Merge tag 'perf-core-for-mingo-20160901' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core

Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:

User visible changes:

- Support generating cross arch probes, i.e. if you specify a vmlinux
  file for different arch than the one in the host machine,

	 $ perf probe --definition function_name args

  will generate the probe definition string needed to append to the
  target machine /sys/kernel/debug/tracing/kprobes_events file, using
  scripting (Masami Hiramatsu).

- Make 'perf probe' skip the function prologue in uprobes if program
  compiled without optimization, using the same strategy as gdb and
  systemtap uses, fixing a bug where:

	$ perf probe -x ./test 'foo i'

  When 'foo(42)' was used on the "./test" executable would produce i=0
  instead of the expected i=42 (Ravi Bangoria)

- Demangle symbols for synthesized @plt entries too (Millian Wolff)

Documentation changes:

- Show default report configuration in 'perf config' example
  and docs (Millian Wolff)

Infrastructure changes:

- Make 'perf test vmlinux' tolerate the symbol aliasing pruning done when
  loading kallsyms and vmlinux (Arnaldo Carvalho de Melo)

- Improve output of 'perf test vmlinux' test, to help identify on the verbose
  output which lines are warning and which are errors (Arnaldo Carvalho de Melo)

- Prep work to stop having to pass symbol_filter_t to lots of functions,
  simplifying symtab loading routines (Arnaldo Carvalho de Melo)

- Honor symbol_conf.allow_aliases when loading kallsyms as well, it was using
  it only when loading vmlinux files (Arnaldo Carvalho de Melo)

- Fixup symbol->end before doing alias pruning when loading symbol tables
  (Arnaldo Carvalho de Melo)

- Fix error handling of lzma kernel module decompression (Shawn Lin)

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 54 insertions, 32 deletions

diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index a811c13a74d6..295d3147a803 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -206,6 +206,37 @@ Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
 	return NULL;
 }
 
+static bool want_demangle(bool is_kernel_sym)
+{
+	return is_kernel_sym ? symbol_conf.demangle_kernel : symbol_conf.demangle;
+}
+
+static char *demangle_sym(struct dso *dso, int kmodule, const char *elf_name)
+{
+	int demangle_flags = verbose ? (DMGL_PARAMS | DMGL_ANSI) : DMGL_NO_OPTS;
+	char *demangled = NULL;
+
+	/*
+	 * We need to figure out if the object was created from C++ sources
+	 * DWARF DW_compile_unit has this, but we don't always have access
+	 * to it...
+	 */
+	if (!want_demangle(dso->kernel || kmodule))
+	    return demangled;
+
+	demangled = bfd_demangle(NULL, elf_name, demangle_flags);
+	if (demangled == NULL)
+		demangled = java_demangle_sym(elf_name, JAVA_DEMANGLE_NORET);
+	else if (rust_is_mangled(demangled))
+		/*
+		    * Input to Rust demangling is the BFD-demangled
+		    * name which it Rust-demangles in place.
+		    */
+		rust_demangle_sym(demangled);
+
+	return demangled;
+}
+
 #define elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_entries) \
 	for (idx = 0, pos = gelf_getrel(reldata, 0, &pos_mem); \
 	     idx < nr_entries; \
@@ -301,11 +332,19 @@ int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss, struct map *
 
 		elf_section__for_each_rela(reldata, pos, pos_mem, idx,
 					   nr_rel_entries) {
+			const char *elf_name = NULL;
+			char *demangled = NULL;
 			symidx = GELF_R_SYM(pos->r_info);
 			plt_offset += shdr_plt.sh_entsize;
 			gelf_getsym(syms, symidx, &sym);
+
+			elf_name = elf_sym__name(&sym, symstrs);
+			demangled = demangle_sym(dso, 0, elf_name);
+			if (demangled != NULL)
+				elf_name = demangled;
 			snprintf(sympltname, sizeof(sympltname),
-				 "%s@plt", elf_sym__name(&sym, symstrs));
+				 "%s@plt", elf_name);
+			free(demangled);
 
 			f = symbol__new(plt_offset, shdr_plt.sh_entsize,
 					STB_GLOBAL, sympltname);
@@ -323,11 +362,19 @@ int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss, struct map *
 		GElf_Rel pos_mem, *pos;
 		elf_section__for_each_rel(reldata, pos, pos_mem, idx,
 					  nr_rel_entries) {
+			const char *elf_name = NULL;
+			char *demangled = NULL;
 			symidx = GELF_R_SYM(pos->r_info);
 			plt_offset += shdr_plt.sh_entsize;
 			gelf_getsym(syms, symidx, &sym);
+
+			elf_name = elf_sym__name(&sym, symstrs);
+			demangled = demangle_sym(dso, 0, elf_name);
+			if (demangled != NULL)
+				elf_name = demangled;
 			snprintf(sympltname, sizeof(sympltname),
-				 "%s@plt", elf_sym__name(&sym, symstrs));
+				 "%s@plt", elf_name);
+			free(demangled);
 
 			f = symbol__new(plt_offset, shdr_plt.sh_entsize,
 					STB_GLOBAL, sympltname);
@@ -685,7 +732,7 @@ int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
 	}
 
 	/* Always reject images with a mismatched build-id: */
-	if (dso->has_build_id) {
+	if (dso->has_build_id && !symbol_conf.ignore_vmlinux_buildid) {
 		u8 build_id[BUILD_ID_SIZE];
 
 		if (elf_read_build_id(elf, build_id, BUILD_ID_SIZE) < 0) {
@@ -775,11 +822,6 @@ 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;
-}
-
 void __weak arch__sym_update(struct symbol *s __maybe_unused,
 		GElf_Sym *sym __maybe_unused) { }
 
@@ -1070,29 +1112,10 @@ int dso__load_sym(struct dso *dso, struct map *map,
 			sym.st_value -= shdr.sh_addr - shdr.sh_offset;
 		}
 new_symbol:
-		/*
-		 * We need to figure out if the object was created from C++ sources
-		 * DWARF DW_compile_unit has this, but we don't always have access
-		 * to it...
-		 */
-		if (want_demangle(dso->kernel || kmodule)) {
-			int demangle_flags = DMGL_NO_OPTS;
-			if (verbose)
-				demangle_flags = DMGL_PARAMS | DMGL_ANSI;
-
-			demangled = bfd_demangle(NULL, elf_name, demangle_flags);
-			if (demangled == NULL)
-				demangled = java_demangle_sym(elf_name, JAVA_DEMANGLE_NORET);
-			else if (rust_is_mangled(demangled))
-				/*
-				 * Input to Rust demangling is the BFD-demangled
-				 * name which it Rust-demangles in place.
-				 */
-				rust_demangle_sym(demangled);
+		demangled = demangle_sym(dso, kmodule, elf_name);
+		if (demangled != NULL)
+			elf_name = demangled;
 
-			if (demangled != NULL)
-				elf_name = demangled;
-		}
 		f = symbol__new(sym.st_value, sym.st_size,
 				GELF_ST_BIND(sym.st_info), elf_name);
 		free(demangled);
@@ -1113,9 +1136,8 @@ new_symbol:
 	 * For misannotated, zeroed, ASM function sizes.
 	 */
 	if (nr > 0) {
-		if (!symbol_conf.allow_aliases)
-			symbols__fixup_duplicate(&dso->symbols[map->type]);
 		symbols__fixup_end(&dso->symbols[map->type]);
+		symbols__fixup_duplicate(&dso->symbols[map->type]);
 		if (kmap) {
 			/*
 			 * We need to fixup this here too because we create new