.. | .. |
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11 | 11 | #include <linux/atomic.h> |
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12 | 12 | #include <linux/static_key.h> |
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13 | 13 | |
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| 14 | +struct static_call_key; |
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| 15 | + |
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14 | 16 | struct trace_print_flags { |
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15 | 17 | unsigned long mask; |
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16 | 18 | const char *name; |
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.. | .. |
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30 | 32 | struct tracepoint { |
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31 | 33 | const char *name; /* Tracepoint name */ |
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32 | 34 | struct static_key key; |
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| 35 | + struct static_call_key *static_call_key; |
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| 36 | + void *static_call_tramp; |
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| 37 | + void *iterator; |
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33 | 38 | int (*regfunc)(void); |
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34 | 39 | void (*unregfunc)(void); |
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35 | 40 | struct tracepoint_func __rcu *funcs; |
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.. | .. |
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45 | 50 | struct tracepoint *tp; |
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46 | 51 | void *bpf_func; |
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47 | 52 | u32 num_args; |
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| 53 | + u32 writable_size; |
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48 | 54 | } __aligned(32); |
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49 | 55 | |
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| 56 | +/* |
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| 57 | + * If a tracepoint needs to be called from a header file, it is not |
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| 58 | + * recommended to call it directly, as tracepoints in header files |
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| 59 | + * may cause side-effects and bloat the kernel. Instead, use |
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| 60 | + * tracepoint_enabled() to test if the tracepoint is enabled, then if |
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| 61 | + * it is, call a wrapper function defined in a C file that will then |
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| 62 | + * call the tracepoint. |
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| 63 | + * |
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| 64 | + * For "trace_foo_bar()", you would need to create a wrapper function |
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| 65 | + * in a C file to call trace_foo_bar(): |
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| 66 | + * void do_trace_foo_bar(args) { trace_foo_bar(args); } |
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| 67 | + * Then in the header file, declare the tracepoint: |
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| 68 | + * DECLARE_TRACEPOINT(foo_bar); |
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| 69 | + * And call your wrapper: |
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| 70 | + * static inline void some_inlined_function() { |
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| 71 | + * [..] |
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| 72 | + * if (tracepoint_enabled(foo_bar)) |
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| 73 | + * do_trace_foo_bar(args); |
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| 74 | + * [..] |
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| 75 | + * } |
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| 76 | + * |
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| 77 | + * Note: tracepoint_enabled(foo_bar) is equivalent to trace_foo_bar_enabled() |
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| 78 | + * but is safe to have in headers, where trace_foo_bar_enabled() is not. |
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| 79 | + */ |
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| 80 | +#define DECLARE_TRACEPOINT(tp) \ |
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| 81 | + extern struct tracepoint __tracepoint_##tp |
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| 82 | + |
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| 83 | +#ifdef CONFIG_TRACEPOINTS |
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| 84 | +# define tracepoint_enabled(tp) \ |
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| 85 | + static_key_false(&(__tracepoint_##tp).key) |
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| 86 | +#else |
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| 87 | +# define tracepoint_enabled(tracepoint) false |
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| 88 | +#endif |
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| 89 | + |
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50 | 90 | #endif |
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