kernel/linux.git/tools/testing/selftests/resctrl/resctrl_val.c, branch v6.1.168

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

2024-12-14T18:53:23+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: Allow ->setup() to return errors

2023-05-11T14:03:06+00:00

[ Upstream commit fa10366cc6f4cc862871f8938426d85c2481f084 ] resctrl_val() assumes ->setup() always returns either 0 to continue tests or < 0 in case of the normal termination of tests after x runs. The latter overlaps with normal error returns. Define END_OF_TESTS (=1) to differentiate the normal termination of tests and return errors as negative values. Alter callers of ->setup() to handle errors properly. Fixes: 790bf585b0ee ("selftests/resctrl: Add Cache Allocation Technology (CAT) selftest") Fixes: ecdbb911f22d ("selftests/resctrl: Add MBM test") Signed-off-by: Ilpo Järvinen Reviewed-by: Reinette Chatre Signed-off-by: Shuah Khan Signed-off-by: Sasha Levin

selftests/resctrl: Move ->setup() call outside of test specific branches

2023-05-11T14:03:06+00:00

[ Upstream commit c90b3b588e369c20087699316259fa5ebbb16f2d ] resctrl_val() function is called only by MBM, MBA, and CMT tests which means the else branch is never used. Both test branches call param->setup(). Remove the unused else branch and place the ->setup() call outside of the test specific branches reducing code duplication. Co-developed-by: Fenghua Yu Signed-off-by: Fenghua Yu Signed-off-by: Ilpo Järvinen Reviewed-by: Reinette Chatre Signed-off-by: Shuah Khan Stable-dep-of: fa10366cc6f4 ("selftests/resctrl: Allow ->setup() to return errors") Signed-off-by: Sasha Levin

selftests/resctrl: Kill child process before parent process terminates if SIGTERM is received

2022-04-25T23:06:41+00:00

In kselftest framework, a sub test is run using the timeout utility and it will send SIGTERM to the test upon timeout. In resctrl_tests, a child process is created by fork() to run benchmark but SIGTERM is not set in sigaction(). If SIGTERM signal is received, the parent process will be killed, but the child process still exists. Kill child process before the parent process terminates if SIGTERM signal is received. Reviewed-by: Shuah Khan Reviewed-by: Reinette Chatre Reviewed-by: Fenghua Yu Signed-off-by: Shaopeng Tan Signed-off-by: Shuah Khan

selftests/resctrl: Fix checking for < 0 for unsigned values

2021-04-02T19:58:37+00:00

Dan reported following static checker warnings tools/testing/selftests/resctrl/resctrl_val.c:545 measure_vals() warn: 'bw_imc' unsigned <= 0 tools/testing/selftests/resctrl/resctrl_val.c:549 measure_vals() warn: 'bw_resc_end' unsigned <= 0 These warnings are reported because 1. measure_vals() declares 'bw_imc' and 'bw_resc_end' as unsigned long variables 2. Return value of get_mem_bw_imc() and get_mem_bw_resctrl() are assigned to 'bw_imc' and 'bw_resc_end' respectively 3. The returned values are checked for <= 0 to see if the calls failed Checking for < 0 for an unsigned value doesn't make any sense. Fix this issue by changing the implementation of get_mem_bw_imc() and get_mem_bw_resctrl() such that they now accept reference to a variable and set the variable appropriately upon success and return 0, else return < 0 on error. Reported-by: Dan Carpenter Tested-by: Babu Moger Signed-off-by: Fenghua Yu Signed-off-by: Shuah Khan

selftests/resctrl: Fix incorrect parsing of iMC counters

2021-04-02T19:58:31+00:00

iMC (Integrated Memory Controller) counters are usually at "/sys/bus/event_source/devices/" and are named as "uncore_imc_". num_of_imcs() function tries to count number of such iMC counters so that it could appropriately initialize required number of perf_attr structures that could be used to read these iMC counters. num_of_imcs() function assumes that all the directories under this path that start with "uncore_imc" are iMC counters. But, on some systems there could be directories named as "uncore_imc_free_running" which aren't iMC counters. Trying to read from such directories will result in "not found file" errors and MBM/MBA tests will fail. Hence, fix the logic in num_of_imcs() such that it looks at the first character after "uncore_imc_" to check if it's a numerical digit or not. If it's a digit then the directory represents an iMC counter, else, skip the directory. Reported-by: Reinette Chatre Tested-by: Babu Moger Signed-off-by: Fenghua Yu Signed-off-by: Shuah Khan

selftests/resctrl: Call kselftest APIs to log test results

2021-04-02T19:54:08+00:00

Call kselftest APIs instead of using printf() to log test results for cleaner code and better future extension. Suggested-by: Shuah Khan Tested-by: Babu Moger Signed-off-by: Fenghua Yu Signed-off-by: Shuah Khan

selftests/resctrl: Rename CQM test as CMT test

2021-04-02T19:53:54+00:00

CMT (Cache Monitoring Technology) [1] is a H/W feature that reports cache occupancy of a process. resctrl selftest suite has a unit test to test CMT for LLC but the test is named as CQM (Cache Quality Monitoring). Furthermore, the unit test source file is named as cqm_test.c and several functions, variables, comments, preprocessors and statements widely use "cqm" as either suffix or prefix. This rampant misusage of CQM for CMT might confuse someone who is newly looking at resctrl selftests because this feature is named CMT in the Intel Software Developer's Manual. Hence, rename all the occurrences (unit test source file name, functions, variables, comments and preprocessors) of cqm with cmt. [1] Please see Intel SDM, Volume 3, chapter 17 and section 18 for more information on CMT: https://software.intel.com/content/www/us/en/develop/articles/intel-sdm.html Suggested-by: Reinette Chatre Tested-by: Babu Moger Signed-off-by: Fenghua Yu Signed-off-by: Shuah Khan

selftests/resctrl: Clean up resctrl features check

2021-04-02T19:51:36+00:00

Checking resctrl features call strcmp() to compare feature strings (e.g. "mba", "cat" etc). The checkings are error prone and don't have good coding style. Define the constant strings in macros and call strncmp() to solve the potential issues. Suggested-by: Shuah Khan Tested-by: Babu Moger Signed-off-by: Fenghua Yu Signed-off-by: Shuah Khan

selftests/resctrl: Add Cache QoS Monitoring (CQM) selftest

2020-02-11T01:42:57+00:00

Cache QoS Monitoring (CQM) selftest starts stressful cache benchmark with specified size of memory to access the cache. Last Level cache occupancy reported by CQM should be close to the size of the memory. Co-developed-by: Sai Praneeth Prakhya Signed-off-by: Sai Praneeth Prakhya Co-developed-by: Babu Moger Signed-off-by: Babu Moger Signed-off-by: Fenghua Yu Signed-off-by: Shuah Khan