diff options
| -rw-r--r-- | ChangeLog | 11 | ||||
| -rw-r--r-- | TODO | 46 | ||||
| -rw-r--r-- | binfile.c | 4 | ||||
| -rw-r--r-- | binparser.c | 216 | ||||
| -rw-r--r-- | collector.c | 2 | ||||
| -rw-r--r-- | elfparser.c | 59 | ||||
| -rw-r--r-- | elfparser.h | 12 | ||||
| -rw-r--r-- | module/Makefile | 2 | ||||
| -rw-r--r-- | module/sysprof-module.c | 31 | ||||
| -rw-r--r-- | testelf.c | 4 |
10 files changed, 141 insertions, 246 deletions
@@ -1,3 +1,14 @@ +2006-08-27 Soren Sandmann <sandmann@redhat.com> + + * binparser.c: Remove old commented out code + +2006-08-27 Soren Sandmann <sandmann@redhat.com> + + * module/Makefile ($(MODULE).o): Add dependency on sysprof-module.h + + * elfparser.c (elf_parser_get_eh_frame): Add this function. + Remove some commented out code. + Sat Aug 26 19:05:51 2006 Søren Sandmann <sandmann@redhat.com> * Formatting fixes in header files. @@ -32,6 +32,52 @@ Before 1.0.4: Before 1.2: +* Elf bugs: + + - when an elf file is read, it should be checked that the various + sections are of the right type. For example the debug information + for emacs is just a stub file where all the sections are NOBITS. + + - Also error handling for bin_parser is necessary. + + - Can .gnu_debuglink recurse? + +* Strategies for taking reliable stacktraces. + + Three different kinds of files + + - kernel + - vdso + - regular elf files + + - kernel + - eh_frame annotations, in kernel or in kernel debug + - /proc/kallsyms + - userspace can look at _stext and _etext to determine + start and end of kernel text segment + - copying kernel stack to userspace + - heuristically determine functions based on address + - is eh_frame usually loaded into memory during normal + operation + + - vdso + - assume its the same across processes, just look at + sysprof's own copy. + - send copy of it to userspace once, or for every + sample + + - regular elf + - usually have eh_frame section which is mapped into memory + during normal operation + - is usually mapped into memory + - do stackwalk in kernel based on eh_frame + - do stackwalk in userland based on eh_frame + - do ebp based stackwalk in kernel + - do ebp based stackwalk in userland + - do heuristic stackwalk in kernel + - do heuristic stackwalk in userland + - + * "Expand all" is horrendously slow because update screenshot gets called for every "expanded" signal. @@ -68,6 +68,9 @@ separate_debug_file_exists (const char *name, guint32 crc) if (!parser) return NULL; + g_print ("debug for the debug file: %s\n", + elf_parser_get_debug_link (parser, &file_crc)); + file_crc = elf_parser_get_crc32 (parser); if (file_crc != crc) @@ -188,6 +191,7 @@ bin_file_lookup_symbol (BinFile *bin_file, { if (bin_file->elf) { + g_print ("lookup in %s\n", bin_file->filename); const ElfSym *sym = elf_parser_lookup_symbol (bin_file->elf, address); if (sym) diff --git a/binparser.c b/binparser.c index 56817db..94eb322 100644 --- a/binparser.c +++ b/binparser.c @@ -173,6 +173,9 @@ convert_uint (const guchar *data, guint16 r16; guint32 r32; guint64 r64; + + if (width == 4) + g_print ("converting at %p %d %d %d %d\n", data, data[0], data[1], data[2], data[3]); switch (width) { @@ -378,12 +381,18 @@ bin_record_get_uint (BinRecord *record, field = get_field (record->format, name); pos = record->parser->data + record->offset + field->offset; + g_print (" record offset: %d\n", record->offset); + g_print (" record index: %d\n", record->index); + g_print (" field offset %d\n", field->offset); + if (record->offset + field->offset + field->width > record->parser->length) { /* FIXME: generate error */ return 0; } + g_print (" uint %d at %p => %d\n", field->width, pos, convert_uint (pos, record->format->big_endian, field->width)); + return convert_uint (pos, record->format->big_endian, field->width); } @@ -415,210 +424,3 @@ bin_field_new_fixed_array (int n_elements, field->align = element_size; return field; } - -#if 0 -#include <elf.h> - -static gboolean -find_elf_type (const guchar *data, gsize length, - gboolean *is_64, gboolean *is_be) -{ - /* FIXME: this function should be able to return an error */ - if (length < EI_NIDENT) - return FALSE; - - /* 32 or 64? */ - - switch (data[EI_CLASS]) - { - case ELFCLASS32: - *is_64 = FALSE; - break; - - case ELFCLASS64: - *is_64 = TRUE; - break; - - default: - /* return ERROR */ - return FALSE; - break; - } - - /* big or little endian? */ - switch (data[EI_DATA]) - { - case ELFDATA2LSB: - *is_be = FALSE; - break; - - case ELFDATA2MSB: - *is_be = TRUE; - break; - - default: - /* return Error */ - return FALSE; - break; - } - - g_print ("This elf file is %s %s\n", - *is_64? "64 bit" : "32 bit", - *is_be? "big endiann" : "little endian"); - - return TRUE; -} - -void -parse_elf (const guchar *data, - gsize length) -{ - gboolean is_64, is_big_endian; - BinFormat *elf_header; - BinFormat *shn_entry; - const guchar *section_header; - BinParser *parser; - BinParser *sh_parser; - BinFormat *sym; - int i; - - find_elf_type (data, length, &is_64, &is_big_endian); - - elf_header = bin_format_new ( - is_big_endian, - "e_ident", bin_field_new_fixed_array (EI_NIDENT, 1), - - "e_type", bin_field_new_uint16 (), - "e_machine", bin_field_new_uint16 (), - "e_version", bin_field_new_uint32 (), - - "e_entry", make_word (is_64), - "e_phoff", make_word (is_64), - - "e_shoff", make_word (is_64), - "e_flags", make_uint32 (), - "e_ehsize", make_uint16(), - "e_phentsize", make_uint16 (), - "e_phnum", make_uint16 (), - "e_shentsize", make_uint16 (), - "e_shnum", make_uint16 (), - "e_shstrndx", make_uint16 (), - NULL); - - shn_entry = bin_format_new ( - is_big_endian, - "sh_name", make_uint32(), - "sh_type", make_uint32(), - "sh_flags", make_word (is_64), - "sh_addr", make_word (is_64), - "sh_offset", make_word (is_64), - "sh_size", make_word (is_64), - "sh_link", make_uint32(), - "sh_info", make_uint32(), - "sh_addralign", make_word (is_64), - "sh_entsize", make_word (is_64), - NULL); - - if (is_64) - { - sym = bin_format_new ( - is_big_endian, - "st_name", make_uint32(), - "st_info", make_uint8 (), - "st_other", make_uint8 (), - "st_shndx", make_uint16 (), - "st_value", make_uint64 (), - "st_size", make_uint64 (), - NULL); - } - else - { - sym = bin_format_new ( - is_big_endian, - "st_name", make_uint32 (), - "st_value", make_uint32 (), - "st_size", make_uint32 (), - "st_info", make_uint8 (), - "st_other", make_uint8 (), - "st_shndx", make_uint16 ()); - } - - parser = bin_parser_new (elf_header, data, length); - - section_header = data + bin_parser_get_uint (parser, "e_shoff"); - -#if 0 - g_print ("section header offset: %u\n", - section_header - data); - - g_print ("There are %llu sections\n", - bin_parser_get_uint (parser, "e_shnum")); -#endif - - /* should think through how to deal with offsets, and whether parsers - * are always considered parsers of an array. If yes, then it - * may be reasonable to just pass the length of the array. - * - * Hmm, although the parser still needs to know the end of the data. - * Maybe create yet another structure, a subparser, that also contains - * an offset in addition to the beginning and length. - * - * Ie., bin_sub_parser_new (parser, section_header, shn_entry, n_headers); - * - * In that case, it might be interesting to merge format and parser, - * and just call it 'file' or something, then call the subparser "parser" - * - * Also, how do we deal with strings? - * - * "asdf", make_string()? - * - */ - sh_parser = bin_parser_new (shn_entry, section_header, (guint)-1); - - for (i = 0; i < bin_parser_get_uint (parser, "e_shnum"); ++i) - { -#if 0 - bin_parser_set_index (sh_parser, i); -#endif - -#if 0 - bin_parser_get_uint - parser, data + i * bin_format_length (shn_entry)); - section_header = - data + bin_parser_get_uint (parser, "e_shoff"); - - parser = bin_parser_new ( -#endif - } - -#if 0 - bin_format_array_get_string (shn_table, data, "sh_name"); - - bin_format_array_get_uint (shn_table, data, "sh_addr"); -#endif -} - -static void -disaster (const char *str) -{ - g_printerr ("%s\n", str); - - exit (-1); -} - -int -main () -{ - GMappedFile *libgtk; - - libgtk = g_mapped_file_new ("/usr/lib/libgtk-x11-2.0.so", FALSE, NULL); - - if (!libgtk) - disaster ("Could not map the file\n"); - - parse_elf ((const guchar *)g_mapped_file_get_contents (libgtk), - g_mapped_file_get_length (libgtk)); - - return 0 ; -} -#endif diff --git a/collector.c b/collector.c index d81aeb3..c3f87bf 100644 --- a/collector.c +++ b/collector.c @@ -129,7 +129,6 @@ on_read (gpointer data) if (diff >= 0.0 && diff < RESET_DEAD_PERIOD) return; -#if 0 { int i; g_print ("pid: %d (%d)\n", trace.pid, trace.n_addresses); @@ -137,7 +136,6 @@ on_read (gpointer data) g_print ("rd: %08x\n", trace.addresses[i]); g_print ("-=-\n"); } -#endif if (rd > 0) { diff --git a/elfparser.c b/elfparser.c index b6c0ca6..b82a6a7 100644 --- a/elfparser.c +++ b/elfparser.c @@ -55,9 +55,17 @@ section_new (BinRecord *record, section->name = bin_record_get_string_indirect ( record, "sh_name", name_table); + + g_print ("new section: %s\n", section->name); + section->size = bin_record_get_uint (record, "sh_size"); + + g_print ("size: %d\n", section->size); + section->offset = bin_record_get_uint (record, "sh_offset"); + g_print ("offset: %d\n", section->offset); + flags = bin_record_get_uint (record, "sh_flags"); section->allocated = !!(flags & SHF_ALLOC); @@ -80,14 +88,21 @@ find_section (ElfParser *parser, const char *name) { int i; + + g_print ("looking for section %s ... ", name); for (i = 0; i < parser->n_sections; ++i) { Section *section = parser->sections[i]; if (strcmp (section->name, name) == 0) + { + g_print ("found it as number %d with offset %d\n", i, section->offset); return section; + } } + + g_print ("not found\n"); return NULL; } @@ -122,6 +137,9 @@ parser_new_from_data (const guchar *data, gsize length) parser->n_sections = bin_record_get_uint (elf_header, "e_shnum"); section_names_idx = bin_record_get_uint (elf_header, "e_shstrndx"); section_headers = bin_record_get_uint (elf_header, "e_shoff"); + g_print ("e_shoff %d\n", section_headers); + g_print ("header size: %d\n", bin_record_get_uint (elf_header, "e_shentsize")); + g_print ("real size: %d\n", bin_format_get_size (parser->shn_entry)); bin_record_free (elf_header); @@ -162,6 +180,8 @@ elf_parser_new (const char *filename, data = (guchar *)g_mapped_file_get_contents (file); length = g_mapped_file_get_length (file); + g_print ("data %p: for %s\n", data, filename); + parser = parser_new_from_data (data, length); parser->file = file; @@ -305,10 +325,10 @@ read_table (ElfParser *parser, parser->n_symbols = sym_table->size / sym_size; parser->symbols = g_new (ElfSym, parser->n_symbols); -#if 0 g_print ("\nreading %d symbols (@%d bytes) from %s\n", parser->n_symbols, sym_size, sym_table->name); -#endif + + g_print ("table offset: %d\n", str_table->offset); symbol = bin_parser_get_record (parser->parser, parser->sym_format, sym_table->offset); @@ -367,6 +387,7 @@ read_symbols (ElfParser *parser) } else if (dynsym && dynstr) { + g_print ("reading from dynstr at offset %d\n", dynstr->offset); read_table (parser, dynsym, dynstr); } else @@ -498,36 +519,16 @@ elf_parser_get_debug_link (ElfParser *parser, guint32 *crc32) return result; } -#if 0 -get_debug_link_info (bfd *abfd, unsigned long *crc32_out) +const guchar * +elf_parser_get_eh_frame (ElfParser *parser) { - asection *sect; - bfd_size_type debuglink_size; - unsigned long crc32; - char *contents; - int crc_offset; - - sect = bfd_get_section_by_name (abfd, ".gnu_debuglink"); - - if (sect == NULL) + const Section *eh_frame = find_section (parser, ".eh_frame"); + + if (eh_frame) + return bin_parser_get_data (parser->parser) + eh_frame->offset; + else return NULL; - - debuglink_size = bfd_section_size (abfd, sect); - - contents = g_malloc (debuglink_size); - bfd_get_section_contents (abfd, sect, contents, - (file_ptr)0, (bfd_size_type)debuglink_size); - - /* Crc value is stored after the filename, aligned up to 4 bytes. */ - crc_offset = strlen (contents) + 1; - crc_offset = (crc_offset + 3) & ~3; - - crc32 = bfd_get_32 (abfd, (bfd_byte *) (contents + crc_offset)); - - *crc32_out = crc32; - return contents; } -#endif const char * elf_parser_get_sym_name (ElfParser *parser, diff --git a/elfparser.h b/elfparser.h index 7a05a35..4c8003c 100644 --- a/elfparser.h +++ b/elfparser.h @@ -3,12 +3,12 @@ typedef struct ElfSym ElfSym; typedef struct ElfParser ElfParser; -ElfParser * elf_parser_new (const char *filename, - GError **err); -void elf_parser_free (ElfParser *parser); -const char *elf_parser_get_debug_link (ElfParser *parser, - guint32 *crc32); - +ElfParser * elf_parser_new (const char *filename, + GError **err); +void elf_parser_free (ElfParser *parser); +const char * elf_parser_get_debug_link (ElfParser *parser, + guint32 *crc32); +const guchar *elf_parser_get_eh_frame (ElfParser *parser); /* Lookup a symbol in the file. * diff --git a/module/Makefile b/module/Makefile index 850c896..f89c2e3 100644 --- a/module/Makefile +++ b/module/Makefile @@ -28,7 +28,7 @@ endif # build module -$(MODULE).o: $(MODULE).c +$(MODULE).o: $(MODULE).c $(MODULE).h $(KMAKE) modules diff --git a/module/sysprof-module.c b/module/sysprof-module.c index d4f30b4..e5ea800 100644 --- a/module/sysprof-module.c +++ b/module/sysprof-module.c @@ -126,6 +126,7 @@ timer_notify (struct pt_regs *regs) StackFrame frame; int result; static atomic_t in_timer_notify = ATOMIC_INIT(1); + int stacksize; if (((++get_cpu_var(n_samples)) % INTERVAL) != 0) return 0; @@ -157,11 +158,41 @@ timer_notify (struct pt_regs *regs) trace->addresses[i++] = (void *)regs->REG_INS_PTR; frame_pointer = (void *)regs->REG_FRAME_PTR; + + { + /* In principle we should use get_task_mm() but + * that will use task_lock() leading to deadlock + * if somebody already has the lock + */ + if (spin_is_locked (¤t->alloc_lock)) + printk ("alreadylocked\n"); + { + struct mm_struct *mm = current->mm; + if (mm) + { + printk (KERN_ALERT "stack size: %d (%d)\n", + mm->start_stack - regs->REG_STACK_PTR, + current->pid); + + stacksize = mm->start_stack - regs->REG_STACK_PTR; + } + else + stacksize = 1; + } +#if 0 + else + printk (KERN_ALERT "could not lock on %d\n", current->pid); +#endif + } + if (stacksize < 100000) + goto out; + while (((result = read_frame (frame_pointer, &frame)) == 0) && i < SYSPROF_MAX_ADDRESSES && (unsigned long)frame_pointer >= regs->REG_STACK_PTR) { + printk ("frame pointer: %p (retaddr: %p)\n", frame_pointer, frame.return_address); trace->addresses[i++] = (void *)frame.return_address; frame_pointer = (StackFrame *)frame.next; } @@ -44,9 +44,11 @@ main () return -1; } + g_print ("eh frame starts at %p\n", elf_parser_get_eh_frame (elf)); + elf_parser_get_crc32 (elf); - for (i = 0; i < 5000000; ++i) + for (i = 0; i < 1; ++i) { elf_parser_get_crc32 (elf); check (elf, 0x077c80f0 - (0x07787000 - 0)); /* gtk_about_dialog_set_artists (add - (map - offset)) */ |