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0a4e1ae6 JO |
1 | #include <linux/compiler.h> |
2 | #include <linux/rbtree.h> | |
3 | #include <string.h> | |
4 | #include "map.h" | |
5 | #include "symbol.h" | |
6 | #include "util.h" | |
7 | #include "tests.h" | |
8 | #include "debug.h" | |
9 | #include "machine.h" | |
10 | ||
11 | static int vmlinux_matches_kallsyms_filter(struct map *map __maybe_unused, | |
12 | struct symbol *sym) | |
13 | { | |
14 | bool *visited = symbol__priv(sym); | |
15 | *visited = true; | |
16 | return 0; | |
17 | } | |
18 | ||
82e75d00 AH |
19 | #define UM(x) kallsyms_map->unmap_ip(kallsyms_map, (x)) |
20 | ||
0a4e1ae6 JO |
21 | int test__vmlinux_matches_kallsyms(void) |
22 | { | |
23 | int err = -1; | |
24 | struct rb_node *nd; | |
25 | struct symbol *sym; | |
26 | struct map *kallsyms_map, *vmlinux_map; | |
27 | struct machine kallsyms, vmlinux; | |
28 | enum map_type type = MAP__FUNCTION; | |
d380b348 | 29 | u64 mem_start, mem_end; |
0a4e1ae6 JO |
30 | |
31 | /* | |
32 | * Step 1: | |
33 | * | |
34 | * Init the machines that will hold kernel, modules obtained from | |
35 | * both vmlinux + .ko files and from /proc/kallsyms split by modules. | |
36 | */ | |
37 | machine__init(&kallsyms, "", HOST_KERNEL_ID); | |
38 | machine__init(&vmlinux, "", HOST_KERNEL_ID); | |
39 | ||
40 | /* | |
41 | * Step 2: | |
42 | * | |
43 | * Create the kernel maps for kallsyms and the DSO where we will then | |
44 | * load /proc/kallsyms. Also create the modules maps from /proc/modules | |
45 | * and find the .ko files that match them in /lib/modules/`uname -r`/. | |
46 | */ | |
47 | if (machine__create_kernel_maps(&kallsyms) < 0) { | |
48 | pr_debug("machine__create_kernel_maps "); | |
c0aab59f | 49 | goto out; |
0a4e1ae6 JO |
50 | } |
51 | ||
52 | /* | |
53 | * Step 3: | |
54 | * | |
55 | * Load and split /proc/kallsyms into multiple maps, one per module. | |
56 | */ | |
57 | if (machine__load_kallsyms(&kallsyms, "/proc/kallsyms", type, NULL) <= 0) { | |
58 | pr_debug("dso__load_kallsyms "); | |
59 | goto out; | |
60 | } | |
61 | ||
62 | /* | |
63 | * Step 4: | |
64 | * | |
65 | * kallsyms will be internally on demand sorted by name so that we can | |
66 | * find the reference relocation * symbol, i.e. the symbol we will use | |
67 | * to see if the running kernel was relocated by checking if it has the | |
68 | * same value in the vmlinux file we load. | |
69 | */ | |
70 | kallsyms_map = machine__kernel_map(&kallsyms, type); | |
71 | ||
0a4e1ae6 JO |
72 | /* |
73 | * Step 5: | |
74 | * | |
75 | * Now repeat step 2, this time for the vmlinux file we'll auto-locate. | |
76 | */ | |
77 | if (machine__create_kernel_maps(&vmlinux) < 0) { | |
78 | pr_debug("machine__create_kernel_maps "); | |
79 | goto out; | |
80 | } | |
81 | ||
82 | vmlinux_map = machine__kernel_map(&vmlinux, type); | |
0a4e1ae6 JO |
83 | |
84 | /* | |
85 | * Step 6: | |
86 | * | |
87 | * Locate a vmlinux file in the vmlinux path that has a buildid that | |
88 | * matches the one of the running kernel. | |
89 | * | |
90 | * While doing that look if we find the ref reloc symbol, if we find it | |
91 | * we'll have its ref_reloc_symbol.unrelocated_addr and then | |
92 | * maps__reloc_vmlinux will notice and set proper ->[un]map_ip routines | |
93 | * to fixup the symbols. | |
94 | */ | |
95 | if (machine__load_vmlinux_path(&vmlinux, type, | |
96 | vmlinux_matches_kallsyms_filter) <= 0) { | |
531f67bb ACM |
97 | pr_debug("Couldn't find a vmlinux that matches the kernel running on this machine, skipping test\n"); |
98 | err = TEST_SKIP; | |
0a4e1ae6 JO |
99 | goto out; |
100 | } | |
101 | ||
102 | err = 0; | |
103 | /* | |
104 | * Step 7: | |
105 | * | |
106 | * Now look at the symbols in the vmlinux DSO and check if we find all of them | |
107 | * in the kallsyms dso. For the ones that are in both, check its names and | |
108 | * end addresses too. | |
109 | */ | |
110 | for (nd = rb_first(&vmlinux_map->dso->symbols[type]); nd; nd = rb_next(nd)) { | |
111 | struct symbol *pair, *first_pair; | |
112 | bool backwards = true; | |
113 | ||
114 | sym = rb_entry(nd, struct symbol, rb_node); | |
115 | ||
116 | if (sym->start == sym->end) | |
117 | continue; | |
118 | ||
d380b348 AH |
119 | mem_start = vmlinux_map->unmap_ip(vmlinux_map, sym->start); |
120 | mem_end = vmlinux_map->unmap_ip(vmlinux_map, sym->end); | |
121 | ||
122 | first_pair = machine__find_kernel_symbol(&kallsyms, type, | |
123 | mem_start, NULL, NULL); | |
0a4e1ae6 JO |
124 | pair = first_pair; |
125 | ||
82e75d00 | 126 | if (pair && UM(pair->start) == mem_start) { |
0a4e1ae6 JO |
127 | next_pair: |
128 | if (strcmp(sym->name, pair->name) == 0) { | |
129 | /* | |
130 | * kallsyms don't have the symbol end, so we | |
131 | * set that by using the next symbol start - 1, | |
132 | * in some cases we get this up to a page | |
133 | * wrong, trace_kmalloc when I was developing | |
134 | * this code was one such example, 2106 bytes | |
135 | * off the real size. More than that and we | |
136 | * _really_ have a problem. | |
137 | */ | |
82e75d00 | 138 | s64 skew = mem_end - UM(pair->end); |
5888a8c2 JO |
139 | if (llabs(skew) >= page_size) |
140 | pr_debug("%#" PRIx64 ": diff end addr for %s v: %#" PRIx64 " k: %#" PRIx64 "\n", | |
d380b348 | 141 | mem_start, sym->name, mem_end, |
82e75d00 | 142 | UM(pair->end)); |
5888a8c2 JO |
143 | |
144 | /* | |
145 | * Do not count this as a failure, because we | |
146 | * could really find a case where it's not | |
147 | * possible to get proper function end from | |
148 | * kallsyms. | |
149 | */ | |
150 | continue; | |
0a4e1ae6 | 151 | |
0a4e1ae6 JO |
152 | } else { |
153 | struct rb_node *nnd; | |
154 | detour: | |
155 | nnd = backwards ? rb_prev(&pair->rb_node) : | |
156 | rb_next(&pair->rb_node); | |
157 | if (nnd) { | |
158 | struct symbol *next = rb_entry(nnd, struct symbol, rb_node); | |
159 | ||
82e75d00 | 160 | if (UM(next->start) == mem_start) { |
0a4e1ae6 JO |
161 | pair = next; |
162 | goto next_pair; | |
163 | } | |
164 | } | |
165 | ||
166 | if (backwards) { | |
167 | backwards = false; | |
168 | pair = first_pair; | |
169 | goto detour; | |
170 | } | |
171 | ||
172 | pr_debug("%#" PRIx64 ": diff name v: %s k: %s\n", | |
d380b348 | 173 | mem_start, sym->name, pair->name); |
0a4e1ae6 JO |
174 | } |
175 | } else | |
d380b348 AH |
176 | pr_debug("%#" PRIx64 ": %s not on kallsyms\n", |
177 | mem_start, sym->name); | |
0a4e1ae6 JO |
178 | |
179 | err = -1; | |
180 | } | |
181 | ||
182 | if (!verbose) | |
183 | goto out; | |
184 | ||
185 | pr_info("Maps only in vmlinux:\n"); | |
186 | ||
187 | for (nd = rb_first(&vmlinux.kmaps.maps[type]); nd; nd = rb_next(nd)) { | |
188 | struct map *pos = rb_entry(nd, struct map, rb_node), *pair; | |
189 | /* | |
190 | * If it is the kernel, kallsyms is always "[kernel.kallsyms]", while | |
191 | * the kernel will have the path for the vmlinux file being used, | |
192 | * so use the short name, less descriptive but the same ("[kernel]" in | |
193 | * both cases. | |
194 | */ | |
195 | pair = map_groups__find_by_name(&kallsyms.kmaps, type, | |
196 | (pos->dso->kernel ? | |
197 | pos->dso->short_name : | |
198 | pos->dso->name)); | |
199 | if (pair) | |
200 | pair->priv = 1; | |
201 | else | |
202 | map__fprintf(pos, stderr); | |
203 | } | |
204 | ||
205 | pr_info("Maps in vmlinux with a different name in kallsyms:\n"); | |
206 | ||
207 | for (nd = rb_first(&vmlinux.kmaps.maps[type]); nd; nd = rb_next(nd)) { | |
208 | struct map *pos = rb_entry(nd, struct map, rb_node), *pair; | |
209 | ||
d380b348 AH |
210 | mem_start = vmlinux_map->unmap_ip(vmlinux_map, pos->start); |
211 | mem_end = vmlinux_map->unmap_ip(vmlinux_map, pos->end); | |
212 | ||
213 | pair = map_groups__find(&kallsyms.kmaps, type, mem_start); | |
0a4e1ae6 JO |
214 | if (pair == NULL || pair->priv) |
215 | continue; | |
216 | ||
d380b348 | 217 | if (pair->start == mem_start) { |
0a4e1ae6 JO |
218 | pair->priv = 1; |
219 | pr_info(" %" PRIx64 "-%" PRIx64 " %" PRIx64 " %s in kallsyms as", | |
220 | pos->start, pos->end, pos->pgoff, pos->dso->name); | |
d380b348 AH |
221 | if (mem_end != pair->end) |
222 | pr_info(":\n*%" PRIx64 "-%" PRIx64 " %" PRIx64, | |
0a4e1ae6 JO |
223 | pair->start, pair->end, pair->pgoff); |
224 | pr_info(" %s\n", pair->dso->name); | |
225 | pair->priv = 1; | |
226 | } | |
227 | } | |
228 | ||
229 | pr_info("Maps only in kallsyms:\n"); | |
230 | ||
231 | for (nd = rb_first(&kallsyms.kmaps.maps[type]); | |
232 | nd; nd = rb_next(nd)) { | |
233 | struct map *pos = rb_entry(nd, struct map, rb_node); | |
234 | ||
235 | if (!pos->priv) | |
236 | map__fprintf(pos, stderr); | |
237 | } | |
238 | out: | |
c0aab59f ACM |
239 | machine__exit(&kallsyms); |
240 | machine__exit(&vmlinux); | |
0a4e1ae6 JO |
241 | return err; |
242 | } |