9 files changed, 23 insertions, 1 deletions

diff --git a/tools/perf/Documentation/perf-probe.txt b/tools/perf/Documentation/perf-probe.txt
index 1513935c399b..aaa869be3dc1 100644
--- a/tools/perf/Documentation/perf-probe.txt
+++ b/tools/perf/Documentation/perf-probe.txt
@@ -104,6 +104,9 @@ OPTIONS
         Specify path to the executable or shared library file for user
         space tracing. Can also be used with --funcs option.
 
+--demangle-kernel::
+        Demangle kernel symbols.
+
 In absence of -m/-x options, perf probe checks if the first argument after
 the options is an absolute path name. If its an absolute path, perf probe
 uses it as a target module/target user space binary to probe.
diff --git a/tools/perf/Documentation/perf-report.txt b/tools/perf/Documentation/perf-report.txt
index d561e0214f52..0927bf4e6c2a 100644
--- a/tools/perf/Documentation/perf-report.txt
+++ b/tools/perf/Documentation/perf-report.txt
@@ -276,6 +276,9 @@ OPTIONS
         Demangle symbol names to human readable form. It's enabled by default,
         disable with --no-demangle.
 
+--demangle-kernel::
+        Demangle kernel symbol names to human readable form (for C++ kernels).
+
 --mem-mode::
         Use the data addresses of samples in addition to instruction addresses
         to build the histograms.  To generate meaningful output, the perf.data
diff --git a/tools/perf/Documentation/perf-top.txt b/tools/perf/Documentation/perf-top.txt
index 28fdee394880..3265b1070518 100644
--- a/tools/perf/Documentation/perf-top.txt
+++ b/tools/perf/Documentation/perf-top.txt
@@ -98,6 +98,9 @@ Default is to monitor all CPUS.
 --hide_user_symbols::
         Hide user symbols.
 
+--demangle-kernel::
+        Demangle kernel symbols.
+
 -D::
 --dump-symtab::
         Dump the symbol table used for profiling.
diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c
index 347729e29a92..4d6858dbebea 100644
--- a/tools/perf/builtin-probe.c
+++ b/tools/perf/builtin-probe.c
@@ -376,6 +376,8 @@ __cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused)
                         "target executable name or path", opt_set_target),
         OPT_BOOLEAN(0, "demangle", &symbol_conf.demangle,
                     "Disable symbol demangling"),
+        OPT_BOOLEAN(0, "demangle-kernel", &symbol_conf.demangle_kernel,
+                    "Enable kernel symbol demangling"),
         OPT_END()
         };
         int ret;
diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 3da59a87ec7c..8c0b3f22412a 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -680,6 +680,8 @@ int cmd_report(int argc, const char **argv, const char *prefix __maybe_unused)
                    "objdump binary to use for disassembly and annotations"),
         OPT_BOOLEAN(0, "demangle", &symbol_conf.demangle,
                     "Disable symbol demangling"),
+        OPT_BOOLEAN(0, "demangle-kernel", &symbol_conf.demangle_kernel,
+                    "Enable kernel symbol demangling"),
         OPT_BOOLEAN(0, "mem-mode", &report.mem_mode, "mem access profile"),
         OPT_CALLBACK(0, "percent-limit", &report, "percent",
                      "Don't show entries under that percent", parse_percent_limit),
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 9848e270b92c..7da2c46ea38f 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -1142,6 +1142,8 @@ int cmd_top(int argc, const char **argv, const char *prefix __maybe_unused)
                     "Interleave source code with assembly code (default)"),
         OPT_BOOLEAN(0, "asm-raw", &symbol_conf.annotate_asm_raw,
                     "Display raw encoding of assembly instructions (default)"),
+        OPT_BOOLEAN(0, "demangle-kernel", &symbol_conf.demangle_kernel,
+                    "Enable kernel symbol demangling"),
         OPT_STRING(0, "objdump", &objdump_path, "path",
                     "objdump binary to use for disassembly and annotations"),
         OPT_STRING('M', "disassembler-style", &disassembler_style, "disassembler style",
diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index 9fb5e9e9f161..9c9b27fbc78d 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -680,6 +680,11 @@ static u64 ref_reloc(struct kmap *kmap)
         return 0;
 }
 
+static bool want_demangle(bool is_kernel_sym)
+{
+        return is_kernel_sym ? symbol_conf.demangle_kernel : symbol_conf.demangle;
+}
+
 int dso__load_sym(struct dso *dso, struct map *map,
                   struct symsrc *syms_ss, struct symsrc *runtime_ss,
                   symbol_filter_t filter, int kmodule)
@@ -938,7 +943,7 @@ new_symbol:
                  * DWARF DW_compile_unit has this, but we don't always have access
                  * to it...
                  */
-                if (symbol_conf.demangle) {
+                if (want_demangle(dso->kernel || kmodule)) {
                         int demangle_flags = DMGL_NO_OPTS;
                         if (verbose)
                                 demangle_flags = DMGL_PARAMS | DMGL_ANSI;
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index ac098a3c2a31..1adb143867e3 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -34,6 +34,7 @@ struct symbol_conf symbol_conf = {
         .try_vmlinux_path       = true,
         .annotate_src           = true,
         .demangle               = true,
+        .demangle_kernel        = false,
         .cumulate_callchain     = true,
         .show_hist_headers      = true,
         .symfs                  = "",
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index 3f95ea0357e3..bec4b7bd09de 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -120,6 +120,7 @@ struct symbol_conf {
                         annotate_src,
                         event_group,
                         demangle,
+                        demangle_kernel,
                         filter_relative,
                         show_hist_headers;
         const char      *vmlinux_name,