From 0ba32f84fcd17a7a92ea1ff251fb2245ff29180a Mon Sep 17 00:00:00 2001 From: Tengda Wu Date: Wed, 16 Sep 2026 01:29:22 +0000 Subject: [PATCH] perf annotate: Adapt arch__dwarf_regnum() for arm64 Currently, arch__dwarf_regnum() assumes that all architectures use a register prefix character (e.g., '%' for x86) defined by arch->objdump.register_char, and uses it to match register names in objdump output. However, this assumption does not hold for arm64, where assembly syntax uses bare register names like 'x0', 'w1' without any prefix. As a result, arm64 builds may fail to correctly recognize register names from objdump disassembly, leading to incomplete or incorrect annotation output. To address this: - Make the register prefix check optional, allowing architectures without a prefix character to be parsed correctly. - Extend the delimiter set in strpbrk() to include the closing square bracket ']'. In arm64 assembly, memory operands often use bracketed syntax such as '[x1, #16]' or '[x2]'. Adding ']' ensures clean extraction of register names like 'x2' without trailing characters. Reviewed-by: Ian Rogers Reviewed-by: Namhyung Kim Signed-off-by: Tengda Wu Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/annotate.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c index d3482eba9283..86a4beec6528 100644 --- a/tools/perf/util/annotate.c +++ b/tools/perf/util/annotate.c @@ -2582,19 +2582,21 @@ int annotate_check_args(void) int arch__dwarf_regnum(const struct arch *arch, const char *str) { - const char *p; + const char *p = str; char *regname, *q; int reg; - p = strchr(str, arch->objdump.register_char); - if (p == NULL) - return -1; + if (arch->objdump.register_char) { + p = strchr(str, arch->objdump.register_char); + if (p == NULL) + return -1; + } regname = strdup(p); if (regname == NULL) return -1; - q = strpbrk(regname, ",) "); + q = strpbrk(regname, ",)] "); if (q) *q = '\0';