[PATCH] efi_loader: fix FinalEvent table initial position
When initializing the final event table in create_final_event() we are setting the initial buffer position to sizeof(*final_event). Although we clear the buffer correctly and won't cause any problems, we should start logging events starting from zero. While at it add a cast when defining the final_event.
Signed-off-by: Ilias Apalodimas ilias.apalodimas@linaro.org --- lib/efi_loader/efi_tcg2.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/lib/efi_loader/efi_tcg2.c b/lib/efi_loader/efi_tcg2.c index 189e4a5ba59c..634556342a7c 100644 --- a/lib/efi_loader/efi_tcg2.c +++ b/lib/efi_loader/efi_tcg2.c @@ -1257,10 +1257,11 @@ static efi_status_t create_final_event(void) goto out;
memset(event_log.final_buffer, 0xff, TPM2_EVENT_LOG_SIZE); - final_event = event_log.final_buffer; + final_event = + (struct efi_tcg2_final_events_table *)event_log.final_buffer; final_event->number_of_events = 0; final_event->version = EFI_TCG2_FINAL_EVENTS_TABLE_VERSION; - event_log.final_pos = sizeof(*final_event); + event_log.final_pos = 0; ret = efi_install_configuration_table(&efi_guid_final_events, final_event); if (ret != EFI_SUCCESS) {
Hi Heinrich,
On Wed, 17 Nov 2021 at 01:24, Ilias Apalodimas ilias.apalodimas@linaro.org wrote:
When initializing the final event table in create_final_event() we are setting the initial buffer position to sizeof(*final_event). Although we clear the buffer correctly and won't cause any problems, we should start logging events starting from zero. While at it add a cast when defining the final_event.
Signed-off-by: Ilias Apalodimas ilias.apalodimas@linaro.org
lib/efi_loader/efi_tcg2.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/lib/efi_loader/efi_tcg2.c b/lib/efi_loader/efi_tcg2.c index 189e4a5ba59c..634556342a7c 100644 --- a/lib/efi_loader/efi_tcg2.c +++ b/lib/efi_loader/efi_tcg2.c @@ -1257,10 +1257,11 @@ static efi_status_t create_final_event(void) goto out;
memset(event_log.final_buffer, 0xff, TPM2_EVENT_LOG_SIZE);
final_event = event_log.final_buffer;
final_event =(struct efi_tcg2_final_events_table *)event_log.final_buffer; final_event->number_of_events = 0; final_event->version = EFI_TCG2_FINAL_EVENTS_TABLE_VERSION;
event_log.final_pos = sizeof(*final_event);
event_log.final_pos = 0; ret = efi_install_configuration_table(&efi_guid_final_events, final_event); if (ret != EFI_SUCCESS) {-- 2.33.1
After sending this I just realized it's wrong. The current code is correct, since we have to account for the number of events and version
Sorry for the noise
Cheers /Ilias
On 11/17/21 00:24, Ilias Apalodimas wrote:
When initializing the final event table in create_final_event() we are setting the initial buffer position to sizeof(*final_event). Although we clear the buffer correctly and won't cause any problems, we should start logging events starting from zero. While at it add a cast when defining the final_event.
Signed-off-by: Ilias Apalodimas ilias.apalodimas@linaro.org
lib/efi_loader/efi_tcg2.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/lib/efi_loader/efi_tcg2.c b/lib/efi_loader/efi_tcg2.c index 189e4a5ba59c..634556342a7c 100644 --- a/lib/efi_loader/efi_tcg2.c +++ b/lib/efi_loader/efi_tcg2.c @@ -1257,10 +1257,11 @@ static efi_status_t create_final_event(void) goto out;
memset(event_log.final_buffer, 0xff, TPM2_EVENT_LOG_SIZE);
- final_event = event_log.final_buffer;
- final_event =
(struct efi_tcg2_final_events_table *)event_log.final_buffer;
final_buffer is defined as void *. So this cast is superfluous and should be avoided. Cf. https://www.kernel.org/doc/html/latest/process/coding-style.html#allocating-...
There is a further unneeded conversion of the same type in the file.
Why didn't you define component final_buffer as struct efi_tcg2_final_events_table * and just added a void ** conversion to the efi_allocate_pool() call?
This would allow to eliminate the variable final_event here and in tcg2_agile_log_append().
Best regards
Heinrich
final_event->number_of_events = 0; final_event->version = EFI_TCG2_FINAL_EVENTS_TABLE_VERSION;
- event_log.final_pos = sizeof(*final_event);
- event_log.final_pos = 0; ret = efi_install_configuration_table(&efi_guid_final_events, final_event); if (ret != EFI_SUCCESS) {
On Wed, 17 Nov 2021 at 11:10, Heinrich Schuchardt xypron.glpk@gmx.de wrote:
On 11/17/21 00:24, Ilias Apalodimas wrote:
When initializing the final event table in create_final_event() we are setting the initial buffer position to sizeof(*final_event). Although we clear the buffer correctly and won't cause any problems, we should start logging events starting from zero. While at it add a cast when defining the final_event.
Signed-off-by: Ilias Apalodimas ilias.apalodimas@linaro.org
lib/efi_loader/efi_tcg2.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/lib/efi_loader/efi_tcg2.c b/lib/efi_loader/efi_tcg2.c index 189e4a5ba59c..634556342a7c 100644 --- a/lib/efi_loader/efi_tcg2.c +++ b/lib/efi_loader/efi_tcg2.c @@ -1257,10 +1257,11 @@ static efi_status_t create_final_event(void) goto out;
memset(event_log.final_buffer, 0xff, TPM2_EVENT_LOG_SIZE);
final_event = event_log.final_buffer;
final_event =(struct efi_tcg2_final_events_table *)event_log.final_buffer;final_buffer is defined as void *. So this cast is superfluous and should be avoided. Cf. https://www.kernel.org/doc/html/latest/process/coding-style.html#allocating-...
There is a further unneeded conversion of the same type in the file.
Why didn't you define component final_buffer as struct efi_tcg2_final_events_table * and just added a void ** conversion to the efi_allocate_pool() call?
This would allow to eliminate the variable final_event here and in tcg2_agile_log_append().
Because both the buffer and the final_buffer describe log events of different type that need to be appended on the eventlog using the same functions. Due to all the ptr arithmetic that takes place, I though having them as void would be easier to read. In any case this patch shouldn't be applied.
Cheers /Ilias
Best regards
Heinrich
final_event->number_of_events = 0; final_event->version = EFI_TCG2_FINAL_EVENTS_TABLE_VERSION;
event_log.final_pos = sizeof(*final_event);
event_log.final_pos = 0; ret = efi_install_configuration_table(&efi_guid_final_events, final_event); if (ret != EFI_SUCCESS) {
participants (2)
-
Heinrich Schuchardt -
Ilias Apalodimas