Assignment of CAP_PERFMON [1] Linux capability to an executable located on a file system requires extended attributes (xattrs) [2] to be supported by the file system. Even if the file system supports xattrs an fs device should be mounted with permission to use xattrs for files located on the device (e.g. without nosuid option [3]). No xattrs support and nosuid mounts are quite common in HPC and Cloud multiuser environments thus applicability of privileged Perf user groups based on file capabilities [4] is limited in that environments. Alternative method to confer Linux capabilities into a process does still exist and it is thru creation of capabilities-enabled-semi-privileged shell environment. Usage of this method to extend privileged Perf user groups approach is documented in this patch set as an extension to perf-security.rst admin guide file. [1] https://man7.org/linux/man-pages/man7/capabilities.7.html [2] https://man7.org/linux/man-pages/man7/xattr.7.html [3] https://man7.org/linux/man-pages/man8/mount.8.html [4] https://www.kernel.org/doc/html/latest/admin-guide/perf-security.html#privileged-perf-users-groups --- Alexey Budankov (2): doc/admin-guide: note credentials consolidation under CAP_PERFMON doc/admin-guide: document creation of CAP_PERFMON privileged shell Documentation/admin-guide/perf-security.rst | 81 ++++++++++++++++++--- 1 file changed, 70 insertions(+), 11 deletions(-) -- 2.24.1
