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e7ee404757
Before this patch, if a sample is triggered inside a module not in /lib/modules/`uname -r`/, even if the module is in buildid-cache, 'perf report' will still be unable to find the correct symbol. For example: # rm -rf ~/.debug/ # perf buildid-cache -a ./mymodule.ko # perf probe -m ./mymodule.ko -a get_mymodule_val Added new event: probe:get_mymodule_val (on get_mymodule_val in mymodule) You can now use it in all perf tools, such as: perf record -e probe:get_mymodule_val -aR sleep 1 # perf record -e probe:get_mymodule_val cat /proc/mymodule mymodule:3 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.011 MB perf.data (1 samples) ] # perf report --stdio [SNIP] # # Overhead Command Shared Object Symbol # ........ ....... ................ ...................... # 100.00% cat [mymodule] [k] 0x0000000000000001 # perf report -vvvv --stdio dso__load_sym: adjusting symbol: st_value: 0 sh_addr: 0 sh_offset: 0x70 symbol__new: get_mymodule_val 0x70-0x8a [SNIP] This is caused by dso__load() -> dso__load_sym(). In dso__load(), kmod is true only when its file is found in some well know directories. All files loaded from buildid-cache are treated as user programs. Following dso__load_sym() set map->pgoff incorrectly. This patch gives kernel modules in buildid-cache a chance to adjust value of kmod. After dso__load() get the type of symbols, if it is buildid, check the last 3 chars of original filename against '.ko', and adjust the value of kmod if the file is a kernel module. Signed-off-by: Wang Nan <wangnan0@huawei.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: Cody P Schafer <dev@codyps.com> Cc: He Kuang <hekuang@huawei.com> Cc: Jeremie Galarneau <jeremie.galarneau@efficios.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Kirill Smelkov <kirr@nexedi.com> Cc: Li Zefan <lizefan@huawei.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1454680939-24963-3-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
596 lines
13 KiB
C
596 lines
13 KiB
C
/*
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* build-id.c
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*
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* build-id support
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*
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* Copyright (C) 2009, 2010 Red Hat Inc.
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* Copyright (C) 2009, 2010 Arnaldo Carvalho de Melo <acme@redhat.com>
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*/
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#include "util.h"
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#include <stdio.h>
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#include "build-id.h"
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#include "event.h"
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#include "symbol.h"
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#include <linux/kernel.h>
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#include "debug.h"
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#include "session.h"
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#include "tool.h"
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#include "header.h"
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#include "vdso.h"
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static bool no_buildid_cache;
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int build_id__mark_dso_hit(struct perf_tool *tool __maybe_unused,
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union perf_event *event,
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struct perf_sample *sample,
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struct perf_evsel *evsel __maybe_unused,
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struct machine *machine)
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{
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struct addr_location al;
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u8 cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
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struct thread *thread = machine__findnew_thread(machine, sample->pid,
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sample->tid);
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if (thread == NULL) {
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pr_err("problem processing %d event, skipping it.\n",
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event->header.type);
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return -1;
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}
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thread__find_addr_map(thread, cpumode, MAP__FUNCTION, sample->ip, &al);
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if (al.map != NULL)
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al.map->dso->hit = 1;
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thread__put(thread);
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return 0;
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}
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static int perf_event__exit_del_thread(struct perf_tool *tool __maybe_unused,
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union perf_event *event,
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struct perf_sample *sample
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__maybe_unused,
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struct machine *machine)
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{
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struct thread *thread = machine__findnew_thread(machine,
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event->fork.pid,
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event->fork.tid);
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dump_printf("(%d:%d):(%d:%d)\n", event->fork.pid, event->fork.tid,
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event->fork.ppid, event->fork.ptid);
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if (thread) {
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machine__remove_thread(machine, thread);
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thread__put(thread);
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}
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return 0;
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}
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struct perf_tool build_id__mark_dso_hit_ops = {
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.sample = build_id__mark_dso_hit,
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.mmap = perf_event__process_mmap,
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.mmap2 = perf_event__process_mmap2,
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.fork = perf_event__process_fork,
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.exit = perf_event__exit_del_thread,
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.attr = perf_event__process_attr,
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.build_id = perf_event__process_build_id,
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.ordered_events = true,
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};
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int build_id__sprintf(const u8 *build_id, int len, char *bf)
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{
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char *bid = bf;
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const u8 *raw = build_id;
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int i;
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for (i = 0; i < len; ++i) {
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sprintf(bid, "%02x", *raw);
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++raw;
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bid += 2;
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}
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return (bid - bf) + 1;
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}
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int sysfs__sprintf_build_id(const char *root_dir, char *sbuild_id)
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{
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char notes[PATH_MAX];
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u8 build_id[BUILD_ID_SIZE];
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int ret;
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if (!root_dir)
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root_dir = "";
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scnprintf(notes, sizeof(notes), "%s/sys/kernel/notes", root_dir);
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ret = sysfs__read_build_id(notes, build_id, sizeof(build_id));
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if (ret < 0)
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return ret;
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return build_id__sprintf(build_id, sizeof(build_id), sbuild_id);
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}
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int filename__sprintf_build_id(const char *pathname, char *sbuild_id)
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{
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u8 build_id[BUILD_ID_SIZE];
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int ret;
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ret = filename__read_build_id(pathname, build_id, sizeof(build_id));
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if (ret < 0)
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return ret;
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else if (ret != sizeof(build_id))
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return -EINVAL;
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return build_id__sprintf(build_id, sizeof(build_id), sbuild_id);
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}
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/* asnprintf consolidates asprintf and snprintf */
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static int asnprintf(char **strp, size_t size, const char *fmt, ...)
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{
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va_list ap;
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int ret;
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if (!strp)
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return -EINVAL;
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va_start(ap, fmt);
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if (*strp)
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ret = vsnprintf(*strp, size, fmt, ap);
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else
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ret = vasprintf(strp, fmt, ap);
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va_end(ap);
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return ret;
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}
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static char *build_id__filename(const char *sbuild_id, char *bf, size_t size)
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{
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char *tmp = bf;
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int ret = asnprintf(&bf, size, "%s/.build-id/%.2s/%s", buildid_dir,
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sbuild_id, sbuild_id + 2);
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if (ret < 0 || (tmp && size < (unsigned int)ret))
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return NULL;
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return bf;
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}
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char *dso__build_id_filename(const struct dso *dso, char *bf, size_t size)
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{
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char build_id_hex[SBUILD_ID_SIZE];
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if (!dso->has_build_id)
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return NULL;
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build_id__sprintf(dso->build_id, sizeof(dso->build_id), build_id_hex);
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return build_id__filename(build_id_hex, bf, size);
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}
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bool dso__build_id_is_kmod(const struct dso *dso, char *bf, size_t size)
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{
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char *id_name, *ch;
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struct stat sb;
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id_name = dso__build_id_filename(dso, bf, size);
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if (!id_name)
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goto err;
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if (access(id_name, F_OK))
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goto err;
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if (lstat(id_name, &sb) == -1)
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goto err;
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if ((size_t)sb.st_size > size - 1)
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goto err;
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if (readlink(id_name, bf, size - 1) < 0)
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goto err;
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bf[sb.st_size] = '\0';
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/*
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* link should be:
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* ../../lib/modules/4.4.0-rc4/kernel/net/ipv4/netfilter/nf_nat_ipv4.ko/a09fe3eb3147dafa4e3b31dbd6257e4d696bdc92
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*/
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ch = strrchr(bf, '/');
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if (!ch)
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goto err;
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if (ch - 3 < bf)
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goto err;
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return strncmp(".ko", ch - 3, 3) == 0;
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err:
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/*
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* If dso__build_id_filename work, get id_name again,
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* because id_name points to bf and is broken.
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*/
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if (id_name)
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id_name = dso__build_id_filename(dso, bf, size);
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pr_err("Invalid build id: %s\n", id_name ? :
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dso->long_name ? :
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dso->short_name ? :
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"[unknown]");
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return false;
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}
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#define dsos__for_each_with_build_id(pos, head) \
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list_for_each_entry(pos, head, node) \
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if (!pos->has_build_id) \
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continue; \
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else
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static int write_buildid(const char *name, size_t name_len, u8 *build_id,
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pid_t pid, u16 misc, int fd)
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{
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int err;
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struct build_id_event b;
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size_t len;
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len = name_len + 1;
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len = PERF_ALIGN(len, NAME_ALIGN);
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memset(&b, 0, sizeof(b));
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memcpy(&b.build_id, build_id, BUILD_ID_SIZE);
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b.pid = pid;
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b.header.misc = misc;
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b.header.size = sizeof(b) + len;
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err = writen(fd, &b, sizeof(b));
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if (err < 0)
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return err;
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return write_padded(fd, name, name_len + 1, len);
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}
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static int machine__write_buildid_table(struct machine *machine, int fd)
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{
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int err = 0;
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char nm[PATH_MAX];
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struct dso *pos;
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u16 kmisc = PERF_RECORD_MISC_KERNEL,
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umisc = PERF_RECORD_MISC_USER;
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if (!machine__is_host(machine)) {
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kmisc = PERF_RECORD_MISC_GUEST_KERNEL;
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umisc = PERF_RECORD_MISC_GUEST_USER;
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}
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dsos__for_each_with_build_id(pos, &machine->dsos.head) {
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const char *name;
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size_t name_len;
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bool in_kernel = false;
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if (!pos->hit)
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continue;
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if (dso__is_vdso(pos)) {
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name = pos->short_name;
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name_len = pos->short_name_len + 1;
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} else if (dso__is_kcore(pos)) {
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machine__mmap_name(machine, nm, sizeof(nm));
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name = nm;
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name_len = strlen(nm) + 1;
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} else {
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name = pos->long_name;
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name_len = pos->long_name_len + 1;
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}
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in_kernel = pos->kernel ||
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is_kernel_module(name,
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PERF_RECORD_MISC_CPUMODE_UNKNOWN);
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err = write_buildid(name, name_len, pos->build_id, machine->pid,
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in_kernel ? kmisc : umisc, fd);
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if (err)
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break;
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}
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return err;
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}
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int perf_session__write_buildid_table(struct perf_session *session, int fd)
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{
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struct rb_node *nd;
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int err = machine__write_buildid_table(&session->machines.host, fd);
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if (err)
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return err;
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for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
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struct machine *pos = rb_entry(nd, struct machine, rb_node);
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err = machine__write_buildid_table(pos, fd);
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if (err)
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break;
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}
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return err;
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}
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static int __dsos__hit_all(struct list_head *head)
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{
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struct dso *pos;
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list_for_each_entry(pos, head, node)
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pos->hit = true;
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return 0;
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}
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static int machine__hit_all_dsos(struct machine *machine)
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{
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return __dsos__hit_all(&machine->dsos.head);
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}
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int dsos__hit_all(struct perf_session *session)
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{
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struct rb_node *nd;
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int err;
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err = machine__hit_all_dsos(&session->machines.host);
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if (err)
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return err;
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for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
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struct machine *pos = rb_entry(nd, struct machine, rb_node);
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err = machine__hit_all_dsos(pos);
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if (err)
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return err;
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}
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return 0;
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}
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void disable_buildid_cache(void)
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{
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no_buildid_cache = true;
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}
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static char *build_id_cache__dirname_from_path(const char *name,
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bool is_kallsyms, bool is_vdso)
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{
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char *realname = (char *)name, *filename;
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bool slash = is_kallsyms || is_vdso;
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if (!slash) {
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realname = realpath(name, NULL);
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if (!realname)
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return NULL;
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}
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if (asprintf(&filename, "%s%s%s", buildid_dir, slash ? "/" : "",
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is_vdso ? DSO__NAME_VDSO : realname) < 0)
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filename = NULL;
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if (!slash)
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free(realname);
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return filename;
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}
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int build_id_cache__list_build_ids(const char *pathname,
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struct strlist **result)
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{
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struct strlist *list;
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char *dir_name;
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DIR *dir;
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struct dirent *d;
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int ret = 0;
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list = strlist__new(NULL, NULL);
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dir_name = build_id_cache__dirname_from_path(pathname, false, false);
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if (!list || !dir_name) {
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ret = -ENOMEM;
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goto out;
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}
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/* List up all dirents */
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dir = opendir(dir_name);
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if (!dir) {
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ret = -errno;
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goto out;
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}
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while ((d = readdir(dir)) != NULL) {
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if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
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continue;
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strlist__add(list, d->d_name);
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}
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closedir(dir);
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out:
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free(dir_name);
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if (ret)
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strlist__delete(list);
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else
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*result = list;
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return ret;
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}
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int build_id_cache__add_s(const char *sbuild_id, const char *name,
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bool is_kallsyms, bool is_vdso)
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{
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const size_t size = PATH_MAX;
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char *realname = NULL, *filename = NULL, *dir_name = NULL,
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*linkname = zalloc(size), *targetname, *tmp;
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int err = -1;
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if (!is_kallsyms) {
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realname = realpath(name, NULL);
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if (!realname)
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goto out_free;
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}
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dir_name = build_id_cache__dirname_from_path(name, is_kallsyms, is_vdso);
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if (!dir_name)
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goto out_free;
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if (mkdir_p(dir_name, 0755))
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goto out_free;
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if (asprintf(&filename, "%s/%s", dir_name, sbuild_id) < 0) {
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filename = NULL;
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goto out_free;
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}
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if (access(filename, F_OK)) {
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if (is_kallsyms) {
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if (copyfile("/proc/kallsyms", filename))
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goto out_free;
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} else if (link(realname, filename) && errno != EEXIST &&
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copyfile(name, filename))
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goto out_free;
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}
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if (!build_id__filename(sbuild_id, linkname, size))
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goto out_free;
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tmp = strrchr(linkname, '/');
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*tmp = '\0';
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if (access(linkname, X_OK) && mkdir_p(linkname, 0755))
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goto out_free;
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*tmp = '/';
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targetname = filename + strlen(buildid_dir) - 5;
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memcpy(targetname, "../..", 5);
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if (symlink(targetname, linkname) == 0)
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err = 0;
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out_free:
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if (!is_kallsyms)
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free(realname);
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free(filename);
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free(dir_name);
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free(linkname);
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return err;
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}
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static int build_id_cache__add_b(const u8 *build_id, size_t build_id_size,
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const char *name, bool is_kallsyms,
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bool is_vdso)
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{
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char sbuild_id[SBUILD_ID_SIZE];
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build_id__sprintf(build_id, build_id_size, sbuild_id);
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return build_id_cache__add_s(sbuild_id, name, is_kallsyms, is_vdso);
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}
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bool build_id_cache__cached(const char *sbuild_id)
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{
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bool ret = false;
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char *filename = build_id__filename(sbuild_id, NULL, 0);
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if (filename && !access(filename, F_OK))
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ret = true;
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free(filename);
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return ret;
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}
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int build_id_cache__remove_s(const char *sbuild_id)
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{
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const size_t size = PATH_MAX;
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char *filename = zalloc(size),
|
|
*linkname = zalloc(size), *tmp;
|
|
int err = -1;
|
|
|
|
if (filename == NULL || linkname == NULL)
|
|
goto out_free;
|
|
|
|
if (!build_id__filename(sbuild_id, linkname, size))
|
|
goto out_free;
|
|
|
|
if (access(linkname, F_OK))
|
|
goto out_free;
|
|
|
|
if (readlink(linkname, filename, size - 1) < 0)
|
|
goto out_free;
|
|
|
|
if (unlink(linkname))
|
|
goto out_free;
|
|
|
|
/*
|
|
* Since the link is relative, we must make it absolute:
|
|
*/
|
|
tmp = strrchr(linkname, '/') + 1;
|
|
snprintf(tmp, size - (tmp - linkname), "%s", filename);
|
|
|
|
if (unlink(linkname))
|
|
goto out_free;
|
|
|
|
err = 0;
|
|
out_free:
|
|
free(filename);
|
|
free(linkname);
|
|
return err;
|
|
}
|
|
|
|
static int dso__cache_build_id(struct dso *dso, struct machine *machine)
|
|
{
|
|
bool is_kallsyms = dso->kernel && dso->long_name[0] != '/';
|
|
bool is_vdso = dso__is_vdso(dso);
|
|
const char *name = dso->long_name;
|
|
char nm[PATH_MAX];
|
|
|
|
if (dso__is_kcore(dso)) {
|
|
is_kallsyms = true;
|
|
machine__mmap_name(machine, nm, sizeof(nm));
|
|
name = nm;
|
|
}
|
|
return build_id_cache__add_b(dso->build_id, sizeof(dso->build_id), name,
|
|
is_kallsyms, is_vdso);
|
|
}
|
|
|
|
static int __dsos__cache_build_ids(struct list_head *head,
|
|
struct machine *machine)
|
|
{
|
|
struct dso *pos;
|
|
int err = 0;
|
|
|
|
dsos__for_each_with_build_id(pos, head)
|
|
if (dso__cache_build_id(pos, machine))
|
|
err = -1;
|
|
|
|
return err;
|
|
}
|
|
|
|
static int machine__cache_build_ids(struct machine *machine)
|
|
{
|
|
return __dsos__cache_build_ids(&machine->dsos.head, machine);
|
|
}
|
|
|
|
int perf_session__cache_build_ids(struct perf_session *session)
|
|
{
|
|
struct rb_node *nd;
|
|
int ret;
|
|
|
|
if (no_buildid_cache)
|
|
return 0;
|
|
|
|
if (mkdir(buildid_dir, 0755) != 0 && errno != EEXIST)
|
|
return -1;
|
|
|
|
ret = machine__cache_build_ids(&session->machines.host);
|
|
|
|
for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
|
|
struct machine *pos = rb_entry(nd, struct machine, rb_node);
|
|
ret |= machine__cache_build_ids(pos);
|
|
}
|
|
return ret ? -1 : 0;
|
|
}
|
|
|
|
static bool machine__read_build_ids(struct machine *machine, bool with_hits)
|
|
{
|
|
return __dsos__read_build_ids(&machine->dsos.head, with_hits);
|
|
}
|
|
|
|
bool perf_session__read_build_ids(struct perf_session *session, bool with_hits)
|
|
{
|
|
struct rb_node *nd;
|
|
bool ret = machine__read_build_ids(&session->machines.host, with_hits);
|
|
|
|
for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
|
|
struct machine *pos = rb_entry(nd, struct machine, rb_node);
|
|
ret |= machine__read_build_ids(pos, with_hits);
|
|
}
|
|
|
|
return ret;
|
|
}
|