cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

machine.c (2242B)

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