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7cd5738d0d
Since 'perf probe' heavily depends on debuginfo, debuginfod gives us
many benefits on the 'perf probe' command on remote machine.
Especially, this will be helpful for the embedded devices which will not
have enough storage, or boot with a cross-build kernel whose source code
is in the host machine.
This will work as similar to commit c7a14fdcb3 ("perf build-ids:
Fall back to debuginfod query if debuginfo not found")
Tested with:
(host) $ cd PATH/TO/KBUILD/DIR/
(host) $ debuginfod -F .
...
(remote) # perf probe -L vfs_read
Failed to find the path for the kernel: No such file or directory
Error: Failed to show lines.
(remote) # export DEBUGINFOD_URLS="http://$HOST_IP:8002/"
(remote) # perf probe -L vfs_read
<vfs_read@...>
0 ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos)
{
2 ssize_t ret;
if (!(file->f_mode & FMODE_READ))
return -EBADF;
6 if (!(file->f_mode & FMODE_CAN_READ))
return -EINVAL;
8 if (unlikely(!access_ok(buf, count)))
return -EFAULT;
11 ret = rw_verify_area(READ, file, pos, count);
12 if (ret)
return ret;
if (count > MAX_RW_COUNT)
...
(remote) # perf probe -a "vfs_read count"
Added new event:
probe:vfs_read (on vfs_read with count)
(remote) # perf probe -l
probe:vfs_read (on vfs_read@ksrc/linux/fs/read_write.c with count)
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Frank Ch. Eigler <fche@redhat.com>
Cc: Aaron Merey <amerey@redhat.com>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Link: http://lore.kernel.org/lkml/160041610083.912668.13659563860278615846.stgit@devnote2
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
127 lines
3.5 KiB
C
127 lines
3.5 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _PROBE_FINDER_H
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#define _PROBE_FINDER_H
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#include <stdbool.h>
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#include "intlist.h"
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#include "build-id.h"
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#include "probe-event.h"
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#include <linux/ctype.h>
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#define MAX_PROBE_BUFFER 1024
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#define MAX_PROBES 128
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#define MAX_PROBE_ARGS 128
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#define PROBE_ARG_VARS "$vars"
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#define PROBE_ARG_PARAMS "$params"
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static inline int is_c_varname(const char *name)
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{
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/* TODO */
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return isalpha(name[0]) || name[0] == '_';
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}
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#ifdef HAVE_DWARF_SUPPORT
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#include "dwarf-aux.h"
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/* TODO: export debuginfo data structure even if no dwarf support */
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/* debug information structure */
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struct debuginfo {
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Dwarf *dbg;
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Dwfl_Module *mod;
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Dwfl *dwfl;
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Dwarf_Addr bias;
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const unsigned char *build_id;
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};
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/* This also tries to open distro debuginfo */
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struct debuginfo *debuginfo__new(const char *path);
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void debuginfo__delete(struct debuginfo *dbg);
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/* Find probe_trace_events specified by perf_probe_event from debuginfo */
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int debuginfo__find_trace_events(struct debuginfo *dbg,
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struct perf_probe_event *pev,
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struct probe_trace_event **tevs);
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/* Find a perf_probe_point from debuginfo */
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int debuginfo__find_probe_point(struct debuginfo *dbg, unsigned long addr,
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struct perf_probe_point *ppt);
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int debuginfo__get_text_offset(struct debuginfo *dbg, Dwarf_Addr *offs,
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bool adjust_offset);
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/* Find a line range */
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int debuginfo__find_line_range(struct debuginfo *dbg, struct line_range *lr);
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/* Find available variables */
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int debuginfo__find_available_vars_at(struct debuginfo *dbg,
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struct perf_probe_event *pev,
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struct variable_list **vls);
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/* Find a src file from a DWARF tag path */
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int find_source_path(const char *raw_path, const char *sbuild_id,
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const char *comp_dir, char **new_path);
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struct probe_finder {
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struct perf_probe_event *pev; /* Target probe event */
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struct debuginfo *dbg;
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/* Callback when a probe point is found */
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int (*callback)(Dwarf_Die *sc_die, struct probe_finder *pf);
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/* For function searching */
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int lno; /* Line number */
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Dwarf_Addr addr; /* Address */
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const char *fname; /* Real file name */
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Dwarf_Die cu_die; /* Current CU */
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Dwarf_Die sp_die;
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struct intlist *lcache; /* Line cache for lazy match */
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/* For variable searching */
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#if _ELFUTILS_PREREQ(0, 142)
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/* Call Frame Information from .eh_frame */
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Dwarf_CFI *cfi_eh;
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/* Call Frame Information from .debug_frame */
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Dwarf_CFI *cfi_dbg;
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#endif
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Dwarf_Op *fb_ops; /* Frame base attribute */
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unsigned int machine; /* Target machine arch */
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struct perf_probe_arg *pvar; /* Current target variable */
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struct probe_trace_arg *tvar; /* Current result variable */
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bool skip_empty_arg; /* Skip non-exist args */
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};
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struct trace_event_finder {
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struct probe_finder pf;
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Dwfl_Module *mod; /* For solving symbols */
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struct probe_trace_event *tevs; /* Found trace events */
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int ntevs; /* Number of trace events */
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int max_tevs; /* Max number of trace events */
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};
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struct available_var_finder {
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struct probe_finder pf;
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Dwfl_Module *mod; /* For solving symbols */
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struct variable_list *vls; /* Found variable lists */
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int nvls; /* Number of variable lists */
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int max_vls; /* Max no. of variable lists */
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bool child; /* Search child scopes */
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};
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struct line_finder {
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struct line_range *lr; /* Target line range */
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const char *fname; /* File name */
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int lno_s; /* Start line number */
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int lno_e; /* End line number */
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Dwarf_Die cu_die; /* Current CU */
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Dwarf_Die sp_die;
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int found;
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};
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#endif /* HAVE_DWARF_SUPPORT */
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#endif /*_PROBE_FINDER_H */
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