diff options
| -rw-r--r-- | lib/libsys/x86/pkru.3 | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/lib/libsys/x86/pkru.3 b/lib/libsys/x86/pkru.3 index 06837a39858d..75580953e6ed 100644 --- a/lib/libsys/x86/pkru.3 +++ b/lib/libsys/x86/pkru.3 @@ -71,13 +71,16 @@ Only one key may apply to a given range at a time. The default protection key index is zero, it is used even if no key was explicitly assigned to the address, or if the key was removed. .Pp -The protection prevents the system from accessing user addresses as well -as the user applications. -When a system call was unable to read or write user memory due to key -protection, it returns the -.Er EFAULT -error code. -Note that some side effects may have occurred if this error is reported. +If the user application attempts a memory access which is prohibited by the +PKRU register, the offending thread receives a synchronous +.Dv SIGSEGV +signal with +.Va si_code +set to +.Dv SEGV_PKUERR . +PKRU protections might prevent the kernel from accessing protected +user addresses when handling system calls, but this is not guaranteed and +must not be relied upon. .Pp Both 64-bit and 32-bit applications can use protection keys. More information about the hardware feature is provided in the IA32 Software |