Index: gdb/solib-svr4.c =================================================================== RCS file: /cvs/src/src/gdb/solib-svr4.c,v retrieving revision 1.154 diff -u -p -r1.154 solib-svr4.c --- gdb/solib-svr4.c 30 Aug 2011 02:48:05 -0000 1.154 +++ gdb/solib-svr4.c 29 Sep 2011 13:31:00 -0000 @@ -1181,6 +1181,39 @@ cmp_name_and_sec_flags (asymbol *sym, vo return (strcmp (sym->name, (const char *) data) == 0 && (sym->section->flags & (SEC_CODE | SEC_DATA)) != 0); } + +/* Use dynamic linker bfd and try to figure out solib break + address using _r_debug.r_brk. It is expected that at this point + it is unrelocated filled with relative address of solib + break function. This case may happen if solib break function + is defined as static in the dynamic linker, and dynmic linker + library is completely stripped. */ + +static CORE_ADDR +svr4_fetch_solib_break_from_r_debug (bfd *const tmp_bfd, + const CORE_ADDR load_addr) +{ + const CORE_ADDR r_debug_sym_addr + = gdb_bfd_lookup_symbol (tmp_bfd, cmp_name_and_sec_flags, + (void *) "_r_debug"); + const struct link_map_offsets *const lmo = svr4_fetch_link_map_offsets (); + const int ptrsz = gdbarch_ptr_bit (target_gdbarch); + gdb_byte r_brk_addr[ptrsz]; + + if (target_read_memory (load_addr + r_debug_sym_addr + lmo->r_brk_offset, + r_brk_addr, ptrsz) == 0) + { + const enum bfd_endian byte_order + = gdbarch_byte_order (target_gdbarch); + + return extract_unsigned_integer (r_brk_addr, ptrsz, byte_order); + } + return 0; +} + + + + /* Arrange for dynamic linker to hit breakpoint. Both the SunOS and the SVR4 dynamic linkers have, as part of their @@ -1435,6 +1468,11 @@ enable_break (struct svr4_info *info, in break; } + /* Failing the above methods of locating debug base, use + _r_debug.r_brk structure. */ + if (sym_addr == 0 && load_addr_found) + sym_addr = svr4_fetch_solib_break_from_r_debug (tmp_bfd, load_addr); + if (sym_addr != 0) /* Convert 'sym_addr' from a function pointer to an address. Because we pass tmp_bfd_target instead of the current