diff options
Diffstat (limited to 'tools/perf/util/llvm.c')
| -rw-r--r-- | tools/perf/util/llvm.c | 326 |
1 files changed, 326 insertions, 0 deletions
diff --git a/tools/perf/util/llvm.c b/tools/perf/util/llvm.c new file mode 100644 index 000000000000..ddc737194692 --- /dev/null +++ b/tools/perf/util/llvm.c @@ -0,0 +1,326 @@ +// SPDX-License-Identifier: GPL-2.0 +#include "llvm.h" +#include "annotate.h" +#include "debug.h" +#include "dso.h" +#include "map.h" +#include "namespaces.h" +#include "srcline.h" +#include "symbol.h" +#include <fcntl.h> +#include <unistd.h> +#include <linux/zalloc.h> + +#ifdef HAVE_LIBLLVM_SUPPORT +#include "llvm-c-helpers.h" +#include <llvm-c/Disassembler.h> +#include <llvm-c/Target.h> +#endif + +#ifdef HAVE_LIBLLVM_SUPPORT +static void free_llvm_inline_frames(struct llvm_a2l_frame *inline_frames, + int num_frames) +{ + if (inline_frames != NULL) { + for (int i = 0; i < num_frames; ++i) { + zfree(&inline_frames[i].filename); + zfree(&inline_frames[i].funcname); + } + zfree(&inline_frames); + } +} +#endif + +int llvm__addr2line(const char *dso_name __maybe_unused, u64 addr __maybe_unused, + char **file __maybe_unused, unsigned int *line __maybe_unused, + struct dso *dso __maybe_unused, bool unwind_inlines __maybe_unused, + struct inline_node *node __maybe_unused, struct symbol *sym __maybe_unused) +{ +#ifdef HAVE_LIBLLVM_SUPPORT + struct llvm_a2l_frame *inline_frames = NULL; + int num_frames = llvm_addr2line(dso_name, addr, file, line, + node && unwind_inlines, &inline_frames); + + if (num_frames == 0 || !inline_frames) { + /* Error, or we didn't want inlines. */ + return num_frames; + } + + for (int i = 0; i < num_frames; ++i) { + struct symbol *inline_sym = + new_inline_sym(dso, sym, inline_frames[i].funcname); + char *srcline = NULL; + + if (inline_frames[i].filename) { + srcline = + srcline_from_fileline(inline_frames[i].filename, + inline_frames[i].line); + } + if (inline_list__append(inline_sym, srcline, node) != 0) { + free_llvm_inline_frames(inline_frames, num_frames); + return 0; + } + } + free_llvm_inline_frames(inline_frames, num_frames); + + return num_frames; +#else + return -1; +#endif +} + +void dso__free_a2l_llvm(struct dso *dso __maybe_unused) +{ + /* Nothing to free. */ +} + + +#if defined(HAVE_LIBLLVM_SUPPORT) +struct find_file_offset_data { + u64 ip; + u64 offset; +}; + +/* This will be called for each PHDR in an ELF binary */ +static int find_file_offset(u64 start, u64 len, u64 pgoff, void *arg) +{ + struct find_file_offset_data *data = arg; + + if (start <= data->ip && data->ip < start + len) { + data->offset = pgoff + data->ip - start; + return 1; + } + return 0; +} + +static u8 * +read_symbol(const char *filename, struct map *map, struct symbol *sym, + u64 *len, bool *is_64bit) +{ + struct dso *dso = map__dso(map); + struct nscookie nsc; + u64 start = map__rip_2objdump(map, sym->start); + u64 end = map__rip_2objdump(map, sym->end); + int fd, count; + u8 *buf = NULL; + struct find_file_offset_data data = { + .ip = start, + }; + + *is_64bit = false; + + nsinfo__mountns_enter(dso__nsinfo(dso), &nsc); + fd = open(filename, O_RDONLY); + nsinfo__mountns_exit(&nsc); + if (fd < 0) + return NULL; + + if (file__read_maps(fd, /*exe=*/true, find_file_offset, &data, + is_64bit) == 0) + goto err; + + *len = end - start; + buf = malloc(*len); + if (buf == NULL) + goto err; + + count = pread(fd, buf, *len, data.offset); + close(fd); + fd = -1; + + if ((u64)count != *len) + goto err; + + return buf; + +err: + if (fd >= 0) + close(fd); + free(buf); + return NULL; +} +#endif + +/* + * Whenever LLVM wants to resolve an address into a symbol, it calls this + * callback. We don't ever actually _return_ anything (in particular, because + * it puts quotation marks around what we return), but we use this as a hint + * that there is a branch or PC-relative address in the expression that we + * should add some textual annotation for after the instruction. The caller + * will use this information to add the actual annotation. + */ +#ifdef HAVE_LIBLLVM_SUPPORT +struct symbol_lookup_storage { + u64 branch_addr; + u64 pcrel_load_addr; +}; + +static const char * +symbol_lookup_callback(void *disinfo, uint64_t value, + uint64_t *ref_type, + uint64_t address __maybe_unused, + const char **ref __maybe_unused) +{ + struct symbol_lookup_storage *storage = disinfo; + + if (*ref_type == LLVMDisassembler_ReferenceType_In_Branch) + storage->branch_addr = value; + else if (*ref_type == LLVMDisassembler_ReferenceType_In_PCrel_Load) + storage->pcrel_load_addr = value; + *ref_type = LLVMDisassembler_ReferenceType_InOut_None; + return NULL; +} +#endif + +int symbol__disassemble_llvm(const char *filename, struct symbol *sym, + struct annotate_args *args __maybe_unused) +{ +#ifdef HAVE_LIBLLVM_SUPPORT + struct annotation *notes = symbol__annotation(sym); + struct map *map = args->ms.map; + struct dso *dso = map__dso(map); + u64 start = map__rip_2objdump(map, sym->start); + u8 *buf; + u64 len; + u64 pc; + bool is_64bit; + char triplet[64]; + char disasm_buf[2048]; + size_t disasm_len; + struct disasm_line *dl; + LLVMDisasmContextRef disasm = NULL; + struct symbol_lookup_storage storage; + char *line_storage = NULL; + size_t line_storage_len = 0; + int ret = -1; + + if (args->options->objdump_path) + return -1; + + LLVMInitializeAllTargetInfos(); + LLVMInitializeAllTargetMCs(); + LLVMInitializeAllDisassemblers(); + + buf = read_symbol(filename, map, sym, &len, &is_64bit); + if (buf == NULL) + return -1; + + if (arch__is(args->arch, "x86")) { + if (is_64bit) + scnprintf(triplet, sizeof(triplet), "x86_64-pc-linux"); + else + scnprintf(triplet, sizeof(triplet), "i686-pc-linux"); + } else { + scnprintf(triplet, sizeof(triplet), "%s-linux-gnu", + args->arch->name); + } + + disasm = LLVMCreateDisasm(triplet, &storage, 0, NULL, + symbol_lookup_callback); + if (disasm == NULL) + goto err; + + if (args->options->disassembler_style && + !strcmp(args->options->disassembler_style, "intel")) + LLVMSetDisasmOptions(disasm, + LLVMDisassembler_Option_AsmPrinterVariant); + + /* + * This needs to be set after AsmPrinterVariant, due to a bug in LLVM; + * setting AsmPrinterVariant makes a new instruction printer, making it + * forget about the PrintImmHex flag (which is applied before if both + * are given to the same call). + */ + LLVMSetDisasmOptions(disasm, LLVMDisassembler_Option_PrintImmHex); + + /* add the function address and name */ + scnprintf(disasm_buf, sizeof(disasm_buf), "%#"PRIx64" <%s>:", + start, sym->name); + + args->offset = -1; + args->line = disasm_buf; + args->line_nr = 0; + args->fileloc = NULL; + args->ms.sym = sym; + + dl = disasm_line__new(args); + if (dl == NULL) + goto err; + + annotation_line__add(&dl->al, ¬es->src->source); + + pc = start; + for (u64 offset = 0; offset < len; ) { + unsigned int ins_len; + + storage.branch_addr = 0; + storage.pcrel_load_addr = 0; + + ins_len = LLVMDisasmInstruction(disasm, buf + offset, + len - offset, pc, + disasm_buf, sizeof(disasm_buf)); + if (ins_len == 0) + goto err; + disasm_len = strlen(disasm_buf); + + if (storage.branch_addr != 0) { + char *name = llvm_name_for_code(dso, filename, + storage.branch_addr); + if (name != NULL) { + disasm_len += scnprintf(disasm_buf + disasm_len, + sizeof(disasm_buf) - + disasm_len, + " <%s>", name); + free(name); + } + } + if (storage.pcrel_load_addr != 0) { + char *name = llvm_name_for_data(dso, filename, + storage.pcrel_load_addr); + disasm_len += scnprintf(disasm_buf + disasm_len, + sizeof(disasm_buf) - disasm_len, + " # %#"PRIx64, + storage.pcrel_load_addr); + if (name) { + disasm_len += scnprintf(disasm_buf + disasm_len, + sizeof(disasm_buf) - + disasm_len, + " <%s>", name); + free(name); + } + } + + args->offset = offset; + args->line = expand_tabs(disasm_buf, &line_storage, + &line_storage_len); + args->line_nr = 0; + args->fileloc = NULL; + args->ms.sym = sym; + + llvm_addr2line(filename, pc, &args->fileloc, + (unsigned int *)&args->line_nr, false, NULL); + + dl = disasm_line__new(args); + if (dl == NULL) + goto err; + + annotation_line__add(&dl->al, ¬es->src->source); + + free(args->fileloc); + pc += ins_len; + offset += ins_len; + } + + ret = 0; + +err: + LLVMDisasmDispose(disasm); + free(buf); + free(line_storage); + return ret; +#else // HAVE_LIBLLVM_SUPPORT + pr_debug("The LLVM disassembler isn't linked in for %s in %s\n", + sym->name, filename); + return -1; +#endif +} |