[v1] tpm_emulator: Report an error if chardev is missing

[PATCH] tpm_emulator: Report an error if chardev is missing

Posted by Stefan Berger 5 years, 3 months ago

This patch fixes the odd error reporting when trying to send a file
descriptor to the TPM emulator if one has not passed a valid chardev.

$ x86_64-softmmu/qemu-system-x86_64 -tpmdev emulator,id=tpm0
qemu-system-x86_64: -tpmdev emulator,id=tpm0: tpm-emulator: Failed to send CMD_SET_DATAFD: Success
qemu-system-x86_64: -tpmdev emulator,id=tpm0: tpm-emulator: Could not cleanly shutdown the TPM: Success

This is the new error report:

$ x86_64-softmmu/qemu-system-x86_64 -tpmdev emulator,id=tpm0
qemu-system-x86_64: -tpmdev emulator,id=tpm0: tpm-emulator: missing chardev

This change does not hide the display of supported TPM types if a non-existent type is passed:

$ x86_64-softmmu/qemu-system-x86_64 -tpmdev nonexistent,id=tpm0
qemu-system-x86_64: -tpmdev nonexistent,id=tpm0: Parameter 'type' expects a TPM backend type
Supported TPM types (choose only one):
 passthrough   Passthrough TPM backend driver
    emulator   TPM emulator backend driver

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
---
 backends/tpm/tpm_emulator.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/backends/tpm/tpm_emulator.c b/backends/tpm/tpm_emulator.c
index 9605339f93..55cbc9c60e 100644
--- a/backends/tpm/tpm_emulator.c
+++ b/backends/tpm/tpm_emulator.c
@@ -568,6 +568,9 @@ static int tpm_emulator_handle_device_opts(TPMEmulator *tpm_emu, QemuOpts *opts)
         }
 
         tpm_emu->options->chardev = g_strdup(value);
+    } else {
+        error_report("tpm-emulator: missing chardev");
+        goto err;
     }
 
     if (tpm_emulator_prepare_data_fd(tpm_emu) < 0) {
@@ -925,6 +928,11 @@ static void tpm_emulator_shutdown(TPMEmulator *tpm_emu)
 {
     ptm_res res;
 
+    if (!tpm_emu->options->chardev) {
+        /* was never properly initialized */
+        return;
+    }
+
     if (tpm_emulator_ctrlcmd(tpm_emu, CMD_SHUTDOWN, &res, 0, sizeof(res)) < 0) {
         error_report("tpm-emulator: Could not cleanly shutdown the TPM: %s",
                      strerror(errno));
-- 
2.24.1

Re: [PATCH] tpm_emulator: Report an error if chardev is missing

Posted by Marc-André Lureau 5 years, 3 months ago

On Fri, Jul 24, 2020 at 5:30 PM Stefan Berger <stefanb@linux.vnet.ibm.com>
wrote:

> This patch fixes the odd error reporting when trying to send a file
> descriptor to the TPM emulator if one has not passed a valid chardev.
>
> $ x86_64-softmmu/qemu-system-x86_64 -tpmdev emulator,id=tpm0
> qemu-system-x86_64: -tpmdev emulator,id=tpm0: tpm-emulator: Failed to send
> CMD_SET_DATAFD: Success
> qemu-system-x86_64: -tpmdev emulator,id=tpm0: tpm-emulator: Could not
> cleanly shutdown the TPM: Success
>
> This is the new error report:
>
> $ x86_64-softmmu/qemu-system-x86_64 -tpmdev emulator,id=tpm0
> qemu-system-x86_64: -tpmdev emulator,id=tpm0: tpm-emulator: missing chardev
>
> This change does not hide the display of supported TPM types if a
> non-existent type is passed:
>
> $ x86_64-softmmu/qemu-system-x86_64 -tpmdev nonexistent,id=tpm0
> qemu-system-x86_64: -tpmdev nonexistent,id=tpm0: Parameter 'type' expects
> a TPM backend type
> Supported TPM types (choose only one):
>  passthrough   Passthrough TPM backend driver
>     emulator   TPM emulator backend driver
>
> Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
>

Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>

---
>  backends/tpm/tpm_emulator.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
>
> diff --git a/backends/tpm/tpm_emulator.c b/backends/tpm/tpm_emulator.c
> index 9605339f93..55cbc9c60e 100644
> --- a/backends/tpm/tpm_emulator.c
> +++ b/backends/tpm/tpm_emulator.c
> @@ -568,6 +568,9 @@ static int tpm_emulator_handle_device_opts(TPMEmulator
> *tpm_emu, QemuOpts *opts)
>          }
>
>          tpm_emu->options->chardev = g_strdup(value);
> +    } else {
> +        error_report("tpm-emulator: missing chardev");
> +        goto err;
>      }
>
>      if (tpm_emulator_prepare_data_fd(tpm_emu) < 0) {
> @@ -925,6 +928,11 @@ static void tpm_emulator_shutdown(TPMEmulator
> *tpm_emu)
>  {
>      ptm_res res;
>
> +    if (!tpm_emu->options->chardev) {
> +        /* was never properly initialized */
> +        return;
> +    }
> +
>      if (tpm_emulator_ctrlcmd(tpm_emu, CMD_SHUTDOWN, &res, 0, sizeof(res))
> < 0) {
>          error_report("tpm-emulator: Could not cleanly shutdown the TPM:
> %s",
>                       strerror(errno));
> --
> 2.24.1
>
>
>

-- 
Marc-André Lureau

Re: [PATCH] tpm_emulator: Report an error if chardev is missing

Posted by Markus Armbruster 5 years, 3 months ago

Stefan Berger <stefanb@linux.vnet.ibm.com> writes:

> This patch fixes the odd error reporting when trying to send a file
> descriptor to the TPM emulator if one has not passed a valid chardev.
>
> $ x86_64-softmmu/qemu-system-x86_64 -tpmdev emulator,id=tpm0
> qemu-system-x86_64: -tpmdev emulator,id=tpm0: tpm-emulator: Failed to send CMD_SET_DATAFD: Success
> qemu-system-x86_64: -tpmdev emulator,id=tpm0: tpm-emulator: Could not cleanly shutdown the TPM: Success
>
> This is the new error report:
>
> $ x86_64-softmmu/qemu-system-x86_64 -tpmdev emulator,id=tpm0
> qemu-system-x86_64: -tpmdev emulator,id=tpm0: tpm-emulator: missing chardev
                                                ~~~~~~~~~~~~~~

The "tpm-emulator: " part looks superfluous.

Hmm, many error messages in this file have it.  Feel free to keep it
now for consistency, and clean it up later.

We usually report missing option parameters like "parameter 'chardev' is
missing".  Please consider sticking to that.

>
> This change does not hide the display of supported TPM types if a non-existent type is passed:
>
> $ x86_64-softmmu/qemu-system-x86_64 -tpmdev nonexistent,id=tpm0
> qemu-system-x86_64: -tpmdev nonexistent,id=tpm0: Parameter 'type' expects a TPM backend type
> Supported TPM types (choose only one):
>  passthrough   Passthrough TPM backend driver
>     emulator   TPM emulator backend driver
>
> Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
> ---
>  backends/tpm/tpm_emulator.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
>
> diff --git a/backends/tpm/tpm_emulator.c b/backends/tpm/tpm_emulator.c
> index 9605339f93..55cbc9c60e 100644
> --- a/backends/tpm/tpm_emulator.c
> +++ b/backends/tpm/tpm_emulator.c
> @@ -568,6 +568,9 @@ static int tpm_emulator_handle_device_opts(TPMEmulator *tpm_emu, QemuOpts *opts)
>          }
>  
>          tpm_emu->options->chardev = g_strdup(value);
> +    } else {
> +        error_report("tpm-emulator: missing chardev");
> +        goto err;
>      }
>  
>      if (tpm_emulator_prepare_data_fd(tpm_emu) < 0) {

This is minimally invasive.

I'd prefer

       Error *err = NULL;
       const char *value;
       Chardev *dev;

       value = qemu_opt_get(opts, "chardev");
       if (!value) {
           error_report("tpm-emulator: missing chardev");
           goto err;
       }

       dev = qemu_chr_find(value);
       if (!dev) {
           error_report("tpm-emulator: tpm chardev '%s' not found.", value);
           goto err;
       }

Your choice.

> @@ -925,6 +928,11 @@ static void tpm_emulator_shutdown(TPMEmulator *tpm_emu)
>  {
>      ptm_res res;
>  
> +    if (!tpm_emu->options->chardev) {
> +        /* was never properly initialized */
> +        return;
> +    }
> +

Is this still reachable?  If yes, how?

If not, drop the hunk and have my
Reviewed-by: Markus Armbruster <armbru@redhat.com>

>      if (tpm_emulator_ctrlcmd(tpm_emu, CMD_SHUTDOWN, &res, 0, sizeof(res)) < 0) {
>          error_report("tpm-emulator: Could not cleanly shutdown the TPM: %s",
>                       strerror(errno));

Re: [PATCH] tpm_emulator: Report an error if chardev is missing

Posted by Stefan Berger 5 years, 3 months ago

On 7/24/20 10:00 AM, Markus Armbruster wrote:
> Stefan Berger <stefanb@linux.vnet.ibm.com> writes:
>
>> This patch fixes the odd error reporting when trying to send a file
>> descriptor to the TPM emulator if one has not passed a valid chardev.
>>
>> $ x86_64-softmmu/qemu-system-x86_64 -tpmdev emulator,id=tpm0
>> qemu-system-x86_64: -tpmdev emulator,id=tpm0: tpm-emulator: Failed to send CMD_SET_DATAFD: Success
>> qemu-system-x86_64: -tpmdev emulator,id=tpm0: tpm-emulator: Could not cleanly shutdown the TPM: Success
>>
>> This is the new error report:
>>
>> $ x86_64-softmmu/qemu-system-x86_64 -tpmdev emulator,id=tpm0
>> qemu-system-x86_64: -tpmdev emulator,id=tpm0: tpm-emulator: missing chardev
>                                                  ~~~~~~~~~~~~~~
>
> The "tpm-emulator: " part looks superfluous.
>
> Hmm, many error messages in this file have it.  Feel free to keep it
> now for consistency, and clean it up later.
>
> We usually report missing option parameters like "parameter 'chardev' is
> missing".  Please consider sticking to that.

Fixed.


>
>> This change does not hide the display of supported TPM types if a non-existent type is passed:
>>
>> $ x86_64-softmmu/qemu-system-x86_64 -tpmdev nonexistent,id=tpm0
>> qemu-system-x86_64: -tpmdev nonexistent,id=tpm0: Parameter 'type' expects a TPM backend type
>> Supported TPM types (choose only one):
>>   passthrough   Passthrough TPM backend driver
>>      emulator   TPM emulator backend driver
>>
>> Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
>> ---
>>   backends/tpm/tpm_emulator.c | 8 ++++++++
>>   1 file changed, 8 insertions(+)
>>
>> diff --git a/backends/tpm/tpm_emulator.c b/backends/tpm/tpm_emulator.c
>> index 9605339f93..55cbc9c60e 100644
>> --- a/backends/tpm/tpm_emulator.c
>> +++ b/backends/tpm/tpm_emulator.c
>> @@ -568,6 +568,9 @@ static int tpm_emulator_handle_device_opts(TPMEmulator *tpm_emu, QemuOpts *opts)
>>           }
>>   
>>           tpm_emu->options->chardev = g_strdup(value);
>> +    } else {
>> +        error_report("tpm-emulator: missing chardev");
>> +        goto err;
>>       }
>>   
>>       if (tpm_emulator_prepare_data_fd(tpm_emu) < 0) {
> This is minimally invasive.
>
> I'd prefer
>
>         Error *err = NULL;
>         const char *value;
>         Chardev *dev;
>
>         value = qemu_opt_get(opts, "chardev");
>         if (!value) {
>             error_report("tpm-emulator: missing chardev");
>             goto err;
>         }
>
>         dev = qemu_chr_find(value);
>         if (!dev) {
>             error_report("tpm-emulator: tpm chardev '%s' not found.", value);
>             goto err;
>         }
>
> Your choice.


Ok, changed it to this.


>
>> @@ -925,6 +928,11 @@ static void tpm_emulator_shutdown(TPMEmulator *tpm_emu)
>>   {
>>       ptm_res res;
>>   
>> +    if (!tpm_emu->options->chardev) {
>> +        /* was never properly initialized */
>> +        return;
>> +    }
>> +
> Is this still reachable?  If yes, how?


tpm_emulator_inst_finalize still runs.


Sending V2. Thanks.

>
> If not, drop the hunk and have my
> Reviewed-by: Markus Armbruster <armbru@redhat.com>
>
>>       if (tpm_emulator_ctrlcmd(tpm_emu, CMD_SHUTDOWN, &res, 0, sizeof(res)) < 0) {
>>           error_report("tpm-emulator: Could not cleanly shutdown the TPM: %s",
>>                        strerror(errno));