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| author | Konstantin Belousov <kib@FreeBSD.org> | 2018-09-04 19:26:54 +0000 |
|---|---|---|
| committer | Konstantin Belousov <kib@FreeBSD.org> | 2018-09-04 19:26:54 +0000 |
| commit | e21c5abc2a941c4b8ee2e434f5aea2dcdc7edb36 (patch) | |
| tree | f6215f3936c406b2646a3e309c44dc15aa7f54cc | |
| parent | 316086bd6c8be194ae394ae72fa3b70cf8899050 (diff) | |
| download | src-e21c5abc2a941c4b8ee2e434f5aea2dcdc7edb36.tar.gz src-e21c5abc2a941c4b8ee2e434f5aea2dcdc7edb36.zip | |
amd64: For non-PTI mode, do not initialize PCPU kcr3 to KPML4phys.
Non-PTI mode does not switch kcr3, which means that kcr3 is almost
always stale. This is important for the NMI handler, which reloads
%cr3 with PCPU(kcr3) if the value is different from PMAP_NO_CR3.
The end result is that curpmap in NMI handler does not match the page
table loaded into hardware. The manifestation was copyin(9) looping
forever when a usermode access page fault cannot be resolved by
vm_fault() updating a different page table.
Reported by: mmacy
Reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 3 days
Approved by: re (gjb)
Notes
Notes:
svn path=/head/; revision=338459
| -rw-r--r-- | sys/amd64/amd64/pmap.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c index cbd76aa48585..8cb09df626be 100644 --- a/sys/amd64/amd64/pmap.c +++ b/sys/amd64/amd64/pmap.c @@ -7582,9 +7582,13 @@ pmap_activate_boot(pmap_t pmap) CPU_SET(cpuid, &pmap->pm_active); #endif PCPU_SET(curpmap, pmap); - kcr3 = pmap->pm_cr3; - if (pmap_pcid_enabled) - kcr3 |= pmap->pm_pcids[cpuid].pm_pcid | CR3_PCID_SAVE; + if (pti) { + kcr3 = pmap->pm_cr3; + if (pmap_pcid_enabled) + kcr3 |= pmap->pm_pcids[cpuid].pm_pcid | CR3_PCID_SAVE; + } else { + kcr3 = PMAP_NO_CR3; + } PCPU_SET(kcr3, kcr3); PCPU_SET(ucr3, PMAP_NO_CR3); } |