[PATCH 4/9] perf symbols: Record whether a symbol is an alias for an IFUNC symbol

From: Adrian Hunter
Date: Fri Jan 27 2023 - 12:03:30 EST


To assist with synthesizing plt symbols for IFUNCs, record whether a
symbol is an alias of an IFUNC symbol.

Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
tools/perf/util/symbol.c | 4 ++++
tools/perf/util/symbol.h | 2 ++
2 files changed, 6 insertions(+)

diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index a024f06f75d8..d05727fcb30d 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -201,10 +201,14 @@ void symbols__fixup_duplicate(struct rb_root_cached *symbols)
continue;

if (choose_best_symbol(curr, next) == SYMBOL_A) {
+ if (next->type == STT_GNU_IFUNC)
+ curr->ifunc_alias = true;
rb_erase_cached(&next->rb_node, symbols);
symbol__delete(next);
goto again;
} else {
+ if (curr->type == STT_GNU_IFUNC)
+ next->ifunc_alias = true;
nd = rb_next(&curr->rb_node);
rb_erase_cached(&curr->rb_node, symbols);
symbol__delete(curr);
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index 2fdeb22bd02f..7558735543c2 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -64,6 +64,8 @@ struct symbol {
u8 inlined:1;
/** Has symbol__annotate2 been performed. */
u8 annotate2:1;
+ /** Symbol is an alias of an STT_GNU_IFUNC */
+ u8 ifunc_alias:1;
/** Architecture specific. Unused except on PPC where it holds st_other. */
u8 arch_sym;
/** The name of length namelen associated with the symbol. */
--
2.34.1