diff options
author | Frederic Weisbecker <fweisbec@gmail.com> | 2009-11-05 17:06:50 -0500 |
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committer | Frederic Weisbecker <fweisbec@gmail.com> | 2009-11-05 17:48:01 -0500 |
commit | 2da3e160cb3d226d87b907fab26850d838ed8d7c (patch) | |
tree | 02ec5cbadf8d3236770d0f3a908e2a571716e382 /include/linux/hw_breakpoint.h | |
parent | 97eaf5300b9d0cd99c310bf8c4a0f2f3296d88a3 (diff) |
hw-breakpoint: Move asm-generic/hw_breakpoint.h to linux/hw_breakpoint.h
We plan to make the breakpoints parameters generic among architectures.
For that it's better to move the asm-generic header to a generic linux
header.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Diffstat (limited to 'include/linux/hw_breakpoint.h')
-rw-r--r-- | include/linux/hw_breakpoint.h | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/include/linux/hw_breakpoint.h b/include/linux/hw_breakpoint.h new file mode 100644 index 000000000000..61ccc8f17eac --- /dev/null +++ b/include/linux/hw_breakpoint.h | |||
@@ -0,0 +1,136 @@ | |||
1 | #ifndef _LINUX_HW_BREAKPOINT_H | ||
2 | #define _LINUX_HW_BREAKPOINT_H | ||
3 | |||
4 | |||
5 | #ifdef __KERNEL__ | ||
6 | #include <linux/list.h> | ||
7 | #include <linux/types.h> | ||
8 | #include <linux/kallsyms.h> | ||
9 | |||
10 | /** | ||
11 | * struct hw_breakpoint - unified kernel/user-space hardware breakpoint | ||
12 | * @triggered: callback invoked after target address access | ||
13 | * @info: arch-specific breakpoint info (address, length, and type) | ||
14 | * | ||
15 | * %hw_breakpoint structures are the kernel's way of representing | ||
16 | * hardware breakpoints. These are data breakpoints | ||
17 | * (also known as "watchpoints", triggered on data access), and the breakpoint's | ||
18 | * target address can be located in either kernel space or user space. | ||
19 | * | ||
20 | * The breakpoint's address, length, and type are highly | ||
21 | * architecture-specific. The values are encoded in the @info field; you | ||
22 | * specify them when registering the breakpoint. To examine the encoded | ||
23 | * values use hw_breakpoint_get_{kaddress,uaddress,len,type}(), declared | ||
24 | * below. | ||
25 | * | ||
26 | * The address is specified as a regular kernel pointer (for kernel-space | ||
27 | * breakponts) or as an %__user pointer (for user-space breakpoints). | ||
28 | * With register_user_hw_breakpoint(), the address must refer to a | ||
29 | * location in user space. The breakpoint will be active only while the | ||
30 | * requested task is running. Conversely with | ||
31 | * register_kernel_hw_breakpoint(), the address must refer to a location | ||
32 | * in kernel space, and the breakpoint will be active on all CPUs | ||
33 | * regardless of the current task. | ||
34 | * | ||
35 | * The length is the breakpoint's extent in bytes, which is subject to | ||
36 | * certain limitations. include/asm/hw_breakpoint.h contains macros | ||
37 | * defining the available lengths for a specific architecture. Note that | ||
38 | * the address's alignment must match the length. The breakpoint will | ||
39 | * catch accesses to any byte in the range from address to address + | ||
40 | * (length - 1). | ||
41 | * | ||
42 | * The breakpoint's type indicates the sort of access that will cause it | ||
43 | * to trigger. Possible values may include: | ||
44 | * | ||
45 | * %HW_BREAKPOINT_RW (triggered on read or write access), | ||
46 | * %HW_BREAKPOINT_WRITE (triggered on write access), and | ||
47 | * %HW_BREAKPOINT_READ (triggered on read access). | ||
48 | * | ||
49 | * Appropriate macros are defined in include/asm/hw_breakpoint.h; not all | ||
50 | * possibilities are available on all architectures. Execute breakpoints | ||
51 | * must have length equal to the special value %HW_BREAKPOINT_LEN_EXECUTE. | ||
52 | * | ||
53 | * When a breakpoint gets hit, the @triggered callback is | ||
54 | * invoked in_interrupt with a pointer to the %hw_breakpoint structure and the | ||
55 | * processor registers. | ||
56 | * Data breakpoints occur after the memory access has taken place. | ||
57 | * Breakpoints are disabled during execution @triggered, to avoid | ||
58 | * recursive traps and allow unhindered access to breakpointed memory. | ||
59 | * | ||
60 | * This sample code sets a breakpoint on pid_max and registers a callback | ||
61 | * function for writes to that variable. Note that it is not portable | ||
62 | * as written, because not all architectures support HW_BREAKPOINT_LEN_4. | ||
63 | * | ||
64 | * ---------------------------------------------------------------------- | ||
65 | * | ||
66 | * #include <asm/hw_breakpoint.h> | ||
67 | * | ||
68 | * struct hw_breakpoint my_bp; | ||
69 | * | ||
70 | * static void my_triggered(struct hw_breakpoint *bp, struct pt_regs *regs) | ||
71 | * { | ||
72 | * printk(KERN_DEBUG "Inside triggered routine of breakpoint exception\n"); | ||
73 | * dump_stack(); | ||
74 | * .......<more debugging output>........ | ||
75 | * } | ||
76 | * | ||
77 | * static struct hw_breakpoint my_bp; | ||
78 | * | ||
79 | * static int init_module(void) | ||
80 | * { | ||
81 | * ..........<do anything>............ | ||
82 | * my_bp.info.type = HW_BREAKPOINT_WRITE; | ||
83 | * my_bp.info.len = HW_BREAKPOINT_LEN_4; | ||
84 | * | ||
85 | * my_bp.installed = (void *)my_bp_installed; | ||
86 | * | ||
87 | * rc = register_kernel_hw_breakpoint(&my_bp); | ||
88 | * ..........<do anything>............ | ||
89 | * } | ||
90 | * | ||
91 | * static void cleanup_module(void) | ||
92 | * { | ||
93 | * ..........<do anything>............ | ||
94 | * unregister_kernel_hw_breakpoint(&my_bp); | ||
95 | * ..........<do anything>............ | ||
96 | * } | ||
97 | * | ||
98 | * ---------------------------------------------------------------------- | ||
99 | */ | ||
100 | struct hw_breakpoint { | ||
101 | void (*triggered)(struct hw_breakpoint *, struct pt_regs *); | ||
102 | struct arch_hw_breakpoint info; | ||
103 | }; | ||
104 | |||
105 | /* | ||
106 | * len and type values are defined in include/asm/hw_breakpoint.h. | ||
107 | * Available values vary according to the architecture. On i386 the | ||
108 | * possibilities are: | ||
109 | * | ||
110 | * HW_BREAKPOINT_LEN_1 | ||
111 | * HW_BREAKPOINT_LEN_2 | ||
112 | * HW_BREAKPOINT_LEN_4 | ||
113 | * HW_BREAKPOINT_RW | ||
114 | * HW_BREAKPOINT_READ | ||
115 | * | ||
116 | * On other architectures HW_BREAKPOINT_LEN_8 may be available, and the | ||
117 | * 1-, 2-, and 4-byte lengths may be unavailable. There also may be | ||
118 | * HW_BREAKPOINT_WRITE. You can use #ifdef to check at compile time. | ||
119 | */ | ||
120 | |||
121 | extern int register_user_hw_breakpoint(struct task_struct *tsk, | ||
122 | struct hw_breakpoint *bp); | ||
123 | extern int modify_user_hw_breakpoint(struct task_struct *tsk, | ||
124 | struct hw_breakpoint *bp); | ||
125 | extern void unregister_user_hw_breakpoint(struct task_struct *tsk, | ||
126 | struct hw_breakpoint *bp); | ||
127 | /* | ||
128 | * Kernel breakpoints are not associated with any particular thread. | ||
129 | */ | ||
130 | extern int register_kernel_hw_breakpoint(struct hw_breakpoint *bp); | ||
131 | extern void unregister_kernel_hw_breakpoint(struct hw_breakpoint *bp); | ||
132 | |||
133 | extern unsigned int hbp_kernel_pos; | ||
134 | |||
135 | #endif /* __KERNEL__ */ | ||
136 | #endif /* _LINUX_HW_BREAKPOINT_H */ | ||