[PATCH] format_proc_cpuinfo: add microcode registry lookup values
Brian Inglis
Brian.Inglis@SystematicSw.ab.ca
Tue Jul 7 18:55:09 GMT 2020
Thanks,
I had problems getting anything to run under my test DLLs, so when I finally got
things running, I ran some tests, and everything seemed to work okay, so I
shipped the patch.
As usual, after sending, brain kicked in and I realized why it did not appear to
be picking up some reg keys due to my over-thinko, and nervousness messing
around with the microcode rev reg keys during testing.
Resending retested, refixed patch, and microcode reg keys restored and looking
normal!
On 2020-07-07 12:36, Lavrentiev, Anton (NIH/NLM/NCBI) [C] wrote:
> Hi,
>
> This is shifting up, IMO:
>
> + microcode <<= 32; /* shift them down */
>
> Thanks,
> Anton
>
>> -----Original Message-----
>> From: Brian Inglis <Brian.Inglis@SystematicSW.ab.ca>
>> Sent: Tuesday, July 07, 2020 1:34 PM
>> To: cygwin-patches@cygwin.com
>> Subject: [PATCH] format_proc_cpuinfo: add microcode registry lookup values
>>
>> Re: CPU microcode reported wrong in /proc/cpuinfo
>> https://sourceware.org/pipermail/cygwin/2020-May/245063.html
>> earlier Windows releases used different registry values to store microcode
>> revisions depending on the MSR name being used to get microcode revisions:
>> add these alternative registry values to the cpuinfo registry value lookup;
>> iterate thru the registry data until a valid microcode revision is found;
>> some revision values are in the high bits, so if the low bits are all clear,
>> shift the revision value down into the low bits
>> ---
>> winsup/cygwin/fhandler_proc.cc | 44 +++++++++++++++++++++++++++-------
>> 1 file changed, 35 insertions(+), 9 deletions(-)
>>
>> diff --git a/winsup/cygwin/fhandler_proc.cc b/winsup/cygwin/fhandler_proc.cc
>> index f1bc1c7405..f637dfd8e4 100644
>> --- a/winsup/cygwin/fhandler_proc.cc
>> +++ b/winsup/cygwin/fhandler_proc.cc
>> @@ -692,26 +692,52 @@ format_proc_cpuinfo (void *, char *&destbuf)
>> union
>> {
>> LONG uc_len; /* -max size of buffer before call */
>> - char uc_microcode[16];
>> - } uc;
>> + char uc_microcode[16]; /* at least 8 bytes */
>> + } uc[4]; /* microcode values changed historically */
>>
>> - RTL_QUERY_REGISTRY_TABLE tab[3] =
>> + RTL_QUERY_REGISTRY_TABLE tab[6] =
>> {
>> { NULL, RTL_QUERY_REGISTRY_DIRECT | RTL_QUERY_REGISTRY_NOSTRING,
>> - L"~Mhz", &cpu_mhz, REG_NONE, NULL, 0 },
>> + L"~Mhz", &cpu_mhz, REG_NONE, NULL, 0 },
>> { NULL, RTL_QUERY_REGISTRY_DIRECT | RTL_QUERY_REGISTRY_NOSTRING,
>> - L"Update Revision", &uc, REG_NONE, NULL, 0 },
>> + L"Update Revision", &uc[0], REG_NONE, NULL, 0 },
>> + /* latest MSR */
>> + { NULL, RTL_QUERY_REGISTRY_DIRECT | RTL_QUERY_REGISTRY_NOSTRING,
>> + L"Update Signature", &uc[1], REG_NONE, NULL, 0 },
>> + /* previous MSR */
>> + { NULL, RTL_QUERY_REGISTRY_DIRECT | RTL_QUERY_REGISTRY_NOSTRING,
>> + L"CurrentPatchLevel", &uc[2], REG_NONE, NULL, 0 },
>> + /* earlier MSR */
>> + { NULL, RTL_QUERY_REGISTRY_DIRECT | RTL_QUERY_REGISTRY_NOSTRING,
>> + L"Platform Specific Field1", &uc[3], REG_NONE, NULL, 0 },
>> + /* alternative */
>> { NULL, 0, NULL, NULL, 0, NULL, 0 }
>> };
>>
>> - memset (&uc, 0, sizeof (uc.uc_microcode));
>> - uc.uc_len = -16; /* -max size of microcode buffer */
>> + for (size_t uci = 0; uci < sizeof (uc)/sizeof (*uc); ++uci)
>> + {
>> + memset (&uc[uci], 0, sizeof (uc[uci]));
>> + uc[uci].uc_len = -(LONG)sizeof (uc[0].uc_microcode);
>> + /* neg buffer size */
>> + }
>> +
>> RtlQueryRegistryValues (RTL_REGISTRY_ABSOLUTE, cpu_key, tab,
>> NULL, NULL);
>> cpu_mhz = ((cpu_mhz - 1) / 10 + 1) * 10; /* round up to multiple of 10 */
>> DWORD bogomips = cpu_mhz * 2; /* bogomips is double cpu MHz since MMX */
>> - long long microcode = 0; /* at least 8 bytes for AMD */
>> - memcpy (µcode, &uc, sizeof (microcode));
>> +
>> + unsigned long long microcode = 0; /* needs 8 bytes */
>> + for (size_t uci = 0; uci < sizeof (uc)/sizeof (*uc) && !microcode; ++uci)
>> + {
>> + /* still neg buffer size => no data */
>> + if (-(LONG)sizeof (uc[uci].uc_microcode) != uc[uci].uc_len)
>> + {
>> + memcpy (µcode, uc[uci].uc_microcode, sizeof (microcode));
>> +
>> + if (!(microcode & 0xFFFFFFFFLL)) /* some values in high bits */
>> + microcode <<= 32; /* shift them down */
>> + }
>> + }
>>
>> bufptr += __small_sprintf (bufptr, "processor\t: %d\n", cpu_number);
>> uint32_t maxf, vendor_id[4], unused;
>> --
>> 2.27.0
>
--
Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada
This email may be disturbing to some readers as it contains
too much technical detail. Reader discretion is advised.
[Data in IEC units and prefixes, physical quantities in SI.]
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