1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Manage printing of source lines |
4 | * Copyright (c) 2017, Intel Corporation. |
5 | * Author: Andi Kleen |
6 | */ |
7 | #include <linux/list.h> |
8 | #include <linux/zalloc.h> |
9 | #include <stdlib.h> |
10 | #include <sys/mman.h> |
11 | #include <sys/stat.h> |
12 | #include <fcntl.h> |
13 | #include <unistd.h> |
14 | #include <assert.h> |
15 | #include <string.h> |
16 | #include "srccode.h" |
17 | #include "debug.h" |
18 | #include <internal/lib.h> // page_size |
19 | #include "fncache.h" |
20 | |
21 | #define MAXSRCCACHE (32*1024*1024) |
22 | #define MAXSRCFILES 64 |
23 | #define SRC_HTAB_SZ 64 |
24 | |
25 | struct srcfile { |
26 | struct hlist_node hash_nd; |
27 | struct list_head nd; |
28 | char *fn; |
29 | char **lines; |
30 | char *map; |
31 | unsigned numlines; |
32 | size_t maplen; |
33 | }; |
34 | |
35 | static struct hlist_head srcfile_htab[SRC_HTAB_SZ]; |
36 | static LIST_HEAD(srcfile_list); |
37 | static long map_total_sz; |
38 | static int num_srcfiles; |
39 | |
40 | static int countlines(char *map, int maplen) |
41 | { |
42 | int numl; |
43 | char *end = map + maplen; |
44 | char *p = map; |
45 | |
46 | if (maplen == 0) |
47 | return 0; |
48 | numl = 0; |
49 | while (p < end && (p = memchr(p, '\n', end - p)) != NULL) { |
50 | numl++; |
51 | p++; |
52 | } |
53 | if (p < end) |
54 | numl++; |
55 | return numl; |
56 | } |
57 | |
58 | static void fill_lines(char **lines, int maxline, char *map, int maplen) |
59 | { |
60 | int l; |
61 | char *end = map + maplen; |
62 | char *p = map; |
63 | |
64 | if (maplen == 0 || maxline == 0) |
65 | return; |
66 | l = 0; |
67 | lines[l++] = map; |
68 | while (p < end && (p = memchr(p, '\n', end - p)) != NULL) { |
69 | if (l >= maxline) |
70 | return; |
71 | lines[l++] = ++p; |
72 | } |
73 | if (p < end) |
74 | lines[l] = p; |
75 | } |
76 | |
77 | static void free_srcfile(struct srcfile *sf) |
78 | { |
79 | list_del_init(entry: &sf->nd); |
80 | hlist_del(n: &sf->hash_nd); |
81 | map_total_sz -= sf->maplen; |
82 | munmap(sf->map, sf->maplen); |
83 | zfree(&sf->lines); |
84 | zfree(&sf->fn); |
85 | free(sf); |
86 | num_srcfiles--; |
87 | } |
88 | |
89 | static struct srcfile *find_srcfile(char *fn) |
90 | { |
91 | struct stat st; |
92 | struct srcfile *h; |
93 | int fd; |
94 | unsigned long sz; |
95 | unsigned hval = shash(s: (unsigned char *)fn) % SRC_HTAB_SZ; |
96 | |
97 | hlist_for_each_entry (h, &srcfile_htab[hval], hash_nd) { |
98 | if (!strcmp(fn, h->fn)) { |
99 | /* Move to front */ |
100 | list_move(list: &h->nd, head: &srcfile_list); |
101 | return h; |
102 | } |
103 | } |
104 | |
105 | /* Only prune if there is more than one entry */ |
106 | while ((num_srcfiles > MAXSRCFILES || map_total_sz > MAXSRCCACHE) && |
107 | srcfile_list.next != &srcfile_list) { |
108 | assert(!list_empty(head: &srcfile_list)); |
109 | h = list_entry(srcfile_list.prev, struct srcfile, nd); |
110 | free_srcfile(sf: h); |
111 | } |
112 | |
113 | fd = open(fn, O_RDONLY); |
114 | if (fd < 0 || fstat(fd, &st) < 0) { |
115 | pr_debug("cannot open source file %s\n" , fn); |
116 | return NULL; |
117 | } |
118 | |
119 | h = malloc(sizeof(struct srcfile)); |
120 | if (!h) |
121 | return NULL; |
122 | |
123 | h->fn = strdup(fn); |
124 | if (!h->fn) |
125 | goto out_h; |
126 | |
127 | h->maplen = st.st_size; |
128 | sz = (h->maplen + page_size - 1) & ~(page_size - 1); |
129 | h->map = mmap(NULL, sz, PROT_READ, MAP_SHARED, fd, 0); |
130 | close(fd); |
131 | if (h->map == (char *)-1) { |
132 | pr_debug("cannot mmap source file %s\n" , fn); |
133 | goto out_fn; |
134 | } |
135 | h->numlines = countlines(map: h->map, maplen: h->maplen); |
136 | h->lines = calloc(h->numlines, sizeof(char *)); |
137 | if (!h->lines) |
138 | goto out_map; |
139 | fill_lines(lines: h->lines, maxline: h->numlines, map: h->map, maplen: h->maplen); |
140 | list_add(new: &h->nd, head: &srcfile_list); |
141 | hlist_add_head(n: &h->hash_nd, h: &srcfile_htab[hval]); |
142 | map_total_sz += h->maplen; |
143 | num_srcfiles++; |
144 | return h; |
145 | |
146 | out_map: |
147 | munmap(h->map, sz); |
148 | out_fn: |
149 | zfree(&h->fn); |
150 | out_h: |
151 | free(h); |
152 | return NULL; |
153 | } |
154 | |
155 | /* Result is not 0 terminated */ |
156 | char *find_sourceline(char *fn, unsigned line, int *lenp) |
157 | { |
158 | char *l, *p; |
159 | struct srcfile *sf = find_srcfile(fn); |
160 | if (!sf) |
161 | return NULL; |
162 | line--; |
163 | if (line >= sf->numlines) |
164 | return NULL; |
165 | l = sf->lines[line]; |
166 | if (!l) |
167 | return NULL; |
168 | p = memchr(l, '\n', sf->map + sf->maplen - l); |
169 | *lenp = p - l; |
170 | return l; |
171 | } |
172 | |