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e9607dbe | 1 | /* Low-level statistical profiling support function. Mostly POSIX.1 version. |
d4697bc9 | 2 | Copyright (C) 1996-2014 Free Software Foundation, Inc. |
478b92f0 UD |
3 | This file is part of the GNU C Library. |
4 | ||
5 | The GNU C Library is free software; you can redistribute it and/or | |
41bdb6e2 AJ |
6 | modify it under the terms of the GNU Lesser General Public |
7 | License as published by the Free Software Foundation; either | |
8 | version 2.1 of the License, or (at your option) any later version. | |
478b92f0 UD |
9 | |
10 | The GNU C Library is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
41bdb6e2 | 13 | Lesser General Public License for more details. |
478b92f0 | 14 | |
41bdb6e2 | 15 | You should have received a copy of the GNU Lesser General Public |
59ba27a6 PE |
16 | License along with the GNU C Library; if not, see |
17 | <http://www.gnu.org/licenses/>. */ | |
e9607dbe RM |
18 | |
19 | #include <sys/types.h> | |
20 | #include <unistd.h> | |
21 | #include <errno.h> | |
22 | #include <signal.h> | |
23 | #include <sys/time.h> | |
f2a2deef | 24 | #include <libc-internal.h> |
e9607dbe RM |
25 | |
26 | #ifndef SIGPROF | |
27 | ||
2826ac7e | 28 | #include <gmon/profil.c> |
e9607dbe RM |
29 | |
30 | #else | |
31 | ||
32 | static u_short *samples; | |
33 | static size_t nsamples; | |
34 | static size_t pc_offset; | |
35 | static u_int pc_scale; | |
36 | ||
37 | static inline void | |
38 | profil_count (void *pc) | |
39 | { | |
b236e99d UD |
40 | size_t i = (pc - pc_offset - (void *) 0) / 2; |
41 | ||
42 | if (sizeof (unsigned long long int) > sizeof (size_t)) | |
43 | i = (unsigned long long int) i * pc_scale / 65536; | |
44 | else | |
45 | i = i / 65536 * pc_scale + i % 65536 * pc_scale / 65536; | |
46 | ||
e9607dbe RM |
47 | if (i < nsamples) |
48 | ++samples[i]; | |
49 | } | |
50 | ||
51 | /* Get the machine-dependent definition of `profil_counter', the signal | |
52 | handler for SIGPROF. It calls `profil_count' (above) with the PC of the | |
53 | interrupted code. */ | |
54 | #include "profil-counter.h" | |
55 | ||
56 | /* Enable statistical profiling, writing samples of the PC into at most | |
57 | SIZE bytes of SAMPLE_BUFFER; every processor clock tick while profiling | |
58 | is enabled, the system examines the user PC and increments | |
59 | SAMPLE_BUFFER[((PC - OFFSET) / 2) * SCALE / 65536]. If SCALE is zero, | |
60 | disable profiling. Returns zero on success, -1 on error. */ | |
61 | ||
62 | int | |
9a0a462c | 63 | __profil (u_short *sample_buffer, size_t size, size_t offset, u_int scale) |
e9607dbe | 64 | { |
de7e6366 UD |
65 | struct sigaction act; |
66 | struct itimerval timer; | |
a3848485 | 67 | #if !IS_IN (rtld) |
ce6e047f UD |
68 | static struct sigaction oact; |
69 | static struct itimerval otimer; | |
70 | # define oact_ptr &oact | |
71 | # define otimer_ptr &otimer | |
e9607dbe RM |
72 | |
73 | if (sample_buffer == NULL) | |
74 | { | |
75 | /* Disable profiling. */ | |
76 | if (samples == NULL) | |
77 | /* Wasn't turned on. */ | |
78 | return 0; | |
e9607dbe | 79 | |
50304ef0 | 80 | if (__setitimer (ITIMER_PROF, &otimer, NULL) < 0) |
e9607dbe | 81 | return -1; |
b236e99d | 82 | samples = NULL; |
c0b50509 | 83 | return __sigaction (SIGPROF, &oact, NULL); |
e9607dbe RM |
84 | } |
85 | ||
57ba7bb4 UD |
86 | if (samples) |
87 | { | |
88 | /* Was already turned on. Restore old timer and signal handler | |
89 | first. */ | |
50304ef0 | 90 | if (__setitimer (ITIMER_PROF, &otimer, NULL) < 0 |
c0b50509 | 91 | || __sigaction (SIGPROF, &oact, NULL) < 0) |
57ba7bb4 UD |
92 | return -1; |
93 | } | |
ce6e047f UD |
94 | #else |
95 | /* In ld.so profiling should never be disabled once it runs. */ | |
96 | //assert (sample_buffer != NULL); | |
97 | # define oact_ptr NULL | |
98 | # define otimer_ptr NULL | |
99 | #endif | |
57ba7bb4 | 100 | |
e9607dbe RM |
101 | samples = sample_buffer; |
102 | nsamples = size / sizeof *samples; | |
103 | pc_offset = offset; | |
104 | pc_scale = scale; | |
105 | ||
106 | act.sa_handler = (sighandler_t) &profil_counter; | |
107 | act.sa_flags = SA_RESTART; | |
284128f6 | 108 | __sigfillset (&act.sa_mask); |
ce6e047f | 109 | if (__sigaction (SIGPROF, &act, oact_ptr) < 0) |
e9607dbe RM |
110 | return -1; |
111 | ||
112 | timer.it_value.tv_sec = 0; | |
f2a2deef | 113 | timer.it_value.tv_usec = 1000000 / __profile_frequency (); |
e9607dbe | 114 | timer.it_interval = timer.it_value; |
ce6e047f | 115 | return __setitimer (ITIMER_PROF, &timer, otimer_ptr); |
e9607dbe | 116 | } |
9a0a462c | 117 | weak_alias (__profil, profil) |
e9607dbe RM |
118 | |
119 | #endif |