commit ebb12643876810931ed23992f92b7c77c2c36883 Author: Dave Hansen Date: Mon Dec 7 08:42:57 2015 -0800 pkeys diff --git a/man2/mprotect.2 b/man2/mprotect.2 index ae305f6..a3c1e62 100644 --- a/man2/mprotect.2 +++ b/man2/mprotect.2 @@ -38,16 +38,19 @@ .\" .TH MPROTECT 2 2015-07-23 "Linux" "Linux Programmer's Manual" .SH NAME -mprotect \- set protection on a region of memory +mprotect, mprotect_key \- set protection on a region of memory .SH SYNOPSIS .nf .B #include .sp .BI "int mprotect(void *" addr ", size_t " len ", int " prot ); +.BI "int mprotect_key(void *" addr ", size_t " len ", int " prot , " int " key); .fi .SH DESCRIPTION .BR mprotect () -changes protection for the calling process's memory page(s) +and +.BR mprotect_key () +change protection for the calling process's memory page(s) containing any part of the address range in the interval [\fIaddr\fP,\ \fIaddr\fP+\fIlen\fP\-1]. .I addr @@ -74,10 +77,17 @@ The memory can be modified. .TP .B PROT_EXEC The memory can be executed. +.PP +.I key +is the protection or storage key to assign to the memory. +A key must be allocated with pkey_alloc () before it is +passed to pkey_mprotect (). .SH RETURN VALUE On success, .BR mprotect () -returns zero. +and +.BR mprotect_key () +return zero. On error, \-1 is returned, and .I errno is set appropriately. diff --git a/man2/pkey_alloc.2 b/man2/pkey_alloc.2 new file mode 100644 index 0000000..980ce3e --- /dev/null +++ b/man2/pkey_alloc.2 @@ -0,0 +1,72 @@ +.\" Copyright (C) 2007 Michael Kerrisk +.\" and Copyright (C) 1995 Michael Shields . +.\" +.\" %%%LICENSE_START(VERBATIM) +.\" Permission is granted to make and distribute verbatim copies of this +.\" manual provided the copyright notice and this permission notice are +.\" preserved on all copies. +.\" +.\" Permission is granted to copy and distribute modified versions of this +.\" manual under the conditions for verbatim copying, provided that the +.\" entire resulting derived work is distributed under the terms of a +.\" permission notice identical to this one. +.\" +.\" Since the Linux kernel and libraries are constantly changing, this +.\" manual page may be incorrect or out-of-date. The author(s) assume no +.\" responsibility for errors or omissions, or for damages resulting from +.\" the use of the information contained herein. The author(s) may not +.\" have taken the same level of care in the production of this manual, +.\" which is licensed free of charge, as they might when working +.\" professionally. +.\" +.\" Formatted or processed versions of this manual, if unaccompanied by +.\" the source, must acknowledge the copyright and author of this work. +.\" %%%LICENSE_END +.\" +.\" Modified 2015-12-04 by Dave Hansen +.\" +.\" +.TH PKEY_ALLOC 2 2015-12-04 "Linux" "Linux Programmer's Manual" +.SH NAME +pkey_alloc, pkey_free \- allocate or free a protection key +.SH SYNOPSIS +.nf +.B #include +.sp +.BI "int pkey_alloc(unsigned long" flags ", unsigned long " init_val); +.BI "int pkey_free(int " pkey); +.fi +.SH DESCRIPTION +.BR pkey_alloc () +and +.BR pkey_free () +allow or disallow the calling process's to use the given +protection key for all protection-key-related operations. + +.PP +.I flags +is may contain zero or more disable operation: +.B PKEY_DISABLE_ACCESS +and/or +.B PKEY_DISABLE_WRITE +.SH RETURN VALUE +On success, +.BR pkey_alloc () +and +.BR pkey_free () +return zero. +On error, \-1 is returned, and +.I errno +is set appropriately. +.SH ERRORS +.TP +.B EINVAL +An invalid protection key, flag, or init_val was specified. +.TP +.B ENOSPC +All protection keys available for the current process have +been allocated. +.SH SEE ALSO +.BR mprotect_pkey (2), +.BR pkey_get (2), +.BR pkey_set (2), diff --git a/man2/pkey_get.2 b/man2/pkey_get.2 new file mode 100644 index 0000000..4cfdea9 --- /dev/null +++ b/man2/pkey_get.2 @@ -0,0 +1,76 @@ +.\" Copyright (C) 2007 Michael Kerrisk +.\" and Copyright (C) 1995 Michael Shields . +.\" +.\" %%%LICENSE_START(VERBATIM) +.\" Permission is granted to make and distribute verbatim copies of this +.\" manual provided the copyright notice and this permission notice are +.\" preserved on all copies. +.\" +.\" Permission is granted to copy and distribute modified versions of this +.\" manual under the conditions for verbatim copying, provided that the +.\" entire resulting derived work is distributed under the terms of a +.\" permission notice identical to this one. +.\" +.\" Since the Linux kernel and libraries are constantly changing, this +.\" manual page may be incorrect or out-of-date. The author(s) assume no +.\" responsibility for errors or omissions, or for damages resulting from +.\" the use of the information contained herein. The author(s) may not +.\" have taken the same level of care in the production of this manual, +.\" which is licensed free of charge, as they might when working +.\" professionally. +.\" +.\" Formatted or processed versions of this manual, if unaccompanied by +.\" the source, must acknowledge the copyright and author of this work. +.\" %%%LICENSE_END +.\" +.\" Modified 2015-12-04 by Dave Hansen +.\" +.\" +.TH PKEY_GET 2 2015-12-04 "Linux" "Linux Programmer's Manual" +.SH NAME +pkey_get, pkey_set \- manage protection key access permissions +.SH SYNOPSIS +.nf +.B #include +.sp +.BI "int pkey_get(int " pkey); +.BI "int pkey_set(int " pkey ", unsigned long " access_rights); +.fi +.SH DESCRIPTION +.BR pkey_get () +and +.BR pkey_set () +query or set the current set of rights for the calling +task for the given protection key. +When rights for a key are disabled, any future access +to any memory region with that key set will generate +a SIGSEGV. The rights are local to the calling thread and +do not affect any other threads. +.PP +Upon entering any signal handler, the process is given a +default set of protection key rights which are separate from +the main thread's. Any calls to pkey_set () in a signal +will not persist upon a return to the calling process. +.PP +.I access_rights +is may contain zero or more disable operation: +.B PKEY_DISABLE_ACCESS +and/or +.B PKEY_DISABLE_WRITE +.SH RETURN VALUE +On success, +.BR pkey_get () +and +.BR pkey_set () +return zero. +On error, \-1 is returned, and +.I errno +is set appropriately. +.SH ERRORS +.TP +.B EINVAL +An invalid protection key or access_rights was specified. +.SH SEE ALSO +.BR mprotect_pkey (2), +.BR pkey_alloc (2), +.BR pkey_free (2),