linux/tools/perf/util/probe-finder.h
Yang Jihong 22a665513b perf probe: Fix add event failure when running 32-bit perf in a 64-bit kernel
The "address" member of "struct probe_trace_point" uses long data type.
If kernel is 64-bit and perf program is 32-bit, size of "address"
variable is 32 bits.

As a result, upper 32 bits of address read from kernel are truncated, an
error occurs during address comparison in kprobe_warn_out_range().

Before:

  # perf probe -a schedule
  schedule is out of .text, skip it.
    Error: Failed to add events.

Solution:
  Change data type of "address" variable to u64 and change corresponding
address printing and value assignment.

After:

  # perf.new.new probe -a schedule
  Added new event:
    probe:schedule       (on schedule)

  You can now use it in all perf tools, such as:

          perf record -e probe:schedule -aR sleep 1

  # perf probe -l
    probe:schedule       (on schedule@kernel/sched/core.c)
  # perf record -e probe:schedule -aR sleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.156 MB perf.data (1366 samples) ]
  # perf report --stdio
  # To display the perf.data header info, please use --header/--header-only options.
  #
  #
  # Total Lost Samples: 0
  #
  # Samples: 1K of event 'probe:schedule'
  # Event count (approx.): 1366
  #
  # Overhead  Command          Shared Object      Symbol
  # ........  ...............  .................  ............
  #
       6.22%  migration/0      [kernel.kallsyms]  [k] schedule
       6.22%  migration/1      [kernel.kallsyms]  [k] schedule
       6.22%  migration/2      [kernel.kallsyms]  [k] schedule
       6.22%  migration/3      [kernel.kallsyms]  [k] schedule
       6.15%  migration/10     [kernel.kallsyms]  [k] schedule
       6.15%  migration/11     [kernel.kallsyms]  [k] schedule
       6.15%  migration/12     [kernel.kallsyms]  [k] schedule
       6.15%  migration/13     [kernel.kallsyms]  [k] schedule
       6.15%  migration/14     [kernel.kallsyms]  [k] schedule
       6.15%  migration/15     [kernel.kallsyms]  [k] schedule
       6.15%  migration/4      [kernel.kallsyms]  [k] schedule
       6.15%  migration/5      [kernel.kallsyms]  [k] schedule
       6.15%  migration/6      [kernel.kallsyms]  [k] schedule
       6.15%  migration/7      [kernel.kallsyms]  [k] schedule
       6.15%  migration/8      [kernel.kallsyms]  [k] schedule
       6.15%  migration/9      [kernel.kallsyms]  [k] schedule
       0.22%  rcu_sched        [kernel.kallsyms]  [k] schedule
  ...
  #
  # (Cannot load tips.txt file, please install perf!)
  #

Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jianlin Lv <jianlin.lv@arm.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Li Huafei <lihuafei1@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Link: http://lore.kernel.org/lkml/20210715063723.11926-1-yangjihong1@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-07-18 09:31:15 -03:00

127 lines
3.5 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _PROBE_FINDER_H
#define _PROBE_FINDER_H
#include <stdbool.h>
#include "intlist.h"
#include "build-id.h"
#include "probe-event.h"
#include <linux/ctype.h>
#define MAX_PROBE_BUFFER 1024
#define MAX_PROBES 128
#define MAX_PROBE_ARGS 128
#define PROBE_ARG_VARS "$vars"
#define PROBE_ARG_PARAMS "$params"
static inline int is_c_varname(const char *name)
{
/* TODO */
return isalpha(name[0]) || name[0] == '_';
}
#ifdef HAVE_DWARF_SUPPORT
#include "dwarf-aux.h"
/* TODO: export debuginfo data structure even if no dwarf support */
/* debug information structure */
struct debuginfo {
Dwarf *dbg;
Dwfl_Module *mod;
Dwfl *dwfl;
Dwarf_Addr bias;
const unsigned char *build_id;
};
/* This also tries to open distro debuginfo */
struct debuginfo *debuginfo__new(const char *path);
void debuginfo__delete(struct debuginfo *dbg);
/* Find probe_trace_events specified by perf_probe_event from debuginfo */
int debuginfo__find_trace_events(struct debuginfo *dbg,
struct perf_probe_event *pev,
struct probe_trace_event **tevs);
/* Find a perf_probe_point from debuginfo */
int debuginfo__find_probe_point(struct debuginfo *dbg, u64 addr,
struct perf_probe_point *ppt);
int debuginfo__get_text_offset(struct debuginfo *dbg, Dwarf_Addr *offs,
bool adjust_offset);
/* Find a line range */
int debuginfo__find_line_range(struct debuginfo *dbg, struct line_range *lr);
/* Find available variables */
int debuginfo__find_available_vars_at(struct debuginfo *dbg,
struct perf_probe_event *pev,
struct variable_list **vls);
/* Find a src file from a DWARF tag path */
int find_source_path(const char *raw_path, const char *sbuild_id,
const char *comp_dir, char **new_path);
struct probe_finder {
struct perf_probe_event *pev; /* Target probe event */
struct debuginfo *dbg;
/* Callback when a probe point is found */
int (*callback)(Dwarf_Die *sc_die, struct probe_finder *pf);
/* For function searching */
int lno; /* Line number */
Dwarf_Addr addr; /* Address */
const char *fname; /* Real file name */
Dwarf_Die cu_die; /* Current CU */
Dwarf_Die sp_die;
struct intlist *lcache; /* Line cache for lazy match */
/* For variable searching */
#if _ELFUTILS_PREREQ(0, 142)
/* Call Frame Information from .eh_frame */
Dwarf_CFI *cfi_eh;
/* Call Frame Information from .debug_frame */
Dwarf_CFI *cfi_dbg;
#endif
Dwarf_Op *fb_ops; /* Frame base attribute */
unsigned int machine; /* Target machine arch */
struct perf_probe_arg *pvar; /* Current target variable */
struct probe_trace_arg *tvar; /* Current result variable */
bool skip_empty_arg; /* Skip non-exist args */
};
struct trace_event_finder {
struct probe_finder pf;
Dwfl_Module *mod; /* For solving symbols */
struct probe_trace_event *tevs; /* Found trace events */
int ntevs; /* Number of trace events */
int max_tevs; /* Max number of trace events */
};
struct available_var_finder {
struct probe_finder pf;
Dwfl_Module *mod; /* For solving symbols */
struct variable_list *vls; /* Found variable lists */
int nvls; /* Number of variable lists */
int max_vls; /* Max no. of variable lists */
bool child; /* Search child scopes */
};
struct line_finder {
struct line_range *lr; /* Target line range */
const char *fname; /* File name */
int lno_s; /* Start line number */
int lno_e; /* End line number */
Dwarf_Die cu_die; /* Current CU */
Dwarf_Die sp_die;
int found;
};
#endif /* HAVE_DWARF_SUPPORT */
#endif /*_PROBE_FINDER_H */