svn commit: r267651 - in head: share/man/man4 sys/dev/cpuctl sys/sys usr.sbin/cpucontrol

[Attilio Rao]

On Fri, Jun 20, 2014 at 6:08 AM, Konstantin Belousov
<kostikbel at gmail.com> wrote:
> On Thu, Jun 19, 2014 at 09:54:41PM +0000, Attilio Rao wrote:
>> Author: attilio
>> Date: Thu Jun 19 21:54:41 2014
>> New Revision: 267651
>> URL: http://svnweb.freebsd.org/changeset/base/267651
>>
>> Log:
>>   Following comments in r242565 add the possibility to specify ecx when
>>   performing cpuid calls.
>>   Add also a new way to specify the level type to cpucontrol(8) as
>>   reported in the manpage.
>>
>>   Sponsored by:       EMC / Isilon storage division
>>   Reviewed by:        bdrewery, gcooper
>>   Testerd by: bdrewery
>> Modified: head/sys/sys/cpuctl.h
>> ==============================================================================
>> --- head/sys/sys/cpuctl.h     Thu Jun 19 21:05:07 2014        (r267650)
>> +++ head/sys/sys/cpuctl.h     Thu Jun 19 21:54:41 2014        (r267651)
>> @@ -35,7 +35,8 @@ typedef struct {
>>  } cpuctl_msr_args_t;
>>
>>  typedef struct {
>> -     int             level;  /* CPUID level */
>> +     int             level;          /* CPUID level */
>> +     int             level_type;     /* CPUID level type */
>>       uint32_t        data[4];
>>  } cpuctl_cpuid_args_t;
>>
>> @@ -50,5 +51,6 @@ typedef struct {
>>  #define      CPUCTL_UPDATE   _IOWR('c', 4, cpuctl_update_args_t)
>>  #define      CPUCTL_MSRSBIT  _IOWR('c', 5, cpuctl_msr_args_t)
>>  #define      CPUCTL_MSRCBIT  _IOWR('c', 6, cpuctl_msr_args_t)
>> +#define      CPUCTL_CPUID_COUNT _IOWR('c', 7, cpuctl_cpuid_args_t)
>>
>>  #endif /* _CPUCTL_H_ */
>
> The cpuctl(4) is used by third-party code, and this change breaks its
> ABI. The numeric value for CPUCTL_CPUID is changed, which means that
> old binaries call non-existing ioctl now. This is at least a visible
> breakage, since the argument for the ioctl changed the layout as well.
>
> The following patch restored the CPUCTL_CPUID for me.  I considered
> naming its argument differently, instead of renaming the argument
> of CPUCTL_CPUID_COUNT (which you tried to do ?), but decided not,
> to preserve the API as well.

No, breaking the ABI is fine for -CURRENT so I don't see why we need the bloat.
I don't plan on MFC this patch. If I need to (or any user requests
that) I will do with the appropriate ABI-compliant way (ie. adding a
new argument like this one).

Attilio


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