linux/tools/perf/util/probe-file.h
Masami Hiramatsu 1e032f7cfa perf-probe: Add user memory access attribute support
Add user memory access attribute for kprobe event arguments.
If a given 'local variable' is in user-space, User can
specify memory access method by '@user' suffix. This is
not only for string but also for data structure.

If we access a field of data structure in user memory from
kernel on some arch, it will fail. e.g.

 perf probe -a "sched_setscheduler param->sched_priority"

This will fail to access the "param->sched_priority" because
the param is __user pointer. Instead, we can now specify
@user suffix for such argument.

 perf probe -a "sched_setscheduler param->sched_priority@user"

Note that kernel memory access with "@user" must always fail
on any arch.

Link: http://lkml.kernel.org/r/155789874562.26965.10836126971405890891.stgit@devnote2

Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-05-25 23:04:42 -04:00

82 lines
2.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __PROBE_FILE_H
#define __PROBE_FILE_H
#include "probe-event.h"
struct strlist;
struct strfilter;
/* Cache of probe definitions */
struct probe_cache_entry {
struct list_head node;
bool sdt;
struct perf_probe_event pev;
char *spev;
struct strlist *tevlist;
};
struct probe_cache {
int fd;
struct list_head entries;
};
enum probe_type {
PROBE_TYPE_U = 0,
PROBE_TYPE_S,
PROBE_TYPE_X,
PROBE_TYPE_STRING,
PROBE_TYPE_BITFIELD,
PROBE_TYPE_END,
};
#define PF_FL_UPROBE 1
#define PF_FL_RW 2
#define for_each_probe_cache_entry(entry, pcache) \
list_for_each_entry(entry, &pcache->entries, node)
/* probe-file.c depends on libelf */
#ifdef HAVE_LIBELF_SUPPORT
int open_trace_file(const char *trace_file, bool readwrite);
int probe_file__open(int flag);
int probe_file__open_both(int *kfd, int *ufd, int flag);
struct strlist *probe_file__get_namelist(int fd);
struct strlist *probe_file__get_rawlist(int fd);
int probe_file__add_event(int fd, struct probe_trace_event *tev);
int probe_file__del_events(int fd, struct strfilter *filter);
int probe_file__get_events(int fd, struct strfilter *filter,
struct strlist *plist);
int probe_file__del_strlist(int fd, struct strlist *namelist);
int probe_cache_entry__get_event(struct probe_cache_entry *entry,
struct probe_trace_event **tevs);
struct probe_cache *probe_cache__new(const char *target, struct nsinfo *nsi);
int probe_cache__add_entry(struct probe_cache *pcache,
struct perf_probe_event *pev,
struct probe_trace_event *tevs, int ntevs);
int probe_cache__scan_sdt(struct probe_cache *pcache, const char *pathname);
int probe_cache__commit(struct probe_cache *pcache);
void probe_cache__purge(struct probe_cache *pcache);
void probe_cache__delete(struct probe_cache *pcache);
int probe_cache__filter_purge(struct probe_cache *pcache,
struct strfilter *filter);
struct probe_cache_entry *probe_cache__find(struct probe_cache *pcache,
struct perf_probe_event *pev);
struct probe_cache_entry *probe_cache__find_by_name(struct probe_cache *pcache,
const char *group, const char *event);
int probe_cache__show_all_caches(struct strfilter *filter);
bool probe_type_is_available(enum probe_type type);
bool kretprobe_offset_is_supported(void);
bool uprobe_ref_ctr_is_supported(void);
bool user_access_is_supported(void);
#else /* ! HAVE_LIBELF_SUPPORT */
static inline struct probe_cache *probe_cache__new(const char *tgt __maybe_unused, struct nsinfo *nsi __maybe_unused)
{
return NULL;
}
#define probe_cache__delete(pcache) do {} while (0)
#endif
#endif