Commit | Line | Data |
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d75f054a HD |
1 | /* |
2 | * Code for tracing calls in Linux kernel. | |
366dd4ea | 3 | * Copyright (C) 2009-2016 Helge Deller <deller@gmx.de> |
d75f054a HD |
4 | * |
5 | * based on code for x86 which is: | |
6 | * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> | |
7 | * | |
8 | * future possible enhancements: | |
9 | * - add CONFIG_DYNAMIC_FTRACE | |
10 | * - add CONFIG_STACK_TRACER | |
11 | */ | |
12 | ||
13 | #include <linux/init.h> | |
14 | #include <linux/ftrace.h> | |
15 | ||
366dd4ea | 16 | #include <asm/assembly.h> |
d75f054a HD |
17 | #include <asm/sections.h> |
18 | #include <asm/ftrace.h> | |
19 | ||
20 | ||
d75f054a | 21 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
d75f054a HD |
22 | /* |
23 | * Hook the return address and push it in the stack of return addrs | |
24 | * in current thread info. | |
25 | */ | |
366dd4ea | 26 | static void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr) |
d75f054a HD |
27 | { |
28 | unsigned long old; | |
d75f054a | 29 | struct ftrace_graph_ent trace; |
366dd4ea | 30 | extern int parisc_return_to_handler; |
d75f054a | 31 | |
3a46588e SRRH |
32 | if (unlikely(ftrace_graph_is_dead())) |
33 | return; | |
34 | ||
d75f054a HD |
35 | if (unlikely(atomic_read(¤t->tracing_graph_pause))) |
36 | return; | |
37 | ||
38 | old = *parent; | |
d75f054a | 39 | |
366dd4ea HD |
40 | trace.func = self_addr; |
41 | trace.depth = current->curr_ret_stack + 1; | |
d75f054a | 42 | |
366dd4ea HD |
43 | /* Only trace if the calling function expects to */ |
44 | if (!ftrace_graph_entry(&trace)) | |
d75f054a | 45 | return; |
d75f054a | 46 | |
366dd4ea HD |
47 | if (ftrace_push_return_trace(old, self_addr, &trace.depth, |
48 | 0 ) == -EBUSY) | |
49 | return; | |
d75f054a | 50 | |
366dd4ea HD |
51 | /* activate parisc_return_to_handler() as return point */ |
52 | *parent = (unsigned long) &parisc_return_to_handler; | |
d75f054a | 53 | } |
d75f054a HD |
54 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
55 | ||
366dd4ea | 56 | void notrace ftrace_function_trampoline(unsigned long parent, |
d75f054a HD |
57 | unsigned long self_addr, |
58 | unsigned long org_sp_gr3) | |
59 | { | |
366dd4ea HD |
60 | extern ftrace_func_t ftrace_trace_function; /* depends on CONFIG_DYNAMIC_FTRACE */ |
61 | extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace); | |
d75f054a | 62 | |
d75f054a | 63 | if (ftrace_trace_function != ftrace_stub) { |
366dd4ea HD |
64 | /* struct ftrace_ops *op, struct pt_regs *regs); */ |
65 | ftrace_trace_function(parent, self_addr, NULL, NULL); | |
d75f054a HD |
66 | return; |
67 | } | |
366dd4ea | 68 | |
d75f054a | 69 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
366dd4ea HD |
70 | if (ftrace_graph_return != (trace_func_graph_ret_t) ftrace_stub || |
71 | ftrace_graph_entry != ftrace_graph_entry_stub) { | |
d75f054a HD |
72 | unsigned long *parent_rp; |
73 | ||
d75f054a | 74 | /* calculate pointer to %rp in stack */ |
366dd4ea | 75 | parent_rp = (unsigned long *) (org_sp_gr3 - RP_OFFSET); |
d75f054a HD |
76 | /* sanity check: parent_rp should hold parent */ |
77 | if (*parent_rp != parent) | |
78 | return; | |
366dd4ea | 79 | |
d75f054a HD |
80 | prepare_ftrace_return(parent_rp, self_addr); |
81 | return; | |
82 | } | |
83 | #endif | |
84 | } | |
85 |