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Even though ERET always causes a jump to another address, aarch64 CPUs
speculatively execute following instructions as if the ERET
instruction was not a jump instruction.
The speculative execution does not cross privilege-levels (to the jump
target as one would expect), but it continues on the kernel privilege
level as if the ERET instruction did not change the control flow -
thus execution anything that is accidentally linked after the ERET
instruction. Later, the results of this speculative execution are
always architecturally discarded, however they can leak data using
microarchitectural side channels. This speculative execution is very
reliable (seems to be unconditional) and it manages to complete even
relatively performance-heavy operations (e.g. multiple dependent
fetches from uncached memory).

This was fixed in Linux, FreeBSD, OpenBSD and Optee OS:
https://github.com/torvalds/linux/commit/679db70801da9fda91d26caf13bf5b5ccc74e8e8
https://github.com/freebsd/freebsd/commit/29fb48ace4186a41c409fde52bcf4216e9e50b61
https://github.com/openbsd/src/commit/3a08873ece1cb28ace89fd65e8f3c1375cc98de2
https://github.com/OP-TEE/optee_os/commit/abfd092aa19f9c0251e3d5551e2d68a9ebcfec8a

It is demonstrated in a SafeSide example:
https://github.com/google/safeside/blob/master/demos/eret_hvc_smc_wrapper.cc
https://github.com/google/safeside/blob/master/kernel_modules/kmod_eret_hvc_smc/eret_hvc_smc_module.c

Signed-off-by: Anthony Steinhauser <asteinhauser@google.com>
Change-Id: Iead39b0b9fb4b8d8b5609daaa8be81497ba63a0f

Some platforms are extremely memory constrained and must split BL31
between multiple non-contiguous areas in SRAM. Allow the NOBITS
sections (.bss, stacks, page tables, and coherent memory) to be placed
in a separate region of RAM from the loaded firmware image.

Because the NOBITS region may be at a lower address than the rest of
BL31, __RW_{START,END}__ and __BL31_{START,END}__ cannot include this
region, or el3_entrypoint_common would attempt to invalidate the dcache
for the entire address space. New symbols __NOBITS_{START,END}__ are
added when SEPARATE_NOBITS_REGION is enabled, and the dcached for the
NOBITS region is invalidated separately.
Signed-off-by: Samuel Holland <samuel@sholland.org>
Change-Id: Idedfec5e4dbee77e94f2fdd356e6ae6f4dc79d37

When a Firmware is complied as Position Independent Executable it needs
to request GDT fixup by passing size of the memory region to
el3_entrypoint_common macro.
The Global descriptor table fixup will be done early on during cold boot
process of primary core.

Currently only BL31 supports PIE, but in future when BL2_AT_EL3 will be
compiled as PIE, it can simply pass fixup size to the common el3
entrypoint macro to fixup GDT.

The reason for this patch was to overcome the bug introduced by SHA
330ead80

 which called fixup routine for each core causing
re-initializing of global pointers thus overwriting any changes
done by the previous core.

Change-Id: I55c792cc3ea9e7eef34c2e4653afd04572c4f055
Signed-off-by: Manish Pandey <manish.pandey2@arm.com>

Check that entry point information requesting S-EL2
has AArch64 as an execution state during context setup.
Signed-off-by: Artsem Artsemenka <artsem.artsemenka@arm.com>
Change-Id: I447263692fed6e55c1b076913e6eb73b1ea735b7

This patch adds support for enabling S-EL2 if this EL is specified in the entry
point information being used to initialise a secure context. It is the caller's
responsibility to check if S-EL2 is available on the system before requesting
this EL through the entry point information.
Signed-off-by: Achin Gupta <achin.gupta@arm.com>
Change-Id: I2752964f078ab528b2e80de71c7d2f35e60569e1

From AArch64 state, arguments are passed in registers W0-W7(X0-X7)
and results are returned in W0-W7(X0-X7) for SMC32(SMC64) calls.
From AArch32 state, arguments are passed in registers R0-R7 and
results are returned in registers R0-R7 for SMC32 calls.

Most of the functions and macros already existed to support using
upto 8 registers for passing/returning parameters/results. Added
few helper macros for SMC calls from AArch32 state.

Link to the specification:
https://developer.arm.com/docs/den0028/c



Change-Id: I87976b42454dc3fc45c8343e9640aa78210e9741
Signed-off-by: Madhukar Pappireddy <madhukar.pappireddy@arm.com>

Currently the MDCR_EL3 initialisation implicitly disables
MDCR_EL3.SPME by using mov_imm.

This patch makes the SPME bit more visible by explicitly
disabling it and documenting its use in different versions
of the architecture.
Signed-off-by: Petre-Ionut Tudor <petre-ionut.tudor@arm.com>
Change-Id: I221fdf314f01622f46ac5aa43388f59fa17a29b3

Add the missing flag for aarch32 XIP memory mode. It was
previously added in aarch64 only.
Minor: Correct the aarch64 missing flag.
Signed-off-by: Lionel Debieve <lionel.debieve@st.com>
Change-Id: Iac0a7581a1fd580aececa75f97deb894858f776f

This patch changes implementation for disabling Secure Cycle
Counter. For ARMv8.5 the counter gets disabled by setting
SDCR.SCCD bit on CPU cold/warm boot. For the earlier
architectures PMCR register is saved/restored on secure
world entry/exit from/to Non-secure state, and cycle counting
gets disabled by setting PMCR.DP bit.
In 'include\aarch32\arch.h' header file new
ARMv8.5-PMU related definitions were added.

Change-Id: Ia8845db2ebe8de940d66dff479225a5b879316f8
Signed-off-by: Alexei Fedorov <Alexei.Fedorov@arm.com>

This patch provides the following features and makes modifications
listed below:
- Individual APIAKey key generation for each CPU.
- New key generation on every BL31 warm boot and TSP CPU On event.
- Per-CPU storage of APIAKey added in percpu_data[]
  of cpu_data structure.
- `plat_init_apiakey()` function replaced with `plat_init_apkey()`
  which returns 128-bit value and uses Generic timer physical counter
  value to increase the randomness of the generated key.
  The new function can be used for generation of all ARMv8.3-PAuth keys
- ARMv8.3-PAuth specific code placed in `lib\extensions\pauth`.
- New `pauth_init_enable_el1()` and `pauth_init_enable_el3()` functions
  generate, program and enable APIAKey_EL1 for EL1 and EL3 respectively;
  pauth_disable_el1()` and `pauth_disable_el3()` functions disable
  PAuth for EL1 and EL3 respectively;
  `pauth_load_bl31_apiakey()` loads saved per-CPU APIAKey_EL1 from
  cpu-data structure.
- Combined `save_gp_pauth_registers()` function replaces calls to
  `save_gp_registers()` and `pauth_context_save()`;
  `restore_gp_pauth_registers()` replaces `pauth_context_restore()`
  and `restore_gp_registers()` calls.
- `restore_gp_registers_eret()` function removed with corresponding
  code placed in `el3_exit()`.
- Fixed the issue when `pauth_t pauth_ctx` structure allocated space
  for 12 uint64_t PAuth registers instead of 10 by removal of macro
  CTX_PACGAKEY_END from `include/lib/el3_runtime/aarch64/context.h`
  and assigning its value to CTX_PAUTH_REGS_END.
- Use of MODE_SP_ELX and MODE_SP_EL0 macro definitions
  in `msr	spsel`  instruction instead of hard-coded values.
- Changes in documentation related to ARMv8.3-PAuth and ARMv8.5-BTI.

Change-Id: Id18b81cc46f52a783a7e6a09b9f149b6ce803211
Signed-off-by: Alexei Fedorov <Alexei.Fedorov@arm.com>

Some of the platform (ie. Agilex) make use of CCU IPs which will only be
initialized during bl2_el3_early_platform_setup. Any operation to the
cache beforehand will crash the platform. Hence, this will provide an
option to skip the data cache invalidation upon bl2 entry at EL3
Signed-off-by: Hadi Asyrafi <muhammad.hadi.asyrafi.abdul.halim@intel.com>
Change-Id: I2c924ed0589a72d0034714c31be8fe57237d1f06

This patch adds support for the Undefined Behaviour sanitizer. There are
two types of support offered - minimalistic trapping support which
essentially immediately crashes on undefined behaviour and full support
with full debug messages.

The full support relies on ubsan.c which has been adapted from code used
by OPTEE.

Change-Id: I417c810f4fc43dcb56db6a6a555bfd0b38440727
Signed-off-by: Justin Chadwell <justin.chadwell@arm.com>

This patch adds support for the new Memory Tagging Extension arriving in
ARMv8.5. MTE support is now enabled by default on systems that support
at EL0. To enable it at ELx for both the non-secure and the secure
world, the compiler flag CTX_INCLUDE_MTE_REGS includes register saving
and restoring when necessary in order to prevent register leakage
between the worlds.

Change-Id: I2d4ea993d6b11654ea0d4757d00ca20d23acf36c
Signed-off-by: Justin Chadwell <justin.chadwell@arm.com>

This patch fixes an issue when secure world timing information
can be leaked because Secure Cycle Counter is not disabled.
For ARMv8.5 the counter gets disabled by setting MDCR_El3.SCCD
bit on CPU cold/warm boot.
For the earlier architectures PMCR_EL0 register is saved/restored
on secure world entry/exit from/to Non-secure state, and cycle
counting gets disabled by setting PMCR_EL0.DP bit.
'include\aarch64\arch.h' header file was tided up and new
ARMv8.5-PMU related definitions were added.

Change-Id: I6f56db6bc77504634a352388990ad925a69ebbfa
Signed-off-by: Alexei Fedorov <Alexei.Fedorov@arm.com>

This patch fixes FVP_Base_AEMv8A model hang issue with
ARMv8.4+ with cache modelling enabled configuration.
Incorrect L1 cache flush operation to PoU, using CLIDR_EL1
LoUIS field, which is required by the architecture to be
zero for ARMv8.4-A with ARMv8.4-S2FWB feature is replaced
with L1 to L2 and L2 to L3 (if L3 is present) cache flushes.
FVP_Base_AEMv8A model can be configured with L3 enabled by
setting `cluster0.l3cache-size` and `cluster1.l3cache-size`
to non-zero values, and presence of L3 is checked in
`aem_generic_core_pwr_dwn` function by reading
CLIDR_EL1.Ctype3 field value.

Change-Id: If3de3d4eb5ed409e5b4ccdbc2fe6d5a01894a9af
Signed-off-by: Alexei Fedorov <Alexei.Fedorov@arm.com>

NOTE: __ASSEMBLY__ macro is now deprecated in favor of __ASSEMBLER__.

All common C compilers predefine a macro called __ASSEMBLER__ when
preprocessing a .S file. There is no reason for TF-A to define it's own
__ASSEMBLY__ macro for this purpose instead. To unify code with the
export headers (which use __ASSEMBLER__ to avoid one extra dependency),
let's deprecate __ASSEMBLY__ and switch the code base over to the
predefined standard.

Change-Id: Id7d0ec8cf330195da80499c68562b65cb5ab7417
Signed-off-by: Julius Werner <jwerner@chromium.org>

This patch introduces an additional precautionary step to further
enhance protection against variant 4. During the context initialisation
before we enter the various BL stages, the SPSR.SSBS bit is explicitly
set to zero. As such, speculative loads/stores are by default disabled
for all BL stages when they start executing. Subsequently, each BL
stage, can choose to enable speculative loads/stores or keep them
disabled.

This change doesn't affect the initial execution context of BL33 which
is totally platform dependent and, thus, it is intentionally left up to
each platform to initialise.

For Arm platforms, SPSR.SSBS is set to zero for BL33 too. This means
that, for Arm platforms, all BL stages start with speculative
loads/stores disabled.

Change-Id: Ie47d39c391d3f20fc2852fc59dbd336f8cacdd6c
Signed-off-by: John Tsichritzis <john.tsichritzis@arm.com>

Update the skeleton implementation of the console interface.

The 32 bit version was outdated and has been copied from the 64 bit
version.

Change-Id: Ib3e4eb09402ffccb1a30c703a53829a7bf064dfe
Signed-off-by: Ambroise Vincent <ambroise.vincent@arm.com>

This patch enables MTE for Normal world if the CPU suppors it. Enabling
MTE for secure world will be done later.

Change-Id: I9ef64460beaba15e9a9c20ab02da4fb2208b6f7d
Signed-off-by: Soby Mathew <soby.mathew@arm.com>

This patch removes incorrect SCTLR_V_BIT definition and adds
definitions for ARMv8.3-Pauth EnIB, EnDA and EnDB bits.

Change-Id: I1384c0a01f56f3d945833464a827036252c75c2e
Signed-off-by: Alexei Fedorov <Alexei.Fedorov@arm.com>

Those defines are used in STM32MP1 clock driver.
It is better to put them altogether with already defined registers.

Change-Id: I6f8ad8c2477b947af6f76283a4ef5c40212d0027
Signed-off-by: Yann Gautier <yann.gautier@st.com>

This patch adds the functionality needed for platforms to provide
Branch Target Identification (BTI) extension, introduced to AArch64
in Armv8.5-A by adding BTI instruction used to mark valid targets
for indirect branches. The patch sets new GP bit [50] to the stage 1
Translation Table Block and Page entries to denote guarded EL3 code
pages which will cause processor to trap instructions in protected
pages trying to perform an indirect branch to any instruction other
than BTI.
BTI feature is selected by BRANCH_PROTECTION option which supersedes
the previous ENABLE_PAUTH used for Armv8.3-A Pointer Authentication
and is disabled by default. Enabling BTI requires compiler support
and was tested with GCC versions 9.0.0, 9.0.1 and 10.0.0.
The assembly macros and helpers are modified to accommodate the BTI
instruction.
This is an experimental feature.
Note. The previous ENABLE_PAUTH build option to enable PAuth in EL3
is now made as an internal flag and BRANCH_PROTECTION flag should be
used instead to enable Pointer Authentication.
Note. USE_LIBROM=1 option is currently not supported.

Change-Id: Ifaf4438609b16647dc79468b70cd1f47a623362e
Signed-off-by: Alexei Fedorov <Alexei.Fedorov@arm.com>

The workaround for Cortex-A76 errata #1286807 is implemented
in this patch.

Change-Id: I6c15af962ac99ce223e009f6d299cefb41043bed
Signed-off-by: Soby Mathew <soby.mathew@arm.com>

ARMv7 and Cortex-A32(ARMv8/aarch32) uses "arm-linux-gnueabi" toolchain which
has both soft-float and hard-float variants and so there could be scenarios
where soft-float toolchain is used.Even though TF-A documentation recommends
to use hard-float toolchain for aarch32 but there are external projects where
we cannot mandate the selection of toolchain and for those projects at least
the build should not fail.

Current TF-A source fails to build with soft-float toolchain because assembler
does not recognizes "vmsr" instruction which is required to enable floating
point unit.

To avoid this piece of code being compiled with soft-float toolchain add
predefined macro guard " __SOFTFP__" exposed by soft-float toolchain.

Change-Id: I76ba40906a8d622dcd476dd36ab4d277a925996c
Signed-off-by: Manish Pandey <manish.pandey2@arm.com>

Change-Id: I14fcabbdfd53153d1d5f187f6f8b23a045794408
Signed-off-by: Ambroise Vincent <ambroise.vincent@arm.com>

The old version of the macro is deprecated.

Commit cc5859ca

 ("Multi-console: Deprecate the
`finish_console_register` macro") provides more details.

Change-Id: I3d1cdf6496db7d8e6cfbb5804f508ff46ae7e67e
Signed-off-by: Ambroise Vincent <ambroise.vincent@arm.com>

This gives each Secure Partition complete freedom on its address space.
Previously, the memory used by the exception vectors was reserved and
couldn't be used. Also, it always had to be mapped, forcing SPM to
generate translation tables that included the exception vectors as well
as the Partition memory regions. With this change, partitions can reduce
their address space size easily.

Change-Id: I67fb5e9bdf2870b73347f23bff702fab0a8f8711
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

This patch applies the new MSR instruction to directly set the
PSTATE.SSBS bit which controls speculative loads. This new instruction
is available at Neoverse N1 core so it's utilised.

Change-Id: Iee18a8b042c90fdb72d2b98f364dcfbb17510728
Signed-off-by: John Tsichritzis <john.tsichritzis@arm.com>

SSBS support is determined by checking ID_AA64PFR1_EL1 and not
ID_AA64PFR0_EL1.

Fixes ARM-Software/tf-issues#679

Change-Id: I8ecba13b850995ec6a6ede3c2a1e02e69a3a95db
Signed-off-by: Dimitris Papastamos <dimitris.papastamos@arm.com>

Check for both IMPLEMENTATION_DEFINED and Architected algorithms of
Address Authentication.

Change-Id: I209dcc6087172cfef7baf8d09e0454628f02cbd0
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

Complete the MPAM enablement in TF-A for lower ELs by enabling the EL2
traps in MPAMHCR_EL2 and MPAM2_EL2.This prevents an
MPAM-unaware-hypervisor to be restricted by an MPAM-aware-guest.

Change-Id: I47bf3f833fa22baa590f83d49cc0e3f2974e698d
Signed-off-by: Louis Mayencourt <louis.mayencourt@arm.com>

The workarounds for these errata are so closely related that it is
better to only have one patch to make it easier to understand.

Change-Id: I0287fa69aefa8b72f884833f6ed0e7775ca834e9
Signed-off-by: Ambroise Vincent <ambroise.vincent@arm.com>

The previous commit added the infrastructure to load and save
ARMv8.3-PAuth registers during Non-secure <-> Secure world switches, but
didn't actually enable pointer authentication in the firmware.

This patch adds the functionality needed for platforms to provide
authentication keys for the firmware, and a new option (ENABLE_PAUTH) to
enable pointer authentication in the firmware itself. This option is
disabled by default, and it requires CTX_INCLUDE_PAUTH_REGS to be
enabled.

Change-Id: I35127ec271e1198d43209044de39fa712ef202a5
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

ARMv8.3-PAuth adds functionality that supports address authentication of
the contents of a register before that register is used as the target of
an indirect branch, or as a load.

This feature is supported only in AArch64 state.

This feature is mandatory in ARMv8.3 implementations.

This feature adds several registers to EL1. A new option called
CTX_INCLUDE_PAUTH_REGS has been added to select if the TF needs to save
them during Non-secure <-> Secure world switches. This option must be
enabled if the hardware has the registers or the values will be leaked
during world switches.

To prevent leaks, this patch also disables pointer authentication in the
Secure world if CTX_INCLUDE_PAUTH_REGS is 0. Any attempt to use it will
be trapped in EL3.

Change-Id: I27beba9907b9a86c6df1d0c5bf6180c972830855
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

Implicit Error Synchronization Barrier (IESB) might not be correctly
generated in Cortex-A75 r0p0. To prevent this, IESB are enabled at all
expection levels.

Change-Id: I2a1a568668a31e4f3f38d0fba1d632ad9939e5ad
Signed-off-by: Louis Mayencourt <louis.mayencourt@arm.com>

Cortex A5 doesnt support VFP, Large Page addressing and generic timer
which are addressed in this patch. The device tree for Cortex a5
is also included.

Change-Id: I0722345721b145dfcc80bebd36a1afbdc44bb678
Signed-off-by: Usama Arif <usama.arif@arm.com>

Cortex a5 doesnt support hardware division such as sdiv and udiv commands.
This commit adds a software division function in assembly as well as include
appropriate files for software divison.

The software division algorithm is a modified version obtained from:
http://www.keil.com/support/man/docs/armasm/armasm_dom1359731155623.htm



Change-Id: Ib405a330da5f1cea1e68e07e7b520edeef9e2652
Signed-off-by: Usama Arif <usama.arif@arm.com>

In a system with ARMv8.5-PMU implemented:

- If EL3 is using AArch32, setting MDCR_EL3.SCCD to 1 disables counting
  in Secure state in PMCCNTR.

- If EL3 is using AArch64, setting SDCR.SCCD to 1 disables counting in
  Secure state in PMCCNTR_EL0.

So far this effect has been achieved by setting PMCR_EL0.DP (in AArch64)
or PMCR.DP (in AArch32) to 1 instead, but this isn't considered secure
as any EL can change that value.

Change-Id: I82cbb3e48f2e5a55c44d9c4445683c5881ef1f6f
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

Now that setjmp() and longjmp() are compliant with the standard they can
be moved with the other libc files.

Change-Id: Iea3b91c34eb353ace5e171e72f331602d57774d5
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

Instead of having a custom implementation of setjmp() and longjmp() it
is better to follow the C standard.

The comments in setjmp.h are no longer needed as there are no deviations
from the expected one, so they have been removed.

All SDEI code that relied on them has been fixed to use the new function
prototypes and structs.

Change-Id: I6cd2e21cb5a5bcf81ba12283f2e4c067bd5172ca
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>