From 623ba6ea45979fb1d06c5c8f03417ecc3565a851 Mon Sep 17 00:00:00 2001 From: Gary Guo Date: Mon, 5 Jan 2026 15:00:57 +0000 Subject: [PATCH] perf symbol: Remove Rust symbol workarounds MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Due to an off-by-one error introduced in commit 73bbb94466fd3f8b ("kallsyms: support "big" kernel symbols"), long symbols (which are currently only produced by Rust) can have their symbol type being wrongly parsed by kernel/kallsyms.c. This has been fixed in commit f3f9f42232dee596 ("kallsyms: Fix wrong "big" kernel symbol type read from procfs"), and these symbols are now reported correctly. Drop the workaround in perf symbol that filter out these symbol types. Specifically, '1' and 'l' can never be generated by nm -- 'u' does indicate GNU unique, however such symbols are only generated by G++ for C++ templates, and are never generated by LLVM (LLVM generates weak symbols in such cases instead). 'N' can appear if symbols exist inside debug sections, and 'n' may appear for symbols inside note sections, however these sections do not typically have symbol (and they're explicitly filtered out by kallsyms). Therefore, the previous occurrence of these symbols types must be due to the off-by-one error and can be safely removed. Signed-off-by: Gary Guo Acked-by: Miguel Ojeda Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Alice Ryhl Cc: Andi Kleen Cc: Andreas Hindborg Cc: Benno Lossin Cc: Bill Wendling Cc: Björn Roy Baron Cc: Boqun Feng Cc: Danilo Krummrich Cc: Dmitriy Vyukov Cc: Ian Rogers Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: Justin Stitt Cc: Mark Rutland Cc: Namhyung Kim Cc: Nathan Chancellor Cc: Nick Desaulniers Cc: Peter Zijlstra Cc: Stephen Brennan Cc: Trevor Gross Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/symbol.c | 19 ++++--------------- 1 file changed, 4 insertions(+), 15 deletions(-) diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index 814f960fa8f8..8662001e1e25 100644 --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -104,21 +104,10 @@ static enum dso_binary_type binary_type_symtab[] = { #define DSO_BINARY_TYPE__SYMTAB_CNT ARRAY_SIZE(binary_type_symtab) -static bool symbol_type__filter(char __symbol_type) -{ - // Since 'U' == undefined and 'u' == unique global symbol, we can't use toupper there - // 'N' is for debugging symbols, 'n' is a non-data, non-code, non-debug read-only section. - // According to 'man nm'. - // 'N' first seen in: - // ffffffff9b35d130 N __pfx__RNCINvNtNtNtCsbDUBuN8AbD4_4core4iter8adapters3map12map_try_foldjNtCs6vVzKs5jPr6_12drm_panic_qr7VersionuINtNtNtBa_3ops12control_flow11ControlFlowB10_ENcB10_0NCINvNvNtNtNtB8_6traits8iterator8Iterator4find5checkB10_NCNvMB12_B10_13from_segments0E0E0B12_ - // a seemingly Rust mangled name - // Ditto for '1': - // root@x1:~# grep ' 1 ' /proc/kallsyms - // ffffffffb098bc00 1 __pfx__RNCINvNtNtNtCsfwaGRd4cjqE_4core4iter8adapters3map12map_try_foldjNtCskFudTml27HW_12drm_panic_qr7VersionuINtNtNtBa_3ops12control_flow11ControlFlowB10_ENcB10_0NCINvNvNtNtNtB8_6traits8iterator8Iterator4find5checkB10_NCNvMB12_B10_13from_segments0E0E0B12_ - // ffffffffb098bc10 1 _RNCINvNtNtNtCsfwaGRd4cjqE_4core4iter8adapters3map12map_try_foldjNtCskFudTml27HW_12drm_panic_qr7VersionuINtNtNtBa_3ops12control_flow11ControlFlowB10_ENcB10_0NCINvNvNtNtNtB8_6traits8iterator8Iterator4find5checkB10_NCNvMB12_B10_13from_segments0E0E0B12_ - char symbol_type = toupper(__symbol_type); - return symbol_type == 'T' || symbol_type == 'W' || symbol_type == 'D' || symbol_type == 'B' || - __symbol_type == 'u' || __symbol_type == 'l' || __symbol_type == 'N' || __symbol_type == '1'; +static bool symbol_type__filter(char symbol_type) +{ + symbol_type = toupper(symbol_type); + return symbol_type == 'T' || symbol_type == 'W' || symbol_type == 'D' || symbol_type == 'B'; } static int prefix_underscores_count(const char *str) -- 2.47.3