For in-memory BPF DSOs (DSO_BINARY_TYPE__BPF_PROG_INFO), write the JITted instruction buffer to a temporary ELF file on disk using the existing genelf framework (jit_write_elf). Reroute disassembly to this temporary ELF file, allowing objdump and libasm to disassemble it natively. Clean up the temporary file afterward. Assisted-by: Antigravity:Google Gemini 3.5-flash Signed-off-by: Ian Rogers --- tools/perf/util/disasm.c | 107 ++++++++++++++++++++++++++++++++++++--- tools/perf/util/disasm.h | 1 + 2 files changed, 101 insertions(+), 7 deletions(-) diff --git a/tools/perf/util/disasm.c b/tools/perf/util/disasm.c index 42af3603fdff..8c78ef765787 100644 --- a/tools/perf/util/disasm.c +++ b/tools/perf/util/disasm.c @@ -23,6 +23,9 @@ #include "debug.h" #include "disasm.h" #include "libasm.h" +#ifdef HAVE_LIBELF_SUPPORT +#include "genelf.h" +#endif #include "dso.h" #include "dwarf-regs.h" #include "env.h" @@ -1420,7 +1423,7 @@ static int symbol__disassemble_objdump(const char *filename, struct symbol *sym, struct child_process objdump_process; int err; - if (dso__binary_type(dso) == DSO_BINARY_TYPE__BPF_PROG_INFO) + if (dso__binary_type(dso) == DSO_BINARY_TYPE__BPF_PROG_INFO && !args->is_temp_elf) return symbol__disassemble_bpf_libbfd(sym, args); if (dso__binary_type(dso) == DSO_BINARY_TYPE__BPF_IMAGE) @@ -1540,6 +1543,41 @@ static int symbol__disassemble_objdump(const char *filename, struct symbol *sym, return err; } +#ifdef HAVE_LIBELF_SUPPORT +static int symbol__create_bpf_temp_elf(const char *filename, struct symbol *sym, + struct annotate_args *args, + char *tmp_elf, size_t tmp_elf_sz) +{ + struct map *map = args->ms->map; + struct dso *dso = map__dso(map); + u8 *code_buf = NULL; + const u8 *buf; + u64 buf_len; + bool is_64bit; + int tmp_fd; + int err = -1; + + buf = dso__read_symbol(dso, filename, map, sym, &code_buf, &buf_len, &is_64bit); + if (!buf) + return -1; + + snprintf(tmp_elf, tmp_elf_sz, "/tmp/perf-bpf-XXXXXX"); + tmp_fd = mkstemp(tmp_elf); + if (tmp_fd >= 0) { + if (jit_write_elf(tmp_fd, map__rip_2objdump(map, sym->start), + sym->name, buf, buf_len, + NULL, 0, NULL, 0, 0) == 0) { + err = 0; + } + close(tmp_fd); + if (err) + unlink(tmp_elf); + } + free(code_buf); + return err; +} +#endif + int symbol__disassemble(struct symbol *sym, struct annotate_args *args) { struct annotation_options *options = args->options; @@ -1549,8 +1587,11 @@ int symbol__disassemble(struct symbol *sym, struct annotate_args *args) bool delete_extract = false; struct kcore_extract kce; bool decomp = false; - int err = dso__disassemble_filename(dso, symfs_filename, sizeof(symfs_filename)); + int err; + args->is_temp_elf = false; + + err = dso__disassemble_filename(dso, symfs_filename, sizeof(symfs_filename)); if (err) return err; @@ -1605,7 +1646,25 @@ int symbol__disassemble(struct symbol *sym, struct annotate_args *args) /* FIXME: LLVM and CAPSTONE should support source code */ if (options->annotate_src && !options->hide_src_code) { - err = symbol__disassemble_objdump(symfs_filename, sym, args); + const char *disasm_filename = symfs_filename; + bool is_temp = false; + char tmp_elf[PATH_MAX]; + +#ifdef HAVE_LIBELF_SUPPORT + if (dso__binary_type(dso) == DSO_BINARY_TYPE__BPF_PROG_INFO) { + if (symbol__create_bpf_temp_elf(symfs_filename, sym, args, + tmp_elf, sizeof(tmp_elf)) == 0) { + disasm_filename = tmp_elf; + is_temp = true; + args->is_temp_elf = true; + } + } +#endif + err = symbol__disassemble_objdump(disasm_filename, sym, args); + if (is_temp) { + unlink(tmp_elf); + args->is_temp_elf = false; + } if (err == 0) goto out_remove_tmp; } @@ -1613,29 +1672,63 @@ int symbol__disassemble(struct symbol *sym, struct annotate_args *args) err = -1; for (u8 i = 0; i < ARRAY_SIZE(options->disassemblers) && err != 0; i++) { enum perf_disassembler dis = options->disassemblers[i]; + const char *disasm_filename = symfs_filename; + bool is_temp = false; + char tmp_elf[PATH_MAX]; + + switch (dis) { + case PERF_DISASM_LIBASM: + case PERF_DISASM_OBJDUMP: +#ifdef HAVE_LIBELF_SUPPORT + if (dso__binary_type(dso) == DSO_BINARY_TYPE__BPF_PROG_INFO) { + if (symbol__create_bpf_temp_elf(symfs_filename, sym, args, + tmp_elf, sizeof(tmp_elf)) == 0) { + disasm_filename = tmp_elf; + is_temp = true; + args->is_temp_elf = true; + } + } +#endif + break; + case PERF_DISASM_LLVM: + case PERF_DISASM_CAPSTONE: + case PERF_DISASM_UNKNOWN: + default: + break; + } switch (dis) { case PERF_DISASM_LLVM: args->options->disassembler_used = PERF_DISASM_LLVM; - err = symbol__disassemble_llvm(symfs_filename, sym, args); + err = symbol__disassemble_llvm(disasm_filename, sym, args); break; case PERF_DISASM_CAPSTONE: args->options->disassembler_used = PERF_DISASM_CAPSTONE; - err = symbol__disassemble_capstone(symfs_filename, sym, args); + err = symbol__disassemble_capstone(disasm_filename, sym, args); break; case PERF_DISASM_LIBASM: args->options->disassembler_used = PERF_DISASM_LIBASM; - err = symbol__disassemble_libasm(symfs_filename, sym, args); + err = symbol__disassemble_libasm(disasm_filename, sym, args); break; case PERF_DISASM_OBJDUMP: args->options->disassembler_used = PERF_DISASM_OBJDUMP; - err = symbol__disassemble_objdump(symfs_filename, sym, args); + err = symbol__disassemble_objdump(disasm_filename, sym, args); break; case PERF_DISASM_UNKNOWN: /* End of disassemblers. */ default: args->options->disassembler_used = PERF_DISASM_UNKNOWN; + if (is_temp) { + unlink(tmp_elf); + args->is_temp_elf = false; + } goto out_remove_tmp; } + + if (is_temp) { + unlink(tmp_elf); + args->is_temp_elf = false; + } + if (err == 0) pr_debug("Disassembled with %s\n", perf_disassembler__strs[dis]); } diff --git a/tools/perf/util/disasm.h b/tools/perf/util/disasm.h index 25756e3f47e4..32a5b3f5d1c6 100644 --- a/tools/perf/util/disasm.h +++ b/tools/perf/util/disasm.h @@ -106,6 +106,7 @@ struct annotate_args { char *line; int line_nr; char *fileloc; + bool is_temp_elf; }; const struct arch *arch__find(uint16_t e_machine, uint32_t e_flags, const char *cpuid); -- 2.54.0.1064.gd145956f57-goog