1 2012-07-30 Gary Benson <gbenson@redhat.com>
3 * objfiles.h (inhibit_section_map_updates): New function
5 (resume_section_map_updates): Likewise.
6 (resume_section_map_updates_cleanup): Likewise.
7 * objfiles.c (objfile_pspace_info): New field "inhibit_updates".
8 (find_pc_section): Do not update the section map if
9 inhibit_updates is set.
10 (inhibit_section_map_updates): New function.
11 (resume_section_map_updates): Likewise.
12 (resume_section_map_updates_cleanup): Likewise.
13 * solib-svr4.c (svr4_handle_solib_event): Inhibit section map
14 updates for calls to evaluate_probe_argument.
16 Index: gdb-7.4.91.20120814/gdb/objfiles.h
17 ===================================================================
18 --- gdb-7.4.91.20120814.orig/gdb/objfiles.h 2012-08-14 17:16:54.000000000 +0200
19 +++ gdb-7.4.91.20120814/gdb/objfiles.h 2012-08-14 17:20:55.913174609 +0200
20 @@ -526,6 +526,22 @@ extern void set_objfile_data (struct obj
21 extern void *objfile_data (struct objfile *objfile,
22 const struct objfile_data *data);
24 +/* In normal use, the section map will be rebuilt by FIND_PC_SECTION
25 + if objfiles have been added, removed or relocated since it was last
26 + called. Calling INHIBIT_SECTION_MAP_UPDATES will inhibit this
27 + behavior until RESUME_SECTION_MAP_UPDATES is called. If you call
28 + INHIBIT_SECTION_MAP_UPDATES you must ensure that every call to
29 + FIND_PC_SECTION in the inhibited region relates to a section that
30 + is already in the section map and has not since been removed or
32 +extern void inhibit_section_map_updates (void);
34 +/* Resume automatically rebuilding the section map as required. */
35 +extern void resume_section_map_updates (void);
37 +/* Version of the above suitable for use as a cleanup. */
38 +extern void resume_section_map_updates_cleanup (void *arg);
40 extern void default_iterate_over_objfiles_in_search_order
41 (struct gdbarch *gdbarch,
42 iterate_over_objfiles_in_search_order_cb_ftype *cb,
43 Index: gdb-7.4.91.20120814/gdb/objfiles.c
44 ===================================================================
45 --- gdb-7.4.91.20120814.orig/gdb/objfiles.c 2012-08-14 17:16:55.000000000 +0200
46 +++ gdb-7.4.91.20120814/gdb/objfiles.c 2012-08-14 17:20:55.915174609 +0200
47 @@ -70,6 +70,9 @@ struct objfile_pspace_info
48 int objfiles_changed_p;
49 struct obj_section **sections;
52 + /* Nonzero if section map updates should be inhibited. */
53 + int inhibit_updates;
56 /* Per-program-space data key. */
57 @@ -1295,7 +1298,7 @@ find_pc_section (CORE_ADDR pc)
60 pspace_info = get_objfile_pspace_data (current_program_space);
61 - if (pspace_info->objfiles_changed_p != 0)
62 + if (pspace_info->objfiles_changed_p && !pspace_info->inhibit_updates)
64 update_section_map (current_program_space,
65 &pspace_info->sections,
66 @@ -1463,6 +1466,30 @@ objfiles_changed (void)
67 get_objfile_pspace_data (current_program_space)->objfiles_changed_p = 1;
70 +/* See comments in objfiles.h. */
73 +inhibit_section_map_updates (void)
75 + get_objfile_pspace_data (current_program_space)->inhibit_updates = 1;
78 +/* See comments in objfiles.h. */
81 +resume_section_map_updates (void)
83 + get_objfile_pspace_data (current_program_space)->inhibit_updates = 0;
86 +/* See comments in objfiles.h. */
89 +resume_section_map_updates_cleanup (void *arg)
91 + resume_section_map_updates ();
94 /* The default implementation for the "iterate_over_objfiles_in_search_order"
95 gdbarch method. It is equivalent to use the ALL_OBJFILES macro,
96 searching the objfiles in the order they are stored internally,
97 Index: gdb-7.4.91.20120814/gdb/solib-svr4.c
98 ===================================================================
99 --- gdb-7.4.91.20120814.orig/gdb/solib-svr4.c 2012-08-14 17:20:42.000000000 +0200
100 +++ gdb-7.4.91.20120814/gdb/solib-svr4.c 2012-08-14 17:21:14.090169216 +0200
101 @@ -1847,6 +1847,7 @@ svr4_handle_solib_event (bpstat bs)
102 struct svr4_info *info = get_svr4_info ();
103 struct probe_and_info buf, *pi = &buf;
104 enum probe_action action;
105 + struct cleanup *cleanups = NULL;
108 CORE_ADDR debug_base, lm = 0;
109 @@ -1870,6 +1871,19 @@ svr4_handle_solib_event (bpstat bs)
110 if (action == NAMESPACE_NO_ACTION)
113 + /* EVALUATE_PROBE_ARGUMENT looks up symbols in the dynamic linker
114 + using FIND_PC_SECTION. FIND_PC_SECTION is accelerated by a cache
115 + called the section map. The section map is invalidated every
116 + time a shared library is loaded or unloaded, and if the inferior
117 + is generating a lot of shared library events then the section map
118 + will be updated every time SVR4_HANDLE_SOLIB_EVENT is called.
119 + We called FIND_PC_SECTION in SVR4_CREATE_SOLIB_EVENT_BREAKPOINTS,
120 + so we can guarantee that the dynamic linker's sections are in the
121 + section map. We can therefore inhibit section map updates across
122 + these calls to EVALUATE_PROBE_ARGUMENT and save a lot of time. */
123 + inhibit_section_map_updates ();
124 + cleanups = make_cleanup (resume_section_map_updates_cleanup, NULL);
126 val = evaluate_probe_argument (pi->probe, 0);
129 @@ -1901,6 +1915,9 @@ svr4_handle_solib_event (bpstat bs)
130 action = NAMESPACE_RELOAD;
133 + do_cleanups (cleanups);
136 if (action == NAMESPACE_UPDATE_OR_RELOAD)
138 if (namespace_update_incremental (info, lmid, lm, is_initial_ns))
139 @@ -1923,6 +1940,8 @@ svr4_handle_solib_event (bpstat bs)
140 warning (_("Probes-based dynamic linker interface failed.\n"
141 "Reverting to original interface.\n"));
143 + if (cleanups != NULL)
144 + do_cleanups (cleanups);
145 free_namespace_table (info);
147 info->using_probes = 0;