On Wed, 16 Sep 2020 14:47:08 +0300
"Tzvetomir Stoyanov (VMware)" <tz.stoyanov@xxxxxxxxx> wrote:
> +#define RESOLVE_NAME (1 << 0)
> +#define RESOLVE_VMA (1 << 1)
> +#define RESOLVE_FOFFSET (1 << 2)
> +struct trace_obj_job {
> + unsigned int flags;
> + unsigned long long addr_offset;
> + struct debug_symbols *symbols;
> +};
> +
> +struct dwarf_bfd_context {
> + asymbol **table;
> + struct trace_obj_job *job;
> +};
> +
> +static void bfd_dwarf_section(bfd *abfd, asection *section, void *param)
Another small comment. Do not name any function that starts with "bfd_" as
that makes it hard to know the difference between these functions and
functions from the bfd library. The only functions that should have bfd_ as
the start are those in the library.
Could call this: dwarf_bfd_section()?
> +{
> + struct dwarf_bfd_context *context = (struct dwarf_bfd_context *)param;
> + unsigned int discriminator;
> + const char *functionname;
> + struct debug_symbols *s;
> + unsigned long long vma;
> + const char *filename;
> + unsigned int line;
> + bfd_boolean found;
> +
> + if (!(section->flags & SEC_CODE))
> + return;
> +
> + for (s = context->job->symbols; s; s = s->next) {
> + if (s->symbol.vma_near)
> + vma = s->symbol.vma_near;
> + else if (s->symbol.vma_start)
> + vma = s->symbol.vma_start;
> + else
> + continue;
> +
> + if (abfd->flags & DYNAMIC)
> + vma -= context->job->addr_offset;
> + if (vma && section->vma <= vma &&
> + (section->vma + section->size) > vma) {
> + if (!s->symbol.fname)
> + s->symbol.fname = strdup(abfd->filename);
> + if (context->job->flags & RESOLVE_FOFFSET)
> + s->symbol.foffset = section->filepos + (vma - section->vma);
> + if (!s->symbol.name && (context->job->flags & RESOLVE_NAME)) {
> + found = bfd_find_nearest_line_discriminator(abfd, section, context->table,
> + vma - section->vma, &filename,
> + &functionname, &line, &discriminator);
> + if (found)
> + s->symbol.name = strdup(functionname);
> + }
> + }
> + }
> +}
> +
> +static asymbol **get_sym_table(bfd *handle)
> +{
> + bfd_boolean dyn = FALSE;
> + asymbol **symtable;
> + long count;
> + long size;
> +
> + if ((bfd_get_file_flags(handle) & HAS_SYMS) == 0)
> + return NULL;
> + size = bfd_get_symtab_upper_bound(handle);
> + if (size == 0) {
> + size = bfd_get_dynamic_symtab_upper_bound(handle);
> + dyn = TRUE;
> + }
> + if (size <= 0)
> + return NULL;
> +
> + symtable = (asymbol **) calloc(1, size);
> + if (!symtable)
> + return NULL;
> + if (dyn)
> + count = bfd_canonicalize_dynamic_symtab(handle, symtable);
> + else
> + count = bfd_canonicalize_symtab(handle, symtable);
> + if (count <= 0) {
> + free(symtable);
> + return NULL;
> + }
> +/*
> + * alloc = bfd_demangle(cur_bfd, name, demangle_flags);
> + */
> +
> + return symtable;
> +}
> +
> +static int sym_match(char *pattern, regex_t *regex, const char *symbol)
> +{
> + if (strlen(pattern) == strlen(symbol) &&
> + !strcmp(pattern, symbol))
> + return 0;
> + if (regex && !regexec(regex, symbol, 0, NULL, 0))
> + return 1;
> +
> + return -1;
> +}
> +
> +static int bfd_symlookup(struct dwarf_bfd_context *context)
Same here: lookup_bfd_sym()?
> +{
> + struct debug_symbols *s, *last = NULL;
> + struct debug_symbols *new, *new_list = NULL;
> + unsigned long long vma;
> + asymbol **sp;
> + int res = 0;
> + int ret;
> +
> + for (sp = context->table; *sp != NULL; sp++) {
> + if (!((*sp)->flags & BSF_FUNCTION))
> + continue;
> + for (s = context->job->symbols; s; s = s->next) {
> + last = s;
> + ret = sym_match(s->symbol.name, s->regex, (*sp)->name);
> + if (ret < 0)
> + continue;
> + vma = (*sp)->value + (*sp)->section->vma;
> + if ((*sp)->the_bfd->flags & DYNAMIC)
> + vma += context->job->addr_offset;
> + if (ret == 0) { /* exact match */
> + s->symbol.vma_start = vma;
> + } else { /* regex pattern match */
> + new = calloc(1, sizeof(struct debug_symbols));
> + if (!new)
> + break;
> + new->symbol.name = strdup((*sp)->name);
> + new->symbol.vma_start = vma;
> + new->symbol.vma_near = s->symbol.vma_near;
> + new->symbol.foffset = s->symbol.foffset;
> + if (s->symbol.fname)
> + new->symbol.fname = strdup(s->symbol.fname);
> + new->next = new_list;
> + new_list = new;
> + }
> + res++;
> + }
> + }
> + if (last && !last->next)
> + last->next = new_list;
> +
> + return res;
> +}
> +
> +static int bfd_process_object(bfd *abfd, struct trace_obj_job *job)
find_bfd_process_object()?
> +{
> + struct dwarf_bfd_context context;
> + int ret = 0;
> +
> + memset(&context, 0, sizeof(context));
> + context.job = job;
> +
> + if (bfd_check_format_matches(abfd, bfd_object, NULL) ||
> + bfd_check_format_matches(abfd, bfd_core, NULL)) {
> + context.table = get_sym_table(abfd);
> + if (job->flags & RESOLVE_VMA)
> + bfd_symlookup(&context);
> + if ((job->flags & RESOLVE_NAME) || (job->flags & RESOLVE_FOFFSET))
> + bfd_map_over_sections(abfd, bfd_dwarf_section, &context);
> + free(context.table);
> + } else {
> + ret = -1;
> + }
> +
> + return ret;
> +}
> +
> +static int bfd_read_all(bfd *abfd, struct trace_obj_job *job)
read_all_bfd()?
-- Steve
> +{
> + bfd *last_arfile = NULL;
> + bfd *arfile = NULL;
> + int ret = 0;
> +
> + if (bfd_check_format(abfd, bfd_archive)) {
> + for (;;) {
> + bfd_set_error(bfd_error_no_error);
> + arfile = bfd_openr_next_archived_file(abfd, arfile);
> + if (!arfile) {
> + if (bfd_get_error() != bfd_error_no_more_archived_files)
> + break;
> + }
> + ret = bfd_read_all(arfile, job);
> + if (last_arfile)
> + bfd_close(last_arfile);
> + last_arfile = arfile;
> + }
> + if (last_arfile)
> + bfd_close(last_arfile);
> + } else
> + ret = bfd_process_object(abfd, job);
> +
> + return ret;
> +}
> +
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