kernel/linux.git/tools/testing/selftests/resctrl/resctrlfs.c, branch v6.12.80

selftests/resctrl: Protect against array overflow when reading strings

2024-12-14T19:03:41+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: Remove test name comparing from write_bm_pid_to_resctrl()

2024-07-11T17:23:54+00:00

write_bm_pid_to_resctrl() uses resctrl_val to check test name which is not a good interface generic resctrl FS functions should provide. Tests define mongrp when needed. Remove the test name check in write_bm_pid_to_resctrl() to only rely on the mongrp parameter being non-NULL. Remove write_bm_pid_to_resctrl() resctrl_val parameter and resctrl_val member from the struct resctrl_val_param that are not used anymore. Similarly, remove the test name constants that are no longer used. Signed-off-by: Ilpo Järvinen Tested-by: Babu Moger Reviewed-by: Reinette Chatre Signed-off-by: Shuah Khan

selftests/resctrl: Convert ctrlgrp & mongrp to pointers

2024-07-11T17:23:54+00:00

The struct resctrl_val_param has control and monitor groups as char arrays but they are not supposed to be mutated within resctrl_val(). Convert the ctrlgrp and mongrp char array within resctrl_val_param to plain const char pointers and adjust the strlen() based checks to check NULL instead. Signed-off-by: Ilpo Järvinen Tested-by: Babu Moger Reviewed-by: Reinette Chatre Signed-off-by: Shuah Khan

selftests/resctrl: Make some strings passed to resctrlfs functions const

2024-07-11T17:23:54+00:00

Control group, monitor group and resctrl_val are not mutated and should not be mutated within resctrlfs.c functions. Mark this by using const char * for the arguments. Signed-off-by: Ilpo Järvinen Tested-by: Babu Moger Reviewed-by: Reinette Chatre Signed-off-by: Shuah Khan

selftests/resctrl: Simplify bandwidth report type handling

2024-07-11T17:23:54+00:00

bw_report is only needed for selecting the correct value from the values IMC measured. It is a member in the resctrl_val_param struct and is always set to "reads". The value is then checked in resctrl_val() using validate_bw_report_request() that besides validating the input, assumes it can mutate the string which is questionable programming practice. Simplify handling bw_report: - Convert validate_bw_report_request() into get_bw_report_type() that inputs and returns const char *. Use NULL to indicate error. - Validate the report types inside measure_mem_bw(), not in resctrl_val(). - Pass bw_report to measure_mem_bw() from ->measure() hook because resctrl_val() no longer needs bw_report for anything. Signed-off-by: Ilpo Järvinen Tested-by: Babu Moger Reviewed-by: Reinette Chatre Signed-off-by: Shuah Khan

selftests/resctrl: Use correct type for pids

2024-07-11T17:23:53+00:00

A few functions receive PIDs through int arguments. PIDs variables should be of type pid_t, not int. Convert pid arguments from int to pid_t. Before printing PID, match the type to %d by casting to int which is enough for Linux (standard would allow using a longer integer type but generalizing for that would complicate the code unnecessarily, the selftest code does not need to be portable). Signed-off-by: Ilpo Järvinen Tested-by: Babu Moger Reviewed-by: Reinette Chatre Signed-off-by: Shuah Khan

selftests/resctrl: Make "bandwidth" consistent in comments & prints

2024-07-11T17:23:53+00:00

Resctrl selftests refer to "bandwidth" currently in two other forms in the code ("B/W" and "band width"). Use "bandwidth" consistently everywhere. While at it, fix also one "over flow" -> "overflow" on a line that is touched by the change. Suggested-by: Reinette Chatre Signed-off-by: Ilpo Järvinen Tested-by: Babu Moger Reviewed-by: Reinette Chatre Signed-off-by: Shuah Khan

selftests/resctrl: Add resource_info_file_exists()

2024-02-23T22:19:20+00:00

Feature checking done by resctrl_mon_feature_exists() covers features represented by the feature name presence inside the 'mon_features' file in /sys/fs/resctrl/info/L3_MON directory. There exists a different way to represent feature support and that is by the presence of 0 or 1 in a single file in the info/resource directory. In this case the filename represents what feature support is being indicated. Add a generic function to check file presence in the /sys/fs/resctrl/info/ directory. Signed-off-by: Maciej Wieczor-Retman Reviewed-by: Ilpo Järvinen Reviewed-by: Reinette Chatre Signed-off-by: Shuah Khan

selftests/resctrl: Split validate_resctrl_feature_request()

2024-02-23T22:19:15+00:00

validate_resctrl_feature_request() is used to test both if a resource is present in the info directory, and if a passed monitoring feature is present in the mon_features file. Refactor validate_resctrl_feature_request() into two smaller functions that each accomplish one check to give feature checking more granularity: - Resource directory presence in the /sys/fs/resctrl/info directory. - Feature name presence in the /sys/fs/resctrl/info//mon_features file. Signed-off-by: Maciej Wieczor-Retman Reviewed-by: Ilpo Järvinen Reviewed-by: Reinette Chatre Signed-off-by: Shuah Khan

selftests/resctrl: Add a helper for the non-contiguous test

2024-02-23T22:19:09+00:00

The CAT non-contiguous selftests have to read the file responsible for reporting support of non-contiguous CBMs in kernel (resctrl). Then the test compares if that information matches what is reported by CPUID output. Add a generic helper function to read an unsigned number from /sys/fs/resctrl/info//. Signed-off-by: Maciej Wieczor-Retman Reviewed-by: Ilpo Järvinen Reviewed-by: Reinette Chatre Signed-off-by: Shuah Khan