Document and fix the MBEDTLS_xxx_ALT logic for the full config

The intended logic around MBEDTLS_xxx_ALT is to exclude them from full
because they require the alternative implementation of one or more
library functions, except that MBEDTLS_PLATFORM_xxx_ALT are different:
they're alternative implementations of a platform function and they
have a built-in default, so they should be included in full. Document
this.

Fix a bug whereby MBEDTLS_PLATFORM_xxx_ALT didn't catch symbols where
xxx contains an underscore. As a consequence,
MBEDTLS_PLATFORM_GMTIME_R_ALT and MBEDTLS_PLATFORM_NV_SEED_ALT are now
enabled in the full config. Explicitly exclude
MBEDTLS_PLATFORM_SETUP_TEARDOWN_ALT because it behaves like the
non-platform ones, requiring an extra build-time dependency.
Explicitly exclude MBEDTLS_PLATFORM_NV_SEED_ALT from baremetal
because it requires MBEDTLS_ENTROPY_NV_SEED, and likewise explicitly
unset it from builds that unset MBEDTLS_ENTROPY_NV_SEED.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
This commit is contained in:
Gilles Peskine 2020-04-28 10:41:20 +02:00
parent d6189e115d
commit df4f7c1274
2 changed files with 11 additions and 2 deletions

View file

@ -104,15 +104,20 @@ MBEDTLS_MEMORY_BACKTRACE
MBEDTLS_MEMORY_BUFFER_ALLOC_C
MBEDTLS_NET_C
MBEDTLS_PLATFORM_FPRINTF_ALT
MBEDTLS_PLATFORM_NV_SEED_ALT
MBEDTLS_PLATFORM_TIME_ALT
MBEDTLS_THREADING_C
MBEDTLS_THREADING_PTHREAD
MBEDTLS_TIMING_C
);
# Things that should be enabled in "full" even if they match @excluded
# Things that should be enabled in "full" even if they match @excluded.
# Platform ALTs enable global variables that allow configuring the behavior
# but default to the default behavior, except for PLATFORM_SETUP_TEARDOWN_ALT
# which requires the application to provide relevant functions like
# non-platform ALTs.
my @non_excluded = qw(
PLATFORM_[A-Z0-9]+_ALT
PLATFORM_(?!SETUP_TEARDOWN_)[A-Z_0-9]+_ALT
);
# Things that should be enabled in "baremetal"

View file

@ -886,6 +886,7 @@ component_test_check_params_without_platform () {
scripts/config.pl unset MBEDTLS_PLATFORM_TIME_ALT
scripts/config.pl unset MBEDTLS_PLATFORM_FPRINTF_ALT
scripts/config.pl unset MBEDTLS_PLATFORM_MEMORY
scripts/config.pl unset MBEDTLS_PLATFORM_NV_SEED_ALT
scripts/config.pl unset MBEDTLS_PLATFORM_PRINTF_ALT
scripts/config.pl unset MBEDTLS_PLATFORM_SNPRINTF_ALT
scripts/config.pl unset MBEDTLS_ENTROPY_NV_SEED
@ -915,6 +916,7 @@ component_test_no_platform () {
scripts/config.pl unset MBEDTLS_PLATFORM_SNPRINTF_ALT
scripts/config.pl unset MBEDTLS_PLATFORM_TIME_ALT
scripts/config.pl unset MBEDTLS_PLATFORM_EXIT_ALT
scripts/config.pl unset MBEDTLS_PLATFORM_NV_SEED_ALT
scripts/config.pl unset MBEDTLS_ENTROPY_NV_SEED
scripts/config.pl unset MBEDTLS_FS_IO
# Note, _DEFAULT_SOURCE needs to be defined for platforms using glibc version >2.19,
@ -929,6 +931,7 @@ component_build_no_std_function () {
scripts/config.pl full
scripts/config.pl set MBEDTLS_PLATFORM_NO_STD_FUNCTIONS
scripts/config.pl unset MBEDTLS_ENTROPY_NV_SEED
scripts/config.pl unset MBEDTLS_PLATFORM_NV_SEED_ALT
make CC=gcc CFLAGS='-Werror -Wall -Wextra -Os'
}
@ -1013,6 +1016,7 @@ component_test_null_entropy () {
scripts/config.pl set MBEDTLS_NO_DEFAULT_ENTROPY_SOURCES
scripts/config.pl set MBEDTLS_ENTROPY_C
scripts/config.pl unset MBEDTLS_ENTROPY_NV_SEED
scripts/config.pl unset MBEDTLS_PLATFORM_NV_SEED_ALT
scripts/config.pl unset MBEDTLS_ENTROPY_HARDWARE_ALT
scripts/config.pl unset MBEDTLS_HAVEGE_C
CC=gcc cmake -D CMAKE_BUILD_TYPE:String=Asan -D UNSAFE_BUILD=ON .