| 3a1b0676 | 19-Jan-2018 |
Dimitris Papastamos <dimitris.papastamos@arm.com> |
Implement support for SMCCC v1.1
SMCCC v1.1 comes with a relaxed calling convention for AArch64
callers. The caller only needs to save x0-x3 before doing an SMC
call.
This patch adds support for S
Implement support for SMCCC v1.1
SMCCC v1.1 comes with a relaxed calling convention for AArch64
callers. The caller only needs to save x0-x3 before doing an SMC
call.
This patch adds support for SMCCC_VERSION and SMCCC_ARCH_FEATURES.
Refer to "Firmware Interfaces for mitigating CVE_2017_5715 System
Software on Arm Systems"[0] for more information.
[0] https://developer.arm.com/-/media/developer/pdf/ARM%20DEN%200070A%20Firmware%20interfaces%20for%20mitigating%20CVE-2017-5715_V1.0.pdf
Change-Id: If5b1c55c17d6c5c7cb9c2c3ed355d3a91cdad0a9
Signed-off-by: Dimitris Papastamos <dimitris.papastamos@arm.com>
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| a1781a21 | 18-Dec-2017 |
Dimitris Papastamos <dimitris.papastamos@arm.com> |
Workaround for CVE-2017-5715 on Cortex A73 and A75
Invalidate the Branch Target Buffer (BTB) on entry to EL3 by
temporarily dropping into AArch32 Secure-EL1 and executing the
`BPIALL` instruction.
Workaround for CVE-2017-5715 on Cortex A73 and A75
Invalidate the Branch Target Buffer (BTB) on entry to EL3 by
temporarily dropping into AArch32 Secure-EL1 and executing the
`BPIALL` instruction.
This is achieved by using 3 vector tables. There is the runtime
vector table which is used to handle exceptions and 2 additional
tables which are required to implement this workaround. The
additional tables are `vbar0` and `vbar1`.
The sequence of events for handling a single exception is
as follows:
1) Install vector table `vbar0` which saves the CPU context on entry
to EL3 and sets up the Secure-EL1 context to execute in AArch32 mode
with the MMU disabled and I$ enabled. This is the default vector table.
2) Before doing an ERET into Secure-EL1, switch vbar to point to
another vector table `vbar1`. This is required to restore EL3 state
when returning from the workaround, before proceeding with normal EL3
exception handling.
3) While in Secure-EL1, the `BPIALL` instruction is executed and an
SMC call back to EL3 is performed.
4) On entry to EL3 from Secure-EL1, the saved context from step 1) is
restored. The vbar is switched to point to `vbar0` in preparation to
handle further exceptions. Finally a branch to the runtime vector
table entry is taken to complete the handling of the original
exception.
This workaround is enabled by default on the affected CPUs.
NOTE
====
There are 4 different stubs in Secure-EL1. Each stub corresponds to
an exception type such as Sync/IRQ/FIQ/SError. Each stub will move a
different value in `R0` before doing an SMC call back into EL3.
Without this piece of information it would not be possible to know
what the original exception type was as we cannot use `ESR_EL3` to
distinguish between IRQs and FIQs.
Change-Id: I90b32d14a3735290b48685d43c70c99daaa4b434
Signed-off-by: Dimitris Papastamos <dimitris.papastamos@arm.com>
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| 155a1006 | 12-Dec-2017 |
Julius Werner <jwerner@chromium.org> |
utils_def: Add REGSZ and make BIT() assembly-compatible
In assembly code it can be useful to have a constant for the width of a
register in the current architecture, so this patch adds one to
<utils
utils_def: Add REGSZ and make BIT() assembly-compatible
In assembly code it can be useful to have a constant for the width of a
register in the current architecture, so this patch adds one to
<utils_def.h> and replaces the existing custom one in crash_reporting.S
with that. It also fixes up the BIT() macro in the same file so that it
can be safely used in assembly code.
Change-Id: I10513a311f3379e767396e6ddfbae8d2d8201464
Signed-off-by: Julius Werner <jwerner@chromium.org>
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| 1a853370 | 20-Oct-2017 |
David Cunado <david.cunado@arm.com> |
Enable SVE for Non-secure world
This patch adds a new build option, ENABLE_SVE_FOR_NS, which when set
to one EL3 will check to see if the Scalable Vector Extension (SVE) is
implemented when entering
Enable SVE for Non-secure world
This patch adds a new build option, ENABLE_SVE_FOR_NS, which when set
to one EL3 will check to see if the Scalable Vector Extension (SVE) is
implemented when entering and exiting the Non-secure world.
If SVE is implemented, EL3 will do the following:
- Entry to Non-secure world: SIMD, FP and SVE functionality is enabled.
- Exit from Non-secure world: SIMD, FP and SVE functionality is
disabled. As SIMD and FP registers are part of the SVE Z-registers
then any use of SIMD / FP functionality would corrupt the SVE
registers.
The build option default is 1. The SVE functionality is only supported
on AArch64 and so the build option is set to zero when the target
archiecture is AArch32.
This build option is not compatible with the CTX_INCLUDE_FPREGS - an
assert will be raised on platforms where SVE is implemented and both
ENABLE_SVE_FOR_NS and CTX_INCLUDE_FPREGS are set to 1.
Also note this change prevents secure world use of FP&SIMD registers on
SVE-enabled platforms. Existing Secure-EL1 Payloads will not work on
such platforms unless ENABLE_SVE_FOR_NS is set to 0.
Additionally, on the first entry into the Non-secure world the SVE
functionality is enabled and the SVE Z-register length is set to the
maximum size allowed by the architecture. This includes the use case
where EL2 is implemented but not used.
Change-Id: Ie2d733ddaba0b9bef1d7c9765503155188fe7dae
Signed-off-by: David Cunado <david.cunado@arm.com>
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| 3d732e23 | 04-Oct-2017 |
Jeenu Viswambharan <jeenu.viswambharan@arm.com> |
BL31: Program Priority Mask for SMC handling
On GICv3 systems, as a side effect of adding provision to handle EL3
interrupts (unconditionally routing FIQs to EL3), pending Non-secure
interrupts (sig
BL31: Program Priority Mask for SMC handling
On GICv3 systems, as a side effect of adding provision to handle EL3
interrupts (unconditionally routing FIQs to EL3), pending Non-secure
interrupts (signalled as FIQs) may preempt execution in lower Secure ELs
[1]. This will inadvertently disrupt the semantics of Fast SMC
(previously called Atomic SMC) calls.
To retain semantics of Fast SMCs, the GIC PMR must be programmed to
prevent Non-secure interrupts from preempting Secure execution. To that
effect, two new functions in the Exception Handling Framework subscribe
to events introduced in an earlier commit:
- Upon 'cm_exited_normal_world', the Non-secure PMR is stashed, and
the PMR is programmed to the highest Non-secure interrupt priority.
- Upon 'cm_entering_normal_world', the previously stashed Non-secure
PMR is restored.
The above sequence however prevents Yielding SMCs from being preempted
by Non-secure interrupts as intended. To facilitate this, the public API
exc_allow_ns_preemption() is introduced that programs the PMR to the
original Non-secure PMR value. Another API
exc_is_ns_preemption_allowed() is also introduced to check if
exc_allow_ns_preemption() had been called previously.
API documentation to follow.
[1] On GICv2 systems, this isn't a problem as, unlike GICv3, pending NS
IRQs during Secure execution are signalled as IRQs, which aren't
routed to EL3.
Change-Id: Ief96b162b0067179b1012332cd991ee1b3051dd0
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>
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