While working on commit b5372fe5dc84 ("exec: load_script: Do not exec
truncated interpreter path"), I wrote a series of test scripts to verify
corner cases. However, soon after, commit 6eb3c3d0a52d ("exec: increase
BINPRM_BUF_SIZE to 256") landed, resulting in the tests needing to be
refactored for the larger BINPRM_BUF_SIZE, which got lost on my TODO
list. During the recent exec refactoring work[1], the need for these tests
resurfaced, so I've finished them up for addition to the kernel selftests.
[1] https://lore.kernel.org/lkml/202005191144.E3112135@keescook/
Signed-off-by: Kees Cook <keescook(a)chromium.org>
---
tools/testing/selftests/exec/Makefile | 1 +
tools/testing/selftests/exec/binfmt_script | 171 +++++++++++++++++++++
2 files changed, 172 insertions(+)
create mode 100755 tools/testing/selftests/exec/binfmt_script
diff --git a/tools/testing/selftests/exec/Makefile b/tools/testing/selftests/exec/Makefile
index 33339e31e365..7f4527f897c4 100644
--- a/tools/testing/selftests/exec/Makefile
+++ b/tools/testing/selftests/exec/Makefile
@@ -3,6 +3,7 @@ CFLAGS = -Wall
CFLAGS += -Wno-nonnull
CFLAGS += -D_GNU_SOURCE
+TEST_PROGS := binfmt_script
TEST_GEN_PROGS := execveat
TEST_GEN_FILES := execveat.symlink execveat.denatured script subdir
# Makefile is a run-time dependency, since it's accessed by the execveat test
diff --git a/tools/testing/selftests/exec/binfmt_script b/tools/testing/selftests/exec/binfmt_script
new file mode 100755
index 000000000000..05f94a741c7a
--- /dev/null
+++ b/tools/testing/selftests/exec/binfmt_script
@@ -0,0 +1,171 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+#
+# Test that truncation of bprm->buf doesn't cause unexpected execs paths, along
+# with various other pathological cases.
+import os, subprocess
+
+# Relevant commits
+#
+# b5372fe5dc84 ("exec: load_script: Do not exec truncated interpreter path")
+# 6eb3c3d0a52d ("exec: increase BINPRM_BUF_SIZE to 256")
+
+# BINPRM_BUF_SIZE
+SIZE=256
+
+NAME_MAX=int(subprocess.check_output(["getconf", "NAME_MAX", "."]))
+
+test_num=0
+
+code='''#!/usr/bin/perl
+print "Executed interpreter! Args:\n";
+print "0 : '$0'\n";
+$counter = 1;
+foreach my $a (@ARGV) {
+ print "$counter : '$a'\n";
+ $counter++;
+}
+'''
+
+##
+# test - produce a binfmt_script hashbang line for testing
+#
+# @size: bytes for bprm->buf line, including hashbang but not newline
+# @good: whether this script is expected to execute correctly
+# @hashbang: the special 2 bytes for running binfmt_script
+# @leading: any leading whitespace before the executable path
+# @root: start of executable pathname
+# @target: end of executable pathname
+# @arg: bytes following the executable pathname
+# @fill: character to fill between @root and @target to reach @size bytes
+# @newline: character to use as newline, not counted towards @size
+# ...
+def test(name, size, good=True, leading="", root="./", target="/perl",
+ fill="A", arg="", newline="\n", hashbang="#!"):
+ global test_num, tests, NAME_MAX
+ test_num += 1
+ if test_num > tests:
+ raise ValueError("more binfmt_script tests than expected! (want %d, expected %d)"
+ % (test_num, tests))
+
+ middle = ""
+ remaining = size - len(hashbang) - len(leading) - len(root) - len(target) - len(arg)
+ # The middle of the pathname must not exceed NAME_MAX
+ while remaining >= NAME_MAX:
+ middle += fill * (NAME_MAX - 1)
+ middle += '/'
+ remaining -= NAME_MAX
+ middle += fill * remaining
+
+ dirpath = root + middle
+ binary = dirpath + target
+ if len(target):
+ os.makedirs(dirpath, mode=0o755, exist_ok=True)
+ open(binary, "w").write(code)
+ os.chmod(binary, 0o755)
+
+ buf=hashbang + leading + root + middle + target + arg + newline
+ if len(newline) > 0:
+ buf += 'echo this is not really perl\n'
+
+ script = "binfmt_script-%s" % (name)
+ open(script, "w").write(buf)
+ os.chmod(script, 0o755)
+
+ proc = subprocess.Popen(["./%s" % (script)], shell=True,
+ stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
+ stdout = proc.communicate()[0]
+
+ if proc.returncode == 0 and b'Executed interpreter' in stdout:
+ if good:
+ print("ok %d - binfmt_script %s (successful good exec)"
+ % (test_num, name))
+ else:
+ print("not ok %d - binfmt_script %s succeeded when it should have failed"
+ % (test_num, name))
+ else:
+ if good:
+ print("not ok %d - binfmt_script %s failed when it should have succeeded (rc:%d)"
+ % (test_num, name, proc.returncode))
+ else:
+ print("ok %d - binfmt_script %s (correctly failed bad exec)"
+ % (test_num, name))
+
+ # Clean up crazy binaries
+ os.unlink(script)
+ if len(target):
+ elements = binary.split('/')
+ os.unlink(binary)
+ elements.pop()
+ while len(elements) > 1:
+ os.rmdir("/".join(elements))
+ elements.pop()
+
+tests=27
+print("TAP version 1.3")
+print("1..%d" % (tests))
+
+### FAIL (8 tests)
+
+# Entire path is well past the BINFMT_BUF_SIZE.
+test(name="too-big", size=SIZE+80, good=False)
+# Path is right at max size, making it impossible to tell if it was truncated.
+test(name="exact", size=SIZE, good=False)
+# Same as above, but with leading whitespace.
+test(name="exact-space", size=SIZE, good=False, leading=" ")
+# Huge buffer of only whitespace.
+test(name="whitespace-too-big", size=SIZE+71, good=False, root="",
+ fill=" ", target="")
+# A good path, but it gets truncated due to leading whitespace.
+test(name="truncated", size=SIZE+17, good=False, leading=" " * 19)
+# Entirely empty except for #!
+test(name="empty", size=2, good=False, root="",
+ fill="", target="", newline="")
+# Within size, but entirely spaces
+test(name="spaces", size=SIZE-1, good=False, root="", fill=" ",
+ target="", newline="")
+# Newline before binary.
+test(name="newline-prefix", size=SIZE-1, good=False, leading="\n",
+ root="", fill=" ", target="")
+
+### ok (19 tests)
+
+# The original test case that was broken by commit:
+# 8099b047ecc4 ("exec: load_script: don't blindly truncate shebang string")
+test(name="test.pl", size=439, leading=" ",
+ root="./nix/store/bwav8kz8b3y471wjsybgzw84mrh4js9-perl-5.28.1/bin",
+ arg=" -I/nix/store/x6yyav38jgr924nkna62q3pkp0dgmzlx-perl5.28.1-File-Slurp-9999.25/lib/perl5/site_perl -I/nix/store/ha8v67sl8dac92r9z07vzr4gv1y9nwqz-perl5.28.1-Net-DBus-1.1.0/lib/perl5/site_perl -I/nix/store/dcrkvnjmwh69ljsvpbdjjdnqgwx90a9d-perl5.28.1-XML-Parser-2.44/lib/perl5/site_perl -I/nix/store/rmji88k2zz7h4zg97385bygcydrf2q8h-perl5.28.1-XML-Twig-3.52/lib/perl5/site_perl")
+# One byte under size, leaving newline visible.
+test(name="one-under", size=SIZE-1)
+# Two bytes under size, leaving newline visible.
+test(name="two-under", size=SIZE-2)
+# Exact size, but trailing whitespace visible instead of newline
+test(name="exact-trunc-whitespace", size=SIZE, arg=" ")
+# Exact size, but trailing space and first arg char visible instead of newline.
+test(name="exact-trunc-arg", size=SIZE, arg=" f")
+# One bute under, with confirmed non-truncated arg since newline now visible.
+test(name="one-under-full-arg", size=SIZE-1, arg=" f")
+# Short read buffer by one byte.
+test(name="one-under-no-nl", size=SIZE-1, newline="")
+# Short read buffer by half buffer size.
+test(name="half-under-no-nl", size=int(SIZE/2), newline="")
+# One byte under with whitespace arg. leaving wenline visible.
+test(name="one-under-trunc-arg", size=SIZE-1, arg=" ")
+# One byte under with whitespace leading. leaving wenline visible.
+test(name="one-under-leading", size=SIZE-1, leading=" ")
+# One byte under with whitespace leading and as arg. leaving newline visible.
+test(name="one-under-leading-trunc-arg", size=SIZE-1, leading=" ", arg=" ")
+# Same as above, but with 2 bytes under
+test(name="two-under-no-nl", size=SIZE-2, newline="")
+test(name="two-under-trunc-arg", size=SIZE-2, arg=" ")
+test(name="two-under-leading", size=SIZE-2, leading=" ")
+test(name="two-under-leading-trunc-arg", size=SIZE-2, leading=" ", arg=" ")
+# Same as above, but with buffer half filled
+test(name="two-under-no-nl", size=int(SIZE/2), newline="")
+test(name="two-under-trunc-arg", size=int(SIZE/2), arg=" ")
+test(name="two-under-leading", size=int(SIZE/2), leading=" ")
+test(name="two-under-lead-trunc-arg", size=int(SIZE/2), leading=" ", arg=" ")
+
+if test_num != tests:
+ raise ValueError("fewer binfmt_script tests than expected! (ran %d, expected %d"
+ % (test_num, tests))
--
2.20.1
--
Kees Cook
Getting a clean BPF selftests run involves ensuring latest trunk LLVM/clang
are used, pahole is recent (>=1.16) and config matches the specified
config file as closely as possible. Document all of this in the general
README.rst file. Also note how to work around timeout failures.
Signed-off-by: Alan Maguire <alan.maguire(a)oracle.com>
---
tools/testing/selftests/bpf/README.rst | 46 ++++++++++++++++++++++++++++++++++
1 file changed, 46 insertions(+)
diff --git a/tools/testing/selftests/bpf/README.rst b/tools/testing/selftests/bpf/README.rst
index 0f67f1b..b00eebb 100644
--- a/tools/testing/selftests/bpf/README.rst
+++ b/tools/testing/selftests/bpf/README.rst
@@ -1,6 +1,52 @@
==================
BPF Selftest Notes
==================
+First verify the built kernel config options match the config options
+specified in the config file in this directory. Test failures for
+unknown helpers, inability to find BTF etc will be observed otherwise.
+
+To ensure the maximum number of tests pass, it is best to use the latest
+trunk LLVM/clang, i.e.
+
+git clone https://github.com/llvm/llvm-project
+
+Build/install trunk LLVM:
+
+.. code-block:: bash
+ git clone https://github.com/llvm/llvm-project
+ cd llvm-project
+ mkdir build/llvm
+ cd build/llvm
+ cmake ../../llvm/
+ make
+ sudo make install
+ cd ../../
+
+Build/install trunk clang:
+
+.. code-block:: bash
+ mkdir -p build/clang
+ cd build/clang
+ cmake ../../clang
+ make
+ sudo make install
+
+When building the kernel with CONFIG_DEBUG_INFO_BTF, pahole
+version 16 or later is also required for BTF function
+support. pahole can be built from the source at
+
+https://github.com/acmel/dwarves
+
+It is often available in "dwarves/libdwarves" packages also,
+but be aware that versions prior to 1.16 will fail with
+errors that functions cannot be found in BTF.
+
+When running selftests, the default timeout of 45 seconds
+can be exceeded by some tests. We can override the default
+timeout via a "settings" file; for example:
+
+.. code-block:: bash
+ echo "timeout=120" > tools/testing/selftests/bpf/settings
Additional information about selftest failures are
documented here.
--
1.8.3.1
The gen_kselftest_tar.sh always packages *all* selftests and doesn't
pass along any variables to `make install` to influence what should be
built. This can result in an early error on the command line ("Unknown
tarball format TARGETS=XXX"), or unexpected test failures as the
tarball contains tests people wanted to skip on purpose.
Since the makefile already contains all the logic, we can add a target
for packaging. Keep the default .gz target the script uses, and actually
extend the supported formats by using tar's autodetection.
To not break current workflows, keep the gen_kselftest_tar.sh script as
it is, with an added suggestion to use the makefile target instead.
Signed-off-by: Veronika Kabatova <vkabatov(a)redhat.com>
---
v2: overriden -> overridden, sent from the matching email address
Documentation/dev-tools/kselftest.rst | 23 ++++++++++++++++++++
tools/testing/selftests/Makefile | 9 +++++++-
tools/testing/selftests/gen_kselftest_tar.sh | 5 +++++
3 files changed, 36 insertions(+), 1 deletion(-)
diff --git a/Documentation/dev-tools/kselftest.rst b/Documentation/dev-tools/kselftest.rst
index 61ae13c44f91..3fc559bcb597 100644
--- a/Documentation/dev-tools/kselftest.rst
+++ b/Documentation/dev-tools/kselftest.rst
@@ -151,6 +151,29 @@ note some tests will require root privileges::
$ cd kselftest
$ ./run_kselftest.sh
+Packaging selftests
+===================
+
+In some cases packaging is desired, such as when tests need to run on a
+different system. To package selftests, run::
+
+ $ make -C tools/testing/selftests gen_tar
+
+This generates a tarball in the `INSTALL_PATH/kselftest-packages` directory. By
+default, `.gz` format is used. The tar format can be overridden by specifying
+a `FORMAT` make variable. Any value recognized by `tar's auto-compress`_ option
+is supported, such as::
+
+ $ make -C tools/testing/selftests gen_tar FORMAT=.xz
+
+`make gen_tar` invokes `make install` so you can use it to package a subset of
+tests by using variables specified in `Running a subset of selftests`_
+section::
+
+ $ make -C tools/testing/selftests gen_tar TARGETS="bpf" FORMAT=.xz
+
+.. _tar's auto-compress: https://www.gnu.org/software/tar/manual/html_node/gzip.html#auto_002dcompre…
+
Contributing new tests
======================
diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index 2ff68702fd41..1195bd85af38 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -249,10 +249,17 @@ else
$(error Error: set INSTALL_PATH to use install)
endif
+FORMAT ?= .gz
+TAR_PATH = $(abspath ${INSTALL_PATH}/kselftest-packages/kselftest.tar${FORMAT})
+gen_tar: install
+ @mkdir -p ${INSTALL_PATH}/kselftest-packages/
+ @tar caf ${TAR_PATH} --exclude=kselftest-packages -C ${INSTALL_PATH} .
+ @echo "Created ${TAR_PATH}"
+
clean:
@for TARGET in $(TARGETS); do \
BUILD_TARGET=$$BUILD/$$TARGET; \
$(MAKE) OUTPUT=$$BUILD_TARGET -C $$TARGET clean;\
done;
-.PHONY: khdr all run_tests hotplug run_hotplug clean_hotplug run_pstore_crash install clean
+.PHONY: khdr all run_tests hotplug run_hotplug clean_hotplug run_pstore_crash install clean gen_tar
diff --git a/tools/testing/selftests/gen_kselftest_tar.sh b/tools/testing/selftests/gen_kselftest_tar.sh
index 8b2b6088540d..4a974bc03385 100755
--- a/tools/testing/selftests/gen_kselftest_tar.sh
+++ b/tools/testing/selftests/gen_kselftest_tar.sh
@@ -49,6 +49,11 @@ main()
# directory
./kselftest_install.sh "$install_dir"
(cd "$install_work"; tar $copts "$dest"/kselftest${ext} $install_name)
+
+ # Don't put the message at the actual end as people may be parsing the
+ # "archive created" line in their scripts.
+ echo -e "\nConsider using 'make gen_tar' instead of this script\n"
+
echo "Kselftest archive kselftest${ext} created!"
# clean up top-level install work directory
--
2.25.1
The gen_kselftest_tar.sh always packages *all* selftests and doesn't
pass along any variables to `make install` to influence what should be
built. This can result in an early error on the command line ("Unknown
tarball format TARGETS=XXX"), or unexpected test failures as the
tarball contains tests people wanted to skip on purpose.
Since the makefile already contains all the logic, we can add a target
for packaging. Keep the default .gz target the script uses, and actually
extend the supported formats by using tar's autodetection.
To not break current workflows, keep the gen_kselftest_tar.sh script as
it is, with an added suggestion to use the makefile target instead.
Signed-off-by: Veronika Kabatova <vkabatov(a)redhat.com>
Reviewed-by: Stefano Brivio <sbrivio(a)redhat.com>
---
Documentation/dev-tools/kselftest.rst | 23 ++++++++++++++++++++
tools/testing/selftests/Makefile | 9 +++++++-
tools/testing/selftests/gen_kselftest_tar.sh | 5 +++++
3 files changed, 36 insertions(+), 1 deletion(-)
diff --git a/Documentation/dev-tools/kselftest.rst b/Documentation/dev-tools/kselftest.rst
index 61ae13c44f91..3fc559bcb597 100644
--- a/Documentation/dev-tools/kselftest.rst
+++ b/Documentation/dev-tools/kselftest.rst
@@ -151,6 +151,29 @@ note some tests will require root privileges::
$ cd kselftest
$ ./run_kselftest.sh
+Packaging selftests
+===================
+
+In some cases packaging is desired, such as when tests need to run on a
+different system. To package selftests, run::
+
+ $ make -C tools/testing/selftests gen_tar
+
+This generates a tarball in the `INSTALL_PATH/kselftest-packages` directory. By
+default, `.gz` format is used. The tar format can be overriden by specifying
+a `FORMAT` make variable. Any value recognized by `tar's auto-compress`_ option
+is supported, such as::
+
+ $ make -C tools/testing/selftests gen_tar FORMAT=.xz
+
+`make gen_tar` invokes `make install` so you can use it to package a subset of
+tests by using variables specified in `Running a subset of selftests`_
+section::
+
+ $ make -C tools/testing/selftests gen_tar TARGETS="bpf" FORMAT=.xz
+
+.. _tar's auto-compress: https://www.gnu.org/software/tar/manual/html_node/gzip.html#auto_002dcompre…
+
Contributing new tests
======================
diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index 2ff68702fd41..1195bd85af38 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -249,10 +249,17 @@ else
$(error Error: set INSTALL_PATH to use install)
endif
+FORMAT ?= .gz
+TAR_PATH = $(abspath ${INSTALL_PATH}/kselftest-packages/kselftest.tar${FORMAT})
+gen_tar: install
+ @mkdir -p ${INSTALL_PATH}/kselftest-packages/
+ @tar caf ${TAR_PATH} --exclude=kselftest-packages -C ${INSTALL_PATH} .
+ @echo "Created ${TAR_PATH}"
+
clean:
@for TARGET in $(TARGETS); do \
BUILD_TARGET=$$BUILD/$$TARGET; \
$(MAKE) OUTPUT=$$BUILD_TARGET -C $$TARGET clean;\
done;
-.PHONY: khdr all run_tests hotplug run_hotplug clean_hotplug run_pstore_crash install clean
+.PHONY: khdr all run_tests hotplug run_hotplug clean_hotplug run_pstore_crash install clean gen_tar
diff --git a/tools/testing/selftests/gen_kselftest_tar.sh b/tools/testing/selftests/gen_kselftest_tar.sh
index 8b2b6088540d..4a974bc03385 100755
--- a/tools/testing/selftests/gen_kselftest_tar.sh
+++ b/tools/testing/selftests/gen_kselftest_tar.sh
@@ -49,6 +49,11 @@ main()
# directory
./kselftest_install.sh "$install_dir"
(cd "$install_work"; tar $copts "$dest"/kselftest${ext} $install_name)
+
+ # Don't put the message at the actual end as people may be parsing the
+ # "archive created" line in their scripts.
+ echo -e "\nConsider using 'make gen_tar' instead of this script\n"
+
echo "Kselftest archive kselftest${ext} created!"
# clean up top-level install work directory
--
2.25.1
The test driver uses an xa_array to store virtual to physical address
translations for a simulated hardware device. The MMU notifier
invalidation callback is used to keep the table consistent with the CPU
page table and is frequently called only for a page or two. However, if
the test process exits unexpectedly or is killed, the range can be
[0..ULONG_MAX] in which case calling xa_erase() for every possible PFN
results in CPU timeouts.
Use xa_for_each_range() to efficiently erase entries in the range.
Signed-off-by: Ralph Campbell <rcampbell(a)nvidia.com>
---
This patch is based on Jason Gunthorpe's hmm tree and should be folded
into the ("mm/hmm/test: add selftest driver for HMM") patch once this
patch is reviewed, etc.
v1 -> v2:
Use xa_for_each_range() instead of special casing [0..ULONG_MAX].
lib/test_hmm.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/lib/test_hmm.c b/lib/test_hmm.c
index 8b36c26b717b..5c1858e325ba 100644
--- a/lib/test_hmm.c
+++ b/lib/test_hmm.c
@@ -196,13 +196,15 @@ static void dmirror_do_update(struct dmirror *dmirror, unsigned long start,
unsigned long end)
{
unsigned long pfn;
+ void *entry;
/*
* The XArray doesn't hold references to pages since it relies on
* the mmu notifier to clear page pointers when they become stale.
* Therefore, it is OK to just clear the entry.
*/
- for (pfn = start >> PAGE_SHIFT; pfn < (end >> PAGE_SHIFT); pfn++)
+ xa_for_each_range(&dmirror->pt, pfn, entry, start >> PAGE_SHIFT,
+ end >> PAGE_SHIFT)
xa_erase(&dmirror->pt, pfn);
}
--
2.20.1
Here's a couple of tiny fixes, just so we can cleanly build
selftests/vm. These apply to today's linux.git. Some merge notes:
* The .gitignore fix is appropriate for linux.git, but it is a subset of
what's required for linux-next and mmotm. In order to fix things now
in linux.git, and keep it fixed in mmotm and linux-next, but without
manual intervention required in git merges, I'm adding the missing
item ("mremap_dontunmap") to the *top* of .gitignore for this patch.
And then I'll send a separate patch to be applied to mmotm and
linux-next, that will also add a different item ("khugepaged") to the
*bottom* of .gitignore.
* The write_to_hugetlbfs.c fix is already applied to linux-next, but
doesn't seem to be getting picked up for linux.git. Maybe it's in
the merge pipeline, but if not, let's fix it here, before the -rc
cycle is over.
John Hubbard (2):
selftests/vm/write_to_hugetlbfs.c: fix unused variable warning
selftests/vm/.gitignore: add mremap_dontunmap
tools/testing/selftests/vm/.gitignore | 1 +
tools/testing/selftests/vm/write_to_hugetlbfs.c | 2 --
2 files changed, 1 insertion(+), 2 deletions(-)
base-commit: 3d1c1e5931ce45b3a3f309385bbc00c78e9951c6
--
2.26.2