linux/tools/perf/arch/x86/util/machine.c
Jiri Olsa 20f2be1d48 libperf: Move 'page_size' global variable to libperf
We need the 'page_size' variable in libperf, so move it there.

Add a libperf_init() as a global libperf init function to obtain this
value via sysconf() at tool start.

Committer notes:

Add internal/lib.h to tools/perf/ files using 'page_size', sometimes
replacing util.h with it if that was the only reason for having util.h
included.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lore.kernel.org/lkml/20190913132355.21634-33-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-09-25 09:51:48 -03:00

106 lines
2.2 KiB
C

// 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