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fhandler_proc.cc(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
This commit is contained in:
Brian Inglis 2020-07-07 13:00:36 -06:00 committed by Corinna Vinschen
parent 104caeb7b1
commit 54bb6589c3
1 changed files with 35 additions and 9 deletions
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42
winsup/cygwin/fhandler_proc.cc
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@ -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 },
{ 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 (&microcode, &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 (&microcode, 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;