 1
|
|
|
|
/*
|
|
* Functions each KGDB-supporting architecture must provide:
|
|
*/
|
|
|
|
/**
|
|
* kgdb_arch_init - Perform any architecture specific initalization.
|
|
*
|
|
* This function will handle the initalization of any architecture
|
|
* specific callbacks.
|
|
*/
|
|
extern int kgdb_arch_init(void);
|
|
|
|
/**
|
|
* kgdb_arch_exit - Perform any architecture specific uninitalization.
|
|
*
|
|
* This function will handle the uninitalization of any architecture
|
|
* specific callbacks, for dynamic registration and unregistration.
|
|
*/
|
|
extern void kgdb_arch_exit(void);
|
|
|
|
/**
|
|
* pt_regs_to_gdb_regs - Convert ptrace regs to GDB regs
|
|
* @gdb_regs: A pointer to hold the registers in the order GDB wants.
|
|
* @regs: The &struct pt_regs of the current process.
|
|
*
|
|
* Convert the pt_regs in @regs into the format for registers that
|
|
* GDB expects, stored in @gdb_regs.
|
|
*/
|
|
extern void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs);
|
|
|
|
/**
|
|
* sleeping_thread_to_gdb_regs - Convert ptrace regs to GDB regs
|
|
* @gdb_regs: A pointer to hold the registers in the order GDB wants.
|
|
* @p: The &struct task_struct of the desired process.
|
|
*
|
|
* Convert the register values of the sleeping process in @p to
|
|
* the format that GDB expects.
|
|
* This function is called when kgdb does not have access to the
|
|
* &struct pt_regs and therefore it should fill the gdb registers
|
|
* @gdb_regs with what has been saved in &struct thread_struct
|
|
* thread field during switch_to.
|
|
*/
|
|
extern void
|
|
sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p);
|
|
|
|
/**
|
|
* gdb_regs_to_pt_regs - Convert GDB regs to ptrace regs.
|
|
* @gdb_regs: A pointer to hold the registers we've received from GDB.
|
|
* @regs: A pointer to a &struct pt_regs to hold these values in.
|
|
*
|
|
* Convert the GDB regs in @gdb_regs into the pt_regs, and store them
|
|
* in @regs.
|
|
*/
|
|
extern void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs);
|
|
|
|
/**
|
|
* kgdb_arch_handle_exception - Handle architecture specific GDB packets.
|
|
* @vector: The error vector of the exception that happened.
|
|
* @signo: The signal number of the exception that happened.
|
|
* @err_code: The error code of the exception that happened.
|
|
* @remcom_in_buffer: The buffer of the packet we have read.
|
|
* @remcom_out_buffer: The buffer of %BUFMAX bytes to write a packet into.
|
|
* @regs: The &struct pt_regs of the current process.
|
|
*
|
|
* This function MUST handle the 'c' and 's' command packets,
|
|
* as well packets to set / remove a hardware breakpoint, if used.
|
|
* If there are additional packets which the hardware needs to handle,
|
|
* they are handled here. The code should return -1 if it wants to
|
|
* process more packets, and a %0 or %1 if it wants to exit from the
|
|
* kgdb callback.
|
|
*/
|
|
extern int
|
|
kgdb_arch_handle_exception(int vector, int signo, int err_code,
|
|
char *remcom_in_buffer,
|
|
char *remcom_out_buffer,
|
|
struct pt_regs *regs);
|
|
|
|
/**
|
|
* kgdb_call_nmi_hook - Call kgdb_nmicallback() on the current CPU
|
|
* @ignored: This parameter is only here to match the prototype.
|
|
*
|
|
* If you're using the default implementation of kgdb_roundup_cpus()
|
|
* this function will be called per CPU. If you don't implement
|
|
* kgdb_call_nmi_hook() a default will be used.
|
|
*/
|
|
|
|
extern void kgdb_call_nmi_hook(void *ignored);
|
|
|
|
/**
|
|
* kgdb_roundup_cpus - Get other CPUs into a holding pattern
|
|
*
|
|
* On SMP systems, we need to get the attention of the other CPUs
|
|
* and get them into a known state. This should do what is needed
|
|
* to get the other CPUs to call kgdb_wait(). Note that on some arches,
|
|
* the NMI approach is not used for rounding up all the CPUs. Normally
|
|
* those architectures can just not implement this and get the default.
|
|
*
|
|
* On non-SMP systems, this is not called.
|
|
*/
|
|
extern void kgdb_roundup_cpus(void);
|
|
|
|
/**
|
|
* 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(struct kgdb_bkpt *bpt);
|
|
extern int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt);
|
|
|
|
/**
|
|
* kgdb_arch_late - Perform any architecture specific initalization.
|
|
*
|
|
* This function will handle the late initalization of any
|
|
* architecture specific callbacks. This is an optional function for
|
|
* handling things like late initialization of hw breakpoints. The
|
|
* default implementation does nothing.
|
|
*/
|
|
extern void kgdb_arch_late(void);
|
|
|
|
|
|
/**
|
|
* struct kgdb_arch - Describe architecture specific values.
|
|
* @gdb_bpt_instr: The instruction to trigger a breakpoint.
|
|
* @flags: Flags for the breakpoint, currently just %KGDB_HW_BREAKPOINT.
|
|
* @set_breakpoint: Allow an architecture to specify how to set a software
|
|
* breakpoint.
|
|
* @remove_breakpoint: Allow an architecture to specify how to remove a
|
|
* software breakpoint.
|
|
* @set_hw_breakpoint: Allow an architecture to specify how to set a hardware
|
|
* breakpoint.
|
|
* @remove_hw_breakpoint: Allow an architecture to specify how to remove a
|
|
* hardware breakpoint.
|
|
* @disable_hw_break: Allow an architecture to specify how to disable
|
|
* hardware breakpoints for a single cpu.
|
|
* @remove_all_hw_break: Allow an architecture to specify how to remove all
|
|
* hardware breakpoints.
|
|
* @correct_hw_break: Allow an architecture to specify how to correct the
|
|
* hardware debug registers.
|
|
* @enable_nmi: Manage NMI-triggered entry to KGDB
|
|
*/
|
|
struct kgdb_arch {
|
|
unsigned char gdb_bpt_instr[BREAK_INSTR_SIZE];
|
|
unsigned long flags;
|
|
|
|
int (*set_breakpoint)(unsigned long, char *);
|
|
int (*remove_breakpoint)(unsigned long, char *);
|
|
int (*set_hw_breakpoint)(unsigned long, int, enum kgdb_bptype);
|
|
int (*remove_hw_breakpoint)(unsigned long, int, enum kgdb_bptype);
|
|
void (*disable_hw_break)(struct pt_regs *regs);
|
|
void (*remove_all_hw_break)(void);
|
|
void (*correct_hw_break)(void);
|
|
|
|
void (*enable_nmi)(bool on);
|
|
};
|
|
|
|
/**
|
|
* struct kgdb_io - Describe the interface for an I/O driver to talk with KGDB.
|
|
* @name: Name of the I/O driver.
|
|
* @read_char: Pointer to a function that will return one char.
|
|
* @write_char: Pointer to a function that will write one char.
|
|
* @flush: Pointer to a function that will flush any pending writes.
|
|
* @init: Pointer to a function that will initialize the device.
|
|
* @deinit: Pointer to a function that will deinit the device. Implies that
|
|
* this I/O driver is temporary and expects to be replaced. Called when
|
|
* an I/O driver is replaced or explicitly unregistered.
|
|
* @pre_exception: Pointer to a function that will do any prep work for
|
|
* the I/O driver.
|
|
* @post_exception: Pointer to a function that will do any cleanup work
|
|
* for the I/O driver.
|
|
* @cons: valid if the I/O device is a console; else NULL.
|
|
*/
|
|
struct kgdb_io {
|
|
const char *name;
|
|
int (*read_char) (void);
|
|
void (*write_char) (u8);
|
|
void (*flush) (void);
|
|
int (*init) (void);
|
|
void (*deinit) (void);
|
|
void (*pre_exception) (void);
|
|
void (*post_exception) (void);
|
|
struct console *cons;
|
|
};
|
|
|
|
extern const struct kgdb_arch arch_kgdb_ops;
|
|
|
|
extern unsigned long kgdb_arch_pc(int exception, struct pt_regs *regs);
|
|
|
|
#ifdef CONFIG_SERIAL_KGDB_NMI
|
|
extern int kgdb_register_nmi_console(void);
|
|
extern int kgdb_unregister_nmi_console(void);
|
|
extern bool kgdb_nmi_poll_knock(void);
|
|
#else
|
|
static inline int kgdb_register_nmi_console(void) { return 0; }
|
|
static inline int kgdb_unregister_nmi_console(void) { return 0; }
|
|
static inline bool kgdb_nmi_poll_knock(void) { return true; }
|
|
#endif
|
|
|
|
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 char *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,
|
|
struct pt_regs *regs);
|
|
extern int kgdb_nmicallback(int cpu, void *regs);
|
|
extern int kgdb_nmicallin(int cpu, int trapnr, void *regs, int err_code,
|
|
atomic_t *snd_rdy);
|
|
extern void gdbstub_exit(int status);
|
|
|
|
extern int kgdb_single_step;
|
|
extern atomic_t kgdb_active;
|
|
#define in_dbg_master() \
|
|
(irqs_disabled() && (smp_processor_id() == atomic_read(&kgdb_active)))
|
|
extern bool dbg_is_early;
|
|
extern void __init dbg_late_init(void);
|
|
extern void kgdb_panic(const char *msg);
|
|
#else /* ! CONFIG_KGDB */
|
|
#define in_dbg_master() (0)
|
|
#define dbg_late_init()
|
|
static inline void kgdb_panic(const char *msg) {}
|
|
#endif /* ! CONFIG_KGDB */
|
|
#endif /* _KGDB_H_ */
|