6.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Namhyung Kim namhyung@kernel.org
[ Upstream commit 932dcc2c39aedf54ef291bc0b4129a54f5fe1e84 ]
The die_collect_vars() is to find all variable information in the scope including function parameters. The struct die_var_type is to save the type of the variable with the location (reg and offset) as well as where it's defined in the code (addr).
Signed-off-by: Namhyung Kim namhyung@kernel.org Acked-by: Masami Hiramatsu mhiramat@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: Peter Zijlstra peterz@infradead.org Cc: Stephane Eranian eranian@google.com Link: https://lore.kernel.org/r/20240319055115.4063940-3-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Stable-dep-of: c9d492378fae ("perf dwarf-aux: Fix build with HAVE_DWARF_CFI_SUPPORT") Signed-off-by: Sasha Levin sashal@kernel.org --- tools/perf/util/dwarf-aux.c | 118 +++++++++++++++++++++++++++--------- tools/perf/util/dwarf-aux.h | 17 ++++++ 2 files changed, 107 insertions(+), 28 deletions(-)
diff --git a/tools/perf/util/dwarf-aux.c b/tools/perf/util/dwarf-aux.c index f7f7171539d3c..ff1874ae0832e 100644 --- a/tools/perf/util/dwarf-aux.c +++ b/tools/perf/util/dwarf-aux.c @@ -1136,6 +1136,40 @@ int die_get_varname(Dwarf_Die *vr_die, struct strbuf *buf) return ret < 0 ? ret : strbuf_addf(buf, "\t%s", dwarf_diename(vr_die)); }
+#if defined(HAVE_DWARF_GETLOCATIONS_SUPPORT) || defined(HAVE_DWARF_CFI_SUPPORT) +static int reg_from_dwarf_op(Dwarf_Op *op) +{ + switch (op->atom) { + case DW_OP_reg0 ... DW_OP_reg31: + return op->atom - DW_OP_reg0; + case DW_OP_breg0 ... DW_OP_breg31: + return op->atom - DW_OP_breg0; + case DW_OP_regx: + case DW_OP_bregx: + return op->number; + default: + break; + } + return -1; +} + +static int offset_from_dwarf_op(Dwarf_Op *op) +{ + switch (op->atom) { + case DW_OP_reg0 ... DW_OP_reg31: + case DW_OP_regx: + return 0; + case DW_OP_breg0 ... DW_OP_breg31: + return op->number; + case DW_OP_bregx: + return op->number2; + default: + break; + } + return -1; +} +#endif /* HAVE_DWARF_GETLOCATIONS_SUPPORT || HAVE_DWARF_CFI_SUPPORT */ + #ifdef HAVE_DWARF_GETLOCATIONS_SUPPORT /** * die_get_var_innermost_scope - Get innermost scope range of given variable DIE @@ -1493,41 +1527,69 @@ Dwarf_Die *die_find_variable_by_addr(Dwarf_Die *sc_die, Dwarf_Addr pc, *offset = data.offset; return result; } -#endif /* HAVE_DWARF_GETLOCATIONS_SUPPORT */
-#ifdef HAVE_DWARF_CFI_SUPPORT -static int reg_from_dwarf_op(Dwarf_Op *op) +static int __die_collect_vars_cb(Dwarf_Die *die_mem, void *arg) { - switch (op->atom) { - case DW_OP_reg0 ... DW_OP_reg31: - return op->atom - DW_OP_reg0; - case DW_OP_breg0 ... DW_OP_breg31: - return op->atom - DW_OP_breg0; - case DW_OP_regx: - case DW_OP_bregx: - return op->number; - default: - break; - } - return -1; + struct die_var_type **var_types = arg; + Dwarf_Die type_die; + int tag = dwarf_tag(die_mem); + Dwarf_Attribute attr; + Dwarf_Addr base, start, end; + Dwarf_Op *ops; + size_t nops; + struct die_var_type *vt; + + if (tag != DW_TAG_variable && tag != DW_TAG_formal_parameter) + return DIE_FIND_CB_SIBLING; + + if (dwarf_attr(die_mem, DW_AT_location, &attr) == NULL) + return DIE_FIND_CB_SIBLING; + + /* + * Only collect the first location as it can reconstruct the + * remaining state by following the instructions. + * start = 0 means it covers the whole range. + */ + if (dwarf_getlocations(&attr, 0, &base, &start, &end, &ops, &nops) <= 0) + return DIE_FIND_CB_SIBLING; + + if (die_get_real_type(die_mem, &type_die) == NULL) + return DIE_FIND_CB_SIBLING; + + vt = malloc(sizeof(*vt)); + if (vt == NULL) + return DIE_FIND_CB_END; + + vt->die_off = dwarf_dieoffset(&type_die); + vt->addr = start; + vt->reg = reg_from_dwarf_op(ops); + vt->offset = offset_from_dwarf_op(ops); + vt->next = *var_types; + *var_types = vt; + + return DIE_FIND_CB_SIBLING; }
-static int offset_from_dwarf_op(Dwarf_Op *op) +/** + * die_collect_vars - Save all variables and parameters + * @sc_die: a scope DIE + * @var_types: a pointer to save the resulting list + * + * Save all variables and parameters in the @sc_die and save them to @var_types. + * The @var_types is a singly-linked list containing type and location info. + * Actual type can be retrieved using dwarf_offdie() with 'die_off' later. + * + * Callers should free @var_types. + */ +void die_collect_vars(Dwarf_Die *sc_die, struct die_var_type **var_types) { - switch (op->atom) { - case DW_OP_reg0 ... DW_OP_reg31: - case DW_OP_regx: - return 0; - case DW_OP_breg0 ... DW_OP_breg31: - return op->number; - case DW_OP_bregx: - return op->number2; - default: - break; - } - return -1; + Dwarf_Die die_mem; + + die_find_child(sc_die, __die_collect_vars_cb, (void *)var_types, &die_mem); } +#endif /* HAVE_DWARF_GETLOCATIONS_SUPPORT */
+#ifdef HAVE_DWARF_CFI_SUPPORT /** * die_get_cfa - Get frame base information * @dwarf: a Dwarf info diff --git a/tools/perf/util/dwarf-aux.h b/tools/perf/util/dwarf-aux.h index 85dd527ae1f70..efafd3a1f5b6f 100644 --- a/tools/perf/util/dwarf-aux.h +++ b/tools/perf/util/dwarf-aux.h @@ -135,6 +135,15 @@ void die_skip_prologue(Dwarf_Die *sp_die, Dwarf_Die *cu_die, /* Get the list of including scopes */ int die_get_scopes(Dwarf_Die *cu_die, Dwarf_Addr pc, Dwarf_Die **scopes);
+/* Variable type information */ +struct die_var_type { + struct die_var_type *next; + u64 die_off; + u64 addr; + int reg; + int offset; +}; + #ifdef HAVE_DWARF_GETLOCATIONS_SUPPORT
/* Get byte offset range of given variable DIE */ @@ -150,6 +159,9 @@ Dwarf_Die *die_find_variable_by_addr(Dwarf_Die *sc_die, Dwarf_Addr pc, Dwarf_Addr addr, Dwarf_Die *die_mem, int *offset);
+/* Save all variables and parameters in this scope */ +void die_collect_vars(Dwarf_Die *sc_die, struct die_var_type **var_types); + #else /* HAVE_DWARF_GETLOCATIONS_SUPPORT */
static inline int die_get_var_range(Dwarf_Die *sp_die __maybe_unused, @@ -178,6 +190,11 @@ static inline Dwarf_Die *die_find_variable_by_addr(Dwarf_Die *sc_die __maybe_unu return NULL; }
+static inline void die_collect_vars(Dwarf_Die *sc_die __maybe_unused, + struct die_var_type **var_types __maybe_unused) +{ +} + #endif /* HAVE_DWARF_GETLOCATIONS_SUPPORT */
#ifdef HAVE_DWARF_CFI_SUPPORT