mirrors
/
linux-stable
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
1
0
Fork 0
Code Issues Releases Wiki Activity

A single fix for x86: 

- Prevent a bogus setting for the number of HT siblings, which is caused
    by the CPUID evaluation trainwreck of X86. That recomputes the value
    for each CPU, so the last CPU "wins". That can cause completely bogus
    sibling values.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAmRzBxMTHHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYodfbEACp+oRBD2zIcmf8kpakMxIbH2CkDAxl
 AgqGHYVKAvsqKPQZhYmOFEsk+0isMzssuVaub9gMeLRmpMQxUqv7K20pluvWmuQm
 h7MTYEAvCZpBU2BGB1mixp57tQ/gpLSB4uaJU2Q5hh9po6uImvalIdqThf7ArxgA
 mm3BhtbFObLGwRaV2981zdsEs8Cjs9RusnAOrX5LbBBb6ibcnrqWy7DAhySMA0zr
 7RfaGyG/T9z6/BgX54FBQ7aDNU/RkZ8YYQoMj0kAFXdM3V+sa3oPfMRQpACPHKm4
 kwskJfWVdMq06kgOD7N9+WrOfBAgIsmzasT6VhTuGAGNo4CiEOthLqXDHwf4NLhN
 hj0XReHVyBiQ1KuI2lGNJ71c30KRkh7SCdGNiEFtnlpteXnS4bRnzWtfMf/+2SCC
 WOziRRYRzuAvvoTwoQS1BYJrDAB9f5jOX8FTYbC12rEk/RPOB6t4iFNLUzid7u1H
 yPYphoftXlQlli7EajVc5pSZCftMHRCzWernptiPFU5tMvyagYppcg25JY54rquC
 CTJQqoa/HPAEZhBjgZElwO9QBgu+VyJUq3R/Z+LbkQuz5z+PVDfqeDuDWhaqbcz1
 WGtdGdNo4bqVhwqgwyHjgKCFe05mF6tPuotnYZE/VSkXUCvLkjGEVg8HQ7WiPhJd
 IYDqxkIhX5h1Mg==
 =l43p
 -----END PGP SIGNATURE-----

Merge tag 'x86-urgent-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 cpu fix from Thomas Gleixner:
 "A single fix for x86:

   - Prevent a bogus setting for the number of HT siblings, which is
     caused by the CPUID evaluation trainwreck of X86. That recomputes
     the value for each CPU, so the last CPU "wins". That can cause
     completely bogus sibling values"

* tag 'x86-urgent-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/topology: Fix erroneous smp_num_siblings on Intel Hybrid platforms
This commit is contained in:
Linus Torvalds 2023-05-28 07:42:05 -04:00
parent 2d5438f4c6 edc0a2b595
commit f8b2507c26
1 changed files with 3 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
arch/x86/kernel/cpu/topology.c
View File

@ -79,7 +79,7 @@ int detect_extended_topology_early(struct cpuinfo_x86 *c)
* initial apic id, which also represents 32-bit extended x2apic id.
*/
c->initial_apicid = edx;
smp_num_siblings = LEVEL_MAX_SIBLINGS(ebx);
smp_num_siblings = max_t(int, smp_num_siblings, LEVEL_MAX_SIBLINGS(ebx));
#endif
return 0;
}
@ -109,7 +109,8 @@ int detect_extended_topology(struct cpuinfo_x86 *c)
*/
cpuid_count(leaf, SMT_LEVEL, &eax, &ebx, &ecx, &edx);
c->initial_apicid = edx;
core_level_siblings = smp_num_siblings = LEVEL_MAX_SIBLINGS(ebx);
core_level_siblings = LEVEL_MAX_SIBLINGS(ebx);
smp_num_siblings = max_t(int, smp_num_siblings, LEVEL_MAX_SIBLINGS(ebx));
core_plus_mask_width = ht_mask_width = BITS_SHIFT_NEXT_LEVEL(eax);
die_level_siblings = LEVEL_MAX_SIBLINGS(ebx);
pkg_mask_width = die_plus_mask_width = BITS_SHIFT_NEXT_LEVEL(eax);