From 6fbf07cd381e44b05e69db61080d0c9184def6fd Mon Sep 17 00:00:00 2001 From: Paul Pluzhnikov Date: Mon, 14 Sep 2009 17:12:07 +0000 Subject: [PATCH] 2009-09-14 Paul Pluzhnikov * objfiles.c (qsort_cmp): Remove asserts. (insert_section_p, filter_debuginfo_sections): New function. (filter_overlapping_sections): Likewise. (update_section_map): Adjust. --- gdb/ChangeLog | 7 ++ gdb/objfiles.c | 265 +++++++++++++++++++++++++++++++++++++++---------- 2 files changed, 221 insertions(+), 51 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index a1e66e62eae..ebfed25983a 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,10 @@ +2009-09-14 Paul Pluzhnikov + + * objfiles.c (qsort_cmp): Remove asserts. + (insert_section_p, filter_debuginfo_sections): New function. + (filter_overlapping_sections): Likewise. + (update_section_map): Adjust. + 2009-09-13 Daniel Jacobowitz * frame.c (get_frame_id): Default to outer_frame_id if the this_id diff --git a/gdb/objfiles.c b/gdb/objfiles.c index 2c9da3d4b77..1f7489f22d8 100644 --- a/gdb/objfiles.c +++ b/gdb/objfiles.c @@ -51,6 +51,7 @@ #include "arch-utils.h" #include "exec.h" #include "observer.h" +#include "complaints.h" /* Prototypes for local functions */ @@ -802,16 +803,72 @@ qsort_cmp (const void *a, const void *b) const CORE_ADDR sect2_addr = obj_section_addr (sect2); if (sect1_addr < sect2_addr) - { - gdb_assert (obj_section_endaddr (sect1) <= sect2_addr); - return -1; - } + return -1; else if (sect1_addr > sect2_addr) - { - gdb_assert (sect1_addr >= obj_section_endaddr (sect2)); - return 1; - } - + return 1; + else + { + /* Sections are at the same address. This could happen if + A) we have an objfile and a separate debuginfo. + B) we are confused, and have added sections without proper relocation, + or something like that. */ + + const struct objfile *const objfile1 = sect1->objfile; + const struct objfile *const objfile2 = sect2->objfile; + + if (objfile1->separate_debug_objfile == objfile2 + || objfile2->separate_debug_objfile == objfile1) + { + /* Case A. The ordering doesn't matter: separate debuginfo files + will be filtered out later. */ + + return 0; + } + + /* Case B. Maintain stable sort order, so bugs in GDB are easier to + triage. This section could be slow (since we iterate over all + objfiles in each call to qsort_cmp), but this shouldn't happen + very often (GDB is already in a confused state; one hopes this + doesn't happen at all). If you discover that significant time is + spent in the loops below, do 'set complaints 100' and examine the + resulting complaints. */ + + if (objfile1 == objfile2) + { + /* Both sections came from the same objfile. We are really confused. + Sort on sequence order of sections within the objfile. */ + + const struct obj_section *osect; + + ALL_OBJFILE_OSECTIONS (objfile1, osect) + if (osect == sect1) + return -1; + else if (osect == sect2) + return 1; + + /* We should have found one of the sections before getting here. */ + gdb_assert (0); + } + else + { + /* Sort on sequence number of the objfile in the chain. */ + + const struct objfile *objfile; + + ALL_OBJFILES (objfile) + if (objfile == objfile1) + return -1; + else if (objfile == objfile2) + return 1; + + /* We should have found one of the objfiles before getting here. */ + gdb_assert (0); + } + + } + + /* Unreachable. */ + gdb_assert (0); return 0; } @@ -835,12 +892,146 @@ preferred_obj_section (struct obj_section *a, struct obj_section *b) return b; } -/* Update PMAP, PMAP_SIZE with non-TLS sections from all objfiles. */ +/* Return 1 if SECTION should be inserted into the section map. + We want to insert only non-overlay and non-TLS section. */ + +static int +insert_section_p (const struct bfd *abfd, + const struct bfd_section *section) +{ + const bfd_vma lma = bfd_section_lma (abfd, section); + + if (lma != 0 && lma != bfd_section_vma (abfd, section) + && (bfd_get_file_flags (abfd) & BFD_IN_MEMORY) == 0) + /* This is an overlay section. IN_MEMORY check is needed to avoid + discarding sections from the "system supplied DSO" (aka vdso) + on some Linux systems (e.g. Fedora 11). */ + return 0; + if ((bfd_get_section_flags (abfd, section) & SEC_THREAD_LOCAL) != 0) + /* This is a TLS section. */ + return 0; + + return 1; +} + +/* Filter out overlapping sections where one section came from the real + objfile, and the other from a separate debuginfo file. + Return the size of table after redundant sections have been eliminated. */ + +static int +filter_debuginfo_sections (struct obj_section **map, int map_size) +{ + int i, j; + + for (i = 0, j = 0; i < map_size - 1; i++) + { + struct obj_section *const sect1 = map[i]; + struct obj_section *const sect2 = map[i + 1]; + const struct objfile *const objfile1 = sect1->objfile; + const struct objfile *const objfile2 = sect2->objfile; + const CORE_ADDR sect1_addr = obj_section_addr (sect1); + const CORE_ADDR sect2_addr = obj_section_addr (sect2); + + if (sect1_addr == sect2_addr + && (objfile1->separate_debug_objfile == objfile2 + || objfile2->separate_debug_objfile == objfile1)) + { + map[j++] = preferred_obj_section (sect1, sect2); + ++i; + } + else + map[j++] = sect1; + } + + if (i < map_size) + { + gdb_assert (i == map_size - 1); + map[j++] = map[i]; + } + + /* The map should not have shrunk to less than half the original size. */ + gdb_assert (map_size / 2 <= j); + + return j; +} + +/* Filter out overlapping sections, issuing a warning if any are found. + Overlapping sections could really be overlay sections which we didn't + classify as such in insert_section_p, or we could be dealing with a + corrupt binary. */ + +static int +filter_overlapping_sections (struct obj_section **map, int map_size) +{ + int i, j; + + for (i = 0, j = 0; i < map_size - 1; ) + { + int k; + + map[j++] = map[i]; + for (k = i + 1; k < map_size; k++) + { + struct obj_section *const sect1 = map[i]; + struct obj_section *const sect2 = map[k]; + const CORE_ADDR sect1_addr = obj_section_addr (sect1); + const CORE_ADDR sect2_addr = obj_section_addr (sect2); + const CORE_ADDR sect1_endaddr = obj_section_endaddr (sect1); + + gdb_assert (sect1_addr <= sect2_addr); + + if (sect1_endaddr <= sect2_addr) + break; + else + { + /* We have an overlap. Report it. */ + + struct objfile *const objf1 = sect1->objfile; + struct objfile *const objf2 = sect2->objfile; + + const struct bfd *const abfd1 = objf1->obfd; + const struct bfd *const abfd2 = objf2->obfd; + + const struct bfd_section *const bfds1 = sect1->the_bfd_section; + const struct bfd_section *const bfds2 = sect2->the_bfd_section; + + const CORE_ADDR sect2_endaddr = obj_section_endaddr (sect2); + + struct gdbarch *const gdbarch = get_objfile_arch (objf1); + + complaint (&symfile_complaints, + _("unexpected overlap between:\n" + " (A) section `%s' from `%s' [%s, %s)\n" + " (B) section `%s' from `%s' [%s, %s).\n" + "Will ignore section B"), + bfd_section_name (abfd1, bfds1), objf1->name, + paddress (gdbarch, sect1_addr), + paddress (gdbarch, sect1_endaddr), + bfd_section_name (abfd2, bfds2), objf2->name, + paddress (gdbarch, sect2_addr), + paddress (gdbarch, sect2_endaddr)); + } + } + i = k; + } + + if (i < map_size) + { + gdb_assert (i == map_size - 1); + map[j++] = map[i]; + } + + return j; +} + + +/* Update PMAP, PMAP_SIZE with sections from all objfiles, excluding any + TLS, overlay and overlapping sections. */ static void update_section_map (struct obj_section ***pmap, int *pmap_size) { - int map_size, i, j; + int alloc_size, map_size, i; struct obj_section *s, **map; struct objfile *objfile; @@ -849,55 +1040,27 @@ update_section_map (struct obj_section ***pmap, int *pmap_size) map = *pmap; xfree (map); -#define insert_p(objf, sec) \ - ((bfd_get_section_flags ((objf)->obfd, (sec)->the_bfd_section) \ - & SEC_THREAD_LOCAL) == 0) - - map_size = 0; + alloc_size = 0; ALL_OBJSECTIONS (objfile, s) - if (insert_p (objfile, s)) - map_size += 1; + if (insert_section_p (objfile->obfd, s->the_bfd_section)) + alloc_size += 1; - map = xmalloc (map_size * sizeof (*map)); + map = xmalloc (alloc_size * sizeof (*map)); i = 0; ALL_OBJSECTIONS (objfile, s) - if (insert_p (objfile, s)) + if (insert_section_p (objfile->obfd, s->the_bfd_section)) map[i++] = s; -#undef insert_p + qsort (map, alloc_size, sizeof (*map), qsort_cmp); + map_size = filter_debuginfo_sections(map, alloc_size); + map_size = filter_overlapping_sections(map, map_size); - qsort (map, map_size, sizeof (*map), qsort_cmp); - - /* With separate debuginfo files, we may have up to two (almost) - identical copies of some obj_sections in the map. - Filter out duplicates. */ - for (i = 0, j = 0; i < map_size; ++i) - { - struct obj_section *sect1 = map[i]; - struct obj_section *sect2 = (i + 1 < map_size) ? map[i + 1] : NULL; - - if (sect2 == NULL - || obj_section_addr (sect1) != obj_section_addr (sect2)) - map[j++] = sect1; - else - { - map[j++] = preferred_obj_section (sect1, sect2); - ++i; - } - } - - if (j < map_size) - { - /* Some duplicates were eliminated. - The new size shouldn't be less than half of the original. */ - gdb_assert (map_size / 2 <= j); - map_size = j; - - map = xrealloc (map, map_size * sizeof (*map)); /* Trim excess space. */ - } + if (map_size < alloc_size) + /* Some sections were eliminated. Trim excess space. */ + map = xrealloc (map, map_size * sizeof (*map)); else - gdb_assert (j == map_size); + gdb_assert (alloc_size == map_size); *pmap = map; *pmap_size = map_size; -- 2.30.2