Re: [PATCH v2 01/11] test_firmware: enable custom fallback testing on limited kernel configs

2018-02-27 Thread Kees Cook 
On Fri, Feb 23, 2018 at 6:46 PM, Luis R. Rodriguez  wrote:
> When a kernel is not built with:
>
> CONFIG_HAS_FW_LOADER_USER_HELPER_FALLBACK=y
>
> We don't currently enable testing fw_fallback.sh. For kernels that
> still enable the fallback mechanism, its possible to use the async
> request firmware API call request_firmware_nowait() using the custom
> interface to use the fallback mechanism, so we should be able to test
> this but we currently cannot.
>
> We can enable testing without CONFIG_HAS_FW_LOADER_USER_HELPER_FALLBACK=y
> by relying on /proc/config.gz (CONFIG_IKCONFIG_PROC), if present. If you
> don't have this we'll have no option but to rely on old heuristics for now.
>
> Signed-off-by: Luis R. Rodriguez 
> ---
>  tools/testing/selftests/firmware/config |  4 +++
>  tools/testing/selftests/firmware/fw_fallback.sh | 45 
> -
>  2 files changed, 48 insertions(+), 1 deletion(-)
>
> diff --git a/tools/testing/selftests/firmware/config 
> b/tools/testing/selftests/firmware/config
> index c8137f70e291..bf634dda0720 100644
> --- a/tools/testing/selftests/firmware/config
> +++ b/tools/testing/selftests/firmware/config
> @@ -1 +1,5 @@
>  CONFIG_TEST_FIRMWARE=y
> +CONFIG_FW_LOADER=y
> +CONFIG_FW_LOADER_USER_HELPER=y
> +CONFIG_IKCONFIG=y
> +CONFIG_IKCONFIG_PROC=y
> diff --git a/tools/testing/selftests/firmware/fw_fallback.sh 
> b/tools/testing/selftests/firmware/fw_fallback.sh
> index 722cad91df74..a42e437363d9 100755
> --- a/tools/testing/selftests/firmware/fw_fallback.sh
> +++ b/tools/testing/selftests/firmware/fw_fallback.sh
> @@ -6,7 +6,46 @@
>  # won't find so that we can do the load ourself manually.
>  set -e
>
> +PROC_CONFIG="/proc/config.gz"
> +TEST_DIR=$(dirname $0)
> +
>  modprobe test_firmware
> +if [ ! -f $PROC_CONFIG ]; then
> +   if modprobe configs 2>/dev/null; then
> +   echo "Loaded configs module"
> +   if [ ! -f $PROC_CONFIG ]; then
> +   echo "You must have the following enabled in your 
> kernel:" >&2
> +   cat $TEST_DIR/config >&2
> +   echo "Resorting to old heuristics" >&2
> +   fi
> +   else
> +   echo "Failed to load configs module, using old heuristics" >&2
> +   fi
> +fi
> +
> +kconfig_has()
> +{
> +   if [ -f $PROC_CONFIG ]; then
> +   if zgrep -q $1 $PROC_CONFIG 2>/dev/null; then
> +   echo "yes"
> +   else
> +   echo "no"
> +   fi
> +   else
> +   # We currently don't have easy heuristics to infer this
> +   # so best we can do is just try to use the kernel assuming
> +   # you had enabled it. This matches the old behaviour.
> +   if [ "$1" = "CONFIG_FW_LOADER_USER_HELPER_FALLBACK=y" ]; then
> +   echo "yes"
> +   elif [ "$1" = "CONFIG_FW_LOADER_USER_HELPER=y" ]; then
> +   if [ -d /sys/class/firmware/ ]; then
> +   echo yes
> +   else
> +   echo no
> +   fi
> +   fi
> +   fi
> +}

Some day when we have more formalized CONFIG-scanning for selftests,
we can probably describe all of this better in a cleaner way. In the
meantime, yeah, this seems fine.

>
>  DIR=/sys/devices/virtual/misc/test_firmware
>
> @@ -14,6 +53,7 @@ DIR=/sys/devices/virtual/misc/test_firmware
>  # These days no one enables CONFIG_FW_LOADER_USER_HELPER so check for that
>  # as an indicator for CONFIG_FW_LOADER_USER_HELPER.
>  HAS_FW_LOADER_USER_HELPER=$(if [ -d /sys/class/firmware/ ]; then echo yes; 
> else echo no; fi)
> +HAS_FW_LOADER_USER_HELPER_FALLBACK=$(kconfig_has 
> CONFIG_FW_LOADER_USER_HELPER_FALLBACK=y)
>
>  if [ "$HAS_FW_LOADER_USER_HELPER" = "yes" ]; then
> OLD_TIMEOUT=$(cat /sys/class/firmware/timeout)
> @@ -286,7 +326,10 @@ run_sysfs_custom_load_tests()
> fi
>  }
>
> -run_sysfs_main_tests
> +if [ "$HAS_FW_LOADER_USER_HELPER_FALLBACK" = "yes" ]; then
> +   run_sysfs_main_tests
> +fi
> +
>  run_sysfs_custom_load_tests
>
>  exit 0
> --
> 2.16.2
>

Acked-by: Kees Cook 

-Kees

-- 
Kees Cook
Pixel Security

Re: [PATCH v2 01/11] test_firmware: enable custom fallback testing on limited kernel configs

2018-02-27 Thread Kees Cook 
On Fri, Feb 23, 2018 at 6:46 PM, Luis R. Rodriguez  wrote:
> When a kernel is not built with:
>
> CONFIG_HAS_FW_LOADER_USER_HELPER_FALLBACK=y
>
> We don't currently enable testing fw_fallback.sh. For kernels that
> still enable the fallback mechanism, its possible to use the async
> request firmware API call request_firmware_nowait() using the custom
> interface to use the fallback mechanism, so we should be able to test
> this but we currently cannot.
>
> We can enable testing without CONFIG_HAS_FW_LOADER_USER_HELPER_FALLBACK=y
> by relying on /proc/config.gz (CONFIG_IKCONFIG_PROC), if present. If you
> don't have this we'll have no option but to rely on old heuristics for now.
>
> Signed-off-by: Luis R. Rodriguez 
> ---
>  tools/testing/selftests/firmware/config |  4 +++
>  tools/testing/selftests/firmware/fw_fallback.sh | 45 
> -
>  2 files changed, 48 insertions(+), 1 deletion(-)
>
> diff --git a/tools/testing/selftests/firmware/config 
> b/tools/testing/selftests/firmware/config
> index c8137f70e291..bf634dda0720 100644
> --- a/tools/testing/selftests/firmware/config
> +++ b/tools/testing/selftests/firmware/config
> @@ -1 +1,5 @@
>  CONFIG_TEST_FIRMWARE=y
> +CONFIG_FW_LOADER=y
> +CONFIG_FW_LOADER_USER_HELPER=y
> +CONFIG_IKCONFIG=y
> +CONFIG_IKCONFIG_PROC=y
> diff --git a/tools/testing/selftests/firmware/fw_fallback.sh 
> b/tools/testing/selftests/firmware/fw_fallback.sh
> index 722cad91df74..a42e437363d9 100755
> --- a/tools/testing/selftests/firmware/fw_fallback.sh
> +++ b/tools/testing/selftests/firmware/fw_fallback.sh
> @@ -6,7 +6,46 @@
>  # won't find so that we can do the load ourself manually.
>  set -e
>
> +PROC_CONFIG="/proc/config.gz"
> +TEST_DIR=$(dirname $0)
> +
>  modprobe test_firmware
> +if [ ! -f $PROC_CONFIG ]; then
> +   if modprobe configs 2>/dev/null; then
> +   echo "Loaded configs module"
> +   if [ ! -f $PROC_CONFIG ]; then
> +   echo "You must have the following enabled in your 
> kernel:" >&2
> +   cat $TEST_DIR/config >&2
> +   echo "Resorting to old heuristics" >&2
> +   fi
> +   else
> +   echo "Failed to load configs module, using old heuristics" >&2
> +   fi
> +fi
> +
> +kconfig_has()
> +{
> +   if [ -f $PROC_CONFIG ]; then
> +   if zgrep -q $1 $PROC_CONFIG 2>/dev/null; then
> +   echo "yes"
> +   else
> +   echo "no"
> +   fi
> +   else
> +   # We currently don't have easy heuristics to infer this
> +   # so best we can do is just try to use the kernel assuming
> +   # you had enabled it. This matches the old behaviour.
> +   if [ "$1" = "CONFIG_FW_LOADER_USER_HELPER_FALLBACK=y" ]; then
> +   echo "yes"
> +   elif [ "$1" = "CONFIG_FW_LOADER_USER_HELPER=y" ]; then
> +   if [ -d /sys/class/firmware/ ]; then
> +   echo yes
> +   else
> +   echo no
> +   fi
> +   fi
> +   fi
> +}

Some day when we have more formalized CONFIG-scanning for selftests,
we can probably describe all of this better in a cleaner way. In the
meantime, yeah, this seems fine.

>
>  DIR=/sys/devices/virtual/misc/test_firmware
>
> @@ -14,6 +53,7 @@ DIR=/sys/devices/virtual/misc/test_firmware
>  # These days no one enables CONFIG_FW_LOADER_USER_HELPER so check for that
>  # as an indicator for CONFIG_FW_LOADER_USER_HELPER.
>  HAS_FW_LOADER_USER_HELPER=$(if [ -d /sys/class/firmware/ ]; then echo yes; 
> else echo no; fi)
> +HAS_FW_LOADER_USER_HELPER_FALLBACK=$(kconfig_has 
> CONFIG_FW_LOADER_USER_HELPER_FALLBACK=y)
>
>  if [ "$HAS_FW_LOADER_USER_HELPER" = "yes" ]; then
> OLD_TIMEOUT=$(cat /sys/class/firmware/timeout)
> @@ -286,7 +326,10 @@ run_sysfs_custom_load_tests()
> fi
>  }
>
> -run_sysfs_main_tests
> +if [ "$HAS_FW_LOADER_USER_HELPER_FALLBACK" = "yes" ]; then
> +   run_sysfs_main_tests
> +fi
> +
>  run_sysfs_custom_load_tests
>
>  exit 0
> --
> 2.16.2
>

Acked-by: Kees Cook 

-Kees

-- 
Kees Cook
Pixel Security

[PATCH v2 01/11] test_firmware: enable custom fallback testing on limited kernel configs

2018-02-23 Thread Luis R. Rodriguez 
When a kernel is not built with:

CONFIG_HAS_FW_LOADER_USER_HELPER_FALLBACK=y

We don't currently enable testing fw_fallback.sh. For kernels that
still enable the fallback mechanism, its possible to use the async
request firmware API call request_firmware_nowait() using the custom
interface to use the fallback mechanism, so we should be able to test
this but we currently cannot.

We can enable testing without CONFIG_HAS_FW_LOADER_USER_HELPER_FALLBACK=y
by relying on /proc/config.gz (CONFIG_IKCONFIG_PROC), if present. If you
don't have this we'll have no option but to rely on old heuristics for now.

Signed-off-by: Luis R. Rodriguez 
---
 tools/testing/selftests/firmware/config |  4 +++
 tools/testing/selftests/firmware/fw_fallback.sh | 45 -
 2 files changed, 48 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/firmware/config 
b/tools/testing/selftests/firmware/config
index c8137f70e291..bf634dda0720 100644
--- a/tools/testing/selftests/firmware/config
+++ b/tools/testing/selftests/firmware/config
@@ -1 +1,5 @@
 CONFIG_TEST_FIRMWARE=y
+CONFIG_FW_LOADER=y
+CONFIG_FW_LOADER_USER_HELPER=y
+CONFIG_IKCONFIG=y
+CONFIG_IKCONFIG_PROC=y
diff --git a/tools/testing/selftests/firmware/fw_fallback.sh 
b/tools/testing/selftests/firmware/fw_fallback.sh
index 722cad91df74..a42e437363d9 100755
--- a/tools/testing/selftests/firmware/fw_fallback.sh
+++ b/tools/testing/selftests/firmware/fw_fallback.sh
@@ -6,7 +6,46 @@
 # won't find so that we can do the load ourself manually.
 set -e
 
+PROC_CONFIG="/proc/config.gz"
+TEST_DIR=$(dirname $0)
+
 modprobe test_firmware
+if [ ! -f $PROC_CONFIG ]; then
+   if modprobe configs 2>/dev/null; then
+   echo "Loaded configs module"
+   if [ ! -f $PROC_CONFIG ]; then
+   echo "You must have the following enabled in your 
kernel:" >&2
+   cat $TEST_DIR/config >&2
+   echo "Resorting to old heuristics" >&2
+   fi
+   else
+   echo "Failed to load configs module, using old heuristics" >&2
+   fi
+fi
+
+kconfig_has()
+{
+   if [ -f $PROC_CONFIG ]; then
+   if zgrep -q $1 $PROC_CONFIG 2>/dev/null; then
+   echo "yes"
+   else
+   echo "no"
+   fi
+   else
+   # We currently don't have easy heuristics to infer this
+   # so best we can do is just try to use the kernel assuming
+   # you had enabled it. This matches the old behaviour.
+   if [ "$1" = "CONFIG_FW_LOADER_USER_HELPER_FALLBACK=y" ]; then
+   echo "yes"
+   elif [ "$1" = "CONFIG_FW_LOADER_USER_HELPER=y" ]; then
+   if [ -d /sys/class/firmware/ ]; then
+   echo yes
+   else
+   echo no
+   fi
+   fi
+   fi
+}
 
 DIR=/sys/devices/virtual/misc/test_firmware
 
@@ -14,6 +53,7 @@ DIR=/sys/devices/virtual/misc/test_firmware
 # These days no one enables CONFIG_FW_LOADER_USER_HELPER so check for that
 # as an indicator for CONFIG_FW_LOADER_USER_HELPER.
 HAS_FW_LOADER_USER_HELPER=$(if [ -d /sys/class/firmware/ ]; then echo yes; 
else echo no; fi)
+HAS_FW_LOADER_USER_HELPER_FALLBACK=$(kconfig_has 
CONFIG_FW_LOADER_USER_HELPER_FALLBACK=y)
 
 if [ "$HAS_FW_LOADER_USER_HELPER" = "yes" ]; then
OLD_TIMEOUT=$(cat /sys/class/firmware/timeout)
@@ -286,7 +326,10 @@ run_sysfs_custom_load_tests()
fi
 }
 
-run_sysfs_main_tests
+if [ "$HAS_FW_LOADER_USER_HELPER_FALLBACK" = "yes" ]; then
+   run_sysfs_main_tests
+fi
+
 run_sysfs_custom_load_tests
 
 exit 0
-- 
2.16.2

[PATCH v2 01/11] test_firmware: enable custom fallback testing on limited kernel configs

2018-02-23 Thread Luis R. Rodriguez 
When a kernel is not built with:

CONFIG_HAS_FW_LOADER_USER_HELPER_FALLBACK=y

We don't currently enable testing fw_fallback.sh. For kernels that
still enable the fallback mechanism, its possible to use the async
request firmware API call request_firmware_nowait() using the custom
interface to use the fallback mechanism, so we should be able to test
this but we currently cannot.

We can enable testing without CONFIG_HAS_FW_LOADER_USER_HELPER_FALLBACK=y
by relying on /proc/config.gz (CONFIG_IKCONFIG_PROC), if present. If you
don't have this we'll have no option but to rely on old heuristics for now.

Signed-off-by: Luis R. Rodriguez 
---
 tools/testing/selftests/firmware/config |  4 +++
 tools/testing/selftests/firmware/fw_fallback.sh | 45 -
 2 files changed, 48 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/firmware/config 
b/tools/testing/selftests/firmware/config
index c8137f70e291..bf634dda0720 100644
--- a/tools/testing/selftests/firmware/config
+++ b/tools/testing/selftests/firmware/config
@@ -1 +1,5 @@
 CONFIG_TEST_FIRMWARE=y
+CONFIG_FW_LOADER=y
+CONFIG_FW_LOADER_USER_HELPER=y
+CONFIG_IKCONFIG=y
+CONFIG_IKCONFIG_PROC=y
diff --git a/tools/testing/selftests/firmware/fw_fallback.sh 
b/tools/testing/selftests/firmware/fw_fallback.sh
index 722cad91df74..a42e437363d9 100755
--- a/tools/testing/selftests/firmware/fw_fallback.sh
+++ b/tools/testing/selftests/firmware/fw_fallback.sh
@@ -6,7 +6,46 @@
 # won't find so that we can do the load ourself manually.
 set -e
 
+PROC_CONFIG="/proc/config.gz"
+TEST_DIR=$(dirname $0)
+
 modprobe test_firmware
+if [ ! -f $PROC_CONFIG ]; then
+   if modprobe configs 2>/dev/null; then
+   echo "Loaded configs module"
+   if [ ! -f $PROC_CONFIG ]; then
+   echo "You must have the following enabled in your 
kernel:" >&2
+   cat $TEST_DIR/config >&2
+   echo "Resorting to old heuristics" >&2
+   fi
+   else
+   echo "Failed to load configs module, using old heuristics" >&2
+   fi
+fi
+
+kconfig_has()
+{
+   if [ -f $PROC_CONFIG ]; then
+   if zgrep -q $1 $PROC_CONFIG 2>/dev/null; then
+   echo "yes"
+   else
+   echo "no"
+   fi
+   else
+   # We currently don't have easy heuristics to infer this
+   # so best we can do is just try to use the kernel assuming
+   # you had enabled it. This matches the old behaviour.
+   if [ "$1" = "CONFIG_FW_LOADER_USER_HELPER_FALLBACK=y" ]; then
+   echo "yes"
+   elif [ "$1" = "CONFIG_FW_LOADER_USER_HELPER=y" ]; then
+   if [ -d /sys/class/firmware/ ]; then
+   echo yes
+   else
+   echo no
+   fi
+   fi
+   fi
+}
 
 DIR=/sys/devices/virtual/misc/test_firmware
 
@@ -14,6 +53,7 @@ DIR=/sys/devices/virtual/misc/test_firmware
 # These days no one enables CONFIG_FW_LOADER_USER_HELPER so check for that
 # as an indicator for CONFIG_FW_LOADER_USER_HELPER.
 HAS_FW_LOADER_USER_HELPER=$(if [ -d /sys/class/firmware/ ]; then echo yes; 
else echo no; fi)
+HAS_FW_LOADER_USER_HELPER_FALLBACK=$(kconfig_has 
CONFIG_FW_LOADER_USER_HELPER_FALLBACK=y)
 
 if [ "$HAS_FW_LOADER_USER_HELPER" = "yes" ]; then
OLD_TIMEOUT=$(cat /sys/class/firmware/timeout)
@@ -286,7 +326,10 @@ run_sysfs_custom_load_tests()
fi
 }
 
-run_sysfs_main_tests
+if [ "$HAS_FW_LOADER_USER_HELPER_FALLBACK" = "yes" ]; then
+   run_sysfs_main_tests
+fi
+
 run_sysfs_custom_load_tests
 
 exit 0
-- 
2.16.2

[PATCH v2 01/11] test_firmware: enable custom fallback testing on limited kernel configs

2018-02-13 Thread Luis R. Rodriguez 
When a kernel is not built with:

CONFIG_HAS_FW_LOADER_USER_HELPER_FALLBACK=y

We don't currently enable testing fw_fallback.sh. For kernels that
still enable the fallback mechanism, its possible to use the async
request firmware API call request_firmware_nowait() using the custom
interface to use the fallback mechanism, so we should be able to test
this but we currently cannot.

We can enable testing without CONFIG_HAS_FW_LOADER_USER_HELPER_FALLBACK=y
by relying on /proc/config.gz (CONFIG_IKCONFIG_PROC), if present. If you
don't have this we'll have no option but to rely on old heuristics for now.

Signed-off-by: Luis R. Rodriguez 
---
 tools/testing/selftests/firmware/config |  4 +++
 tools/testing/selftests/firmware/fw_fallback.sh | 45 -
 2 files changed, 48 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/firmware/config 
b/tools/testing/selftests/firmware/config
index c8137f70e291..bf634dda0720 100644
--- a/tools/testing/selftests/firmware/config
+++ b/tools/testing/selftests/firmware/config
@@ -1 +1,5 @@
 CONFIG_TEST_FIRMWARE=y
+CONFIG_FW_LOADER=y
+CONFIG_FW_LOADER_USER_HELPER=y
+CONFIG_IKCONFIG=y
+CONFIG_IKCONFIG_PROC=y
diff --git a/tools/testing/selftests/firmware/fw_fallback.sh 
b/tools/testing/selftests/firmware/fw_fallback.sh
index 722cad91df74..a42e437363d9 100755
--- a/tools/testing/selftests/firmware/fw_fallback.sh
+++ b/tools/testing/selftests/firmware/fw_fallback.sh
@@ -6,7 +6,46 @@
 # won't find so that we can do the load ourself manually.
 set -e
 
+PROC_CONFIG="/proc/config.gz"
+TEST_DIR=$(dirname $0)
+
 modprobe test_firmware
+if [ ! -f $PROC_CONFIG ]; then
+   if modprobe configs 2>/dev/null; then
+   echo "Loaded configs module"
+   if [ ! -f $PROC_CONFIG ]; then
+   echo "You must have the following enabled in your 
kernel:" >&2
+   cat $TEST_DIR/config >&2
+   echo "Resorting to old heuristics" >&2
+   fi
+   else
+   echo "Failed to load configs module, using old heuristics" >&2
+   fi
+fi
+
+kconfig_has()
+{
+   if [ -f $PROC_CONFIG ]; then
+   if zgrep -q $1 $PROC_CONFIG 2>/dev/null; then
+   echo "yes"
+   else
+   echo "no"
+   fi
+   else
+   # We currently don't have easy heuristics to infer this
+   # so best we can do is just try to use the kernel assuming
+   # you had enabled it. This matches the old behaviour.
+   if [ "$1" = "CONFIG_FW_LOADER_USER_HELPER_FALLBACK=y" ]; then
+   echo "yes"
+   elif [ "$1" = "CONFIG_FW_LOADER_USER_HELPER=y" ]; then
+   if [ -d /sys/class/firmware/ ]; then
+   echo yes
+   else
+   echo no
+   fi
+   fi
+   fi
+}
 
 DIR=/sys/devices/virtual/misc/test_firmware
 
@@ -14,6 +53,7 @@ DIR=/sys/devices/virtual/misc/test_firmware
 # These days no one enables CONFIG_FW_LOADER_USER_HELPER so check for that
 # as an indicator for CONFIG_FW_LOADER_USER_HELPER.
 HAS_FW_LOADER_USER_HELPER=$(if [ -d /sys/class/firmware/ ]; then echo yes; 
else echo no; fi)
+HAS_FW_LOADER_USER_HELPER_FALLBACK=$(kconfig_has 
CONFIG_FW_LOADER_USER_HELPER_FALLBACK=y)
 
 if [ "$HAS_FW_LOADER_USER_HELPER" = "yes" ]; then
OLD_TIMEOUT=$(cat /sys/class/firmware/timeout)
@@ -286,7 +326,10 @@ run_sysfs_custom_load_tests()
fi
 }
 
-run_sysfs_main_tests
+if [ "$HAS_FW_LOADER_USER_HELPER_FALLBACK" = "yes" ]; then
+   run_sysfs_main_tests
+fi
+
 run_sysfs_custom_load_tests
 
 exit 0
-- 
2.16.1

[PATCH v2 01/11] test_firmware: enable custom fallback testing on limited kernel configs

2018-02-13 Thread Luis R. Rodriguez 
When a kernel is not built with:

CONFIG_HAS_FW_LOADER_USER_HELPER_FALLBACK=y

We don't currently enable testing fw_fallback.sh. For kernels that
still enable the fallback mechanism, its possible to use the async
request firmware API call request_firmware_nowait() using the custom
interface to use the fallback mechanism, so we should be able to test
this but we currently cannot.

We can enable testing without CONFIG_HAS_FW_LOADER_USER_HELPER_FALLBACK=y
by relying on /proc/config.gz (CONFIG_IKCONFIG_PROC), if present. If you
don't have this we'll have no option but to rely on old heuristics for now.

Signed-off-by: Luis R. Rodriguez 
---
 tools/testing/selftests/firmware/config |  4 +++
 tools/testing/selftests/firmware/fw_fallback.sh | 45 -
 2 files changed, 48 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/firmware/config 
b/tools/testing/selftests/firmware/config
index c8137f70e291..bf634dda0720 100644
--- a/tools/testing/selftests/firmware/config
+++ b/tools/testing/selftests/firmware/config
@@ -1 +1,5 @@
 CONFIG_TEST_FIRMWARE=y
+CONFIG_FW_LOADER=y
+CONFIG_FW_LOADER_USER_HELPER=y
+CONFIG_IKCONFIG=y
+CONFIG_IKCONFIG_PROC=y
diff --git a/tools/testing/selftests/firmware/fw_fallback.sh 
b/tools/testing/selftests/firmware/fw_fallback.sh
index 722cad91df74..a42e437363d9 100755
--- a/tools/testing/selftests/firmware/fw_fallback.sh
+++ b/tools/testing/selftests/firmware/fw_fallback.sh
@@ -6,7 +6,46 @@
 # won't find so that we can do the load ourself manually.
 set -e
 
+PROC_CONFIG="/proc/config.gz"
+TEST_DIR=$(dirname $0)
+
 modprobe test_firmware
+if [ ! -f $PROC_CONFIG ]; then
+   if modprobe configs 2>/dev/null; then
+   echo "Loaded configs module"
+   if [ ! -f $PROC_CONFIG ]; then
+   echo "You must have the following enabled in your 
kernel:" >&2
+   cat $TEST_DIR/config >&2
+   echo "Resorting to old heuristics" >&2
+   fi
+   else
+   echo "Failed to load configs module, using old heuristics" >&2
+   fi
+fi
+
+kconfig_has()
+{
+   if [ -f $PROC_CONFIG ]; then
+   if zgrep -q $1 $PROC_CONFIG 2>/dev/null; then
+   echo "yes"
+   else
+   echo "no"
+   fi
+   else
+   # We currently don't have easy heuristics to infer this
+   # so best we can do is just try to use the kernel assuming
+   # you had enabled it. This matches the old behaviour.
+   if [ "$1" = "CONFIG_FW_LOADER_USER_HELPER_FALLBACK=y" ]; then
+   echo "yes"
+   elif [ "$1" = "CONFIG_FW_LOADER_USER_HELPER=y" ]; then
+   if [ -d /sys/class/firmware/ ]; then
+   echo yes
+   else
+   echo no
+   fi
+   fi
+   fi
+}
 
 DIR=/sys/devices/virtual/misc/test_firmware
 
@@ -14,6 +53,7 @@ DIR=/sys/devices/virtual/misc/test_firmware
 # These days no one enables CONFIG_FW_LOADER_USER_HELPER so check for that
 # as an indicator for CONFIG_FW_LOADER_USER_HELPER.
 HAS_FW_LOADER_USER_HELPER=$(if [ -d /sys/class/firmware/ ]; then echo yes; 
else echo no; fi)
+HAS_FW_LOADER_USER_HELPER_FALLBACK=$(kconfig_has 
CONFIG_FW_LOADER_USER_HELPER_FALLBACK=y)
 
 if [ "$HAS_FW_LOADER_USER_HELPER" = "yes" ]; then
OLD_TIMEOUT=$(cat /sys/class/firmware/timeout)
@@ -286,7 +326,10 @@ run_sysfs_custom_load_tests()
fi
 }
 
-run_sysfs_main_tests
+if [ "$HAS_FW_LOADER_USER_HELPER_FALLBACK" = "yes" ]; then
+   run_sysfs_main_tests
+fi
+
 run_sysfs_custom_load_tests
 
 exit 0
-- 
2.16.1