Signed-off-by: Li Qiang <liq3ea@163.com>
---
 tests/fw_cfg-test.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/tests/fw_cfg-test.c b/tests/fw_cfg-test.c
index 1c5103fe1c..c28e6c3fb5 100644
--- a/tests/fw_cfg-test.c
+++ b/tests/fw_cfg-test.c
@@ -99,6 +99,15 @@ static void test_fw_cfg_boot_menu(void)
     g_assert_cmpint(qfw_cfg_get_u16(fw_cfg, FW_CFG_BOOT_MENU), ==, boot_menu);
 }
 
+static void test_fw_cfg_reboot_timeout(void)
+{
+    uint32_t reboot_timeout;
+
+    qfw_cfg_get_file(fw_cfg, "etc/boot-fail-wait",
+                     &reboot_timeout, sizeof(reboot_timeout));
+    g_assert_cmpint(reboot_timeout, ==, 15);
+}
+
 int main(int argc, char **argv)
 {
     QTestState *s;
@@ -106,7 +115,8 @@ int main(int argc, char **argv)
 
     g_test_init(&argc, &argv, NULL);
 
-    s = qtest_init("-uuid 4600cb32-38ec-4b2f-8acb-81c6ea54f2d8");
+    s = qtest_init("-uuid 4600cb32-38ec-4b2f-8acb-81c6ea54f2d8 "
+                   "-boot reboot-timeout=15");
 
     fw_cfg = pc_fw_cfg_init(s);
 
@@ -125,6 +135,7 @@ int main(int argc, char **argv)
     qtest_add_func("fw_cfg/max_cpus", test_fw_cfg_max_cpus);
     qtest_add_func("fw_cfg/numa", test_fw_cfg_numa);
     qtest_add_func("fw_cfg/boot_menu", test_fw_cfg_boot_menu);
+    qtest_add_func("fw_cfg/reboot_timeout", test_fw_cfg_reboot_timeout);
 
     ret = g_test_run();
 
-- 
2.17.1

On 01/20/19 08:13, Li Qiang wrote:
> Signed-off-by: Li Qiang <liq3ea@163.com>
> ---
>  tests/fw_cfg-test.c | 13 ++++++++++++-
>  1 file changed, 12 insertions(+), 1 deletion(-)
> 
> diff --git a/tests/fw_cfg-test.c b/tests/fw_cfg-test.c
> index 1c5103fe1c..c28e6c3fb5 100644
> --- a/tests/fw_cfg-test.c
> +++ b/tests/fw_cfg-test.c
> @@ -99,6 +99,15 @@ static void test_fw_cfg_boot_menu(void)
>      g_assert_cmpint(qfw_cfg_get_u16(fw_cfg, FW_CFG_BOOT_MENU), ==, boot_menu);
>  }
>  
> +static void test_fw_cfg_reboot_timeout(void)
> +{
> +    uint32_t reboot_timeout;
> +
> +    qfw_cfg_get_file(fw_cfg, "etc/boot-fail-wait",
> +                     &reboot_timeout, sizeof(reboot_timeout));
> +    g_assert_cmpint(reboot_timeout, ==, 15);
> +}
> +

You don't check the return status of qfw_cfg_get_file(), before reading
"reboot_timeout". If the qfw_cfg_get_file() fails (returning 0), then
the comparison will refer to an indeterminate value. Also, it's
theoretically possible for qfw_cfg_get_file() to overwrite only part of
the "reboot_timeout" object.

So I think we need the function to transfer exactly (sizeof
reboot_timeout) bytes.

BTW, this reminds me, qfw_cfg_get_file() seems to return the number of
bytes that would be necessary for transferring the entire file. That
looks like a good idea, but it should be documented. Please add some
docs on top of qfw_cfg_get_file().

>  int main(int argc, char **argv)
>  {
>      QTestState *s;
> @@ -106,7 +115,8 @@ int main(int argc, char **argv)
>  
>      g_test_init(&argc, &argv, NULL);
>  
> -    s = qtest_init("-uuid 4600cb32-38ec-4b2f-8acb-81c6ea54f2d8");
> +    s = qtest_init("-uuid 4600cb32-38ec-4b2f-8acb-81c6ea54f2d8 "
> +                   "-boot reboot-timeout=15");
>  
>      fw_cfg = pc_fw_cfg_init(s);
>  
> @@ -125,6 +135,7 @@ int main(int argc, char **argv)
>      qtest_add_func("fw_cfg/max_cpus", test_fw_cfg_max_cpus);
>      qtest_add_func("fw_cfg/numa", test_fw_cfg_numa);
>      qtest_add_func("fw_cfg/boot_menu", test_fw_cfg_boot_menu);
> +    qtest_add_func("fw_cfg/reboot_timeout", test_fw_cfg_reboot_timeout);
>  
>      ret = g_test_run();
>  
> 

Looks OK otherwise.

Thanks
Laszlo

Laszlo Ersek <lersek@redhat.com> 于2019年1月22日周二 上午5:38写道：

> On 01/20/19 08:13, Li Qiang wrote:
> > Signed-off-by: Li Qiang <liq3ea@163.com>
> > ---
> >  tests/fw_cfg-test.c | 13 ++++++++++++-
> >  1 file changed, 12 insertions(+), 1 deletion(-)
> >
> > diff --git a/tests/fw_cfg-test.c b/tests/fw_cfg-test.c
> > index 1c5103fe1c..c28e6c3fb5 100644
> > --- a/tests/fw_cfg-test.c
> > +++ b/tests/fw_cfg-test.c
> > @@ -99,6 +99,15 @@ static void test_fw_cfg_boot_menu(void)
> >      g_assert_cmpint(qfw_cfg_get_u16(fw_cfg, FW_CFG_BOOT_MENU), ==,
> boot_menu);
> >  }
> >
> > +static void test_fw_cfg_reboot_timeout(void)
> > +{
> > +    uint32_t reboot_timeout;
> > +
> > +    qfw_cfg_get_file(fw_cfg, "etc/boot-fail-wait",
> > +                     &reboot_timeout, sizeof(reboot_timeout));
> > +    g_assert_cmpint(reboot_timeout, ==, 15);
> > +}
> > +
>
> You don't check the return status of qfw_cfg_get_file(), before reading
> "reboot_timeout". If the qfw_cfg_get_file() fails (returning 0), then
> the comparison will refer to an indeterminate value. Also, it's
> theoretically possible for qfw_cfg_get_file() to overwrite only part of
> the "reboot_timeout" object.
>
>
Right. I will change in the next revision.



> So I think we need the function to transfer exactly (sizeof
> reboot_timeout) bytes.
>
>
What does this mean? check the  return of 'qfw_cfg_get_file' if it is
sizeof(reboot_timeout)?



> BTW, this reminds me, qfw_cfg_get_file() seems to return the number of
> bytes that would be necessary for transferring the entire file. That
> looks like a good idea, but it should be documented. Please add some
> docs on top of qfw_cfg_get_file().
>
>
The docs like "return 0 means failed and non-zero means successful but
the caller need check the exactly size to avoid partially file size" ?

Thanks,
Li Qiang


> >  int main(int argc, char **argv)
> >  {
> >      QTestState *s;
> > @@ -106,7 +115,8 @@ int main(int argc, char **argv)
> >
> >      g_test_init(&argc, &argv, NULL);
> >
> > -    s = qtest_init("-uuid 4600cb32-38ec-4b2f-8acb-81c6ea54f2d8");
> > +    s = qtest_init("-uuid 4600cb32-38ec-4b2f-8acb-81c6ea54f2d8 "
> > +                   "-boot reboot-timeout=15");
> >
> >      fw_cfg = pc_fw_cfg_init(s);
> >
> > @@ -125,6 +135,7 @@ int main(int argc, char **argv)
> >      qtest_add_func("fw_cfg/max_cpus", test_fw_cfg_max_cpus);
> >      qtest_add_func("fw_cfg/numa", test_fw_cfg_numa);
> >      qtest_add_func("fw_cfg/boot_menu", test_fw_cfg_boot_menu);
> > +    qtest_add_func("fw_cfg/reboot_timeout", test_fw_cfg_reboot_timeout);
> >
> >      ret = g_test_run();
> >
> >
>
> Looks OK otherwise.
>
> Thanks
> Laszlo
>

On 01/22/19 02:28, Li Qiang wrote:
> Laszlo Ersek <lersek@redhat.com> 于2019年1月22日周二 上午5:38写道：
> 
>> On 01/20/19 08:13, Li Qiang wrote:
>>> Signed-off-by: Li Qiang <liq3ea@163.com>
>>> ---
>>>  tests/fw_cfg-test.c | 13 ++++++++++++-
>>>  1 file changed, 12 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/tests/fw_cfg-test.c b/tests/fw_cfg-test.c
>>> index 1c5103fe1c..c28e6c3fb5 100644
>>> --- a/tests/fw_cfg-test.c
>>> +++ b/tests/fw_cfg-test.c
>>> @@ -99,6 +99,15 @@ static void test_fw_cfg_boot_menu(void)
>>>      g_assert_cmpint(qfw_cfg_get_u16(fw_cfg, FW_CFG_BOOT_MENU), ==,
>> boot_menu);
>>>  }
>>>
>>> +static void test_fw_cfg_reboot_timeout(void)
>>> +{
>>> +    uint32_t reboot_timeout;
>>> +
>>> +    qfw_cfg_get_file(fw_cfg, "etc/boot-fail-wait",
>>> +                     &reboot_timeout, sizeof(reboot_timeout));
>>> +    g_assert_cmpint(reboot_timeout, ==, 15);
>>> +}
>>> +
>>
>> You don't check the return status of qfw_cfg_get_file(), before reading
>> "reboot_timeout". If the qfw_cfg_get_file() fails (returning 0), then
>> the comparison will refer to an indeterminate value. Also, it's
>> theoretically possible for qfw_cfg_get_file() to overwrite only part of
>> the "reboot_timeout" object.
>>
>>
> Right. I will change in the next revision.
> 
> 
> 
>> So I think we need the function to transfer exactly (sizeof
>> reboot_timeout) bytes.
>>
>>
> What does this mean? check the  return of 'qfw_cfg_get_file' if it is
> sizeof(reboot_timeout)?

Yes, that's what I meant.

>> BTW, this reminds me, qfw_cfg_get_file() seems to return the number of
>> bytes that would be necessary for transferring the entire file. That
>> looks like a good idea, but it should be documented. Please add some
>> docs on top of qfw_cfg_get_file().
>>
>>
> The docs like "return 0 means failed and non-zero means successful but
> the caller need check the exactly size to avoid partially file size" ?

Yes. A bit more precisely, when the return value is nonzero, it means
that some bytes have been transferred. If the fw_cfg file in question is
smaller than the allocated & passed-in buffer, then the buffer has been
populated only in part.

Vice versa, if the fw_cfg file in question is larger than the passed-in
buffer, then the return value explains how much room would have been
necessary in total. And, while the caller's buffer has been fully
populated, it has received only a starting slice of the fw_cfg file.

In the comparison that follows qfw_cfg_get_file(), we want to be sure
that the "reboot_timeout" integer object has been fully populated,
*plus* that we aren't ignoring any trailing bytes from the fw_cfg file.
Hence the strict equality on the size.

Thanks
Laszlo