Commit Graph

9 Commits

Author SHA1 Message Date
David Cunado 18f2efd67d Fully initialise essential control registers
This patch updates the el3_arch_init_common macro so that it fully
initialises essential control registers rather then relying on hardware
to set the reset values.

The context management functions are also updated to fully initialise
the appropriate control registers when initialising the non-secure and
secure context structures and when preparing to leave EL3 for a lower
EL.

This gives better alignement with the ARM ARM which states that software
must initialise RES0 and RES1 fields with 0 / 1.

This patch also corrects the following typos:

"NASCR definitions" -> "NSACR definitions"

Change-Id: Ia8940b8351dc27bc09e2138b011e249655041cfc
Signed-off-by: David Cunado <david.cunado@arm.com>
2017-06-21 17:57:54 +01:00
dp-arm 82cb2c1ad9 Use SPDX license identifiers
To make software license auditing simpler, use SPDX[0] license
identifiers instead of duplicating the license text in every file.

NOTE: Files that have been imported by FreeBSD have not been modified.

[0]: https://spdx.org/

Change-Id: I80a00e1f641b8cc075ca5a95b10607ed9ed8761a
Signed-off-by: dp-arm <dimitris.papastamos@arm.com>
2017-05-03 09:39:28 +01:00
Douglas Raillard 51faada71a Add support for GCC stack protection
Introduce new build option ENABLE_STACK_PROTECTOR. It enables
compilation of all BL images with one of the GCC -fstack-protector-*
options.

A new platform function plat_get_stack_protector_canary() is introduced.
It returns a value that is used to initialize the canary for stack
corruption detection. Returning a random value will prevent an attacker
from predicting the value and greatly increase the effectiveness of the
protection.

A message is printed at the ERROR level when a stack corruption is
detected.

To be effective, the global data must be stored at an address
lower than the base of the stacks. Failure to do so would allow an
attacker to overwrite the canary as part of an attack which would void
the protection.

FVP implementation of plat_get_stack_protector_canary is weak as
there is no real source of entropy on the FVP. It therefore relies on a
timer's value, which could be predictable.

Change-Id: Icaaee96392733b721fa7c86a81d03660d3c1bc06
Signed-off-by: Douglas Raillard <douglas.raillard@arm.com>
2017-03-31 13:58:48 +01:00
danh-arm 1a80e88526 Merge pull request #841 from dp-arm/dp/debug-regs
Disable secure self-hosted debug
2017-02-20 13:58:48 +00:00
dp-arm 85e93ba093 Disable secure self-hosted debug via MDCR_EL3/SDCR
Trusted Firmware currently has no support for secure self-hosted
debug.  To avoid unexpected exceptions, disable software debug
exceptions, other than software breakpoint instruction exceptions,
from all exception levels in secure state.  This applies to both
AArch32 and AArch64 EL3 initialization.

Change-Id: Id097e54a6bbcd0ca6a2be930df5d860d8d09e777
Signed-off-by: dp-arm <dimitris.papastamos@arm.com>
2017-02-15 09:37:33 +00:00
Douglas Raillard 308d359b26 Introduce unified API to zero memory
Introduce zeromem_dczva function on AArch64 that can handle unaligned
addresses and make use of DC ZVA instruction to zero a whole block at a
time. This zeroing takes place directly in the cache to speed it up
without doing external memory access.

Remove the zeromem16 function on AArch64 and replace it with an alias to
zeromem. This zeromem16 function is now deprecated.

Remove the 16-bytes alignment constraint on __BSS_START__ in
firmware-design.md as it is now not mandatory anymore (it used to comply
with zeromem16 requirements).

Change the 16-bytes alignment constraints in SP min's linker script to a
8-bytes alignment constraint as the AArch32 zeromem implementation is now
more efficient on 8-bytes aligned addresses.

Introduce zero_normalmem and zeromem helpers in platform agnostic header
that are implemented this way:
* AArch32:
	* zero_normalmem: zero using usual data access
	* zeromem: alias for zero_normalmem
* AArch64:
	* zero_normalmem: zero normal memory  using DC ZVA instruction
	                  (needs MMU enabled)
	* zeromem: zero using usual data access

Usage guidelines: in most cases, zero_normalmem should be preferred.

There are 2 scenarios where zeromem (or memset) must be used instead:
* Code that must run with MMU disabled (which means all memory is
  considered device memory for data accesses).
* Code that fills device memory with null bytes.

Optionally, the following rule can be applied if performance is
important:
* Code zeroing small areas (few bytes) that are not secrets should use
  memset to take advantage of compiler optimizations.

  Note: Code zeroing security-related critical information should use
  zero_normalmem/zeromem instead of memset to avoid removal by
  compilers' optimizations in some cases or misbehaving versions of GCC.

Fixes ARM-software/tf-issues#408

Change-Id: Iafd9663fc1070413c3e1904e54091cf60effaa82
Signed-off-by: Douglas Raillard <douglas.raillard@arm.com>
2017-02-06 17:01:39 +00:00
Masahiro Yamada 3d8256b2a1 Use #ifdef for IMAGE_BL* instead of #if
One nasty part of ATF is some of boolean macros are always defined
as 1 or 0, and the rest of them are only defined under certain
conditions.

For the former group, "#if FOO" or "#if !FOO" must be used because
"#ifdef FOO" is always true.  (Options passed by $(call add_define,)
are the cases.)

For the latter, "#ifdef FOO" or "#ifndef FOO" should be used because
checking the value of an undefined macro is strange.

Here, IMAGE_BL* is handled by make_helpers/build_macro.mk like
follows:

  $(eval IMAGE := IMAGE_BL$(call uppercase,$(3)))

  $(OBJ): $(2)
          @echo "  CC      $$<"
          $$(Q)$$(CC) $$(TF_CFLAGS) $$(CFLAGS) -D$(IMAGE) -c $$< -o $$@

This means, IMAGE_BL* is defined when building the corresponding
image, but *undefined* for the other images.

So, IMAGE_BL* belongs to the latter group where we should use #ifdef
or #ifndef.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2017-01-24 01:01:21 +09:00
David Cunado 495f3d3c51 Reset debug registers MDCR-EL3/SDCR and MDCR_EL2/HDCR
In order to avoid unexpected traps into EL3/MON mode, this patch
resets the debug registers, MDCR_EL3 and MDCR_EL2 for AArch64,
and SDCR and HDCR for AArch32.

MDCR_EL3/SDCR is zero'ed when EL3/MON mode is entered, at the
start of BL1 and BL31/SMP_MIN.

For MDCR_EL2/HDCR, this patch zero's the bits that are
architecturally UNKNOWN values on reset. This is done when
exiting from EL3/MON mode but only on platforms that support
EL2/HYP mode but choose to exit to EL1/SVC mode.

Fixes ARM-software/tf-issues#430

Change-Id: Idb992232163c072faa08892251b5626ae4c3a5b6
Signed-off-by: David Cunado <david.cunado@arm.com>
2016-11-09 15:45:06 +00:00
Soby Mathew 738b1fd7c0 Rearrange assembly helper macros
This patch moves assembler macros which are not architecture specific
to a new file `asm_macros_common.S` and moves the `el3_common_macros.S`
into `aarch64` specific folder.

Change-Id: I444a1ee3346597bf26a8b827480cd9640b38c826
2016-07-19 10:19:08 +01:00