Author: markj Date: Tue Jul 21 23:07:55 2015 New Revision: 285774 URL: https://svnweb.freebsd.org/changeset/base/285774
Log: Don't return undefined symbols to a DDB symbol lookup. Undefined symbols have a value of zero, so it makes no sense to return such a symbol when performing a lookup by value. This occurs for example when unwinding the stack after calling a NULL function pointer, and we confusingly report the faulting function as uart_sab82532_class() on amd64. Convert db_print_loc_and_inst() to only attempt disassembly if we managed to find a symbol corresponding to the IP. Otherwise we may fault and re-enter the debugger. Reviewed by: jhb Sponsored by: EMC / Isilon Storage Division Differential Revision: https://reviews.freebsd.org/D2858 Modified: head/sys/ddb/db_examine.c head/sys/ddb/db_main.c Modified: head/sys/ddb/db_examine.c ============================================================================== --- head/sys/ddb/db_examine.c Tue Jul 21 23:03:21 2015 (r285773) +++ head/sys/ddb/db_examine.c Tue Jul 21 23:07:55 2015 (r285774) @@ -232,9 +232,13 @@ db_print_cmd(db_expr_t addr, bool have_a void db_print_loc_and_inst(db_addr_t loc) { + db_expr_t off; + db_printsym(loc, DB_STGY_PROC); - db_printf(":\t"); - (void) db_disasm(loc, true); + if (db_search_symbol(loc, DB_STGY_PROC, &off) != C_DB_SYM_NULL) { + db_printf(":\t"); + (void)db_disasm(loc, true); + } } /* Modified: head/sys/ddb/db_main.c ============================================================================== --- head/sys/ddb/db_main.c Tue Jul 21 23:03:21 2015 (r285773) +++ head/sys/ddb/db_main.c Tue Jul 21 23:07:55 2015 (r285774) @@ -110,7 +110,7 @@ X_db_search_symbol(db_symtab_t *symtab, diff = ~0UL; match = NULL; for (sym = (Elf_Sym*)symtab->start; (char*)sym < symtab->end; sym++) { - if (sym->st_name == 0) + if (sym->st_name == 0 || sym->st_shndx == SHN_UNDEF) continue; if (off < sym->st_value) continue; _______________________________________________ svn-src-head@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
