b9c87f536c
The find_data_type() is to get a data type from the memory access at the
given address (IP) using a register and an offset.
It requires DWARF debug info in the DSO and searches the list of
variables and function parameters in the scope.
In a pseudo code, it does basically the following:
find_data_type(dso, ip, reg, offset)
{
pc = map__rip_2objdump(ip);
CU = dwarf_addrdie(dso->dwarf, pc);
scopes = die_get_scopes(CU, pc);
for_each_scope(S, scopes) {
V = die_find_variable_by_reg(S, pc, reg);
if (V && V.type == pointer_type) {
T = die_get_real_type(V);
if (offset < T.size)
return T;
}
}
return NULL;
}
Committer notes:
The 'size' variable in check_variable() is 64-bit, so use PRIu64 and
inttypes.h to debug it.
Ditto at find_data_type_die().
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: linux-toolchains@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Link: https://lore.kernel.org/r/20231213001323.718046-4-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
41 lines
957 B
C
41 lines
957 B
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _PERF_ANNOTATE_DATA_H
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#define _PERF_ANNOTATE_DATA_H
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#include <errno.h>
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#include <linux/compiler.h>
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#include <linux/types.h>
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struct map_symbol;
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/**
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* struct annotated_data_type - Data type to profile
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* @type_name: Name of the data type
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* @type_size: Size of the data type
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*
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* This represents a data type accessed by samples in the profile data.
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*/
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struct annotated_data_type {
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char *type_name;
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int type_size;
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};
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#ifdef HAVE_DWARF_SUPPORT
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/* Returns data type at the location (ip, reg, offset) */
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struct annotated_data_type *find_data_type(struct map_symbol *ms, u64 ip,
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int reg, int offset);
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#else /* HAVE_DWARF_SUPPORT */
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static inline struct annotated_data_type *
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find_data_type(struct map_symbol *ms __maybe_unused, u64 ip __maybe_unused,
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int reg __maybe_unused, int offset __maybe_unused)
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{
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return NULL;
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}
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#endif /* HAVE_DWARF_SUPPORT */
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#endif /* _PERF_ANNOTATE_DATA_H */
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