| #ifndef _LINUX_HW_BREAKPOINT_H |
| #define _LINUX_HW_BREAKPOINT_H |
| |
| |
| #ifdef __KERNEL__ |
| #include <linux/list.h> |
| #include <linux/types.h> |
| #include <linux/kallsyms.h> |
| |
| /** |
| * struct hw_breakpoint - unified kernel/user-space hardware breakpoint |
| * @triggered: callback invoked after target address access |
| * @info: arch-specific breakpoint info (address, length, and type) |
| * |
| * %hw_breakpoint structures are the kernel's way of representing |
| * hardware breakpoints. These are data breakpoints |
| * (also known as "watchpoints", triggered on data access), and the breakpoint's |
| * target address can be located in either kernel space or user space. |
| * |
| * The breakpoint's address, length, and type are highly |
| * architecture-specific. The values are encoded in the @info field; you |
| * specify them when registering the breakpoint. To examine the encoded |
| * values use hw_breakpoint_get_{kaddress,uaddress,len,type}(), declared |
| * below. |
| * |
| * The address is specified as a regular kernel pointer (for kernel-space |
| * breakponts) or as an %__user pointer (for user-space breakpoints). |
| * With register_user_hw_breakpoint(), the address must refer to a |
| * location in user space. The breakpoint will be active only while the |
| * requested task is running. Conversely with |
| * register_kernel_hw_breakpoint(), the address must refer to a location |
| * in kernel space, and the breakpoint will be active on all CPUs |
| * regardless of the current task. |
| * |
| * The length is the breakpoint's extent in bytes, which is subject to |
| * certain limitations. include/asm/hw_breakpoint.h contains macros |
| * defining the available lengths for a specific architecture. Note that |
| * the address's alignment must match the length. The breakpoint will |
| * catch accesses to any byte in the range from address to address + |
| * (length - 1). |
| * |
| * The breakpoint's type indicates the sort of access that will cause it |
| * to trigger. Possible values may include: |
| * |
| * %HW_BREAKPOINT_RW (triggered on read or write access), |
| * %HW_BREAKPOINT_WRITE (triggered on write access), and |
| * %HW_BREAKPOINT_READ (triggered on read access). |
| * |
| * Appropriate macros are defined in include/asm/hw_breakpoint.h; not all |
| * possibilities are available on all architectures. Execute breakpoints |
| * must have length equal to the special value %HW_BREAKPOINT_LEN_EXECUTE. |
| * |
| * When a breakpoint gets hit, the @triggered callback is |
| * invoked in_interrupt with a pointer to the %hw_breakpoint structure and the |
| * processor registers. |
| * Data breakpoints occur after the memory access has taken place. |
| * Breakpoints are disabled during execution @triggered, to avoid |
| * recursive traps and allow unhindered access to breakpointed memory. |
| * |
| * This sample code sets a breakpoint on pid_max and registers a callback |
| * function for writes to that variable. Note that it is not portable |
| * as written, because not all architectures support HW_BREAKPOINT_LEN_4. |
| * |
| * ---------------------------------------------------------------------- |
| * |
| * #include <asm/hw_breakpoint.h> |
| * |
| * struct hw_breakpoint my_bp; |
| * |
| * static void my_triggered(struct hw_breakpoint *bp, struct pt_regs *regs) |
| * { |
| * printk(KERN_DEBUG "Inside triggered routine of breakpoint exception\n"); |
| * dump_stack(); |
| * .......<more debugging output>........ |
| * } |
| * |
| * static struct hw_breakpoint my_bp; |
| * |
| * static int init_module(void) |
| * { |
| * ..........<do anything>............ |
| * my_bp.info.type = HW_BREAKPOINT_WRITE; |
| * my_bp.info.len = HW_BREAKPOINT_LEN_4; |
| * |
| * my_bp.installed = (void *)my_bp_installed; |
| * |
| * rc = register_kernel_hw_breakpoint(&my_bp); |
| * ..........<do anything>............ |
| * } |
| * |
| * static void cleanup_module(void) |
| * { |
| * ..........<do anything>............ |
| * unregister_kernel_hw_breakpoint(&my_bp); |
| * ..........<do anything>............ |
| * } |
| * |
| * ---------------------------------------------------------------------- |
| */ |
| struct hw_breakpoint { |
| void (*triggered)(struct hw_breakpoint *, struct pt_regs *); |
| struct arch_hw_breakpoint info; |
| }; |
| |
| /* |
| * len and type values are defined in include/asm/hw_breakpoint.h. |
| * Available values vary according to the architecture. On i386 the |
| * possibilities are: |
| * |
| * HW_BREAKPOINT_LEN_1 |
| * HW_BREAKPOINT_LEN_2 |
| * HW_BREAKPOINT_LEN_4 |
| * HW_BREAKPOINT_RW |
| * HW_BREAKPOINT_READ |
| * |
| * On other architectures HW_BREAKPOINT_LEN_8 may be available, and the |
| * 1-, 2-, and 4-byte lengths may be unavailable. There also may be |
| * HW_BREAKPOINT_WRITE. You can use #ifdef to check at compile time. |
| */ |
| |
| extern int register_user_hw_breakpoint(struct task_struct *tsk, |
| struct hw_breakpoint *bp); |
| extern int modify_user_hw_breakpoint(struct task_struct *tsk, |
| struct hw_breakpoint *bp); |
| extern void unregister_user_hw_breakpoint(struct task_struct *tsk, |
| struct hw_breakpoint *bp); |
| /* |
| * Kernel breakpoints are not associated with any particular thread. |
| */ |
| extern int register_kernel_hw_breakpoint(struct hw_breakpoint *bp); |
| extern void unregister_kernel_hw_breakpoint(struct hw_breakpoint *bp); |
| |
| extern unsigned int hbp_kernel_pos; |
| |
| #endif /* __KERNEL__ */ |
| #endif /* _LINUX_HW_BREAKPOINT_H */ |