linux/tools/perf/util/probe-event.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

198 lines
6.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _PROBE_EVENT_H
#define _PROBE_EVENT_H
#include <linux/compiler.h>
#include <stdbool.h>
struct intlist;
struct nsinfo;
/* Probe related configurations */
struct probe_conf {
bool show_ext_vars;
bool show_location_range;
bool force_add;
bool no_inlines;
bool cache;
int max_probes;
};
extern struct probe_conf probe_conf;
extern bool probe_event_dry_run;
struct symbol;
/* kprobe-tracer and uprobe-tracer tracing point */
struct probe_trace_point {
char *realname; /* function real name (if needed) */
char *symbol; /* Base symbol */
char *module; /* Module name */
unsigned long offset; /* Offset from symbol */
unsigned long ref_ctr_offset; /* SDT reference counter offset */
unsigned long address; /* Actual address of the trace point */
bool retprobe; /* Return probe flag */
};
/* probe-tracer tracing argument referencing offset */
struct probe_trace_arg_ref {
struct probe_trace_arg_ref *next; /* Next reference */
long offset; /* Offset value */
bool user_access; /* User-memory access */
};
/* kprobe-tracer and uprobe-tracer tracing argument */
struct probe_trace_arg {
char *name; /* Argument name */
char *value; /* Base value */
char *type; /* Type name */
struct probe_trace_arg_ref *ref; /* Referencing offset */
};
/* kprobe-tracer and uprobe-tracer tracing event (point + arg) */
struct probe_trace_event {
char *event; /* Event name */
char *group; /* Group name */
struct probe_trace_point point; /* Trace point */
int nargs; /* Number of args */
bool uprobes; /* uprobes only */
struct probe_trace_arg *args; /* Arguments */
};
/* Perf probe probing point */
struct perf_probe_point {
char *file; /* File path */
char *function; /* Function name */
int line; /* Line number */
bool retprobe; /* Return probe flag */
char *lazy_line; /* Lazy matching pattern */
unsigned long offset; /* Offset from function entry */
unsigned long abs_address; /* Absolute address of the point */
};
/* Perf probe probing argument field chain */
struct perf_probe_arg_field {
struct perf_probe_arg_field *next; /* Next field */
char *name; /* Name of the field */
long index; /* Array index number */
bool ref; /* Referencing flag */
};
/* Perf probe probing argument */
struct perf_probe_arg {
char *name; /* Argument name */
char *var; /* Variable name */
char *type; /* Type name */
struct perf_probe_arg_field *field; /* Structure fields */
bool user_access; /* User-memory access */
};
/* Perf probe probing event (point + arg) */
struct perf_probe_event {
char *event; /* Event name */
char *group; /* Group name */
struct perf_probe_point point; /* Probe point */
int nargs; /* Number of arguments */
bool sdt; /* SDT/cached event flag */
bool uprobes; /* Uprobe event flag */
char *target; /* Target binary */
struct perf_probe_arg *args; /* Arguments */
struct probe_trace_event *tevs;
int ntevs;
struct nsinfo *nsi; /* Target namespace */
};
/* Line range */
struct line_range {
char *file; /* File name */
char *function; /* Function name */
int start; /* Start line number */
int end; /* End line number */
int offset; /* Start line offset */
char *path; /* Real path name */
char *comp_dir; /* Compile directory */
struct intlist *line_list; /* Visible lines */
};
struct strlist;
/* List of variables */
struct variable_list {
struct probe_trace_point point; /* Actual probepoint */
struct strlist *vars; /* Available variables */
};
struct map;
int init_probe_symbol_maps(bool user_only);
void exit_probe_symbol_maps(void);
/* Command string to events */
int parse_perf_probe_command(const char *cmd, struct perf_probe_event *pev);
int parse_probe_trace_command(const char *cmd, struct probe_trace_event *tev);
/* Events to command string */
char *synthesize_perf_probe_command(struct perf_probe_event *pev);
char *synthesize_probe_trace_command(struct probe_trace_event *tev);
char *synthesize_perf_probe_arg(struct perf_probe_arg *pa);
char *synthesize_perf_probe_point(struct perf_probe_point *pp);
int perf_probe_event__copy(struct perf_probe_event *dst,
struct perf_probe_event *src);
bool perf_probe_with_var(struct perf_probe_event *pev);
/* Check the perf_probe_event needs debuginfo */
bool perf_probe_event_need_dwarf(struct perf_probe_event *pev);
/* Release event contents */
void clear_perf_probe_event(struct perf_probe_event *pev);
void clear_probe_trace_event(struct probe_trace_event *tev);
/* Command string to line-range */
int parse_line_range_desc(const char *cmd, struct line_range *lr);
/* Release line range members */
void line_range__clear(struct line_range *lr);
/* Initialize line range */
int line_range__init(struct line_range *lr);
int add_perf_probe_events(struct perf_probe_event *pevs, int npevs);
int convert_perf_probe_events(struct perf_probe_event *pevs, int npevs);
int apply_perf_probe_events(struct perf_probe_event *pevs, int npevs);
int show_probe_trace_events(struct perf_probe_event *pevs, int npevs);
void cleanup_perf_probe_events(struct perf_probe_event *pevs, int npevs);
struct strfilter;
int del_perf_probe_events(struct strfilter *filter);
int show_perf_probe_event(const char *group, const char *event,
struct perf_probe_event *pev,
const char *module, bool use_stdout);
int show_perf_probe_events(struct strfilter *filter);
int show_line_range(struct line_range *lr, const char *module,
struct nsinfo *nsi, bool user);
int show_available_vars(struct perf_probe_event *pevs, int npevs,
struct strfilter *filter);
int show_available_funcs(const char *module, struct nsinfo *nsi,
struct strfilter *filter, bool user);
void arch__fix_tev_from_maps(struct perf_probe_event *pev,
struct probe_trace_event *tev, struct map *map,
struct symbol *sym);
/* If there is no space to write, returns -E2BIG. */
int e_snprintf(char *str, size_t size, const char *format, ...) __printf(3, 4);
/* Maximum index number of event-name postfix */
#define MAX_EVENT_INDEX 1024
int copy_to_probe_trace_arg(struct probe_trace_arg *tvar,
struct perf_probe_arg *pvar);
struct map *get_target_map(const char *target, struct nsinfo *nsi, bool user);
void arch__post_process_probe_trace_events(struct perf_probe_event *pev,
int ntevs);
#endif /*_PROBE_EVENT_H */