[LTP] [PATCH v3 0/8] Sparse based checker and rule proposal

[LTP] [PATCH v3 0/8] Sparse based checker and rule proposal

[Richard Palethorpe]

Hello,

So it turns out that it is quite easy to implement the TST_RET/ERR
check in Sparse. It compiles the code into an IR which is just the
right abstraction for the test. It is also possible to inspect the AST
with Sparse. It appears more difficult to inspect the AST before
macros are expanded.

Sparse is not packaged as a shared library, but has few/no
dependencies and is easy to compile. It seems like it was meant to be
vendored. Including it as a git module seems reasonable to me. Please
see tools/sparse/README.md.

There are still a lot of errors/noise when running 'make check' on the
entire tree. These are mainly caused by old function definitions and
such. They need to be fixed before the tool can be used properly.

Also I have tried to document the rule and created a list of rules. So
this can also be taken as a formal proposal for the rule itself.

Thanks,

V3:
* Rename main to sparse-ltp
* Unify TEST/TST_EXP docs
* Add/fix a couple of links in the docs
* minor formatting changes in sparse-ltp
* Add note on building with -m32

V2:
* Automatically download and build sparse.
* Only build sparse if "make check" is run. It is filtered from "make all".
* Move libtsc.h out of the realtime tests dir. Note that checking of metldown.c
  now fails because it uses a GCC builtin sparse does not recognize.

As mentioned above, there are various errors during checking that need
fixing. For the most part these are legit errors (usually old style
function definitions or redefining of symbols). With stuff like
metldown I am tempted to filter it, but OTOH it looks relatively
straight forward to add a builtin to Sparse upstream. I just need time
to do it. First though I would like to get "make check" working on the
library, so we can put that in CI.

Richard Palethorpe (8):
  Add Sparse based checker and TST_RET/ERR check
  Add 'make check' to the build system
  doc: Add rules and recommendations list
  doc: Remind authors and maintainers to run make check
  doc: Document TEST macro and state TST_RET/ERR rule LTP-002
  Reference LTP-002 rule in Cocci scripts
  API: Move libtsc.h from realtime tests include to tst_tsc.h
  API/tst_tsc: Add guards and remove some boilerplate

 .gitmodules                                   |   3 +
 Makefile                                      |   8 +
 doc/c-test-api.txt                            |  54 ++++++-
 doc/library-api-writing-guidelines.txt        |  14 ++
 doc/maintainer-patch-review-checklist.txt     |   4 +-
 doc/rules.tsv                                 |   3 +
 doc/test-writing-guidelines.txt               |   8 +
 include/mk/env_post.mk                        |   8 +
 include/mk/generic_leaf_target.inc            |   5 +-
 include/mk/generic_trunk_target.inc           |   7 +-
 include/mk/lib.mk                             |   3 +
 include/mk/module.mk                          |   2 +
 include/mk/rules.mk                           |   9 ++
 include/mk/sparse.mk                          |   9 ++
 include/mk/testcases.mk                       |   1 +
 .../include/libtsc.h => include/tst_tsc.h     |  35 +----
 .../coccinelle/libltp-test-macro-vars.cocci   |   6 +-
 scripts/coccinelle/libltp-test-macro.cocci    |   4 +-
 testcases/cve/Makefile                        |   2 -
 testcases/cve/meltdown.c                      |   2 +-
 testcases/open_posix_testsuite/Makefile       |   4 +
 .../func/async_handler/async_handler_tsc.c    |   3 +-
 .../func/measurement/preempt_timing.c         |   3 +-
 .../realtime/func/measurement/rdtsc-latency.c |   3 +-
 tools/Makefile                                |   2 +
 tools/sparse/.gitignore                       |   1 +
 tools/sparse/Makefile                         |  27 ++++
 tools/sparse/README.md                        |  51 ++++++
 tools/sparse/sparse-ltp.c                     | 147 ++++++++++++++++++
 tools/sparse/sparse-src                       |   1 +
 30 files changed, 382 insertions(+), 47 deletions(-)
 create mode 100644 doc/rules.tsv
 create mode 100644 include/mk/sparse.mk
 rename testcases/realtime/include/libtsc.h => include/tst_tsc.h (53%)
 create mode 100644 tools/sparse/.gitignore
 create mode 100644 tools/sparse/Makefile
 create mode 100644 tools/sparse/README.md
 create mode 100644 tools/sparse/sparse-ltp.c
 create mode 160000 tools/sparse/sparse-src

-- 
2.31.1

[LTP] [PATCH v3 1/8] Add Sparse based checker and TST_RET/ERR check

[Richard Palethorpe]

Vendors in Sparse as a git module. Then uses it to check for stores to
TST_RET/ERR within the library.

Signed-off-by: Richard Palethorpe <rpalethorpe@suse.com>
---
 .gitmodules               |   3 +
 tools/Makefile            |   2 +
 tools/sparse/.gitignore   |   1 +
 tools/sparse/Makefile     |  27 +++++++
 tools/sparse/README.md    |  51 +++++++++++++
 tools/sparse/sparse-ltp.c | 147 ++++++++++++++++++++++++++++++++++++++
 tools/sparse/sparse-src   |   1 +
 7 files changed, 232 insertions(+)
 create mode 100644 tools/sparse/.gitignore
 create mode 100644 tools/sparse/Makefile
 create mode 100644 tools/sparse/README.md
 create mode 100644 tools/sparse/sparse-ltp.c
 create mode 160000 tools/sparse/sparse-src

diff --git a/.gitmodules b/.gitmodules
index 1c9e9c38a..a3c34af4b 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,3 +1,6 @@
 [submodule "testcases/kernel/mce-test"]
 	path = testcases/kernel/mce-test
 	url = git://git.kernel.org/pub/scm/linux/kernel/git/gong.chen/mce-test.git
+[submodule "tools/sparse/sparse-src"]
+	path = tools/sparse/sparse-src
+	url = git://git.kernel.org/pub/scm/devel/sparse/sparse.git
diff --git a/tools/Makefile b/tools/Makefile
index def1c6fa9..adbf4fe70 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -28,4 +28,6 @@ INSTALL_TARGETS		:= *.awk *.pl *.sh html_report_header.txt
 
 INSTALL_DIR		:= bin
 
+FILTER_OUT_DIRS		+= sparse
+
 include $(top_srcdir)/include/mk/generic_trunk_target.mk
diff --git a/tools/sparse/.gitignore b/tools/sparse/.gitignore
new file mode 100644
index 000000000..b2d2c37fa
--- /dev/null
+++ b/tools/sparse/.gitignore
@@ -0,0 +1 @@
+sparse-ltp
diff --git a/tools/sparse/Makefile b/tools/sparse/Makefile
new file mode 100644
index 000000000..4247dd86e
--- /dev/null
+++ b/tools/sparse/Makefile
@@ -0,0 +1,27 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+# Copyright (c) 2021 SUSE LLC <rpalethorpe@suse.com>
+
+top_srcdir		?= ../..
+
+include $(top_srcdir)/include/mk/env_pre.mk
+include $(top_srcdir)/include/mk/functions.mk
+
+SPARSE_SRC	?= sparse-src
+
+$(SPARSE_SRC)/Makefile:
+ifeq ($(SPARSE_SRC),sparse-src)
+	git submodule update --init
+else
+	$(error "Can't find $(SPARSE_SRC)/Makefile")
+endif
+
+$(SPARSE_SRC)/libsparse.a: $(SPARSE_SRC)/Makefile
+	$(MAKE) -C $(SPARSE_SRC) libsparse.a
+
+HOST_MAKE_TARGETS	:= sparse-ltp
+MAKE_DEPS		+= $(SPARSE_SRC)/libsparse.a
+HOST_CFLAGS		+= -I$(SPARSE_SRC) -Werror
+HOST_LDLIBS		+= $(SPARSE_SRC)/libsparse.a
+
+
+include $(top_srcdir)/include/mk/generic_leaf_target.mk
diff --git a/tools/sparse/README.md b/tools/sparse/README.md
new file mode 100644
index 000000000..aaf24f7ba
--- /dev/null
+++ b/tools/sparse/README.md
@@ -0,0 +1,51 @@
+# Sparse based linting
+
+This tool checks LTP test and library code for common problems.
+
+## Usage
+
+It is integrated with the LTP build system. Just run `make check` or
+`make check-a_test01`, where `a_test01` is an arbitrary test
+executable or object file.
+
+## Building
+
+The bad news is you must get and build Sparse[^1]. The good news is
+that this only takes a minute and the build system does it for
+you. Just try running `make check` as described above.
+
+However if you want to reuse an existing Sparse checkout. Then you can
+do the following. Where `$SRC_PATH` is the path to the Sparse
+directory.
+
+```sh
+$ cd tools/sparse
+$ make SPARSE_SRC=$SRC_PATH
+```
+You can also manually fetch it via the git submodule
+
+```sh
+$ cd tools/sparse
+$ git submodule update --init
+```
+
+### Modifying CFLAGS and -m32
+
+When compiling the LTP with `-m32` it may break building
+`sparse-ltp`. We do not pass LTP's `CFLAGS` or `HOST_CFLAGS` to
+`libsparse.a`. In the best case it produces a lot of noise, in the
+worst it breaks building anyway.
+
+To avoid issues with m32, just pre-build the checker with a non-m32
+config. It won't need to be built again unless you are modifying the
+tool itself. Similar issues with cross-compiling could be handled in a
+similar way. Simply pre-build `sparse-ltp` and `libsparse.a` with a separate
+config.
+
+### Clang
+
+Note that while it is possible to build Sparse with Clang. This may
+cause some issues. Namely `GCC_BASE` is set to the Clang resource
+directory. This contains some headers Sparse can not parse.
+
+[1]: Many distributions have a Sparse package. This only contains some executables. There is no shared library
diff --git a/tools/sparse/sparse-ltp.c b/tools/sparse/sparse-ltp.c
new file mode 100644
index 000000000..45874e8eb
--- /dev/null
+++ b/tools/sparse/sparse-ltp.c
@@ -0,0 +1,147 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2021 SUSE LLC <rpalethorpe@suse.com>
+ *
+ * Sparse allows us to perform checks on the AST (struct symbol) or on
+ * a linearized representation. In the latter case we are given a set
+ * of entry points (functions) containing basic blocks of
+ * instructions.
+ *
+ * The basic blocks contain byte code in SSA form. This is similar to
+ * the intermediate representation most compilers use during
+ * optimisation.
+ */
+#include <stdarg.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+#include "lib.h"
+#include "allocate.h"
+#include "opcode.h"
+#include "token.h"
+#include "parse.h"
+#include "symbol.h"
+#include "expression.h"
+#include "linearize.h"
+
+/* The rules for test, library and tool code are different */
+enum ltp_tu_kind {
+	LTP_LIB,
+	LTP_OTHER,
+};
+
+static enum ltp_tu_kind tu_kind = LTP_OTHER;
+
+/* Check for LTP-002
+ *
+ * Inspects the destination symbol of each store instruction. If it is
+ * TST_RET or TST_ERR then emit a warning.
+ */
+static void check_lib_sets_TEST_vars(const struct instruction *insn)
+{
+	static struct ident *TST_RES_id, *TST_ERR_id;
+
+	if (!TST_RES_id) {
+		TST_RES_id = built_in_ident("TST_RET");
+		TST_ERR_id = built_in_ident("TST_ERR");
+	}
+
+	if (insn->opcode != OP_STORE)
+		return;
+	if (insn->src->ident != TST_RES_id &&
+	    insn->src->ident != TST_ERR_id)
+		return;
+
+	warning(insn->pos,
+		"LTP-002: Library should not write to TST_RET or TST_ERR");
+}
+
+static void do_basicblock_checks(struct basic_block *bb)
+{
+	struct instruction *insn;
+
+	FOR_EACH_PTR(bb->insns, insn) {
+		if (!bb_reachable(insn->bb))
+			continue;
+
+		if (tu_kind == LTP_LIB)
+			check_lib_sets_TEST_vars(insn);
+	} END_FOR_EACH_PTR(insn);
+}
+
+static void do_entrypoint_checks(struct entrypoint *ep)
+{
+	struct basic_block *bb;
+
+	FOR_EACH_PTR(ep->bbs, bb) {
+		do_basicblock_checks(bb);
+	} END_FOR_EACH_PTR(bb);
+}
+
+/* Compile the AST into a graph of basicblocks */
+static void process_symbols(struct symbol_list *list)
+{
+	struct symbol *sym;
+
+	FOR_EACH_PTR(list, sym) {
+		struct entrypoint *ep;
+
+		expand_symbol(sym);
+		ep = linearize_symbol(sym);
+		if (!ep || !ep->entry)
+			continue;
+
+		do_entrypoint_checks(ep);
+
+		if (dbg_entry)
+			show_entry(ep);
+	} END_FOR_EACH_PTR(sym);
+}
+
+static void collect_info_from_args(const int argc, char *const *const argv)
+{
+	int i;
+
+	for (i = 0; i < argc; i++) {
+		if (!strcmp("-DLTPLIB", argv[i]))
+			tu_kind = LTP_LIB;
+	}
+}
+
+int main(int argc, char **argv)
+{
+	struct string_list *filelist = NULL;
+	char *file;
+
+	Waddress_space = 0;
+	Wbitwise = 0;
+	Wcast_truncate = 0;
+	Wcontext = 0;
+	Wdecl = 0;
+	Wexternal_function_has_definition = 0;
+	Wflexible_array_array = 0;
+	Wimplicit_int = 0;
+	Wint_to_pointer_cast = 0;
+	Wmemcpy_max_count = 0;
+	Wnon_pointer_null = 0;
+	Wone_bit_signed_bitfield = 0;
+	Woverride_init = 0;
+	Wpointer_to_int_cast = 0;
+	Wvla = 0;
+
+	do_output = 0;
+
+	collect_info_from_args(argc, argv);
+
+	process_symbols(sparse_initialize(argc, argv, &filelist));
+	FOR_EACH_PTR(filelist, file) {
+		process_symbols(sparse(file));
+	} END_FOR_EACH_PTR(file);
+
+	report_stats();
+	return 0;
+}
diff --git a/tools/sparse/sparse-src b/tools/sparse/sparse-src
new file mode 160000
index 000000000..8af243292
--- /dev/null
+++ b/tools/sparse/sparse-src
@@ -0,0 +1 @@
+Subproject commit 8af2432923486c753ab52cae70b94ee684121080
-- 
2.31.1

[LTP] [PATCH v3 2/8] Add 'make check' to the build system

[Richard Palethorpe]

Allows one to run 'make check' or 'make check-$TARGET'. Which will
execute the CHECK tool with that target's CC arguments and
CHECK_FLAGS. By default the check tool is tools/sparse/main.

Signed-off-by: Richard Palethorpe <rpalethorpe@suse.com>
---
 Makefile                                | 8 ++++++++
 include/mk/env_post.mk                  | 8 ++++++++
 include/mk/generic_leaf_target.inc      | 5 ++++-
 include/mk/generic_trunk_target.inc     | 7 ++++++-
 include/mk/lib.mk                       | 3 +++
 include/mk/module.mk                    | 2 ++
 include/mk/rules.mk                     | 9 +++++++++
 include/mk/sparse.mk                    | 9 +++++++++
 include/mk/testcases.mk                 | 1 +
 testcases/open_posix_testsuite/Makefile | 4 ++++
 10 files changed, 54 insertions(+), 2 deletions(-)
 create mode 100644 include/mk/sparse.mk

diff --git a/Makefile b/Makefile
index 56812d77b..3b0ba330d 100644
--- a/Makefile
+++ b/Makefile
@@ -79,6 +79,7 @@ BOOTSTRAP_TARGETS	:= $(sort $(COMMON_TARGETS) $(CLEAN_TARGETS) $(INSTALL_TARGETS
 CLEAN_TARGETS		:= $(addsuffix -clean,$(CLEAN_TARGETS))
 INSTALL_TARGETS		:= $(addsuffix -install,$(INSTALL_TARGETS))
 MAKE_TARGETS		:= $(addsuffix -all,$(filter-out lib,$(COMMON_TARGETS)))
+CHECK_TARGETS		:= $(addsuffix -check,testcases lib)
 
 # There's no reason why we should run `all' twice. Otherwise we're just wasting
 # 3+ mins of useful CPU cycles on a modern machine, and even more time on an
@@ -108,6 +109,10 @@ $(MAKE_TARGETS) include-all lib-all libs-all:
 	$(MAKE) -C "$(subst -all,,$@)" \
 		-f "$(abs_top_srcdir)/$(subst -all,,$@)/Makefile" all
 
+$(CHECK_TARGETS): tools-all
+	$(MAKE) -C "$(subst -check,,$@)" \
+		-f "$(abs_top_srcdir)/$(subst -check,,$@)/Makefile" check
+
 # Let's not conflict with ac-clean, maintainer-clean, etc, so.
 $(filter-out include-clean,$(CLEAN_TARGETS))::
 	-$(MAKE) -C "$(subst -clean,,$@)" \
@@ -189,6 +194,9 @@ INSTALL_TARGETS		+= $(addprefix $(DESTDIR)/$(bindir)/,$(BINDIR_INSTALL_SCRIPTS))
 
 $(INSTALL_TARGETS): $(INSTALL_DIR) $(DESTDIR)/$(bindir)
 
+.PHONY: check
+check: $(CHECK_TARGETS)
+
 ## Install
 install: $(INSTALL_TARGETS)
 
diff --git a/include/mk/env_post.mk b/include/mk/env_post.mk
index 1d22f9c53..4722da907 100644
--- a/include/mk/env_post.mk
+++ b/include/mk/env_post.mk
@@ -89,6 +89,14 @@ $(error You must define $$(prefix) before executing install)
 endif # END $(filter-out install,$(MAKECMDGOALS)),$(MAKECMDGOALS)
 endif
 
+CHECK_TARGETS			?= $(addprefix check-,$(notdir $(patsubst %.c,%,$(sort $(wildcard $(abs_srcdir)/*.c)))))
+CHECK_TARGETS			:= $(filter-out $(addprefix check-, $(FILTER_OUT_MAKE_TARGETS)), $(CHECK_TARGETS))
+CHECK				?= $(abs_top_srcdir)/tools/sparse/sparse-ltp
+
+ifeq ($(CHECK),$(abs_top_srcdir)/tools/sparse/sparse-ltp)
+CHECK_DEPS			+= $(CHECK)
+endif
+
 include $(top_srcdir)/include/mk/rules.mk
 
 endif
diff --git a/include/mk/generic_leaf_target.inc b/include/mk/generic_leaf_target.inc
index 64953f89a..aa092a5a3 100644
--- a/include/mk/generic_leaf_target.inc
+++ b/include/mk/generic_leaf_target.inc
@@ -92,7 +92,7 @@
 # INSTALL_DIR			:= $(libdir)
 #
 
-.PHONY: all clean install
+.PHONY: all clean install check
 
 ifneq ($(strip $(MAKE_TARGETS)),)
 $(MAKE_TARGETS) += $(HOST_MAKE_TARGETS)
@@ -109,4 +109,7 @@ $(INSTALL_FILES): | $(INSTALL_DEPS)
 
 install: $(INSTALL_FILES)
 
+$(CHECK_TARGETS): | $(CHECK_DEPS)
+check: $(CHECK_TARGETS)
+
 # vim: syntax=make
diff --git a/include/mk/generic_trunk_target.inc b/include/mk/generic_trunk_target.inc
index fc59f944f..32a108fbf 100644
--- a/include/mk/generic_trunk_target.inc
+++ b/include/mk/generic_trunk_target.inc
@@ -48,7 +48,7 @@
 
 include $(top_srcdir)/include/mk/functions.mk
 
-RECURSIVE_TARGETS		?= all install
+RECURSIVE_TARGETS		?= all install check
 
 $(eval $(get_make_dirs))
 
@@ -68,6 +68,9 @@ $(INSTALL_FILES): | $(INSTALL_DEPS)
 
 trunk-install: $(INSTALL_FILES)
 
+$(CHECK_TARGETS): | $(CHECK_DEPS)
+trunk-check: $(CHECK_TARGETS)
+
 # Avoid creating duplicate .PHONY references to all, clean, and install. IIRC,
 # I've seen some indeterministic behavior when one does this in the past with
 # GNU Make...
@@ -108,4 +111,6 @@ else
 endif
 endif
 
+check: trunk-check
+
 # vim: syntax=make
diff --git a/include/mk/lib.mk b/include/mk/lib.mk
index f9b6c0aff..3bf63bf9e 100644
--- a/include/mk/lib.mk
+++ b/include/mk/lib.mk
@@ -26,6 +26,7 @@
 # Makefile to include for libraries.
 
 include $(top_srcdir)/include/mk/env_pre.mk
+include $(top_srcdir)/include/mk/sparse.mk
 
 INSTALL_DIR	:= $(libdir)
 
@@ -57,6 +58,8 @@ LIBSRCS		:= $(filter-out $(FILTER_OUT_LIBSRCS),$(LIBSRCS))
 
 LIBOBJS		:= $(LIBSRCS:.c=.o)
 
+CHECK_TARGETS	:= $(addprefix check-,$(notdir $(LIBSRCS:.c=)))
+
 $(LIB): $(notdir $(LIBOBJS))
 	@if [ -z "$(strip $^)" ] ; then \
 		echo "Cowardly refusing to create empty archive"; \
diff --git a/include/mk/module.mk b/include/mk/module.mk
index 6c8814b96..3bb7350f1 100644
--- a/include/mk/module.mk
+++ b/include/mk/module.mk
@@ -47,6 +47,8 @@ endif
 
 CLEAN_TARGETS += .dep_modules *.mod built-in.a
 
+CHECK_TARGETS := $(filter-out %.ko, $(CHECK_TARGETS))
+
 MODULE_SOURCES := $(patsubst %.ko,%.c,$(filter %.ko, $(MAKE_TARGETS)))
 
 # Ignoring the exit status of commands is done to be forward compatible with
diff --git a/include/mk/rules.mk b/include/mk/rules.mk
index c8f4bbbbe..2a04b2b67 100644
--- a/include/mk/rules.mk
+++ b/include/mk/rules.mk
@@ -37,3 +37,12 @@ else
 	@$(CC) $(CPPFLAGS) $(CFLAGS) $(LDFLAGS) $^ $(LTPLDLIBS) $(LDLIBS) -o $@
 	@echo CC $(target_rel_dir)$@
 endif
+
+.PHONY: $(CHECK_TARGETS)
+$(CHECK_TARGETS): check-%: %.c
+ifdef VERBOSE
+	$(CHECK) $(CHECK_FLAGS) $(CPPFLAGS) $(CFLAGS) $<
+else
+	@$(CHECK) $(CHECK_FLAGS) $(CPPFLAGS) $(CFLAGS) $<
+	@echo CHECK $(target_rel_dir)$<
+endif
diff --git a/include/mk/sparse.mk b/include/mk/sparse.mk
new file mode 100644
index 000000000..a86928393
--- /dev/null
+++ b/include/mk/sparse.mk
@@ -0,0 +1,9 @@
+# Rules to make sparse tool(s) for inclusion in lib and testcases Makefiles
+
+SPARSE_DIR:= $(abs_top_builddir)/tools/sparse
+
+$(SPARSE_DIR)/sparse-ltp: $(SPARSE_DIR)
+	$(MAKE) -C "$^" all
+
+$(SPARSE_DIR): %:
+	mkdir -p "$@"
diff --git a/include/mk/testcases.mk b/include/mk/testcases.mk
index 1c81773d0..444020f16 100644
--- a/include/mk/testcases.mk
+++ b/include/mk/testcases.mk
@@ -22,6 +22,7 @@
 
 include $(top_srcdir)/include/mk/env_pre.mk
 include $(top_srcdir)/include/mk/functions.mk
+include $(top_srcdir)/include/mk/sparse.mk
 
 APICMDS_DIR	:= $(abs_top_builddir)/tools/apicmds
 
diff --git a/testcases/open_posix_testsuite/Makefile b/testcases/open_posix_testsuite/Makefile
index 205ecdc00..fea6db14b 100644
--- a/testcases/open_posix_testsuite/Makefile
+++ b/testcases/open_posix_testsuite/Makefile
@@ -104,3 +104,7 @@ $(CRITICAL_MAKEFILE): \
 	$(top_srcdir)/LDFLAGS			\
 	$(top_srcdir)/LDLIBS
 	@$(MAKE) generate-makefiles
+
+.PHONY: check
+check:
+	@echo "Checker not yet supported by Open POSIX testsuite"
-- 
2.31.1

[LTP] [PATCH v3 3/8] doc: Add rules and recommendations list

[Richard Palethorpe]

Create a list of rules which are feasible to check automatically. The
file is a table of tab separated values. It's intended to be machine
readable.

For now there is just an ID column, with IDs that look similar to CWE
IDs or CVEs. For now these can just be used with 'git grep'. Also
there is a description column.

Clearly this is not an exhaustive list. It just contains a library
rule already stated in the guide and the issue Sparse checks for.

Signed-off-by: Richard Palethorpe <rpalethorpe@suse.com>
---
 doc/rules.tsv                   | 3 +++
 doc/test-writing-guidelines.txt | 7 +++++++
 2 files changed, 10 insertions(+)
 create mode 100644 doc/rules.tsv

diff --git a/doc/rules.tsv b/doc/rules.tsv
new file mode 100644
index 000000000..d4081ce0f
--- /dev/null
+++ b/doc/rules.tsv
@@ -0,0 +1,3 @@
+ID	DESCRIPTION
+LTP-001	Library source files have tst_ prefix
+LTP-002	TST_RET and TST_ERR are never modified by test library functions
diff --git a/doc/test-writing-guidelines.txt b/doc/test-writing-guidelines.txt
index d57e52655..1197c9a0d 100644
--- a/doc/test-writing-guidelines.txt
+++ b/doc/test-writing-guidelines.txt
@@ -10,6 +10,13 @@ NOTE: See also
       https://github.com/linux-test-project/ltp/wiki/Shell-Test-API[Shell Test API],
       https://github.com/linux-test-project/ltp/wiki/LTP-Library-API-Writing-Guidelines[LTP Library API Writing Guidelines].
 
+Rules and recommendations which are "machine checkable" should be
+tagged with an ID like +LTP-XXX+. There will be a corresponding entry
+in
+https://github.com/linux-test-project/ltp/tree/master/doc/rules.tsv[doc/rules.tsv]. When
+you run 'make check' or 'make check-test' it will display these IDs as
+a reference.
+
 1. Guide to clean and understandable code
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-- 
2.31.1

[LTP] [PATCH v3 4/8] doc: Remind authors and maintainers to run make check

[Richard Palethorpe]

Signed-off-by: Richard Palethorpe <rpalethorpe@suse.com>
---
 doc/maintainer-patch-review-checklist.txt | 4 ++--
 doc/test-writing-guidelines.txt           | 1 +
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/doc/maintainer-patch-review-checklist.txt b/doc/maintainer-patch-review-checklist.txt
index f6682b574..58662bed1 100644
--- a/doc/maintainer-patch-review-checklist.txt
+++ b/doc/maintainer-patch-review-checklist.txt
@@ -39,8 +39,8 @@ New test should
 * Use new https://github.com/linux-test-project/ltp/wiki/Test-Writing-Guidelines#22-writing-a-test-in-c[C API]
 * Test binaries are added into corresponding '.gitignore' files
 * Check coding style with
-  https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/plain/scripts/checkpatch.pl[checkpatch.pl]
-  (more in https://github.com/linux-test-project/ltp/wiki/Test-Writing-Guidelines#131-c-coding-style[C coding style])
+  https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/plain/scripts/checkpatch.pl[checkpatch.pl] and `make check`
+  (more in https://github.com/linux-test-project/ltp/wiki/Test-Writing-Guidelines#21-c-coding-style[C coding style])
 * Docparse documentation
 * If a test is a regression test it should include tags
   (more in https://github.com/linux-test-project/ltp/wiki/Test-Writing-Guidelines#2238-test-tags[Test tags])
diff --git a/doc/test-writing-guidelines.txt b/doc/test-writing-guidelines.txt
index 1197c9a0d..340c80cc6 100644
--- a/doc/test-writing-guidelines.txt
+++ b/doc/test-writing-guidelines.txt
@@ -310,6 +310,7 @@ NOTE: See also
 3. The runtest entires are in place
 4. Test binaries are added into corresponding '.gitignore' files
 5. Patches apply over the latest git
+6. 'make check' does not emit any warnings
 
 6.1 About .gitignore files
 ~~~~~~~~~~~~~~~~~~~~~~~~~~
-- 
2.31.1

[LTP] [PATCH v3 5/8] doc: Document TEST macro and state TST_RET/ERR rule LTP-002

[Richard Palethorpe]

There are cases where these variables can be safely used by the
library. However it is a difficult problem to identify these cases
automatically.

Identifying any library code which uses them is relatively easy. In
fact it is easier to automate it than by code review. Because it is
such a boring thing to repeatedly look for and comment on.

If a test library function needs these variables it can recreate its
own private copies.

Signed-off-by: Richard Palethorpe <rpalethorpe@suse.com>
---
 doc/c-test-api.txt                     | 54 +++++++++++++++++++++++++-
 doc/library-api-writing-guidelines.txt | 14 +++++++
 2 files changed, 66 insertions(+), 2 deletions(-)

diff --git a/doc/c-test-api.txt b/doc/c-test-api.txt
index dd6c608a4..25b9beb7c 100644
--- a/doc/c-test-api.txt
+++ b/doc/c-test-api.txt
@@ -291,8 +291,58 @@ static void test(void)
 }
 -------------------------------------------------------------------------------
 
-The 'TST_EXP_FAIL2()' is the same as 'TST_EXP_FAIL()' except the return value
-is expected to be non-negative integer if call passes.
+The 'TST_EXP_FAIL2()' is the same as 'TST_EXP_FAIL()' except the
+return value is expected to be non-negative integer if call
+passes. These macros build upon the +TEST()+ macro and associated
+variables.
+
+[source,c]
+-------------------------------------------------------------------------------
+TEST(socket(AF_INET, SOCK_RAW, 1));
+if (TST_RET > -1) {
+	tst_res(TFAIL, "Created raw socket");
+	SAFE_CLOSE(TST_RET);
+} else if (TST_ERR != EPERM) {
+	tst_res(TFAIL | TTERRNO,
+		"Failed to create socket for wrong reason");
+} else {
+	tst_res(TPASS | TTERRNO, "Didn't create raw socket");
+}
+-------------------------------------------------------------------------------
+
+The +TEST+ macro sets +TST_RET+ to its argument's return value and
++TST_ERR+ to +errno+. The +TTERNO+ flag can be used to print the error
+number's symbolic value.
+
+No LTP library function or macro, except those in 'tst_test_macros.h',
+will write to these variables (rule 'LTP-002'). So their values will
+not be changed unexpectedly.
+
+[source,c]
+-------------------------------------------------------------------------------
+TST_EXP_POSITIVE(wait(&status));
+
+if (!TST_PASS)
+	return;
+-------------------------------------------------------------------------------
+
+If the return value of 'wait' is positive. This macro will print a
+pass result and set +TST_PASS+ appropriately. If the return value is
+zero or negative, then it will print fail.
+
+As seen above, this and similar macros take optional variadic
+arguments. These begin with a format string and then appropriate
+values to be formatted. So
+
+[source,c]
+-------------------------------------------------------------------------------
+TST_EXP_PASS(chown("a/file", uid, gid), "chown(%s,%d,%d)",
+	     "a/file", uid, gid);
+-------------------------------------------------------------------------------
+
+expects +chown+ to return 0 and emits a pass or a fail. The arguments
+to +chown+ will be printed in either case. There are many similar
+macros to those shown here, please see 'tst_test_macros.h'.
 
 [source,c]
 -------------------------------------------------------------------------------
diff --git a/doc/library-api-writing-guidelines.txt b/doc/library-api-writing-guidelines.txt
index a4393fc54..2819d4177 100644
--- a/doc/library-api-writing-guidelines.txt
+++ b/doc/library-api-writing-guidelines.txt
@@ -21,10 +21,24 @@ Don't forget to update docs when you change the API.
 2. C API
 --------
 
+2.1 LTP-001: Sources have tst_ prefix
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
 API source code is in headers `include/*.h`, `include/lapi/*.h` (backward
 compatibility for old kernel and libc) and C sources in `lib/*.c`. Files have
 'tst_' prefix.
 
+2.2 LTP-002: TST_RET and TST_ERR are not modified
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The test author is guaranteed that the test API will not modify these
+variables. This prevents silent errors where the return value and
+errno are overwritten before the test has chance to check them.
+
+The macros which are clearly intended to update these variables. That
+is +TEST+ and those in 'tst_test_macros.h'. Are of course allowed to
+update these variables.
+
 3. Shell API
 ------------
 
-- 
2.31.1

[LTP] [PATCH v3 6/8] Reference LTP-002 rule in Cocci scripts

[Richard Palethorpe]

Avoid duplication of rule description

Signed-off-by: Richard Palethorpe <rpalethorpe@suse.com>
---
 scripts/coccinelle/libltp-test-macro-vars.cocci | 6 +-----
 scripts/coccinelle/libltp-test-macro.cocci      | 4 +---
 2 files changed, 2 insertions(+), 8 deletions(-)

diff --git a/scripts/coccinelle/libltp-test-macro-vars.cocci b/scripts/coccinelle/libltp-test-macro-vars.cocci
index ed5459a48..e0fe4e2a7 100644
--- a/scripts/coccinelle/libltp-test-macro-vars.cocci
+++ b/scripts/coccinelle/libltp-test-macro-vars.cocci
@@ -1,11 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 // Copyright (c) 2021 SUSE LLC  <rpalethorpe@suse.com>
 
-// The TEST macro should not be used in the library because it sets
-// TST_RET and TST_ERR which are global variables. The test author
-// only expects these to be changed if *they* call TEST directly.
-
-// Find all positions where TEST's variables are used
+// Find violations of LTP-002
 @ find_use exists @
 expression E;
 @@
diff --git a/scripts/coccinelle/libltp-test-macro.cocci b/scripts/coccinelle/libltp-test-macro.cocci
index 7563d23aa..86c55c6c4 100644
--- a/scripts/coccinelle/libltp-test-macro.cocci
+++ b/scripts/coccinelle/libltp-test-macro.cocci
@@ -1,9 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 // Copyright (c) 2021 SUSE LLC  <rpalethorpe@suse.com>
 
-// The TEST macro should not be used in the library because it sets
-// TST_RET and TST_ERR which are global variables. The test author
-// only expects these to be changed if *they* call TEST directly.
+// Find and fix violations of rule LTP-002
 
 // Set with -D fix
 virtual fix
-- 
2.31.1

[LTP] [PATCH v3 7/8] API: Move libtsc.h from realtime tests include to tst_tsc.h

[Richard Palethorpe]

Allow the meltdown test to use this file without modifying the
CFLAGS. This avoids having to add the include also to the CHECK_FLAGS.

Signed-off-by: Richard Palethorpe <rpalethorpe@suse.com>
---
 testcases/realtime/include/libtsc.h => include/tst_tsc.h  | 0
 testcases/cve/Makefile                                    | 2 --
 testcases/cve/meltdown.c                                  | 2 +-
 testcases/realtime/func/async_handler/async_handler_tsc.c | 3 ++-
 testcases/realtime/func/measurement/preempt_timing.c      | 3 ++-
 testcases/realtime/func/measurement/rdtsc-latency.c       | 3 ++-
 6 files changed, 7 insertions(+), 6 deletions(-)
 rename testcases/realtime/include/libtsc.h => include/tst_tsc.h (100%)

diff --git a/testcases/realtime/include/libtsc.h b/include/tst_tsc.h
similarity index 100%
rename from testcases/realtime/include/libtsc.h
rename to include/tst_tsc.h
diff --git a/testcases/cve/Makefile b/testcases/cve/Makefile
index ddf8b6fe1..c5308794d 100644
--- a/testcases/cve/Makefile
+++ b/testcases/cve/Makefile
@@ -18,8 +18,6 @@ ifneq ($(ANDROID),1)
 cve-2014-0196:  LDLIBS += -lutil
 endif
 
-meltdown: CFLAGS += -I$(abs_srcdir)/../realtime/include
-
 ifneq (,$(filter $(HOST_CPU),x86 x86_64))
 meltdown: CFLAGS += -msse2
 endif
diff --git a/testcases/cve/meltdown.c b/testcases/cve/meltdown.c
index a387b3205..5a984aba3 100644
--- a/testcases/cve/meltdown.c
+++ b/testcases/cve/meltdown.c
@@ -19,7 +19,7 @@
 
 #include <emmintrin.h>
 
-#include "libtsc.h"
+#include "tst_tsc.h"
 
 #define TARGET_OFFSET	9
 #define TARGET_SIZE	(1 << TARGET_OFFSET)
diff --git a/testcases/realtime/func/async_handler/async_handler_tsc.c b/testcases/realtime/func/async_handler/async_handler_tsc.c
index 7da4324a5..73d4ee5c6 100644
--- a/testcases/realtime/func/async_handler/async_handler_tsc.c
+++ b/testcases/realtime/func/async_handler/async_handler_tsc.c
@@ -46,7 +46,8 @@
 #include <pthread.h>
 #include <librttest.h>
 #include <libstats.h>
-#include <libtsc.h>
+
+#include "tst_tsc.h"
 
 #define HANDLER_PRIO 98
 #define SIGNAL_PRIO 99
diff --git a/testcases/realtime/func/measurement/preempt_timing.c b/testcases/realtime/func/measurement/preempt_timing.c
index 8b5333480..b84d54692 100644
--- a/testcases/realtime/func/measurement/preempt_timing.c
+++ b/testcases/realtime/func/measurement/preempt_timing.c
@@ -52,7 +52,8 @@
 #include <sys/mman.h>
 #include <stdint.h>
 #include <librttest.h>
-#include <libtsc.h>
+
+#include "tst_tsc.h"
 
 #define ITERATIONS 1000000ULL
 #define INTERVALS 10
diff --git a/testcases/realtime/func/measurement/rdtsc-latency.c b/testcases/realtime/func/measurement/rdtsc-latency.c
index d6ab89ff0..3829947bc 100644
--- a/testcases/realtime/func/measurement/rdtsc-latency.c
+++ b/testcases/realtime/func/measurement/rdtsc-latency.c
@@ -44,7 +44,8 @@
 #include <errno.h>
 #include <stdint.h>
 #include <librttest.h>
-#include <libtsc.h>
+
+#include "tst_tsc.h"
 
 #define ITERATIONS 1000000
 
-- 
2.31.1

[LTP] [PATCH v3 8/8] API/tst_tsc: Add guards and remove some boilerplate

[Richard Palethorpe]

Signed-off-by: Richard Palethorpe <rpalethorpe@suse.com>
---
 include/tst_tsc.h | 35 ++++++++---------------------------
 1 file changed, 8 insertions(+), 27 deletions(-)

diff --git a/include/tst_tsc.h b/include/tst_tsc.h
index 9ad5fd659..3f49a6ca7 100644
--- a/include/tst_tsc.h
+++ b/include/tst_tsc.h
@@ -1,28 +1,6 @@
-/******************************************************************************
- *
- *   Copyright ? International Business Machines  Corp., 2006-2008
- *
- *   This program is free software;  you can redistribute it and/or modify
- *   it under the terms of the GNU General Public License as published by
- *   the Free Software Foundation; either version 2 of the License, or
- *   (at your option) any later version.
- *
- *   This program is distributed in the hope that it will be useful,
- *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
- *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
- *   the GNU General Public License for more details.
- *
- *   You should have received a copy of the GNU General Public License
- *   along with this program;  if not, write to the Free Software
- *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- *
- * NAME
- *       libtsc.h
- *
- * DESCRIPTION
- *
- * USAGE:
- *       To be included in some testcases.
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright ? International Business Machines  Corp., 2006-2008
  *
  * AUTHOR
  *        Darren Hart <dvhltc@us.ibm.com>
@@ -30,8 +8,10 @@
  *
  * HISTORY
  *      It directly comes from the librttest.h (see its HISTORY).
- *
- *****************************************************************************/
+ */
+
+#ifndef TST_TSC_H
+#define TST_TSC_H
 
 #undef TSC_UNSUPPORTED
 
@@ -70,3 +50,4 @@
 #define TSC_UNSUPPORTED
 #endif
 
+#endif
-- 
2.31.1

[LTP] [PATCH v3 5/8] doc: Document TEST macro and state TST_RET/ERR rule LTP-002

[Cyril Hrubis]

Hi!
I've pushed all but this patch, see below.

>  -------------------------------------------------------------------------------
>  
> -The 'TST_EXP_FAIL2()' is the same as 'TST_EXP_FAIL()' except the return value
> -is expected to be non-negative integer if call passes.
> +The 'TST_EXP_FAIL2()' is the same as 'TST_EXP_FAIL()' except the
> +return value is expected to be non-negative integer if call
> +passes. These macros build upon the +TEST()+ macro and associated
> +variables.
> +
> +[source,c]
> +-------------------------------------------------------------------------------
> +TEST(socket(AF_INET, SOCK_RAW, 1));
> +if (TST_RET > -1) {
> +	tst_res(TFAIL, "Created raw socket");
> +	SAFE_CLOSE(TST_RET);
> +} else if (TST_ERR != EPERM) {
> +	tst_res(TFAIL | TTERRNO,
> +		"Failed to create socket for wrong reason");
> +} else {
> +	tst_res(TPASS | TTERRNO, "Didn't create raw socket");
> +}
> +-------------------------------------------------------------------------------
> +
> +The +TEST+ macro sets +TST_RET+ to its argument's return value and
> ++TST_ERR+ to +errno+. The +TTERNO+ flag can be used to print the error
> +number's symbolic value.
> +
> +No LTP library function or macro, except those in 'tst_test_macros.h',
> +will write to these variables (rule 'LTP-002'). So their values will
> +not be changed unexpectedly.
> +
> +[source,c]
> +-------------------------------------------------------------------------------
> +TST_EXP_POSITIVE(wait(&status));
> +
> +if (!TST_PASS)
> +	return;
> +-------------------------------------------------------------------------------
> +
> +If the return value of 'wait' is positive. This macro will print a
> +pass result and set +TST_PASS+ appropriately. If the return value is
> +zero or negative, then it will print fail.
> +
> +As seen above, this and similar macros take optional variadic
> +arguments. These begin with a format string and then appropriate
> +values to be formatted. So
> +
> +[source,c]
> +-------------------------------------------------------------------------------
> +TST_EXP_PASS(chown("a/file", uid, gid), "chown(%s,%d,%d)",
> +	     "a/file", uid, gid);
> +-------------------------------------------------------------------------------
> +
> +expects +chown+ to return 0 and emits a pass or a fail. The arguments
> +to +chown+ will be printed in either case. There are many similar
> +macros to those shown here, please see 'tst_test_macros.h'.

There is already TST_EXP_PASS description before the TST_EXP_FAIL so
this duplicates it. Other than that the rest looks good.

-- 
Cyril Hrubis
chrubis@suse.cz

[LTP] Review of C static analyses tools

[Richard Palethorpe]

Hello All,

For anyone interested I have written a review of the tools we tried
using: https://richiejp.com/custom-c-static-analyses-tools.

If you see any mistakes or have any other suggestions, please let me
know!

-- 
Thank you,
Richard.

[LTP] [PATCH v3 2/8] Add 'make check' to the build system

[Petr Vorel]

Hi Richie,

I see 'make check' requires all to have headers/dependencies installed, is that wanted?

$ make check
...
route-change-netlink.c:13:11: error: unable to open 'libmnl/libmnl.h'

<libmnl/libmnl.h> is guarded by #ifdef HAVE_LIBMNL (config.h). Maybe there is a
way to pass it to sparse. But that'd silently prevent to check code we want to
check, thus it's probably better to just require to have everything installed.

Kind regards,
Petr

[LTP] [PATCH v3 2/8] Add 'make check' to the build system

[Cyril Hrubis]

Hi!
> $ make check
> ...
> route-change-netlink.c:13:11: error: unable to open 'libmnl/libmnl.h'
> 
> <libmnl/libmnl.h> is guarded by #ifdef HAVE_LIBMNL (config.h). Maybe there is a
> way to pass it to sparse. But that'd silently prevent to check code we want to
> check, thus it's probably better to just require to have everything installed.

Well if you are hacking on a test that requires libnl and you want to
run 'make check' before submission it has to be installed anyways. So
this is not a big problem for the intended usage...

-- 
Cyril Hrubis
chrubis@suse.cz

[LTP] [PATCH v3 2/8] Add 'make check' to the build system

[Petr Vorel]

> Hi!
> > $ make check
> > ...
> > route-change-netlink.c:13:11: error: unable to open 'libmnl/libmnl.h'

> > <libmnl/libmnl.h> is guarded by #ifdef HAVE_LIBMNL (config.h). Maybe there is a
> > way to pass it to sparse. But that'd silently prevent to check code we want to
> > check, thus it's probably better to just require to have everything installed.

> Well if you are hacking on a test that requires libnl and you want to
> run 'make check' before submission it has to be installed anyways. So
> this is not a big problem for the intended usage...
Sure, you're right.

Kind regards,
Petr