[PULL,3/5] softmmu/vl: Let -fw_cfg option take a 'gen_id' argument
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Message ID 20200704163927.28188-4-philmd@redhat.com
State New
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Series
  • [PULL,1/5] crypto: Add tls-cipher-suites object
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Commit Message

Philippe Mathieu-Daudé July 4, 2020, 4:39 p.m. UTC
The 'gen_id' argument refers to a QOM object able to produce
data consumable by the fw_cfg device. The producer object must
implement the FW_CFG_DATA_GENERATOR interface.

Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20200623172726.21040-4-philmd@redhat.com>
---
 softmmu/vl.c | 29 +++++++++++++++++++++--------
 1 file changed, 21 insertions(+), 8 deletions(-)

Comments

Peter Maydell July 13, 2020, 1:13 p.m. UTC | #1
On Sat, 4 Jul 2020 at 17:41, Philippe Mathieu-Daudé <philmd@redhat.com> wrote:
>
> The 'gen_id' argument refers to a QOM object able to produce
> data consumable by the fw_cfg device. The producer object must
> implement the FW_CFG_DATA_GENERATOR interface.
>
> Reviewed-by: Laszlo Ersek <lersek@redhat.com>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
> Message-Id: <20200623172726.21040-4-philmd@redhat.com>

Coverity points out (CID 1430396) an issue with the error handling
in this patch:


> @@ -2052,6 +2056,15 @@ static int parse_fw_cfg(void *opaque, QemuOpts *opts, Error **errp)
>      if (nonempty_str(str)) {
>          size = strlen(str); /* NUL terminator NOT included in fw_cfg blob */
>          buf = g_memdup(str, size);
> +    } else if (nonempty_str(gen_id)) {
> +        Error *local_err = NULL;

We set local_err to NULL here...

> +
> +        fw_cfg_add_from_generator(fw_cfg, name, gen_id, errp);

...but we don't pass it to the function here...

> +        if (local_err) {

...so this condition is always false and the body of the if is dead code.

> +            error_propagate(errp, local_err);
> +            return -1;
> +        }
> +        return 0;
>      } else {
>          GError *err = NULL;
>          if (!g_file_get_contents(file, &buf, &size, &err)) {

thanks
-- PMM
Laszlo Ersek July 13, 2020, 2:50 p.m. UTC | #2
On 07/13/20 15:13, Peter Maydell wrote:
> On Sat, 4 Jul 2020 at 17:41, Philippe Mathieu-Daudé <philmd@redhat.com> wrote:
>>
>> The 'gen_id' argument refers to a QOM object able to produce
>> data consumable by the fw_cfg device. The producer object must
>> implement the FW_CFG_DATA_GENERATOR interface.
>>
>> Reviewed-by: Laszlo Ersek <lersek@redhat.com>
>> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
>> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
>> Message-Id: <20200623172726.21040-4-philmd@redhat.com>
> 
> Coverity points out (CID 1430396) an issue with the error handling
> in this patch:
> 
> 
>> @@ -2052,6 +2056,15 @@ static int parse_fw_cfg(void *opaque, QemuOpts *opts, Error **errp)
>>      if (nonempty_str(str)) {
>>          size = strlen(str); /* NUL terminator NOT included in fw_cfg blob */
>>          buf = g_memdup(str, size);
>> +    } else if (nonempty_str(gen_id)) {
>> +        Error *local_err = NULL;
> 
> We set local_err to NULL here...
> 
>> +
>> +        fw_cfg_add_from_generator(fw_cfg, name, gen_id, errp);
> 
> ...but we don't pass it to the function here...

Ugh, I should have noticed that in review. I'm sorry.

Laszlo

> 
>> +        if (local_err) {
> 
> ...so this condition is always false and the body of the if is dead code.
> 
>> +            error_propagate(errp, local_err);
>> +            return -1;
>> +        }
>> +        return 0;
>>      } else {
>>          GError *err = NULL;
>>          if (!g_file_get_contents(file, &buf, &size, &err)) {
> 
> thanks
> -- PMM
>
Peter Maydell July 13, 2020, 2:55 p.m. UTC | #3
On Mon, 13 Jul 2020 at 15:50, Laszlo Ersek <lersek@redhat.com> wrote:
> Ugh, I should have noticed that in review. I'm sorry.

No worries, catching this kind of thing is what static
analysers are for :-)

-- PMM
Philippe Mathieu-Daudé July 14, 2020, 1:04 p.m. UTC | #4
On 7/13/20 4:50 PM, Laszlo Ersek wrote:
> On 07/13/20 15:13, Peter Maydell wrote:
>> On Sat, 4 Jul 2020 at 17:41, Philippe Mathieu-Daudé <philmd@redhat.com> wrote:
>>>
>>> The 'gen_id' argument refers to a QOM object able to produce
>>> data consumable by the fw_cfg device. The producer object must
>>> implement the FW_CFG_DATA_GENERATOR interface.
>>>
>>> Reviewed-by: Laszlo Ersek <lersek@redhat.com>
>>> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
>>> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
>>> Message-Id: <20200623172726.21040-4-philmd@redhat.com>
>>
>> Coverity points out (CID 1430396) an issue with the error handling
>> in this patch:
>>
>>
>>> @@ -2052,6 +2056,15 @@ static int parse_fw_cfg(void *opaque, QemuOpts *opts, Error **errp)
>>>      if (nonempty_str(str)) {
>>>          size = strlen(str); /* NUL terminator NOT included in fw_cfg blob */
>>>          buf = g_memdup(str, size);
>>> +    } else if (nonempty_str(gen_id)) {
>>> +        Error *local_err = NULL;
>>
>> We set local_err to NULL here...
>>
>>> +
>>> +        fw_cfg_add_from_generator(fw_cfg, name, gen_id, errp);
>>
>> ...but we don't pass it to the function here...
> 
> Ugh, I should have noticed that in review. I'm sorry.

You reviewed v9 which was OK, I added it while addressing
Daniel comment for v10, while keeping your R-b tag from v9.
Since you already had reviewed 9 different versions, I didn't
want to overload you for a trivial change, but I should have
dropped your tag to be certain.

Also this has been merged at the same time Markus was doing
a big rework on the Error API, so I was very confused between
reviews of the new API.

So don't be sorry, Daniel/Myself let that in ;)

I'll send a patch, hoping it can be queued via qemu-trivial.

Regards,

Phil.

> Laszlo
> 
>>
>>> +        if (local_err) {
>>
>> ...so this condition is always false and the body of the if is dead code.
>>
>>> +            error_propagate(errp, local_err);
>>> +            return -1;
>>> +        }
>>> +        return 0;
>>>      } else {
>>>          GError *err = NULL;
>>>          if (!g_file_get_contents(file, &buf, &size, &err)) {
>>
>> thanks
>> -- PMM
>>
>

Patch
diff mbox series

diff --git a/softmmu/vl.c b/softmmu/vl.c
index 3e15ee2435..13cada39d6 100644
--- a/softmmu/vl.c
+++ b/softmmu/vl.c
@@ -489,6 +489,11 @@  static QemuOptsList qemu_fw_cfg_opts = {
             .name = "string",
             .type = QEMU_OPT_STRING,
             .help = "Sets content of the blob to be inserted from a string",
+        }, {
+            .name = "gen_id",
+            .type = QEMU_OPT_STRING,
+            .help = "Sets id of the object generating the fw_cfg blob "
+                    "to be inserted",
         },
         { /* end of list */ }
     },
@@ -2020,7 +2025,7 @@  static int parse_fw_cfg(void *opaque, QemuOpts *opts, Error **errp)
 {
     gchar *buf;
     size_t size;
-    const char *name, *file, *str;
+    const char *name, *file, *str, *gen_id;
     FWCfgState *fw_cfg = (FWCfgState *) opaque;
 
     if (fw_cfg == NULL) {
@@ -2030,14 +2035,13 @@  static int parse_fw_cfg(void *opaque, QemuOpts *opts, Error **errp)
     name = qemu_opt_get(opts, "name");
     file = qemu_opt_get(opts, "file");
     str = qemu_opt_get(opts, "string");
+    gen_id = qemu_opt_get(opts, "gen_id");
 
-    /* we need name and either a file or the content string */
-    if (!(nonempty_str(name) && (nonempty_str(file) || nonempty_str(str)))) {
-        error_setg(errp, "invalid argument(s)");
-        return -1;
-    }
-    if (nonempty_str(file) && nonempty_str(str)) {
-        error_setg(errp, "file and string are mutually exclusive");
+    /* we need the name, and exactly one of: file, content string, gen_id */
+    if (!nonempty_str(name) ||
+        nonempty_str(file) + nonempty_str(str) + nonempty_str(gen_id) != 1) {
+        error_setg(errp, "name, plus exactly one of file,"
+                         " string and gen_id, are needed");
         return -1;
     }
     if (strlen(name) > FW_CFG_MAX_FILE_PATH - 1) {
@@ -2052,6 +2056,15 @@  static int parse_fw_cfg(void *opaque, QemuOpts *opts, Error **errp)
     if (nonempty_str(str)) {
         size = strlen(str); /* NUL terminator NOT included in fw_cfg blob */
         buf = g_memdup(str, size);
+    } else if (nonempty_str(gen_id)) {
+        Error *local_err = NULL;
+
+        fw_cfg_add_from_generator(fw_cfg, name, gen_id, errp);
+        if (local_err) {
+            error_propagate(errp, local_err);
+            return -1;
+        }
+        return 0;
     } else {
         GError *err = NULL;
         if (!g_file_get_contents(file, &buf, &size, &err)) {