libabigail/tools
Guillermo E. Martinez e64d32bee3 ctf-reader: Add support to read CTF information from the Linux Kernel
This patch is meant to extract ABI information from the CTF data
stored in the Linux kernel build directory.  It depends on the
vmlinux.ctfa archive file.

In order to generate the CTF information, the Linux Kernel build
system must support the 'make ctf' command, which causes the compiler
to be run with -gctf, thus emitting the CTF information for the
Kernel.

The target 'ctf' in the Linux Makefile generates a 'vmlinux.ctfa' file
that will be used by the ctf reader in libabigail. The 'vmlinux.ctfa'
archive has multiple 'ctf dictionaries' called "CTF archive members".

There is one CTF archive member for built-in kernel modules (in
`vmlinux') and one for each out-of-tree kernel module organized in a
parent-child hierarchy.

There is also a CTF archive member called `shared_ctf' which is a
parent dictionary containing shared symbols and CTF types used by more
than one kernel object.  These common types are stored in 'types_map'
in the ctf reader, ignoring the ctf dictionary name.  The CTF API has
the machinery for looking for a shared type in the parent dictionary
referred to in a given child dictionary. This CTF layout can be dumped
by using the objdump tool.

Due to the fact that the _same_ ctf archive is used to build the
vmlinux corpus the corpora of the kernel module (which, by the way,
all belong to the same corpus group), the high number of open/close on
the CTF archive is very time consuming during the ctf extraction.

So, the performance is improved up to 300% (from ~2m:50s to ~50s) by
keeping the ctf archive open for a given group, and thus, by using the
same ctf_archive_t pointer while building all the various corpora.

We just invoke `reset_read_context' for each new corpus.  Note that
the `read_context::ctfa` data member should be updated if the
corpus::origin data member is set to `LINUX_KERNEL_BINARY_ORIGIN' and
the file to be process is not 'vmlinux'.

Note that `ctf_close' must be called after processing all group's
members so it is executed from the destructor of `reader_context'.

The basic algorithm used to generate the Linux corpus is the
following:

   1. Looking for: vmlinux, *.ko objects, and vmlinux.ctfa files. The
   first files are used to extract the ELF symbols, and the last one
   contains the CTF type information for non-static variables and
   functions symbols.

   2. `process_ctf_archive' iterates on public symbols for vmlinux and
   its modules, using the name of the symbol, ctf reader search for CTF
   information in its dictionary, if the information was found it
   builds a `var_decl' or `function_decl' depending of `ctf_type_kind'
   result.

This algorithm is also applied to ELF files (exec, dyn, rel), so
instead of iterating on all ctf_types it just loops on the public
symbols.

	* abg-elf-reader-common.h: Include ctf-api.h file.
	(read_and_add_corpus_to_group_from_elf, set_read_context_corpus_group)
	(reset_read_context, dic_type_key): Declare new member functions.
	* include/abg-ir.cc (types_defined_same_linux_kernel_corpus_public): Use
	bitwise to know the corpus `origin'.
	* src/abg-ctf-reader.cc: Include map, algorithms header files.
	(read_context::type_map): Change from unordered_map to std::map storing
	ctf dictionary name as part of the key.
	(read_context::is_elf_exec): Add new member variable.
	(read_context::{cur_corpus_, cur_corpus_group_}): Likewise.
	(read_context::unknown_types_set): Likewise.
	(read_context::{current_corpus_group, main_corpus_from_current_group,
	has_corpus_group, current_corpus_is_main_corpus_from_current_group,
	should_reuse_type_from_corpus_group}): Add new member functions.
	(read_context::{add_unknown_type, lookup_unknown_type, initialize}):
	Likewise.
	(read_context::{add_type, lookup_type}): Add new `ctf_dict_t' type
	argument.
	(ctf_reader::{process_ctf_typedef, process_ctf_base_type,
	process_ctf_function_type, process_ctf_forward_type,
	process_ctf_struct_type, process_ctf_union_type, process_ctf_array_type,
	process_ctf_qualified_type, process_ctf_enum_type}): Add code to `reuse'
	types already registered in main corpus `should_reuse_type_from_corpus_group'.
	Use new `lookup_type' and `add_type' operations on `read_context::types_map'.
	Replace function calls to the new ctf interface. Add verifier to not build
	types duplicated by recursive calling chain.
	(ctf_reader::process_ctf_type): Add code to return immediately if the
	ctf type is unknown. Add unknown types to `unknown_types_set'.
	(ctf_reader::process_ctf_archive): Change comment.
	Add code to iterate over global symbols, searching by symbol name in the
	ctf dictionary using `ctf_lookup_{variable,by_symbol_name}' depending of
	the ELF file type and corpus type, creating a `{var,fuc}_decl' using the
	return type of `ctf_type_kind'.  Also close the ctf dict and call
	`canonicalize_all_types'.
	(slurp_elf_info): Set `is_elf_exec' depending of ELF type.  Also return
	success if corpus origin is Linux and symbol table was read.
	(ctf_reader::read_corpus): Add current corpus.  Set corpus origin to
	`LINUX_KERNEL_BINARY_ORIGIN' if `is_linux_kernel' returns true.  Verify
	the ctf reader status, now the ctf archive is 'opened' using
	`ctf_arc{open,bufopen}' depending if the corpus origin has
	`corpus::LINUX_KERNEL_BINARY_ORIGIN' bit set. Use
	`sort_{function,variables}' calls after extract ctf information.
	`ctf_close' is called from `read_context' destructor.
	(read:context::{set_read_context_corpus_group, reset_read_context,
	read_and_add_corpus_to_group_from_elf, dic_type_key): Add new member
	function implementation.
	* include/abg-tools-utils.h (build_corpus_group_from_kernel_dist_under):
	Add `origin' parameter with default `corpus::DWARF_ORIGIN'.
	* src/abg-tools-utils.cc: Use `abg-ctf-reader.h' file.
	(maybe_load_vmlinux_dwarf_corpus): Add new function.
	(maybe_load_vmlinux_ctf_corpus): Likewise.
	(build_corpus_group_from_kernel_dist_under): Update comments.
	Add new `origin' argument. Use `maybe_load_vmlinux_dwarf_corpus'
	or `maybe_load_vmlinux_ctf_corpus' according to `origin' value.
	* src/abg-corpus.h (corpus::origin): Update `origin' type
	values in enum.
	* src/abg-corpus-priv.h (corpus::priv): Replace `origin' type
	from `corpus::origin' to `uint32_t'.
	* src/abg-corpus.cc (corpus::{get,set}_origin): Replace data
	type from `corpus::origin' to `uint32_t'.
	* tools/abidw.cc (main): Use of --ctf argument to set format debug.
	* tests/test-read-ctf.cc: Add new tests to harness.
	* tests/data/test-read-ctf/test-PR27700.abi: New test expected
	  result.
	* tests/data/test-read-ctf/test-anonymous-fields.o.abi: Likewise.
	* tests/data/test-read-ctf/test-enum-many-ctf.o.hash.abi: Likewise.
	* tests/data/test-read-ctf/test-enum-many.o.hash.abi: Likewise.
	* tests/data/test-read-ctf/test-enum-symbol-ctf.o.hash.abi: Likewise.
	* tests/data/test-read-common/test-PR26568-2.o: Adjust.
	* tests/data/test-read-ctf/test-PR26568-1.o.abi: Likewise.
	* tests/data/test-read-ctf/test-PR26568-2.o.abi: Likewise.
	* tests/data/test-read-ctf/test-ambiguous-struct-A.o.hash.abi: Likewise.
	* tests/data/test-read-ctf/test-ambiguous-struct-B.c: Likewise.
	* tests/data/test-read-ctf/test-ambiguous-struct-B.o: Likewise.
	* tests/data/test-read-ctf/test-ambiguous-struct-B.o.hash.abi: Likewise.
	* tests/data/test-read-ctf/test-array-of-pointers.abi: Likewise.
	* tests/data/test-read-ctf/test-callback.abi: Likewise.
	* tests/data/test-read-ctf/test-callback2.abi: Likewise.
	* tests/data/test-read-ctf/test-conflicting-type-syms-a.o.hash.abi:
	Likewise.
	* tests/data/test-read-ctf/test-conflicting-type-syms-b.o.hash.abi:
	Likewise.
	* tests/data/test-read-ctf/test-dynamic-array.o.abi: Likewise.
	* tests/data/test-read-ctf/test-enum-ctf.o.abi: Likewise.
	* tests/data/test-read-ctf/test-enum-symbol.o.hash.abi: Likewise.
	* tests/data/test-read-ctf/test-enum.o.abi: Likewise.
	* tests/data/test-read-ctf/test-forward-type-decl.abi: Likewise.
	* tests/data/test-read-ctf/test-functions-declaration.abi: Likewise.
	* tests/data/test-read-ctf/test-list-struct.abi: Likewise.
	* tests/data/test-read-ctf/test0: Likewise.
	* tests/data/test-read-ctf/test0.abi: Likewise.
	* tests/data/test-read-ctf/test0.c: Likewise.
	* tests/data/test-read-ctf/test0.hash.abi: Likewise.
	* tests/data/test-read-ctf/test1.so.abi: Likewise.
	* tests/data/test-read-ctf/test1.so.hash.abi: Likewise.
	* tests/data/test-read-ctf/test2.so.abi: Likewise.
	* tests/data/test-read-ctf/test2.so.hash.abi: Likewise.
	* tests/data/test-read-ctf/test3.so.abi: Likewise.
	* tests/data/test-read-ctf/test3.so.hash.abi: Likewise.
	* tests/data/test-read-ctf/test4.so.abi: Likewise.
	* tests/data/test-read-ctf/test4.so.hash.abi: Likewise.
	* tests/data/test-read-ctf/test5.o.abi: Likewise.
	* tests/data/test-read-ctf/test7.o.abi: Likewise.
	* tests/data/test-read-ctf/test8.o.abi: Likewise.
	* tests/data/test-read-ctf/test9.o.abi: Likewise.

Signed-off-by: Guillermo E. Martinez <guillermo.e.martinez@oracle.com>
Signed-off-by: Dodji Seketeli <dodji@redhat.com>
2022-05-13 09:11:37 +02:00
..
.gitignore Update .gitignore files to ignore typical dev side products 2019-04-16 16:32:52 +02:00
abicompat.cc Add an option ignore SONAME differences in libraries 2022-05-12 11:58:18 +02:00
abidiff.cc Add an option ignore SONAME differences in libraries 2022-05-12 11:58:18 +02:00
abidw.cc ctf-reader: Add support to read CTF information from the Linux Kernel 2022-05-13 09:11:37 +02:00
abilint.cc abilint --show-type-use: Show results for global decls that have no symbols 2022-02-28 17:30:04 +01:00
abipkgdiff.cc abipkgdiff: Use 'convert_path_to_relative' in 'create_abi_file_path' 2021-12-20 16:42:13 +01:00
abisym.cc Include <libgen.h> in tools/abisym.cc for basename(3) 2022-01-17 14:32:33 +01:00
binilint.cc Re-license the project to Apache v2 With LLVM Exception 2020-12-02 11:49:13 +01:00
fedabipkgdiff Add Logic to detect file type by extension 2022-05-12 12:10:15 +02:00
kmidiff.cc Find fts-standalone on musl 2022-02-07 16:26:30 +01:00
Makefile.am Find fts-standalone on musl 2022-02-07 16:26:30 +01:00