Commit | Line | Data |
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d05f5f99 DM |
1 | #include <linux/spinlock.h> |
2 | #include <linux/hardirq.h> | |
3 | #include <linux/ftrace.h> | |
4 | #include <linux/percpu.h> | |
5 | #include <linux/init.h> | |
6 | #include <linux/list.h> | |
7 | ||
395a59d0 AS |
8 | #include <asm/ftrace.h> |
9 | ||
d05f5f99 DM |
10 | static const u32 ftrace_nop = 0x01000000; |
11 | ||
15adc048 | 12 | unsigned char *ftrace_nop_replace(void) |
d05f5f99 DM |
13 | { |
14 | return (char *)&ftrace_nop; | |
15 | } | |
16 | ||
15adc048 | 17 | unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr) |
d05f5f99 DM |
18 | { |
19 | static u32 call; | |
20 | s32 off; | |
21 | ||
22 | off = ((s32)addr - (s32)ip); | |
23 | call = 0x40000000 | ((u32)off >> 2); | |
24 | ||
25 | return (unsigned char *) &call; | |
26 | } | |
27 | ||
15adc048 | 28 | int |
d05f5f99 DM |
29 | ftrace_modify_code(unsigned long ip, unsigned char *old_code, |
30 | unsigned char *new_code) | |
31 | { | |
32 | u32 old = *(u32 *)old_code; | |
33 | u32 new = *(u32 *)new_code; | |
34 | u32 replaced; | |
35 | int faulted; | |
36 | ||
37 | __asm__ __volatile__( | |
38 | "1: cas [%[ip]], %[old], %[new]\n" | |
39 | " flush %[ip]\n" | |
40 | " mov 0, %[faulted]\n" | |
41 | "2:\n" | |
42 | " .section .fixup,#alloc,#execinstr\n" | |
43 | " .align 4\n" | |
44 | "3: sethi %%hi(2b), %[faulted]\n" | |
45 | " jmpl %[faulted] + %%lo(2b), %%g0\n" | |
46 | " mov 1, %[faulted]\n" | |
47 | " .previous\n" | |
48 | " .section __ex_table,\"a\"\n" | |
49 | " .align 4\n" | |
50 | " .word 1b, 3b\n" | |
51 | " .previous\n" | |
52 | : "=r" (replaced), [faulted] "=r" (faulted) | |
53 | : [new] "0" (new), [old] "r" (old), [ip] "r" (ip) | |
54 | : "memory"); | |
55 | ||
56 | if (replaced != old && replaced != new) | |
57 | faulted = 2; | |
58 | ||
59 | return faulted; | |
60 | } | |
61 | ||
15adc048 | 62 | int ftrace_update_ftrace_func(ftrace_func_t func) |
d05f5f99 DM |
63 | { |
64 | unsigned long ip = (unsigned long)(&ftrace_call); | |
395a59d0 | 65 | unsigned char old[MCOUNT_INSN_SIZE], *new; |
d05f5f99 | 66 | |
395a59d0 | 67 | memcpy(old, &ftrace_call, MCOUNT_INSN_SIZE); |
d05f5f99 DM |
68 | new = ftrace_call_replace(ip, (unsigned long)func); |
69 | return ftrace_modify_code(ip, old, new); | |
70 | } | |
71 | ||
d05f5f99 DM |
72 | int __init ftrace_dyn_arch_init(void *data) |
73 | { | |
74 | ftrace_mcount_set(data); | |
75 | return 0; | |
76 | } |