Lines Matching +full:run +full:- +full:control

1 .. SPDX-License-Identifier: GPL-2.0-or-later
4 DEXCR (Dynamic Execution Control Register)
11 PowerPC ISA 3.1B (Power10) that allows per-cpu control over several dynamic
13 branch target prediction) and enabling return-oriented programming (ROP)
16 The execution control is exposed in hardware as up to 32 bits ('aspects') in
22     A privileged SPR that can control aspects for userspace and kernel space
24     A hypervisor-privileged SPR that can control aspects for the hypervisor and
27     An optional ultravisor-privileged SPR that can control aspects for the ultravisor.
30 provides a non-privileged read-only view of the userspace DEXCR aspects.
31 There is also an SPR that provides a read-only view of the hypervisor enforced
40 -----
42 A process can control its own userspace DEXCR value using the
52 .. flat-table::
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56    * - ``prctl()`` which
57      - Aspect name
58      - Aspect index
60    * - ``PR_PPC_DEXCR_SBHE``
61      - Speculative Branch Hint Enable (SBHE)
62      - 0
64    * - ``PR_PPC_DEXCR_IBRTPD``
65      - Indirect Branch Recurrent Target Prediction Disable (IBRTPD)
66      - 3
68    * - ``PR_PPC_DEXCR_SRAPD``
69      - Subroutine Return Address Prediction Disable (SRAPD)
70      - 4
72    * - ``PR_PPC_DEXCR_NPHIE``
73      - Non-Privileged Hash Instruction Enable (NPHIE)
74      - 5
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80    * - ``prctl()`` ctrl
81      - Meaning
83    * - ``PR_PPC_DEXCR_CTRL_EDITABLE``
84      - This aspect can be configured with PR_PPC_SET_DEXCR (get only)
86    * - ``PR_PPC_DEXCR_CTRL_SET``
87      - This aspect is set / set this aspect
89    * - ``PR_PPC_DEXCR_CTRL_CLEAR``
90      - This aspect is clear / clear this aspect
92    * - ``PR_PPC_DEXCR_CTRL_SET_ONEXEC``
93      - This aspect will be set after exec / set this aspect after exec
95    * - ``PR_PPC_DEXCR_CTRL_CLEAR_ONEXEC``
96      - This aspect will be clear after exec / clear this aspect after exec
106   set, it will be cleared when you run exec, and you can change this with the
124   :manpage:`execve(2)`. The PR_PPC_SET_DEXCR prctl() can control both of these
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138    * - Error
139      - Meaning
141    * - ``EINVAL``
142      - The DEXCR is not supported by the kernel.
144    * - ``ENODEV``
145      - The aspect is not recognised by the kernel or not supported by the
150 .. flat-table::
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154    * - Error
155      - Meaning
157    * - ``EINVAL``
158      - The ctrl value contains unrecognised flags.
160    * - ``EINVAL``
161      - The ctrl value contains mutually conflicting flags (e.g.,
164    * - ``EPERM``
165      - This aspect cannot be modified with prctl() (check for the
168    * - ``EPERM``
169      - The process does not have sufficient privilege to perform the operation.
173 This interface allows a process to control its own DEXCR aspects, and also set
175 child to use an ``*_ONEXEC`` control). This allows fine-grained control over the
176 default value of the DEXCR, for example allowing containers to run with different
186 bits of both registers (corresponding to the non-userspace bits) are masked off.
195 key (potentially all threads from the same parent that have not run ``exec()``).