From: Dave Martin <Dave.Martin@arm.com> To: mtk.manpages@gmail.com Cc: linux-man@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Will Deacon <will@kernel.org>, Catalin Marinas <catalin.marinas@arm.com>, Amit Daniel Kachhap <amit.kachhap@arm.com>, Mark Rutland <mark.rutland@arm.com> Subject: [PATCH 14/14] prctl.2: Add PR_PAC_RESET_KEYS (arm64) Date: Tue, 12 May 2020 17:36:59 +0100 [thread overview] Message-ID: <1589301419-24459-15-git-send-email-Dave.Martin@arm.com> (raw) In-Reply-To: <1589301419-24459-1-git-send-email-Dave.Martin@arm.com> Add documentation for the PR_PAC_RESET_KEYS ioctl added in Linux 5.0 for arm64. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Amit Daniel Kachhap <amit.kachhap@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> --- Note that the comment about PR_PAC_RESET_KEYS(0) being the recommended way to set up a fresh execution context is not present in the existing kernel documentation. I vaguely remember some discussion to this effect; in any case, it seems sensible, given that there must have been _some_ rationale for this feature... Shout if it sounds wrong! --- man2/prctl.2 | 61 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) diff --git a/man2/prctl.2 b/man2/prctl.2 index dd16227..7ea60e2 100644 --- a/man2/prctl.2 +++ b/man2/prctl.2 @@ -950,6 +950,46 @@ behavior. A value of 1 indicates .BR execve (2) will operate in the privilege-restricting mode described above. +.\" prctl PR_PAC_RESET_KEYS +.\" commit ba830885656414101b2f8ca88786524d4bb5e8c1 +.TP +.BR PR_PAC_RESET_KEYS " (since Linux 5.0, only on arm64)" +Securely reset the thread's pointer authentication keys +to fresh random values generated by the kernel. +.IP +The set of keys to be reset is specified by +.IR arg2 , +which must be a logical OR of zero or more of the following: +.RS +.TP +.B PR_PAC_APIAKEY +instruction authentication key A +.TP +.B PR_PAC_APIBKEY +instruction authentication key B +.TP +.B PR_PAC_APDAKEY +data authentication key A +.TP +.B PR_PAC_APDBKEY +data authentication key B +.TP +.B PR_PAC_APGAKEY +generic authentication \(lqA\(rq key. +.IP +(Yes folks, there really is no generic B key.) +.RE +.IP +As a special case, if +.I arg2 +is zero then all the keys are reset. +Since new keys could be added in future, +this is the recommended way to completely wipe the existing keys +when creating a new execution context. +.IP +The remaining arguments +.IR arg3 ", " arg4 " and " arg5 +must all be zero. .\" prctl PR_SET_PDEATHSIG .TP .BR PR_SET_PDEATHSIG " (since Linux 2.1.57)" @@ -1920,6 +1960,27 @@ are not 0. .B EINVAL .I option was +.B PR_PAC_RESET_KEYS +and +.I arg2 +contains non-zero bits other than +.BR +.BR PR_PAC_APIAKEY , +.BR PR_PAC_APIBKEY , +.BR PR_PAC_APDAKEY , +.B PR_PAC_APDBKEY +and +.BR PR_PAC_APGAKEY ; +or +.IR arg3 , +.I arg4 +and +.I arg5 +were not all zero. +.TP +.B EINVAL +.I option +was .B PR_SVE_SET_VL and .I arg2 -- 2.1.4
WARNING: multiple messages have this Message-ID (diff)
From: Dave Martin <Dave.Martin@arm.com> To: mtk.manpages@gmail.com Cc: linux-arch@vger.kernel.org, linux-man@vger.kernel.org, Catalin Marinas <catalin.marinas@arm.com>, Amit Daniel Kachhap <amit.kachhap@arm.com>, Mark Rutland <mark.rutland@arm.com>, Will Deacon <will@kernel.org>, linux-arm-kernel@lists.infradead.org Subject: [PATCH 14/14] prctl.2: Add PR_PAC_RESET_KEYS (arm64) Date: Tue, 12 May 2020 17:36:59 +0100 [thread overview] Message-ID: <1589301419-24459-15-git-send-email-Dave.Martin@arm.com> (raw) In-Reply-To: <1589301419-24459-1-git-send-email-Dave.Martin@arm.com> Add documentation for the PR_PAC_RESET_KEYS ioctl added in Linux 5.0 for arm64. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Amit Daniel Kachhap <amit.kachhap@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> --- Note that the comment about PR_PAC_RESET_KEYS(0) being the recommended way to set up a fresh execution context is not present in the existing kernel documentation. I vaguely remember some discussion to this effect; in any case, it seems sensible, given that there must have been _some_ rationale for this feature... Shout if it sounds wrong! --- man2/prctl.2 | 61 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) diff --git a/man2/prctl.2 b/man2/prctl.2 index dd16227..7ea60e2 100644 --- a/man2/prctl.2 +++ b/man2/prctl.2 @@ -950,6 +950,46 @@ behavior. A value of 1 indicates .BR execve (2) will operate in the privilege-restricting mode described above. +.\" prctl PR_PAC_RESET_KEYS +.\" commit ba830885656414101b2f8ca88786524d4bb5e8c1 +.TP +.BR PR_PAC_RESET_KEYS " (since Linux 5.0, only on arm64)" +Securely reset the thread's pointer authentication keys +to fresh random values generated by the kernel. +.IP +The set of keys to be reset is specified by +.IR arg2 , +which must be a logical OR of zero or more of the following: +.RS +.TP +.B PR_PAC_APIAKEY +instruction authentication key A +.TP +.B PR_PAC_APIBKEY +instruction authentication key B +.TP +.B PR_PAC_APDAKEY +data authentication key A +.TP +.B PR_PAC_APDBKEY +data authentication key B +.TP +.B PR_PAC_APGAKEY +generic authentication \(lqA\(rq key. +.IP +(Yes folks, there really is no generic B key.) +.RE +.IP +As a special case, if +.I arg2 +is zero then all the keys are reset. +Since new keys could be added in future, +this is the recommended way to completely wipe the existing keys +when creating a new execution context. +.IP +The remaining arguments +.IR arg3 ", " arg4 " and " arg5 +must all be zero. .\" prctl PR_SET_PDEATHSIG .TP .BR PR_SET_PDEATHSIG " (since Linux 2.1.57)" @@ -1920,6 +1960,27 @@ are not 0. .B EINVAL .I option was +.B PR_PAC_RESET_KEYS +and +.I arg2 +contains non-zero bits other than +.BR +.BR PR_PAC_APIAKEY , +.BR PR_PAC_APIBKEY , +.BR PR_PAC_APDAKEY , +.B PR_PAC_APDBKEY +and +.BR PR_PAC_APGAKEY ; +or +.IR arg3 , +.I arg4 +and +.I arg5 +were not all zero. +.TP +.B EINVAL +.I option +was .B PR_SVE_SET_VL and .I arg2 -- 2.1.4 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2020-05-12 16:38 UTC|newest] Thread overview: 149+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-05-12 16:36 [PATCH 00/14] prctl.2 man page updates for Linux 5.6 Dave Martin 2020-05-12 16:36 ` Dave Martin 2020-05-12 16:36 ` Dave Martin 2020-05-12 16:36 ` [PATCH 01/14] prctl.2: tfix clarify that prctl can apply to threads Dave Martin 2020-05-12 16:36 ` Dave Martin 2020-05-13 8:30 ` Michael Kerrisk (man-pages) 2020-05-13 8:30 ` Michael Kerrisk (man-pages) 2020-05-13 8:30 ` Michael Kerrisk (man-pages) 2020-05-12 16:36 ` [PATCH 02/14] prctl.2: Add health warning Dave Martin 2020-05-12 16:36 ` Dave Martin 2020-05-12 16:36 ` Dave Martin 2020-05-13 10:10 ` Michael Kerrisk (man-pages) 2020-05-13 10:10 ` Michael Kerrisk (man-pages) 2020-05-13 10:10 ` Michael Kerrisk (man-pages) 2020-05-13 11:13 ` Dave Martin 2020-05-13 11:13 ` Dave Martin 2020-05-13 11:40 ` Michael Kerrisk (man-pages) 2020-05-13 11:40 ` Michael Kerrisk (man-pages) 2020-05-13 11:40 ` Michael Kerrisk (man-pages) 2020-05-13 11:41 ` Dave Martin 2020-05-13 11:41 ` Dave Martin 2020-05-13 11:41 ` Dave Martin 2020-05-12 16:36 ` [PATCH 03/14] prctl.2: tfix mis-description of thread ID values in procfs Dave Martin 2020-05-12 16:36 ` Dave Martin 2020-05-13 8:36 ` Michael Kerrisk (man-pages) 2020-05-13 8:36 ` Michael Kerrisk (man-pages) 2020-05-12 16:36 ` [PATCH 04/14] prctl.2: srcfix add comments for navigation Dave Martin 2020-05-12 16:36 ` Dave Martin 2020-05-13 10:09 ` Michael Kerrisk (man-pages) 2020-05-13 10:09 ` Michael Kerrisk (man-pages) 2020-05-13 10:56 ` Dave Martin 2020-05-13 10:56 ` Dave Martin 2020-05-13 11:03 ` Michael Kerrisk (man-pages) 2020-05-13 11:03 ` Michael Kerrisk (man-pages) 2020-05-13 11:03 ` Michael Kerrisk (man-pages) 2020-05-13 11:15 ` Dave Martin 2020-05-13 11:15 ` Dave Martin 2020-05-13 11:48 ` Michael Kerrisk (man-pages) 2020-05-13 11:48 ` Michael Kerrisk (man-pages) 2020-05-13 11:48 ` Michael Kerrisk (man-pages) 2020-05-13 11:51 ` Dave Martin 2020-05-13 11:51 ` Dave Martin 2020-05-13 11:51 ` Dave Martin 2020-05-12 16:36 ` [PATCH 05/14] prctl.2: tfix listing order of prctls Dave Martin 2020-05-12 16:36 ` Dave Martin 2020-05-12 16:36 ` Dave Martin 2020-05-13 10:10 ` Michael Kerrisk (man-pages) 2020-05-13 10:10 ` Michael Kerrisk (man-pages) 2020-05-13 11:21 ` Dave Martin 2020-05-13 11:21 ` Dave Martin 2020-05-13 11:21 ` Dave Martin 2020-05-13 11:31 ` Michael Kerrisk (man-pages) 2020-05-13 11:31 ` Michael Kerrisk (man-pages) 2020-05-13 11:31 ` Michael Kerrisk (man-pages) 2020-05-13 11:45 ` Dave Martin 2020-05-13 11:45 ` Dave Martin 2020-05-13 11:45 ` Dave Martin 2020-05-12 16:36 ` [PATCH 06/14] prctl.2: ffix quotation mark tweaks Dave Martin 2020-05-12 16:36 ` Dave Martin 2020-05-12 16:36 ` Dave Martin 2020-05-13 10:11 ` Michael Kerrisk (man-pages) 2020-05-13 10:11 ` Michael Kerrisk (man-pages) 2020-05-13 10:11 ` Michael Kerrisk (man-pages) 2020-05-13 11:39 ` Dave Martin 2020-05-13 11:39 ` Dave Martin 2020-05-13 11:39 ` Dave Martin 2020-05-13 11:46 ` Michael Kerrisk (man-pages) 2020-05-13 11:46 ` Michael Kerrisk (man-pages) 2020-05-13 11:51 ` Dave Martin 2020-05-13 11:51 ` Dave Martin 2020-05-13 11:51 ` Dave Martin 2020-05-12 16:36 ` [PATCH 07/14] prctl.2: Document removal of Intel MPX prctls Dave Martin 2020-05-12 16:36 ` Dave Martin 2020-05-12 16:36 ` Dave Martin 2020-05-12 16:41 ` Dave Hansen 2020-05-12 16:41 ` Dave Hansen 2020-05-13 10:11 ` Michael Kerrisk (man-pages) 2020-05-13 10:11 ` Michael Kerrisk (man-pages) 2020-05-13 10:11 ` Michael Kerrisk (man-pages) 2020-05-12 16:36 ` [PATCH 08/14] prctl.2: Work around bogus constant "maxsig" in PR_SET_PDEATHSIG Dave Martin 2020-05-12 16:36 ` Dave Martin 2020-05-13 10:30 ` Michael Kerrisk (man-pages) 2020-05-13 10:30 ` Michael Kerrisk (man-pages) 2020-05-13 10:30 ` Michael Kerrisk (man-pages) 2020-05-12 16:36 ` [PATCH 09/14] prctl.2: tfix minor punctuation in SPECULATION_CTRL prctls Dave Martin 2020-05-12 16:36 ` Dave Martin 2020-05-12 16:36 ` Dave Martin 2020-05-13 10:31 ` Michael Kerrisk (man-pages) 2020-05-13 10:31 ` Michael Kerrisk (man-pages) 2020-05-13 10:31 ` Michael Kerrisk (man-pages) 2020-05-12 16:36 ` [PATCH 10/14] prctl.2: Add PR_SPEC_INDIRECT_BRANCH for " Dave Martin 2020-05-12 16:36 ` Dave Martin 2020-05-12 16:36 ` Dave Martin 2020-05-13 11:21 ` Michael Kerrisk (man-pages) 2020-05-13 11:21 ` Michael Kerrisk (man-pages) 2020-05-13 11:21 ` Michael Kerrisk (man-pages) 2020-05-13 11:49 ` Dave Martin 2020-05-13 11:49 ` Dave Martin 2020-05-13 12:06 ` Michael Kerrisk (man-pages) 2020-05-13 12:06 ` Michael Kerrisk (man-pages) 2020-05-13 12:06 ` Michael Kerrisk (man-pages) 2020-05-13 13:53 ` Dave Martin 2020-05-13 13:53 ` Dave Martin 2020-05-13 13:53 ` Dave Martin 2020-05-12 16:36 ` [PATCH 11/14] prctl.2: Add PR_SPEC_DISABLE_NOEXEC " Dave Martin 2020-05-12 16:36 ` Dave Martin 2020-05-12 16:36 ` [PATCH 12/14] prctl.2: Clarify the unsupported hardware case of EINVAL Dave Martin 2020-05-12 16:36 ` Dave Martin 2020-05-12 16:36 ` Dave Martin 2020-05-13 10:48 ` Michael Kerrisk (man-pages) 2020-05-13 10:48 ` Michael Kerrisk (man-pages) 2020-05-12 16:36 ` [PATCH 13/14] prctl.2: Add SVE prctls (arm64) Dave Martin 2020-05-12 16:36 ` Dave Martin 2020-05-13 8:43 ` Will Deacon 2020-05-13 8:43 ` Will Deacon 2020-05-13 8:43 ` Will Deacon 2020-05-13 10:46 ` Dave Martin 2020-05-13 10:46 ` Dave Martin 2020-05-13 10:46 ` Dave Martin 2020-05-13 11:01 ` Michael Kerrisk (man-pages) 2020-05-13 11:01 ` Michael Kerrisk (man-pages) 2020-05-13 14:02 ` Dave Martin 2020-05-13 14:02 ` Dave Martin 2020-05-13 14:02 ` Dave Martin 2020-05-13 21:11 ` Will Deacon 2020-05-13 21:11 ` Will Deacon 2020-05-13 21:11 ` Will Deacon 2020-05-18 16:37 ` Dave Martin 2020-05-18 16:37 ` Dave Martin 2020-05-26 14:45 ` Dave Martin 2020-05-26 14:45 ` Dave Martin 2020-05-12 16:36 ` Dave Martin [this message] 2020-05-12 16:36 ` [PATCH 14/14] prctl.2: Add PR_PAC_RESET_KEYS (arm64) Dave Martin 2020-05-13 7:25 ` Will Deacon 2020-05-13 7:25 ` Will Deacon 2020-05-13 14:36 ` Dave Martin 2020-05-13 14:36 ` Dave Martin 2020-05-13 14:36 ` Dave Martin 2020-05-13 21:00 ` Will Deacon 2020-05-13 21:00 ` Will Deacon 2020-05-13 21:00 ` Will Deacon 2020-05-18 16:11 ` Dave Martin 2020-05-18 16:11 ` Dave Martin 2020-05-18 16:11 ` Dave Martin 2020-05-18 16:29 ` Will Deacon 2020-05-18 16:29 ` Will Deacon 2020-05-18 16:29 ` Will Deacon 2020-05-13 11:28 ` [PATCH 00/14] prctl.2 man page updates for Linux 5.6 Michael Kerrisk (man-pages) 2020-05-13 11:28 ` Michael Kerrisk (man-pages)
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