On 31.05.2017 10:21, Andrew Jones wrote:
> On Tue, May 30, 2017 at 05:07:24PM +0200, Thomas Huth wrote:
>> When running a powerpc kvm-unit-test, and there is accidentially
>> no device tree available, the test ends up in an endless loop,
>> spamming the console with "rtas_node: /rtas: FDT_ERR_BADMAGIC"
>> messages: Somewhere the code calls abort() due to the missing
>> device tree, and abort() calls exit() which in turn tries to
>> shut down the VM with rtas_power_off(). rtas_power_off() needs
>> the device tree again to look up the right RTAS token and we
>> then end up in the next iteration.
>> Fix it by adding some proper checks to rtas_power_off() and
>> rtas_token().
>>
>> Signed-off-by: Thomas Huth <thuth@xxxxxxxxxx>
>> ---
>> lib/powerpc/rtas.c | 13 ++++++++++++-
>> 1 file changed, 12 insertions(+), 1 deletion(-)
>>
>> diff --git a/lib/powerpc/rtas.c b/lib/powerpc/rtas.c
>> index 3407e25..a1c560b 100644
>> --- a/lib/powerpc/rtas.c
>> +++ b/lib/powerpc/rtas.c
>> @@ -74,6 +74,9 @@ int rtas_token(const char *service)
>> const struct fdt_property *prop;
>> u32 *token;
>>
>> + if (!dt_available())
>> + return RTAS_UNKNOWN_SERVICE;
>> +
>> prop = fdt_get_property(dt_fdt(), rtas_node(), service, NULL);
>> if (prop) {
>> token = (u32 *)prop->data;
>> @@ -116,6 +119,14 @@ int rtas_call(int token, int nargs, int nret, int *outputs, ...)
>>
>> void rtas_power_off(void)
>> {
>> - int ret = rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1);
>> + int token, ret;
>> +
>> + token = rtas_token("power-off");
>> + if (token < 0) {
>
> token == RTAS_UNKNOWN_SERVICE ?
Yes, that's likely better ... though the tokens are normally > 0, I just
had a look at the spec and it does not say anything about whether they
have to be positive or not, so negative tokens could happen, too.
I'll send a v2...
Thanks,
Thomas
>> + puts("RTAS power-off not available\n");
>> + return;
>> + }
>> +
>> + ret = rtas_call(token, 2, 1, NULL, -1, -1);
>> printf("RTAS power-off returned %d\n", ret);
>> }
>> --
>> 1.8.3.1
>>
>
> Thanks,
> drew
>
