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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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![Ian Rogers](/assets/img/avatar_default.png)
Using accessors will make it easier to add reference count checking in later patches. Committer notes: thread->nsinfo wasn't wrapped as it is used together with nsinfo__zput(), where does a trick to set the field with a refcount being dropped to NULL, and that doesn't work well with using thread__nsinfo(thread), that loses the &thread->nsinfo pointer. When refcount checking is added to 'struct thread', later in this series, nsinfo__zput(RC_CHK_ACCESS(thread)->nsinfo) will be used to check the thread pointer. Signed-off-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ali Saidi <alisaidi@amazon.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com> Cc: Brian Robbins <brianrob@linux.microsoft.com> Cc: Changbin Du <changbin.du@huawei.com> Cc: Dmitrii Dolgov <9erthalion6@gmail.com> Cc: Fangrui Song <maskray@google.com> Cc: German Gomez <german.gomez@arm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ivan Babrou <ivan@cloudflare.com> Cc: James Clark <james.clark@arm.com> Cc: Jing Zhang <renyu.zj@linux.alibaba.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Garry <john.g.garry@oracle.com> Cc: K Prateek Nayak <kprateek.nayak@amd.com> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Leo Yan <leo.yan@linaro.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Mike Leach <mike.leach@linaro.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi Bangoria <ravi.bangoria@amd.com> Cc: Sean Christopherson <seanjc@google.com> Cc: Steinar H. Gunderson <sesse@google.com> Cc: Suzuki Poulouse <suzuki.poulose@arm.com> Cc: Wenyu Liu <liuwenyu7@huawei.com> Cc: Will Deacon <will@kernel.org> Cc: Yang Jihong <yangjihong1@huawei.com> Cc: Ye Xingchen <ye.xingchen@zte.com.cn> Cc: Yuan Can <yuancan@huawei.com> Cc: coresight@lists.linaro.org Cc: linux-arm-kernel@lists.infradead.org Link: https://lore.kernel.org/r/20230608232823.4027869-4-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
364 lines
7.2 KiB
C
364 lines
7.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <errno.h>
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#include <unistd.h>
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#include <stdio.h>
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#include <string.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <fcntl.h>
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#include <stdlib.h>
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#include <linux/kernel.h>
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#include "vdso.h"
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#include "dso.h"
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#include <internal/lib.h>
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#include "map.h"
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#include "symbol.h"
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#include "machine.h"
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#include "thread.h"
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#include "linux/string.h"
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#include <linux/zalloc.h>
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#include "debug.h"
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/*
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* Include definition of find_map() also used in perf-read-vdso.c for
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* building perf-read-vdso32 and perf-read-vdsox32.
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*/
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#include "find-map.c"
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#define VDSO__TEMP_FILE_NAME "/tmp/perf-vdso.so-XXXXXX"
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struct vdso_file {
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bool found;
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bool error;
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char temp_file_name[sizeof(VDSO__TEMP_FILE_NAME)];
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const char *dso_name;
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const char *read_prog;
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};
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struct vdso_info {
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struct vdso_file vdso;
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#if BITS_PER_LONG == 64
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struct vdso_file vdso32;
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struct vdso_file vdsox32;
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#endif
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};
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static struct vdso_info *vdso_info__new(void)
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{
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static const struct vdso_info vdso_info_init = {
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.vdso = {
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.temp_file_name = VDSO__TEMP_FILE_NAME,
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.dso_name = DSO__NAME_VDSO,
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},
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#if BITS_PER_LONG == 64
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.vdso32 = {
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.temp_file_name = VDSO__TEMP_FILE_NAME,
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.dso_name = DSO__NAME_VDSO32,
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.read_prog = "perf-read-vdso32",
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},
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.vdsox32 = {
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.temp_file_name = VDSO__TEMP_FILE_NAME,
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.dso_name = DSO__NAME_VDSOX32,
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.read_prog = "perf-read-vdsox32",
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},
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#endif
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};
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return memdup(&vdso_info_init, sizeof(vdso_info_init));
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}
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static char *get_file(struct vdso_file *vdso_file)
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{
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char *vdso = NULL;
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char *buf = NULL;
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void *start, *end;
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size_t size;
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int fd;
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if (vdso_file->found)
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return vdso_file->temp_file_name;
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if (vdso_file->error || find_map(&start, &end, VDSO__MAP_NAME))
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return NULL;
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size = end - start;
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buf = memdup(start, size);
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if (!buf)
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return NULL;
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fd = mkstemp(vdso_file->temp_file_name);
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if (fd < 0)
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goto out;
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if (size == (size_t) write(fd, buf, size))
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vdso = vdso_file->temp_file_name;
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close(fd);
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out:
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free(buf);
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vdso_file->found = (vdso != NULL);
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vdso_file->error = !vdso_file->found;
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return vdso;
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}
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void machine__exit_vdso(struct machine *machine)
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{
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struct vdso_info *vdso_info = machine->vdso_info;
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if (!vdso_info)
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return;
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if (vdso_info->vdso.found)
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unlink(vdso_info->vdso.temp_file_name);
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#if BITS_PER_LONG == 64
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if (vdso_info->vdso32.found)
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unlink(vdso_info->vdso32.temp_file_name);
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if (vdso_info->vdsox32.found)
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unlink(vdso_info->vdsox32.temp_file_name);
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#endif
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zfree(&machine->vdso_info);
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}
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static struct dso *__machine__addnew_vdso(struct machine *machine, const char *short_name,
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const char *long_name)
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{
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struct dso *dso;
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dso = dso__new(short_name);
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if (dso != NULL) {
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__dsos__add(&machine->dsos, dso);
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dso__set_long_name(dso, long_name, false);
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/* Put dso here because __dsos_add already got it */
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dso__put(dso);
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}
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return dso;
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}
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static enum dso_type machine__thread_dso_type(struct machine *machine,
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struct thread *thread)
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{
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enum dso_type dso_type = DSO__TYPE_UNKNOWN;
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struct map_rb_node *rb_node;
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maps__for_each_entry(thread__maps(thread), rb_node) {
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struct dso *dso = map__dso(rb_node->map);
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if (!dso || dso->long_name[0] != '/')
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continue;
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dso_type = dso__type(dso, machine);
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if (dso_type != DSO__TYPE_UNKNOWN)
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break;
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}
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return dso_type;
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}
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#if BITS_PER_LONG == 64
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static int vdso__do_copy_compat(FILE *f, int fd)
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{
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char buf[4096];
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size_t count;
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while (1) {
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count = fread(buf, 1, sizeof(buf), f);
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if (ferror(f))
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return -errno;
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if (feof(f))
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break;
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if (count && writen(fd, buf, count) != (ssize_t)count)
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return -errno;
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}
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return 0;
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}
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static int vdso__copy_compat(const char *prog, int fd)
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{
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FILE *f;
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int err;
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f = popen(prog, "r");
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if (!f)
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return -errno;
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err = vdso__do_copy_compat(f, fd);
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if (pclose(f) == -1)
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return -errno;
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return err;
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}
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static int vdso__create_compat_file(const char *prog, char *temp_name)
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{
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int fd, err;
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fd = mkstemp(temp_name);
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if (fd < 0)
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return -errno;
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err = vdso__copy_compat(prog, fd);
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if (close(fd) == -1)
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return -errno;
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return err;
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}
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static const char *vdso__get_compat_file(struct vdso_file *vdso_file)
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{
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int err;
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if (vdso_file->found)
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return vdso_file->temp_file_name;
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if (vdso_file->error)
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return NULL;
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err = vdso__create_compat_file(vdso_file->read_prog,
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vdso_file->temp_file_name);
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if (err) {
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pr_err("%s failed, error %d\n", vdso_file->read_prog, err);
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vdso_file->error = true;
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return NULL;
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}
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vdso_file->found = true;
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return vdso_file->temp_file_name;
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}
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static struct dso *__machine__findnew_compat(struct machine *machine,
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struct vdso_file *vdso_file)
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{
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const char *file_name;
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struct dso *dso;
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dso = __dsos__find(&machine->dsos, vdso_file->dso_name, true);
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if (dso)
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goto out;
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file_name = vdso__get_compat_file(vdso_file);
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if (!file_name)
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goto out;
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dso = __machine__addnew_vdso(machine, vdso_file->dso_name, file_name);
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out:
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return dso;
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}
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static int __machine__findnew_vdso_compat(struct machine *machine,
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struct thread *thread,
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struct vdso_info *vdso_info,
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struct dso **dso)
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{
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enum dso_type dso_type;
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dso_type = machine__thread_dso_type(machine, thread);
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#ifndef HAVE_PERF_READ_VDSO32
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if (dso_type == DSO__TYPE_32BIT)
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return 0;
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#endif
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#ifndef HAVE_PERF_READ_VDSOX32
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if (dso_type == DSO__TYPE_X32BIT)
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return 0;
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#endif
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switch (dso_type) {
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case DSO__TYPE_32BIT:
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*dso = __machine__findnew_compat(machine, &vdso_info->vdso32);
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return 1;
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case DSO__TYPE_X32BIT:
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*dso = __machine__findnew_compat(machine, &vdso_info->vdsox32);
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return 1;
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case DSO__TYPE_UNKNOWN:
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case DSO__TYPE_64BIT:
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default:
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return 0;
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}
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}
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#endif
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static struct dso *machine__find_vdso(struct machine *machine,
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struct thread *thread)
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{
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struct dso *dso = NULL;
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enum dso_type dso_type;
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dso_type = machine__thread_dso_type(machine, thread);
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switch (dso_type) {
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case DSO__TYPE_32BIT:
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dso = __dsos__find(&machine->dsos, DSO__NAME_VDSO32, true);
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if (!dso) {
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dso = __dsos__find(&machine->dsos, DSO__NAME_VDSO,
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true);
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if (dso && dso_type != dso__type(dso, machine))
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dso = NULL;
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}
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break;
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case DSO__TYPE_X32BIT:
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dso = __dsos__find(&machine->dsos, DSO__NAME_VDSOX32, true);
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break;
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case DSO__TYPE_64BIT:
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case DSO__TYPE_UNKNOWN:
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default:
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dso = __dsos__find(&machine->dsos, DSO__NAME_VDSO, true);
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break;
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}
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return dso;
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}
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struct dso *machine__findnew_vdso(struct machine *machine,
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struct thread *thread)
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{
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struct vdso_info *vdso_info;
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struct dso *dso = NULL;
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down_write(&machine->dsos.lock);
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if (!machine->vdso_info)
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machine->vdso_info = vdso_info__new();
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vdso_info = machine->vdso_info;
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if (!vdso_info)
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goto out_unlock;
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dso = machine__find_vdso(machine, thread);
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if (dso)
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goto out_unlock;
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#if BITS_PER_LONG == 64
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if (__machine__findnew_vdso_compat(machine, thread, vdso_info, &dso))
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goto out_unlock;
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#endif
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dso = __dsos__find(&machine->dsos, DSO__NAME_VDSO, true);
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if (!dso) {
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char *file;
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file = get_file(&vdso_info->vdso);
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if (file)
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dso = __machine__addnew_vdso(machine, DSO__NAME_VDSO, file);
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}
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out_unlock:
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dso__get(dso);
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up_write(&machine->dsos.lock);
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return dso;
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}
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bool dso__is_vdso(struct dso *dso)
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{
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return !strcmp(dso->short_name, DSO__NAME_VDSO) ||
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!strcmp(dso->short_name, DSO__NAME_VDSO32) ||
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!strcmp(dso->short_name, DSO__NAME_VDSOX32);
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}
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