1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun #include <linux/types.h>
3*4882a593Smuzhiyun #include <linux/string.h>
4*4882a593Smuzhiyun #include <limits.h>
5*4882a593Smuzhiyun #include <stdlib.h>
6*4882a593Smuzhiyun
7*4882a593Smuzhiyun #include <internal/lib.h> // page_size
8*4882a593Smuzhiyun #include "../../../util/machine.h"
9*4882a593Smuzhiyun #include "../../../util/map.h"
10*4882a593Smuzhiyun #include "../../../util/symbol.h"
11*4882a593Smuzhiyun #include <linux/ctype.h>
12*4882a593Smuzhiyun
13*4882a593Smuzhiyun #include <symbol/kallsyms.h>
14*4882a593Smuzhiyun
15*4882a593Smuzhiyun #if defined(__x86_64__)
16*4882a593Smuzhiyun
17*4882a593Smuzhiyun struct extra_kernel_map_info {
18*4882a593Smuzhiyun int cnt;
19*4882a593Smuzhiyun int max_cnt;
20*4882a593Smuzhiyun struct extra_kernel_map *maps;
21*4882a593Smuzhiyun bool get_entry_trampolines;
22*4882a593Smuzhiyun u64 entry_trampoline;
23*4882a593Smuzhiyun };
24*4882a593Smuzhiyun
add_extra_kernel_map(struct extra_kernel_map_info * mi,u64 start,u64 end,u64 pgoff,const char * name)25*4882a593Smuzhiyun static int add_extra_kernel_map(struct extra_kernel_map_info *mi, u64 start,
26*4882a593Smuzhiyun u64 end, u64 pgoff, const char *name)
27*4882a593Smuzhiyun {
28*4882a593Smuzhiyun if (mi->cnt >= mi->max_cnt) {
29*4882a593Smuzhiyun void *buf;
30*4882a593Smuzhiyun size_t sz;
31*4882a593Smuzhiyun
32*4882a593Smuzhiyun mi->max_cnt = mi->max_cnt ? mi->max_cnt * 2 : 32;
33*4882a593Smuzhiyun sz = sizeof(struct extra_kernel_map) * mi->max_cnt;
34*4882a593Smuzhiyun buf = realloc(mi->maps, sz);
35*4882a593Smuzhiyun if (!buf)
36*4882a593Smuzhiyun return -1;
37*4882a593Smuzhiyun mi->maps = buf;
38*4882a593Smuzhiyun }
39*4882a593Smuzhiyun
40*4882a593Smuzhiyun mi->maps[mi->cnt].start = start;
41*4882a593Smuzhiyun mi->maps[mi->cnt].end = end;
42*4882a593Smuzhiyun mi->maps[mi->cnt].pgoff = pgoff;
43*4882a593Smuzhiyun strlcpy(mi->maps[mi->cnt].name, name, KMAP_NAME_LEN);
44*4882a593Smuzhiyun
45*4882a593Smuzhiyun mi->cnt += 1;
46*4882a593Smuzhiyun
47*4882a593Smuzhiyun return 0;
48*4882a593Smuzhiyun }
49*4882a593Smuzhiyun
find_extra_kernel_maps(void * arg,const char * name,char type,u64 start)50*4882a593Smuzhiyun static int find_extra_kernel_maps(void *arg, const char *name, char type,
51*4882a593Smuzhiyun u64 start)
52*4882a593Smuzhiyun {
53*4882a593Smuzhiyun struct extra_kernel_map_info *mi = arg;
54*4882a593Smuzhiyun
55*4882a593Smuzhiyun if (!mi->entry_trampoline && kallsyms2elf_binding(type) == STB_GLOBAL &&
56*4882a593Smuzhiyun !strcmp(name, "_entry_trampoline")) {
57*4882a593Smuzhiyun mi->entry_trampoline = start;
58*4882a593Smuzhiyun return 0;
59*4882a593Smuzhiyun }
60*4882a593Smuzhiyun
61*4882a593Smuzhiyun if (is_entry_trampoline(name)) {
62*4882a593Smuzhiyun u64 end = start + page_size;
63*4882a593Smuzhiyun
64*4882a593Smuzhiyun return add_extra_kernel_map(mi, start, end, 0, name);
65*4882a593Smuzhiyun }
66*4882a593Smuzhiyun
67*4882a593Smuzhiyun return 0;
68*4882a593Smuzhiyun }
69*4882a593Smuzhiyun
machine__create_extra_kernel_maps(struct machine * machine,struct dso * kernel)70*4882a593Smuzhiyun int machine__create_extra_kernel_maps(struct machine *machine,
71*4882a593Smuzhiyun struct dso *kernel)
72*4882a593Smuzhiyun {
73*4882a593Smuzhiyun struct extra_kernel_map_info mi = { .cnt = 0, };
74*4882a593Smuzhiyun char filename[PATH_MAX];
75*4882a593Smuzhiyun int ret;
76*4882a593Smuzhiyun int i;
77*4882a593Smuzhiyun
78*4882a593Smuzhiyun machine__get_kallsyms_filename(machine, filename, PATH_MAX);
79*4882a593Smuzhiyun
80*4882a593Smuzhiyun if (symbol__restricted_filename(filename, "/proc/kallsyms"))
81*4882a593Smuzhiyun return 0;
82*4882a593Smuzhiyun
83*4882a593Smuzhiyun ret = kallsyms__parse(filename, &mi, find_extra_kernel_maps);
84*4882a593Smuzhiyun if (ret)
85*4882a593Smuzhiyun goto out_free;
86*4882a593Smuzhiyun
87*4882a593Smuzhiyun if (!mi.entry_trampoline)
88*4882a593Smuzhiyun goto out_free;
89*4882a593Smuzhiyun
90*4882a593Smuzhiyun for (i = 0; i < mi.cnt; i++) {
91*4882a593Smuzhiyun struct extra_kernel_map *xm = &mi.maps[i];
92*4882a593Smuzhiyun
93*4882a593Smuzhiyun xm->pgoff = mi.entry_trampoline;
94*4882a593Smuzhiyun ret = machine__create_extra_kernel_map(machine, kernel, xm);
95*4882a593Smuzhiyun if (ret)
96*4882a593Smuzhiyun goto out_free;
97*4882a593Smuzhiyun }
98*4882a593Smuzhiyun
99*4882a593Smuzhiyun machine->trampolines_mapped = mi.cnt;
100*4882a593Smuzhiyun out_free:
101*4882a593Smuzhiyun free(mi.maps);
102*4882a593Smuzhiyun return ret;
103*4882a593Smuzhiyun }
104*4882a593Smuzhiyun
105*4882a593Smuzhiyun #endif
106