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| author | Tom Tromey <tom@tromey.com> | 2022-08-02 12:01:01 -0600 |
|---|---|---|
| committer | Tom Tromey <tom@tromey.com> | 2022-08-03 13:26:58 -0600 |
| commit | 88c4cce8d28e6be486cb25fbbccf2b42e40da45b (patch) | |
| tree | df842da69d935024ed54f49f827f4fc1cd634b6d /gdb | |
| parent | 075e4d6d95681bfbf53e849c2802a75d1d4cbdca (diff) | |
| download | gdb-88c4cce8d28e6be486cb25fbbccf2b42e40da45b.zip gdb-88c4cce8d28e6be486cb25fbbccf2b42e40da45b.tar.gz gdb-88c4cce8d28e6be486cb25fbbccf2b42e40da45b.tar.bz2 | |
Use unique_ptr to destroy per-bfd object
In some cases, the objfile owns the per-bfd object. This is yet
another object that can sometimes be destroyed before the registry is
destroyed, possibly reslting in a use-after-free. Also, I noticed
that the condition for deleting the object is not the same as the
condition used to create it -- so it could possibly result in a memory
leak in some situations. This patch fixes the problem by introducing
a new unique_ptr that holds this object when necessary.
Diffstat (limited to 'gdb')
| -rw-r--r-- | gdb/objfiles.c | 22 | ||||
| -rw-r--r-- | gdb/objfiles.h | 9 |
2 files changed, 14 insertions, 17 deletions
diff --git a/gdb/objfiles.c b/gdb/objfiles.c index c92da75..31c27e9 100644 --- a/gdb/objfiles.c +++ b/gdb/objfiles.c @@ -117,9 +117,10 @@ objfile_per_bfd_storage::~objfile_per_bfd_storage () NULL, and it already has a per-BFD storage object, use that. Otherwise, allocate a new per-BFD storage object. */ -static struct objfile_per_bfd_storage * -get_objfile_bfd_data (bfd *abfd) +void +set_objfile_per_bfd (struct objfile *objfile) { + bfd *abfd = objfile->obfd.get (); struct objfile_per_bfd_storage *storage = NULL; if (abfd != NULL) @@ -133,21 +134,15 @@ get_objfile_bfd_data (bfd *abfd) enough that this seems reasonable. */ if (abfd != NULL && !gdb_bfd_requires_relocations (abfd)) objfiles_bfd_data.set (abfd, storage); + else + objfile->per_bfd_storage.reset (storage); /* Look up the gdbarch associated with the BFD. */ if (abfd != NULL) storage->gdbarch = gdbarch_from_bfd (abfd); } - return storage; -} - -/* See objfiles.h. */ - -void -set_objfile_per_bfd (struct objfile *objfile) -{ - objfile->per_bfd = get_objfile_bfd_data (objfile->obfd.get ()); + objfile->per_bfd = storage; } /* Set the objfile's per-BFD notion of the "main" name and @@ -353,7 +348,7 @@ objfile::objfile (gdb_bfd_ref_ptr bfd_, const char *name, objfile_flags flags_) build_objfile_section_table (this); } - per_bfd = get_objfile_bfd_data (obfd.get ()); + set_objfile_per_bfd (this); } /* If there is a valid and known entry point, function fills *ENTRY_P with it @@ -555,9 +550,6 @@ objfile::~objfile () if (sf != NULL) (*sf->sym_finish) (this); - if (obfd == nullptr) - delete per_bfd; - /* Before the symbol table code was redone to make it easier to selectively load and remove information particular to a specific linkage unit, gdb used to do these things whenever the monolithic diff --git a/gdb/objfiles.h b/gdb/objfiles.h index ac45fa3..16dab0d 100644 --- a/gdb/objfiles.h +++ b/gdb/objfiles.h @@ -653,11 +653,16 @@ public: gdb_bfd_ref_ptr obfd; - /* The per-BFD data. Note that this is treated specially if OBFD - is NULL. */ + /* The per-BFD data. */ struct objfile_per_bfd_storage *per_bfd = nullptr; + /* In some cases, the per_bfd object is owned by this objfile and + not by the BFD itself. In this situation, this holds the owning + pointer. */ + + std::unique_ptr<objfile_per_bfd_storage> per_bfd_storage; + /* The modification timestamp of the object file, as of the last time we read its symbols. */ |