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 | ||
4df3c9ec HD |
21 | #define __hot __attribute__ ((__section__ (".text.hot"))) |
22 | ||
d75f054a | 23 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
d75f054a HD |
24 | /* |
25 | * Hook the return address and push it in the stack of return addrs | |
26 | * in current thread info. | |
27 | */ | |
4df3c9ec HD |
28 | static void __hot prepare_ftrace_return(unsigned long *parent, |
29 | unsigned long self_addr) | |
d75f054a HD |
30 | { |
31 | unsigned long old; | |
d75f054a | 32 | struct ftrace_graph_ent trace; |
366dd4ea | 33 | extern int parisc_return_to_handler; |
d75f054a | 34 | |
3a46588e SRRH |
35 | if (unlikely(ftrace_graph_is_dead())) |
36 | return; | |
37 | ||
d75f054a HD |
38 | if (unlikely(atomic_read(¤t->tracing_graph_pause))) |
39 | return; | |
40 | ||
41 | old = *parent; | |
d75f054a | 42 | |
366dd4ea HD |
43 | trace.func = self_addr; |
44 | trace.depth = current->curr_ret_stack + 1; | |
d75f054a | 45 | |
366dd4ea HD |
46 | /* Only trace if the calling function expects to */ |
47 | if (!ftrace_graph_entry(&trace)) | |
d75f054a | 48 | return; |
d75f054a | 49 | |
366dd4ea HD |
50 | if (ftrace_push_return_trace(old, self_addr, &trace.depth, |
51 | 0 ) == -EBUSY) | |
52 | return; | |
d75f054a | 53 | |
366dd4ea HD |
54 | /* activate parisc_return_to_handler() as return point */ |
55 | *parent = (unsigned long) &parisc_return_to_handler; | |
d75f054a | 56 | } |
d75f054a HD |
57 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
58 | ||
4df3c9ec | 59 | void notrace __hot ftrace_function_trampoline(unsigned long parent, |
d75f054a HD |
60 | unsigned long self_addr, |
61 | unsigned long org_sp_gr3) | |
62 | { | |
366dd4ea HD |
63 | extern ftrace_func_t ftrace_trace_function; /* depends on CONFIG_DYNAMIC_FTRACE */ |
64 | extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace); | |
d75f054a | 65 | |
d75f054a | 66 | if (ftrace_trace_function != ftrace_stub) { |
366dd4ea HD |
67 | /* struct ftrace_ops *op, struct pt_regs *regs); */ |
68 | ftrace_trace_function(parent, self_addr, NULL, NULL); | |
d75f054a HD |
69 | return; |
70 | } | |
366dd4ea | 71 | |
d75f054a | 72 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
366dd4ea HD |
73 | if (ftrace_graph_return != (trace_func_graph_ret_t) ftrace_stub || |
74 | ftrace_graph_entry != ftrace_graph_entry_stub) { | |
d75f054a HD |
75 | unsigned long *parent_rp; |
76 | ||
d75f054a | 77 | /* calculate pointer to %rp in stack */ |
366dd4ea | 78 | parent_rp = (unsigned long *) (org_sp_gr3 - RP_OFFSET); |
d75f054a HD |
79 | /* sanity check: parent_rp should hold parent */ |
80 | if (*parent_rp != parent) | |
81 | return; | |
366dd4ea | 82 | |
d75f054a HD |
83 | prepare_ftrace_return(parent_rp, self_addr); |
84 | return; | |
85 | } | |
86 | #endif | |
87 | } | |
88 |