From 34439770999ff8e32edcfdf3468e660b317f30ea Mon Sep 17 00:00:00 2001 From: Daniel Jacobowitz Date: Wed, 18 Oct 2006 15:34:39 +0000 Subject: [PATCH] * solib-svr4.c (debug_loader_offset_p, debug_loader_offset) (debug_loader_name, svr4_default_sos): New. (svr4_current_sos): Call svr4_default_sos. (enable_break): Add a comment about AT_BASE. Set the new variables and retry solib_add. (svr4_clear_solib): Clear the new variables. --- gdb/ChangeLog | 11 +++++++++- gdb/solib-svr4.c | 67 ++++++++++++++++++++++++++++++++++++++++++++++++++++---- 2 files changed, 73 insertions(+), 5 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index ab06977..4fe939d 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,4 +1,13 @@ -2006-10-17 Daniel Jacobowitz +2006-10-18 Daniel Jacobowitz + + * solib-svr4.c (debug_loader_offset_p, debug_loader_offset) + (debug_loader_name, svr4_default_sos): New. + (svr4_current_sos): Call svr4_default_sos. + (enable_break): Add a comment about AT_BASE. Set the new + variables and retry solib_add. + (svr4_clear_solib): Clear the new variables. + +2006-10-18 Daniel Jacobowitz * NEWS: Mention support for TLS without debugging information. diff --git a/gdb/solib-svr4.c b/gdb/solib-svr4.c index 9637db9..7bd76a1 100644 --- a/gdb/solib-svr4.c +++ b/gdb/solib-svr4.c @@ -267,6 +267,15 @@ IGNORE_FIRST_LINK_MAP_ENTRY (struct so_list *so) static CORE_ADDR debug_base; /* Base of dynamic linker structures */ static CORE_ADDR breakpoint_addr; /* Address where end bkpt is set */ +/* Validity flag for debug_loader_offset. */ +static int debug_loader_offset_p; + +/* Load address for the dynamic linker, inferred. */ +static CORE_ADDR debug_loader_offset; + +/* Name of the dynamic linker, valid if debug_loader_offset_p. */ +static char *debug_loader_name; + /* Local function prototypes */ static int match_main (char *); @@ -657,6 +666,37 @@ open_symbol_file_object (void *from_ttyp) return 1; } +/* If no shared library information is available from the dynamic + linker, build a fallback list from other sources. */ + +static struct so_list * +svr4_default_sos (void) +{ + struct so_list *head = NULL; + struct so_list **link_ptr = &head; + + if (debug_loader_offset_p) + { + struct so_list *new = XZALLOC (struct so_list); + + new->lm_info = xmalloc (sizeof (struct lm_info)); + + /* Nothing will ever check the cached copy of the link + map if we set l_addr. */ + new->lm_info->l_addr = debug_loader_offset; + new->lm_info->lm = NULL; + + strncpy (new->so_name, debug_loader_name, SO_NAME_MAX_PATH_SIZE - 1); + new->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0'; + strcpy (new->so_original_name, new->so_name); + + *link_ptr = new; + link_ptr = &new->next; + } + + return head; +} + /* LOCAL FUNCTION current_sos -- build a list of currently loaded shared objects @@ -693,12 +733,13 @@ svr4_current_sos (void) /* If we can't find the dynamic linker's base structure, this must not be a dynamically linked executable. Hmm. */ if (! debug_base) - return 0; + return svr4_default_sos (); } /* Walk the inferior's link map list, and build our list of `struct so_list' nodes. */ lm = solib_svr4_r_map (); + while (lm) { struct link_map_offsets *lmo = svr4_fetch_link_map_offsets (); @@ -765,6 +806,9 @@ svr4_current_sos (void) discard_cleanups (old_chain); } + if (head == NULL) + return svr4_default_sos (); + return head; } @@ -983,7 +1027,12 @@ enable_break (void) be trivial on GNU/Linux). Therefore, we have to try an alternate mechanism to find the dynamic linker's base address. */ - tmp_fd = solib_open (buf, &tmp_pathname); + /* TODO drow/2006-09-12: This is somewhat fragile, because it + relies on read_pc. On both Solaris and GNU/Linux we can use + the AT_BASE auxilliary entry, which GDB now knows how to + access, to find the base address. */ + + tmp_fd = solib_open (buf, &tmp_pathname); if (tmp_fd >= 0) tmp_bfd = bfd_fopen (tmp_pathname, gnutarget, FOPEN_RB, tmp_fd); @@ -1022,8 +1071,14 @@ enable_break (void) the current pc (which should point at the entry point for the dynamic linker) and subtracting the offset of the entry point. */ if (!load_addr_found) - load_addr = (read_pc () - - exec_entry_point (tmp_bfd, tmp_bfd_target)); + { + load_addr = (read_pc () + - exec_entry_point (tmp_bfd, tmp_bfd_target)); + debug_loader_name = xstrdup (buf); + debug_loader_offset_p = 1; + debug_loader_offset = load_addr; + solib_add (NULL, 0, NULL, auto_solib_add); + } /* Record the relocated start and end address of the dynamic linker text and plt section for svr4_in_dynsym_resolve_code. */ @@ -1335,6 +1390,10 @@ static void svr4_clear_solib (void) { debug_base = 0; + debug_loader_offset_p = 0; + debug_loader_offset = 0; + xfree (debug_loader_name); + debug_loader_name = NULL; } static void -- 2.7.4