Re: [PATCH 5/8] x86, pkeys: allocation/free syscalls
From: Jonathan Corbet <hidden>
Date: 2016-06-01 18:37:10
Also in:
linux-arch, linux-mm, lkml
Sorry, I have one more obnoxious question...
quoted hunk ↗ jump to hunk
+static inline +int mm_pkey_free(struct mm_struct *mm, int pkey) +{ + /* + * pkey 0 is special, always allocated and can never + * be freed. + */ + if (!pkey || !validate_pkey(pkey)) + return -EINVAL; + if (!mm_pkey_is_allocated(mm, pkey)) + return -EINVAL; + + mm_set_pkey_free(mm, pkey); + + return 0; +}
If I read this right, it doesn't actually remove any pkey restrictions that may have been applied while the key was allocated. So there could be pages with that key assigned that might do surprising things if the key is reallocated for another use later, right? Is that how the API is intended to work? Thanks, jon