linux.git/tools/testing/selftests/resctrl/resctrl_val.c, branch v6.6.131

selftests/resctrl: Protect against array overflow when reading strings

2024-12-14T19:00:01+00:00

[ Upstream commit 46058430fc5d39c114f7e1b9c6ff14c9f41bd531 ]

resctrl selftests discover system properties via a variety of sysfs files.
The MBM and MBA tests need to discover the event and umask with which to
configure the performance event used to measure read memory bandwidth.
This is done by parsing the contents of
/sys/bus/event_source/devices/uncore_imc_/events/cas_count_read
Similarly, the resctrl selftests discover the cache size via
/sys/bus/cpu/devices/cpu/cache/index/size.

Take care to do bounds checking when using fscanf() to read the
contents of files into a string buffer because by default fscanf() assumes
arbitrarily long strings. If the file contains more bytes than the array
can accommodate then an overflow will occur.

Provide a maximum field width to the conversion specifier to protect
against array overflow. The maximum is one less than the array size because
string input stores a terminating null byte that is not covered by the
maximum field width.

Signed-off-by: Reinette Chatre 
Reviewed-by: Ilpo Järvinen 
Signed-off-by: Shuah Khan 
Signed-off-by: Sasha Levin

selftests/resctrl: Protect against array overrun during iMC config parsing

2024-12-09T09:31:58+00:00

[ Upstream commit 48ed4e799e8fbebae838dca404a8527763d41191 ]

The MBM and MBA tests need to discover the event and umask with which to
configure the performance event used to measure read memory bandwidth.
This is done by parsing the
/sys/bus/event_source/devices/uncore_imc_/events/cas_count_read
file for each iMC instance that contains the formatted
output: "event=,umask="

Parsing of cas_count_read contents is done by initializing an array of
MAX_TOKENS elements with tokens (deliminated by "=,") from this file.
Remove the unnecessary append of a delimiter to the string needing to be
parsed. Per the strtok() man page: "delimiter bytes at the start or end of
the string are ignored". This has no impact on the token placement within
the array.

After initialization, the actual event and umask is determined by
parsing the tokens directly following the "event" and "umask" tokens
respectively.

Iterating through the array up to index "i < MAX_TOKENS" but then
accessing index "i + 1" risks array overrun during the final iteration.
Avoid array overrun by ensuring that the index used within for
loop will always be valid.

Fixes: 1d3f08687d76 ("selftests/resctrl: Read memory bandwidth from perf IMC counter and from resctrl file system")
Signed-off-by: Reinette Chatre 
Reviewed-by: Ilpo Järvinen 
Signed-off-by: Shuah Khan 
Signed-off-by: Sasha Levin

selftests/resctrl: Fix closing IMC fds on error and open-code R+W instead of loops

2024-08-03T06:53:43+00:00

[ Upstream commit c44000b6535dc9806b9128d1aed403862b2adab9 ]

The imc perf fd close() calls are missing from all error paths. In
addition, get_mem_bw_imc() handles fds in a for loop but close() is
based on two fixed indexes READ and WRITE.

Open code inner for loops to READ+WRITE entries for clarity and add a
function to close() IMC fds properly in all cases.

Fixes: 7f4d257e3a2a ("selftests/resctrl: Add callback to start a benchmark")
Suggested-by: Reinette Chatre 
Signed-off-by: Ilpo Järvinen 
Tested-by: Babu Moger 
Reviewed-by: Reinette Chatre 
Signed-off-by: Shuah Khan 
Signed-off-by: Sasha Levin

selftests/resctrl: Convert perror() to ksft_perror() or ksft_print_msg()

2024-08-03T06:53:43+00:00

[ Upstream commit cc8ff7f5c85c076297b18fb9f6d45ec5569d3d44 ]

The resctrl selftest code contains a number of perror() calls. Some of
them come with hash character and some don't. The kselftest framework
provides ksft_perror() that is compatible with test output formatting
so it should be used instead of adding custom hash signs.

Some perror() calls are too far away from anything that sets error.
For those call sites, ksft_print_msg() must be used instead.

Convert perror() to ksft_perror() or ksft_print_msg().

Other related changes:
- Remove hash signs
- Remove trailing stops & newlines from ksft_perror()
- Add terminating newlines for converted ksft_print_msg()
- Use consistent capitalization
- Small fixes/tweaks to typos & grammar of the messages
- Extract error printing out of PARENT_EXIT() to be able to
  differentiate

Signed-off-by: Ilpo Järvinen 
Reviewed-by: Reinette Chatre 
Signed-off-by: Shuah Khan 
Stable-dep-of: c44000b6535d ("selftests/resctrl: Fix closing IMC fds on error and open-code R+W instead of loops")
Signed-off-by: Sasha Levin

selftests/resctrl: Move run_benchmark() to a more fitting file

2024-08-03T06:53:43+00:00

[ Upstream commit 508934b5d15ab79fd5895cc2a6063bc9d95f6a55 ]

resctrlfs.c contains mostly functions that interact in some way with
resctrl FS entries while functions inside resctrl_val.c deal with
measurements and benchmarking.

run_benchmark() is located in resctrlfs.c even though it's purpose
is not interacting with the resctrl FS but to execute cache checking
logic.

Move run_benchmark() to resctrl_val.c just before resctrl_val() that
makes use of run_benchmark(). Make run_benchmark() static since it's
not used between multiple files anymore.

Remove return comment from kernel-doc since the function is type void.

Signed-off-by: Maciej Wieczor-Retman 
Reviewed-by: Ilpo Järvinen 
Reviewed-by: Reinette Chatre 
Signed-off-by: Shuah Khan 
Stable-dep-of: c44000b6535d ("selftests/resctrl: Fix closing IMC fds on error and open-code R+W instead of loops")
Signed-off-by: Sasha Levin

selftests/resctrl: Extend signal handler coverage to unmount on receiving signal

2023-11-28T17:20:08+00:00

[ Upstream commit 3aff5146445582454c35900f3c0c972987cdd595 ]

Unmounting resctrl FS has been moved into the per test functions in
resctrl_tests.c by commit caddc0fbe495 ("selftests/resctrl: Move
resctrl FS mount/umount to higher level"). In case a signal (SIGINT,
SIGTERM, or SIGHUP) is received, the running selftest is aborted by
ctrlc_handler() which then unmounts resctrl fs before exiting. The
current section between signal_handler_register() and
signal_handler_unregister(), however, does not cover the entire
duration when resctrl FS is mounted.

Move signal_handler_register() and signal_handler_unregister() calls
from per test files into resctrl_tests.c to properly unmount resctrl
fs. In order to not add signal_handler_register()/unregister() n times,
create helpers test_prepare() and test_cleanup().

Do not call ksft_exit_fail_msg() in test_prepare() but only in the per
test function to keep the control flow cleaner without adding calls to
exit() deep into the call chain.

Adjust child process kill() call in ctrlc_handler() to only be invoked
if the child was already forked.

Fixes: caddc0fbe495 ("selftests/resctrl: Move resctrl FS mount/umount to higher level")
Signed-off-by: Ilpo Järvinen 
Tested-by: Shaopeng Tan 
Reviewed-by: Shaopeng Tan 
Reviewed-by: Reinette Chatre 
Cc: 
Signed-off-by: Shuah Khan 
Signed-off-by: Sasha Levin

selftests/resctrl: Make benchmark command const and build it with pointers

2023-11-28T17:20:08+00:00

[ Upstream commit e33cb5702a9f287d829b0e9e6abe57f6a4aba6d2 ]

Benchmark command is used in multiple tests so it should not be
mutated by the tests but CMT test alters span argument. Due to the
order of tests (CMT test runs last), mutating the span argument in CMT
test does not trigger any real problems currently.

Mark benchmark_cmd strings as const and setup the benchmark command
using pointers. Because the benchmark command becomes const, the input
arguments can be used directly. Besides being simpler, using the input
arguments directly also removes the internal size restriction.

CMT test has to create a copy of the benchmark command before altering
the benchmark command.

Signed-off-by: Ilpo Järvinen 
Tested-by: Shaopeng Tan 
Reviewed-by: Shaopeng Tan 
Reviewed-by: Reinette Chatre 
Reviewed-by: "Wieczor-Retman, Maciej" 
Signed-off-by: Shuah Khan 
Stable-dep-of: 3aff51464455 ("selftests/resctrl: Extend signal handler coverage to unmount on receiving signal")
Signed-off-by: Sasha Levin

selftests/resctrl: Fix uninitialized .sa_flags

2023-11-28T17:20:04+00:00

commit beb7f471847663559bd0fe60af1d70e05a1d7c6c upstream.

signal_handler_unregister() calls sigaction() with uninitializing
sa_flags in the struct sigaction.

Make sure sa_flags is always initialized in signal_handler_unregister()
by initializing the struct sigaction when declaring it. Also add the
initialization to signal_handler_register() even if there are no know
bugs in there because correctness is then obvious from the code itself.

Fixes: 73c55fa5ab55 ("selftests/resctrl: Commonize the signal handler register/unregister for all tests")
Suggested-by: Reinette Chatre 
Signed-off-by: Ilpo Järvinen 
Cc: 
Reviewed-by: Reinette Chatre 
Signed-off-by: Shuah Khan 
Signed-off-by: Greg Kroah-Hartman

selftests/resctrl: Don't use variable argument list for ->setup()

2023-07-25T14:53:53+00:00

struct resctrl_val_param has ->setup() function that accepts variable
argument list. All test cases use only 1 argument as input and it's
the struct resctrl_val_param pointer.

Instead of variable argument list, directly pass struct
resctrl_val_param pointer as the only parameter to ->setup().

Co-developed-by: Fenghua Yu 
Signed-off-by: Fenghua Yu 
Signed-off-by: Ilpo Järvinen 
Reviewed-by: Reinette Chatre 
Tested-by: Babu Moger 
Tested-by: Shaopeng Tan (Fujitsu) 
Signed-off-by: Shuah Khan

selftests/resctrl: Move resctrl FS mount/umount to higher level

2023-07-25T14:52:54+00:00

A few places currently lack umounting resctrl FS on error paths:
  - cmt_resctrl_val() has multiple error paths with direct return.
  - cat_perf_miss_val() has multiple error paths with direct return.
In addition, validate_resctrl_feature_request() is called by
run_mbm_test() and run_mba_test(). Neither MBA nor MBM test tries to
umount resctrl FS.

Each and every test does require resctrl FS to be present already for
feature check. Thus, it makes sense to just mount it on higher level in
resctrl_tests.c and properly pair it with umount.

Move resctrl FS (re)mount/unmount into each test function in
resctrl_tests.c. Make feature validation to simply check that resctrl
FS is mounted.

As there's the final umount in main() before this change, the selftest
should not leave resctrl FS behind after the tests even if one of the
forementioned paths is taken (thus, no fixes tag).

Signed-off-by: Ilpo Järvinen 
Tested-by: Babu Moger 
Tested-by: Shaopeng Tan (Fujitsu) 
Signed-off-by: Shuah Khan