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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /tools/perf/util/genelf_debug.c | |
parent | Initial commit. (diff) | |
download | linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.tar.xz linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tools/perf/util/genelf_debug.c')
-rw-r--r-- | tools/perf/util/genelf_debug.c | 609 |
1 files changed, 609 insertions, 0 deletions
diff --git a/tools/perf/util/genelf_debug.c b/tools/perf/util/genelf_debug.c new file mode 100644 index 000000000..dd40683bd --- /dev/null +++ b/tools/perf/util/genelf_debug.c @@ -0,0 +1,609 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * genelf_debug.c + * Copyright (C) 2015, Google, Inc + * + * Contributed by: + * Stephane Eranian <eranian@google.com> + * + * based on GPLv2 source code from Oprofile + * @remark Copyright 2007 OProfile authors + * @author Philippe Elie + */ +#include <linux/compiler.h> +#include <sys/types.h> +#include <stdio.h> +#include <getopt.h> +#include <stddef.h> +#include <libelf.h> +#include <string.h> +#include <stdlib.h> +#include <inttypes.h> +#include <limits.h> +#include <fcntl.h> +#include <err.h> +#include <dwarf.h> + +#include "genelf.h" +#include "../util/jitdump.h" + +#define BUFFER_EXT_DFL_SIZE (4 * 1024) + +typedef uint32_t uword; +typedef uint16_t uhalf; +typedef int32_t sword; +typedef int16_t shalf; +typedef uint8_t ubyte; +typedef int8_t sbyte; + +struct buffer_ext { + size_t cur_pos; + size_t max_sz; + void *data; +}; + +static void +buffer_ext_dump(struct buffer_ext *be, const char *msg) +{ + size_t i; + warnx("DUMP for %s", msg); + for (i = 0 ; i < be->cur_pos; i++) + warnx("%4zu 0x%02x", i, (((char *)be->data)[i]) & 0xff); +} + +static inline int +buffer_ext_add(struct buffer_ext *be, void *addr, size_t sz) +{ + void *tmp; + size_t be_sz = be->max_sz; + +retry: + if ((be->cur_pos + sz) < be_sz) { + memcpy(be->data + be->cur_pos, addr, sz); + be->cur_pos += sz; + return 0; + } + + if (!be_sz) + be_sz = BUFFER_EXT_DFL_SIZE; + else + be_sz <<= 1; + + tmp = realloc(be->data, be_sz); + if (!tmp) + return -1; + + be->data = tmp; + be->max_sz = be_sz; + + goto retry; +} + +static void +buffer_ext_init(struct buffer_ext *be) +{ + be->data = NULL; + be->cur_pos = 0; + be->max_sz = 0; +} + +static inline size_t +buffer_ext_size(struct buffer_ext *be) +{ + return be->cur_pos; +} + +static inline void * +buffer_ext_addr(struct buffer_ext *be) +{ + return be->data; +} + +struct debug_line_header { + // Not counting this field + uword total_length; + // version number (2 currently) + uhalf version; + // relative offset from next field to + // program statement + uword prolog_length; + ubyte minimum_instruction_length; + ubyte default_is_stmt; + // line_base - see DWARF 2 specs + sbyte line_base; + // line_range - see DWARF 2 specs + ubyte line_range; + // number of opcode + 1 + ubyte opcode_base; + /* follow the array of opcode args nr: ubytes [nr_opcode_base] */ + /* follow the search directories index, zero terminated string + * terminated by an empty string. + */ + /* follow an array of { filename, LEB128, LEB128, LEB128 }, first is + * the directory index entry, 0 means current directory, then mtime + * and filesize, last entry is followed by en empty string. + */ + /* follow the first program statement */ +} __packed; + +/* DWARF 2 spec talk only about one possible compilation unit header while + * binutils can handle two flavours of dwarf 2, 32 and 64 bits, this is not + * related to the used arch, an ELF 32 can hold more than 4 Go of debug + * information. For now we handle only DWARF 2 32 bits comp unit. It'll only + * become a problem if we generate more than 4GB of debug information. + */ +struct compilation_unit_header { + uword total_length; + uhalf version; + uword debug_abbrev_offset; + ubyte pointer_size; +} __packed; + +#define DW_LNS_num_opcode (DW_LNS_set_isa + 1) + +/* field filled at run time are marked with -1 */ +static struct debug_line_header const default_debug_line_header = { + .total_length = -1, + .version = 2, + .prolog_length = -1, + .minimum_instruction_length = 1, /* could be better when min instruction size != 1 */ + .default_is_stmt = 1, /* we don't take care about basic block */ + .line_base = -5, /* sensible value for line base ... */ + .line_range = -14, /* ... and line range are guessed statically */ + .opcode_base = DW_LNS_num_opcode +}; + +static ubyte standard_opcode_length[] = +{ + 0, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 1 +}; +#if 0 +{ + [DW_LNS_advance_pc] = 1, + [DW_LNS_advance_line] = 1, + [DW_LNS_set_file] = 1, + [DW_LNS_set_column] = 1, + [DW_LNS_fixed_advance_pc] = 1, + [DW_LNS_set_isa] = 1, +}; +#endif + +/* field filled at run time are marked with -1 */ +static struct compilation_unit_header default_comp_unit_header = { + .total_length = -1, + .version = 2, + .debug_abbrev_offset = 0, /* we reuse the same abbrev entries for all comp unit */ + .pointer_size = sizeof(void *) +}; + +static void emit_uword(struct buffer_ext *be, uword data) +{ + buffer_ext_add(be, &data, sizeof(uword)); +} + +static void emit_string(struct buffer_ext *be, const char *s) +{ + buffer_ext_add(be, (void *)s, strlen(s) + 1); +} + +static void emit_unsigned_LEB128(struct buffer_ext *be, + unsigned long data) +{ + do { + ubyte cur = data & 0x7F; + data >>= 7; + if (data) + cur |= 0x80; + buffer_ext_add(be, &cur, 1); + } while (data); +} + +static void emit_signed_LEB128(struct buffer_ext *be, long data) +{ + int more = 1; + int negative = data < 0; + int size = sizeof(long) * CHAR_BIT; + while (more) { + ubyte cur = data & 0x7F; + data >>= 7; + if (negative) + data |= - (1 << (size - 7)); + if ((data == 0 && !(cur & 0x40)) || + (data == -1l && (cur & 0x40))) + more = 0; + else + cur |= 0x80; + buffer_ext_add(be, &cur, 1); + } +} + +static void emit_extended_opcode(struct buffer_ext *be, ubyte opcode, + void *data, size_t data_len) +{ + buffer_ext_add(be, (char *)"", 1); + + emit_unsigned_LEB128(be, data_len + 1); + + buffer_ext_add(be, &opcode, 1); + buffer_ext_add(be, data, data_len); +} + +static void emit_opcode(struct buffer_ext *be, ubyte opcode) +{ + buffer_ext_add(be, &opcode, 1); +} + +static void emit_opcode_signed(struct buffer_ext *be, + ubyte opcode, long data) +{ + buffer_ext_add(be, &opcode, 1); + emit_signed_LEB128(be, data); +} + +static void emit_opcode_unsigned(struct buffer_ext *be, ubyte opcode, + unsigned long data) +{ + buffer_ext_add(be, &opcode, 1); + emit_unsigned_LEB128(be, data); +} + +static void emit_advance_pc(struct buffer_ext *be, unsigned long delta_pc) +{ + emit_opcode_unsigned(be, DW_LNS_advance_pc, delta_pc); +} + +static void emit_advance_lineno(struct buffer_ext *be, long delta_lineno) +{ + emit_opcode_signed(be, DW_LNS_advance_line, delta_lineno); +} + +static void emit_lne_end_of_sequence(struct buffer_ext *be) +{ + emit_extended_opcode(be, DW_LNE_end_sequence, NULL, 0); +} + +static void emit_set_file(struct buffer_ext *be, unsigned long idx) +{ + emit_opcode_unsigned(be, DW_LNS_set_file, idx); +} + +static void emit_lne_define_filename(struct buffer_ext *be, + const char *filename) +{ + buffer_ext_add(be, (void *)"", 1); + + /* LNE field, strlen(filename) + zero termination, 3 bytes for: the dir entry, timestamp, filesize */ + emit_unsigned_LEB128(be, strlen(filename) + 5); + emit_opcode(be, DW_LNE_define_file); + emit_string(be, filename); + /* directory index 0=do not know */ + emit_unsigned_LEB128(be, 0); + /* last modification date on file 0=do not know */ + emit_unsigned_LEB128(be, 0); + /* filesize 0=do not know */ + emit_unsigned_LEB128(be, 0); +} + +static void emit_lne_set_address(struct buffer_ext *be, + void *address) +{ + emit_extended_opcode(be, DW_LNE_set_address, &address, sizeof(unsigned long)); +} + +static ubyte get_special_opcode(struct debug_entry *ent, + unsigned int last_line, + unsigned long last_vma) +{ + unsigned int temp; + unsigned long delta_addr; + + /* + * delta from line_base + */ + temp = (ent->lineno - last_line) - default_debug_line_header.line_base; + + if (temp >= default_debug_line_header.line_range) + return 0; + + /* + * delta of addresses + */ + delta_addr = (ent->addr - last_vma) / default_debug_line_header.minimum_instruction_length; + + /* This is not sufficient to ensure opcode will be in [0-256] but + * sufficient to ensure when summing with the delta lineno we will + * not overflow the unsigned long opcode */ + + if (delta_addr <= 256 / default_debug_line_header.line_range) { + unsigned long opcode = temp + + (delta_addr * default_debug_line_header.line_range) + + default_debug_line_header.opcode_base; + + return opcode <= 255 ? opcode : 0; + } + return 0; +} + +static void emit_lineno_info(struct buffer_ext *be, + struct debug_entry *ent, size_t nr_entry, + unsigned long code_addr) +{ + size_t i; + + /* + * Machine state at start of a statement program + * address = 0 + * file = 1 + * line = 1 + * column = 0 + * is_stmt = default_is_stmt as given in the debug_line_header + * basic block = 0 + * end sequence = 0 + */ + + /* start state of the state machine we take care of */ + unsigned long last_vma = 0; + char const *cur_filename = NULL; + unsigned long cur_file_idx = 0; + int last_line = 1; + + emit_lne_set_address(be, (void *)code_addr); + + for (i = 0; i < nr_entry; i++, ent = debug_entry_next(ent)) { + int need_copy = 0; + ubyte special_opcode; + + /* + * check if filename changed, if so add it + */ + if (!cur_filename || strcmp(cur_filename, ent->name)) { + emit_lne_define_filename(be, ent->name); + cur_filename = ent->name; + emit_set_file(be, ++cur_file_idx); + need_copy = 1; + } + + special_opcode = get_special_opcode(ent, last_line, last_vma); + if (special_opcode != 0) { + last_line = ent->lineno; + last_vma = ent->addr; + emit_opcode(be, special_opcode); + } else { + /* + * lines differ, emit line delta + */ + if (last_line != ent->lineno) { + emit_advance_lineno(be, ent->lineno - last_line); + last_line = ent->lineno; + need_copy = 1; + } + /* + * addresses differ, emit address delta + */ + if (last_vma != ent->addr) { + emit_advance_pc(be, ent->addr - last_vma); + last_vma = ent->addr; + need_copy = 1; + } + /* + * add new row to matrix + */ + if (need_copy) + emit_opcode(be, DW_LNS_copy); + } + } +} + +static void add_debug_line(struct buffer_ext *be, + struct debug_entry *ent, size_t nr_entry, + unsigned long code_addr) +{ + struct debug_line_header * dbg_header; + size_t old_size; + + old_size = buffer_ext_size(be); + + buffer_ext_add(be, (void *)&default_debug_line_header, + sizeof(default_debug_line_header)); + + buffer_ext_add(be, &standard_opcode_length, sizeof(standard_opcode_length)); + + // empty directory entry + buffer_ext_add(be, (void *)"", 1); + + // empty filename directory + buffer_ext_add(be, (void *)"", 1); + + dbg_header = buffer_ext_addr(be) + old_size; + dbg_header->prolog_length = (buffer_ext_size(be) - old_size) - + offsetof(struct debug_line_header, minimum_instruction_length); + + emit_lineno_info(be, ent, nr_entry, code_addr); + + emit_lne_end_of_sequence(be); + + dbg_header = buffer_ext_addr(be) + old_size; + dbg_header->total_length = (buffer_ext_size(be) - old_size) - + offsetof(struct debug_line_header, version); +} + +static void +add_debug_abbrev(struct buffer_ext *be) +{ + emit_unsigned_LEB128(be, 1); + emit_unsigned_LEB128(be, DW_TAG_compile_unit); + emit_unsigned_LEB128(be, DW_CHILDREN_yes); + emit_unsigned_LEB128(be, DW_AT_stmt_list); + emit_unsigned_LEB128(be, DW_FORM_data4); + emit_unsigned_LEB128(be, 0); + emit_unsigned_LEB128(be, 0); + emit_unsigned_LEB128(be, 0); +} + +static void +add_compilation_unit(struct buffer_ext *be, + size_t offset_debug_line) +{ + struct compilation_unit_header *comp_unit_header; + size_t old_size = buffer_ext_size(be); + + buffer_ext_add(be, &default_comp_unit_header, + sizeof(default_comp_unit_header)); + + emit_unsigned_LEB128(be, 1); + emit_uword(be, offset_debug_line); + + comp_unit_header = buffer_ext_addr(be) + old_size; + comp_unit_header->total_length = (buffer_ext_size(be) - old_size) - + offsetof(struct compilation_unit_header, version); +} + +static int +jit_process_debug_info(uint64_t code_addr, + void *debug, int nr_debug_entries, + struct buffer_ext *dl, + struct buffer_ext *da, + struct buffer_ext *di) +{ + struct debug_entry *ent = debug; + int i; + + for (i = 0; i < nr_debug_entries; i++) { + ent->addr = ent->addr - code_addr; + ent = debug_entry_next(ent); + } + add_compilation_unit(di, buffer_ext_size(dl)); + add_debug_line(dl, debug, nr_debug_entries, GEN_ELF_TEXT_OFFSET); + add_debug_abbrev(da); + if (0) buffer_ext_dump(da, "abbrev"); + + return 0; +} + +int +jit_add_debug_info(Elf *e, uint64_t code_addr, void *debug, int nr_debug_entries) +{ + Elf_Data *d; + Elf_Scn *scn; + Elf_Shdr *shdr; + struct buffer_ext dl, di, da; + int ret; + + buffer_ext_init(&dl); + buffer_ext_init(&di); + buffer_ext_init(&da); + + ret = jit_process_debug_info(code_addr, debug, nr_debug_entries, &dl, &da, &di); + if (ret) + return -1; + /* + * setup .debug_line section + */ + scn = elf_newscn(e); + if (!scn) { + warnx("cannot create section"); + return -1; + } + + d = elf_newdata(scn); + if (!d) { + warnx("cannot get new data"); + return -1; + } + + d->d_align = 1; + d->d_off = 0LL; + d->d_buf = buffer_ext_addr(&dl); + d->d_type = ELF_T_BYTE; + d->d_size = buffer_ext_size(&dl); + d->d_version = EV_CURRENT; + + shdr = elf_getshdr(scn); + if (!shdr) { + warnx("cannot get section header"); + return -1; + } + + shdr->sh_name = 52; /* .debug_line */ + shdr->sh_type = SHT_PROGBITS; + shdr->sh_addr = 0; /* must be zero or == sh_offset -> dynamic object */ + shdr->sh_flags = 0; + shdr->sh_entsize = 0; + + /* + * setup .debug_info section + */ + scn = elf_newscn(e); + if (!scn) { + warnx("cannot create section"); + return -1; + } + + d = elf_newdata(scn); + if (!d) { + warnx("cannot get new data"); + return -1; + } + + d->d_align = 1; + d->d_off = 0LL; + d->d_buf = buffer_ext_addr(&di); + d->d_type = ELF_T_BYTE; + d->d_size = buffer_ext_size(&di); + d->d_version = EV_CURRENT; + + shdr = elf_getshdr(scn); + if (!shdr) { + warnx("cannot get section header"); + return -1; + } + + shdr->sh_name = 64; /* .debug_info */ + shdr->sh_type = SHT_PROGBITS; + shdr->sh_addr = 0; /* must be zero or == sh_offset -> dynamic object */ + shdr->sh_flags = 0; + shdr->sh_entsize = 0; + + /* + * setup .debug_abbrev section + */ + scn = elf_newscn(e); + if (!scn) { + warnx("cannot create section"); + return -1; + } + + d = elf_newdata(scn); + if (!d) { + warnx("cannot get new data"); + return -1; + } + + d->d_align = 1; + d->d_off = 0LL; + d->d_buf = buffer_ext_addr(&da); + d->d_type = ELF_T_BYTE; + d->d_size = buffer_ext_size(&da); + d->d_version = EV_CURRENT; + + shdr = elf_getshdr(scn); + if (!shdr) { + warnx("cannot get section header"); + return -1; + } + + shdr->sh_name = 76; /* .debug_info */ + shdr->sh_type = SHT_PROGBITS; + shdr->sh_addr = 0; /* must be zero or == sh_offset -> dynamic object */ + shdr->sh_flags = 0; + shdr->sh_entsize = 0; + + /* + * now we update the ELF image with all the sections + */ + if (elf_update(e, ELF_C_WRITE) < 0) { + warnx("elf_update debug failed"); + return -1; + } + return 0; +} |