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// SPDX-License-Identifier: GPL-2.0
#include <linux/types.h>
#include <linux/string.h>
#include <limits.h>
#include <stdlib.h>
#include <internal/lib.h> // page_size
#include "../../util/machine.h"
#include "../../util/map.h"
#include "../../util/symbol.h"
#include <linux/ctype.h>
#include <symbol/kallsyms.h>
#if defined(__x86_64__)
struct extra_kernel_map_info {
int cnt;
int max_cnt;
struct extra_kernel_map *maps;
bool get_entry_trampolines;
u64 entry_trampoline;
};
static int add_extra_kernel_map(struct extra_kernel_map_info *mi, u64 start,
u64 end, u64 pgoff, const char *name)
{
if (mi->cnt >= mi->max_cnt) {
void *buf;
size_t sz;
mi->max_cnt = mi->max_cnt ? mi->max_cnt * 2 : 32;
sz = sizeof(struct extra_kernel_map) * mi->max_cnt;
buf = realloc(mi->maps, sz);
if (!buf)
return -1;
mi->maps = buf;
}
mi->maps[mi->cnt].start = start;
mi->maps[mi->cnt].end = end;
mi->maps[mi->cnt].pgoff = pgoff;
strlcpy(mi->maps[mi->cnt].name, name, KMAP_NAME_LEN);
mi->cnt += 1;
return 0;
}
static int find_extra_kernel_maps(void *arg, const char *name, char type,
u64 start)
{
struct extra_kernel_map_info *mi = arg;
if (!mi->entry_trampoline && kallsyms2elf_binding(type) == STB_GLOBAL &&
!strcmp(name, "_entry_trampoline")) {
mi->entry_trampoline = start;
return 0;
}
if (is_entry_trampoline(name)) {
u64 end = start + page_size;
return add_extra_kernel_map(mi, start, end, 0, name);
}
return 0;
}
int machine__create_extra_kernel_maps(struct machine *machine,
struct dso *kernel)
{
struct extra_kernel_map_info mi = { .cnt = 0, };
char filename[PATH_MAX];
int ret;
int i;
machine__get_kallsyms_filename(machine, filename, PATH_MAX);
if (symbol__restricted_filename(filename, "/proc/kallsyms"))
return 0;
ret = kallsyms__parse(filename, &mi, find_extra_kernel_maps);
if (ret)
goto out_free;
if (!mi.entry_trampoline)
goto out_free;
for (i = 0; i < mi.cnt; i++) {
struct extra_kernel_map *xm = &mi.maps[i];
xm->pgoff = mi.entry_trampoline;
ret = machine__create_extra_kernel_map(machine, kernel, xm);
if (ret)
goto out_free;
}
machine->trampolines_mapped = mi.cnt;
out_free:
free(mi.maps);
return ret;
}
#endif
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