Sometimes faccessat needs to modify current thread's credentials, but calls prepare_creds unconditionally. However, typically resulting credentials are identical to original ones and in that case newcredentials are unnecessary. We can detect this before allocating anything. This patch series adds a helper which allows comparing capability sets and modifies faccessat to use it. Mateusz Guzik (2): CAPABILITIES: add cap_isequal helper fs: avoid unnecessary prepare_creds in faccessat fs/open.c | 53 ++++++++++++++++++++++++++++++---------------- include/linux/capability.h | 10 +++++++++ 2 files changed, 45 insertions(+), 18 deletions(-) -- 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html