| 1 |
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| 2 | |
| 3 | * This provides the callbacks and functions that KGDB needs to share between
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| 4 | * the core, I/O and arch-specific portions.
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| 5 | *
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| 6 | * Author: Amit Kale <[email protected]> and
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| 7 | * Tom Rini <[email protected]>
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| 8 | *
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| 9 | * 2001-2004 (c) Amit S. Kale and 2003-2005 (c) MontaVista Software, Inc.
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| 10 |
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| 11 | #ifndef _KGDB_H_
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| 12 | #define _KGDB_H_
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| 13 |
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| 14 | #include <linux/linkage.h>
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| 15 | #include <linux/init.h>
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| 16 | #include <linux/atomic.h>
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| 17 | #include <linux/kprobes.h>
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| 18 | #ifdef CONFIG_HAVE_ARCH_KGDB
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| 19 | #include <asm/kgdb.h>
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| 20 | #endif
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| 21 |
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| 22 | #ifdef CONFIG_KGDB
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| 23 | struct pt_regs;
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| 24 |
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| 25 | |
| 26 | * kgdb_skipexception - (optional) exit kgdb_handle_exception early
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| 27 | * @exception: Exception vector number
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| 28 | * @regs: Current &struct pt_regs.
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| 29 | *
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| 30 | * On some architectures it is required to skip a breakpoint
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| 31 | * exception when it occurs after a breakpoint has been removed.
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| 32 | * This can be implemented in the architecture specific portion of kgdb.
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| 33 |
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| 34 | extern int kgdb_skipexception(int exception, struct pt_regs *regs);
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| 35 |
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| 36 | struct tasklet_struct;
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| 37 | struct task_struct;
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| 38 | struct uart_port;
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| 39 |
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| 40 | |
| 41 | * kgdb_breakpoint - compiled in breakpoint
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| 42 | *
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| 43 | * This will be implemented as a static inline per architecture. This
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| 44 | * function is called by the kgdb core to execute an architecture
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| 45 | * specific trap to cause kgdb to enter the exception processing.
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| 46 | *
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| 47 |
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| 48 | void kgdb_breakpoint(void);
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| 49 |
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| 50 | extern int kgdb_connected;
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| 51 | extern int kgdb_io_module_registered;
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| 52 |
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| 53 | extern atomic_t kgdb_setting_breakpoint;
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| 54 | extern atomic_t kgdb_cpu_doing_single_step;
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| 55 |
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| 56 | extern struct task_struct *kgdb_usethread;
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| 57 | extern struct task_struct *kgdb_contthread;
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| 58 |
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| 59 | enum kgdb_bptype {
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| 60 | BP_BREAKPOINT = 0,
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| 61 | BP_HARDWARE_BREAKPOINT,
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| 62 | BP_WRITE_WATCHPOINT,
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| 63 | BP_READ_WATCHPOINT,
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| 64 | BP_ACCESS_WATCHPOINT,
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| 65 | BP_POKE_BREAKPOINT,
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| 66 | };
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| 67 |
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| 68 | enum kgdb_bpstate {
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| 69 | BP_UNDEFINED = 0,
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| 70 | BP_REMOVED,
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| 71 | BP_SET,
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| 72 | BP_ACTIVE
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| 73 | };
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| 74 |
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| 75 | struct kgdb_bkpt {
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| 76 | unsigned long bpt_addr;
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| 77 | unsigned char saved_instr[BREAK_INSTR_SIZE];
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| 78 | enum kgdb_bptype type;
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| 79 | enum kgdb_bpstate state;
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| 80 | };
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| 81 |
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| 82 | struct dbg_reg_def_t {
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| 83 | char *name;
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| 84 | int size;
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| 85 | int offset;
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| 86 | };
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| 87 |
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| 88 | #ifndef DBG_MAX_REG_NUM
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| 89 | #define DBG_MAX_REG_NUM 0
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| 90 | #else
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| 91 | extern struct dbg_reg_def_t dbg_reg_def[];
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| 92 | extern char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs);
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| 93 | extern int dbg_set_reg(int regno, void *mem, struct pt_regs *regs);
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| 94 | #endif
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| 95 | #ifndef KGDB_MAX_BREAKPOINTS
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| 96 | # define KGDB_MAX_BREAKPOINTS 1000
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| 97 | #endif
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| 98 |
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| 99 | #define KGDB_HW_BREAKPOINT 1
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| 100 |
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| 101 | |
| 102 | * Functions each KGDB-supporting architecture must provide:
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| 103 |
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| 104 |
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| 105 | |
| 106 | * kgdb_arch_init - Perform any architecture specific initialization.
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| 107 | *
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| 108 | * This function will handle the initialization of any architecture
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| 109 | * specific callbacks.
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| 110 |
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| 111 | extern int kgdb_arch_init(void);
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| 112 |
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| 113 | |
| 114 | * kgdb_arch_exit - Perform any architecture specific uninitalization.
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| 115 | *
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| 116 | * This function will handle the uninitalization of any architecture
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| 117 | * specific callbacks, for dynamic registration and unregistration.
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| 118 |
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| 119 | extern void kgdb_arch_exit(void);
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| 120 |
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| 121 | |
| 122 | * pt_regs_to_gdb_regs - Convert ptrace regs to GDB regs
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| 123 | * @gdb_regs: A pointer to hold the registers in the order GDB wants.
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| 124 | * @regs: The &struct pt_regs of the current process.
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| 125 | *
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| 126 | * Convert the pt_regs in @regs into the format for registers that
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| 127 | * GDB expects, stored in @gdb_regs.
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| 128 |
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| 129 | extern void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs);
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| 130 |
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| 131 | |
| 132 | * sleeping_thread_to_gdb_regs - Convert ptrace regs to GDB regs
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| 133 | * @gdb_regs: A pointer to hold the registers in the order GDB wants.
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| 134 | * @p: The &struct task_struct of the desired process.
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| 135 | *
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| 136 | * Convert the register values of the sleeping process in @p to
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| 137 | * the format that GDB expects.
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| 138 | * This function is called when kgdb does not have access to the
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| 139 | * &struct pt_regs and therefore it should fill the gdb registers
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| 140 | * @gdb_regs with what has been saved in &struct thread_struct
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| 141 | * thread field during switch_to.
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| 142 |
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| 143 | extern void
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| 144 | sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p);
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| 145 |
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| 146 | |
| 147 | * gdb_regs_to_pt_regs - Convert GDB regs to ptrace regs.
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| 148 | * @gdb_regs: A pointer to hold the registers we've received from GDB.
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| 149 | * @regs: A pointer to a &struct pt_regs to hold these values in.
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| 150 | *
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| 151 | * Convert the GDB regs in @gdb_regs into the pt_regs, and store them
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| 152 | * in @regs.
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| 153 |
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| 154 | extern void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs);
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| 155 |
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| 156 | |
| 157 | * kgdb_arch_handle_exception - Handle architecture specific GDB packets.
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| 158 | * @vector: The error vector of the exception that happened.
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| 159 | * @signo: The signal number of the exception that happened.
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| 160 | * @err_code: The error code of the exception that happened.
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| 161 | * @remcom_in_buffer: The buffer of the packet we have read.
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| 162 | * @remcom_out_buffer: The buffer of %BUFMAX bytes to write a packet into.
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| 163 | * @regs: The &struct pt_regs of the current process.
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| 164 | *
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| 165 | * This function MUST handle the 'c' and 's' command packets,
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| 166 | * as well packets to set / remove a hardware breakpoint, if used.
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| 167 | * If there are additional packets which the hardware needs to handle,
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| 168 | * they are handled here. The code should return -1 if it wants to
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| 169 | * process more packets, and a %0 or %1 if it wants to exit from the
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| 170 | * kgdb callback.
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| 171 |
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| 172 | extern int
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| 173 | kgdb_arch_handle_exception(int vector, int signo, int err_code,
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| 174 | char *remcom_in_buffer,
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| 175 | char *remcom_out_buffer,
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| 176 | struct pt_regs *regs);
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| 177 |
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| 178 | |
| 179 | * kgdb_arch_handle_qxfer_pkt - Handle architecture specific GDB XML
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| 180 | * packets.
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| 181 | * @remcom_in_buffer: The buffer of the packet we have read.
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| 182 | * @remcom_out_buffer: The buffer of %BUFMAX bytes to write a packet into.
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| 183 |
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| 184 |
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| 185 | extern void
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| 186 | kgdb_arch_handle_qxfer_pkt(char *remcom_in_buffer,
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| 187 | char *remcom_out_buffer);
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| 188 |
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| 189 | |
| 190 | * kgdb_call_nmi_hook - Call kgdb_nmicallback() on the current CPU
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| 191 | * @ignored: This parameter is only here to match the prototype.
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| 192 | *
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| 193 | * If you're using the default implementation of kgdb_roundup_cpus()
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| 194 | * this function will be called per CPU. If you don't implement
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| 195 | * kgdb_call_nmi_hook() a default will be used.
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| 196 |
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| 197 |
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| 198 | extern void kgdb_call_nmi_hook(void *ignored);
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| 199 |
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| 200 | |
| 201 | * kgdb_roundup_cpus - Get other CPUs into a holding pattern
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| 202 | *
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| 203 | * On SMP systems, we need to get the attention of the other CPUs
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| 204 | * and get them into a known state. This should do what is needed
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| 205 | * to get the other CPUs to call kgdb_handle_exception(). Note that
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| 206 | * on some arches, the NMI approach is not used for rounding up all
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| 207 | * the CPUs. Normally those architectures can just not implement
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| 208 | * this and get the default.
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| 209 | *
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| 210 | * On non-SMP systems, this is not called.
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| 211 |
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| 212 | extern void kgdb_roundup_cpus(void);
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| 213 |
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| 214 | |
| 215 | * kgdb_arch_set_pc - Generic call back to the program counter
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| 216 | * @regs: Current &struct pt_regs.
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| 217 | * @pc: The new value for the program counter
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| 218 | *
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| 219 | * This function handles updating the program counter and requires an
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| 220 | * architecture specific implementation.
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| 221 |
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| 222 | extern void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc);
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| 223 |
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| 224 |
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| 225 |
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| 226 | extern int kgdb_validate_break_address(unsigned long addr);
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| 227 | extern int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt);
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| 228 | extern int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt);
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| 229 |
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| 230 | |
| 231 | * kgdb_arch_late - Perform any architecture specific initialization.
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| 232 | *
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| 233 | * This function will handle the late initialization of any
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| 234 | * architecture specific callbacks. This is an optional function for
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| 235 | * handling things like late initialization of hw breakpoints. The
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| 236 | * default implementation does nothing.
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| 237 |
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| 238 | extern void kgdb_arch_late(void);
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| 239 |
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| 240 |
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| 241 | |
| 242 | * struct kgdb_arch - Describe architecture specific values.
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| 243 | * @gdb_bpt_instr: The instruction to trigger a breakpoint.
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| 244 | * @flags: Flags for the breakpoint, currently just %KGDB_HW_BREAKPOINT.
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| 245 | * @set_breakpoint: Allow an architecture to specify how to set a software
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| 246 | * breakpoint.
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| 247 | * @remove_breakpoint: Allow an architecture to specify how to remove a
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| 248 | * software breakpoint.
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| 249 | * @set_hw_breakpoint: Allow an architecture to specify how to set a hardware
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| 250 | * breakpoint.
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| 251 | * @remove_hw_breakpoint: Allow an architecture to specify how to remove a
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| 252 | * hardware breakpoint.
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| 253 | * @disable_hw_break: Allow an architecture to specify how to disable
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| 254 | * hardware breakpoints for a single cpu.
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| 255 | * @remove_all_hw_break: Allow an architecture to specify how to remove all
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| 256 | * hardware breakpoints.
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| 257 | * @correct_hw_break: Allow an architecture to specify how to correct the
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| 258 | * hardware debug registers.
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| 259 |
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| 260 | struct kgdb_arch {
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| 261 | unsigned char gdb_bpt_instr[BREAK_INSTR_SIZE];
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| 262 | unsigned long flags;
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| 263 |
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| 264 | int (*set_breakpoint)(unsigned long, char *);
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| 265 | int (*remove_breakpoint)(unsigned long, char *);
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| 266 | int (*set_hw_breakpoint)(unsigned long, int, enum kgdb_bptype);
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| 267 | int (*remove_hw_breakpoint)(unsigned long, int, enum kgdb_bptype);
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| 268 | void (*disable_hw_break)(struct pt_regs *regs);
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| 269 | void (*remove_all_hw_break)(void);
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| 270 | void (*correct_hw_break)(void);
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| 271 | };
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| 272 |
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| 273 | |
| 274 | * struct kgdb_io - Describe the interface for an I/O driver to talk with KGDB.
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| 275 | * @name: Name of the I/O driver.
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| 276 | * @read_char: Pointer to a function that will return one char.
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| 277 | * @write_char: Pointer to a function that will write one char.
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| 278 | * @flush: Pointer to a function that will flush any pending writes.
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| 279 | * @init: Pointer to a function that will initialize the device.
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| 280 | * @deinit: Pointer to a function that will deinit the device. Implies that
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| 281 | * this I/O driver is temporary and expects to be replaced. Called when
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| 282 | * an I/O driver is replaced or explicitly unregistered.
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| 283 | * @pre_exception: Pointer to a function that will do any prep work for
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| 284 | * the I/O driver.
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| 285 | * @post_exception: Pointer to a function that will do any cleanup work
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| 286 | * for the I/O driver.
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| 287 | * @cons: valid if the I/O device is a console; else NULL.
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| 288 |
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| 289 | struct kgdb_io {
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| 290 | const char *name;
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| 291 | int (*read_char) (void);
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| 292 | void (*write_char) (u8);
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| 293 | void (*flush) (void);
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| 294 | int (*init) (void);
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| 295 | void (*deinit) (void);
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| 296 | void (*pre_exception) (void);
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| 297 | void (*post_exception) (void);
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| 298 | struct console *cons;
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| 299 | };
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| 300 |
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| 301 | extern const struct kgdb_arch arch_kgdb_ops;
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| 302 |
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| 303 | extern unsigned long kgdb_arch_pc(int exception, struct pt_regs *regs);
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| 304 |
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| 305 | extern int kgdb_register_io_module(struct kgdb_io *local_kgdb_io_ops);
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| 306 | extern void kgdb_unregister_io_module(struct kgdb_io *local_kgdb_io_ops);
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| 307 | extern struct kgdb_io *dbg_io_ops;
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| 308 |
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| 309 | extern int kgdb_hex2long(char **ptr, unsigned long *long_val);
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| 310 | extern char *kgdb_mem2hex(char *mem, char *buf, int count);
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| 311 | extern int kgdb_hex2mem(char *buf, char *mem, int count);
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| 312 |
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| 313 | extern int kgdb_isremovedbreak(unsigned long addr);
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| 314 | extern int kgdb_has_hit_break(unsigned long addr);
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| 315 |
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| 316 | extern int
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| 317 | kgdb_handle_exception(int ex_vector, int signo, int err_code,
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| 318 | struct pt_regs *regs);
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| 319 | extern int kgdb_nmicallback(int cpu, void *regs);
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| 320 | extern int kgdb_nmicallin(int cpu, int trapnr, void *regs, int err_code,
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| 321 | atomic_t *snd_rdy);
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| 322 | extern void gdbstub_exit(int status);
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| 323 |
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| 324 | |
| 325 | * kgdb and kprobes both use the same (kprobe) blocklist (which makes sense
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| 326 | * given they are both typically hooked up to the same trap meaning on most
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| 327 | * architectures one cannot be used to debug the other)
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| 328 | *
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| 329 | * However on architectures where kprobes is not (yet) implemented we permit
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| 330 | * breakpoints everywhere rather than blocking everything by default.
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| 331 |
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| 332 | static inline bool kgdb_within_blocklist(unsigned long addr)
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| 333 | {
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| 334 | #ifdef CONFIG_KGDB_HONOUR_BLOCKLIST
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| 335 | return within_kprobe_blacklist(addr);
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| 336 | #else
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| 337 | return false;
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| 338 | #endif
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| 339 | }
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| 340 |
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| 341 | extern int kgdb_single_step;
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| 342 | extern atomic_t kgdb_active;
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| 343 | #define in_dbg_master() \
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| 344 | (irqs_disabled() && (smp_processor_id() == atomic_read(&kgdb_active)))
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| 345 | extern bool dbg_is_early;
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| 346 | extern void __init dbg_late_init(void);
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| 347 | extern void kgdb_panic(const char *msg);
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| 348 | extern void kgdb_free_init_mem(void);
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| 349 | #else
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| 350 | #define in_dbg_master() (0)
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| 351 | #define dbg_late_init()
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| 352 | static inline void kgdb_panic(const char *msg) {}
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| 353 | static inline void kgdb_free_init_mem(void) { }
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| 354 | static inline int kgdb_nmicallback(int cpu, void *regs) { return 1; }
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| 355 | #endif
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| 356 | #endif
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