svn commit: r337773 - in head/sys/amd64: amd64 include
Konstantin Belousov
kib at FreeBSD.org
Tue Aug 14 16:37:16 UTC 2018
Author: kib
Date: Tue Aug 14 16:37:14 2018
New Revision: 337773
URL: https://svnweb.freebsd.org/changeset/base/337773
Log:
amd64: ensure that curproc->p_vmspace pmap always matches PCPU
curpmap.
When performing context switch on a machine without PCID, if current
%cr3 equals to the new pmap %cr3, which is typical for kernel_pmap
vs. kernel process, I overlooked to update PCPU curpmap value. Remove
check for %cr3 not equal to pm_cr3 for doing the update. It is
believed that this case cannot happen at all, due to other changes in
this revision.
Also, do not set the very first curpmap to kernel_pmap, it should be
vmspace0 pmap instead to match curproc.
Move the common code to activate the initial pmap both on BSP and APs
into pmap_activate_boot() helper.
Reported by: eadler, ambrisko
Discussed with: kevans
Reviewed by: alc, markj (previous version)
Tested by: ambrisko (previous version)
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D16618
Modified:
head/sys/amd64/amd64/mp_machdep.c
head/sys/amd64/amd64/pmap.c
head/sys/amd64/include/pmap.h
Modified: head/sys/amd64/amd64/mp_machdep.c
==============================================================================
--- head/sys/amd64/amd64/mp_machdep.c Tue Aug 14 16:33:30 2018 (r337772)
+++ head/sys/amd64/amd64/mp_machdep.c Tue Aug 14 16:37:14 2018 (r337773)
@@ -58,6 +58,7 @@ __FBSDID("$FreeBSD$");
#include <vm/vm_param.h>
#include <vm/pmap.h>
#include <vm/vm_kern.h>
+#include <vm/vm_map.h>
#include <vm/vm_extern.h>
#include <x86/apicreg.h>
@@ -297,7 +298,6 @@ init_secondary(void)
pc->pc_gs32p = &gdt[NGDT * cpu + GUGS32_SEL];
pc->pc_ldt = (struct system_segment_descriptor *)&gdt[NGDT * cpu +
GUSERLDT_SEL];
- pc->pc_curpmap = kernel_pmap;
pc->pc_pcid_gen = 1;
pc->pc_pcid_next = PMAP_PCID_KERN + 1;
common_tss[cpu].tss_rsp0 = 0;
@@ -342,6 +342,7 @@ init_secondary(void)
while (atomic_load_acq_int(&aps_ready) == 0)
ia32_pause();
+ pmap_activate_boot(vmspace_pmap(proc0.p_vmspace));
init_secondary_tail();
}
Modified: head/sys/amd64/amd64/pmap.c
==============================================================================
--- head/sys/amd64/amd64/pmap.c Tue Aug 14 16:33:30 2018 (r337772)
+++ head/sys/amd64/amd64/pmap.c Tue Aug 14 16:37:14 2018 (r337773)
@@ -2655,9 +2655,7 @@ pmap_pinit0(pmap_t pmap)
__pcpu[i].pc_ucr3 = PMAP_NO_CR3;
}
}
- PCPU_SET(curpmap, kernel_pmap);
- pmap_activate(curthread);
- CPU_FILL(&kernel_pmap->pm_active);
+ pmap_activate_boot(pmap);
}
void
@@ -7529,7 +7527,7 @@ pmap_activate_sw(struct thread *td)
intr_restore(rflags);
if (cached)
PCPU_INC(pm_save_cnt);
- } else if (cr3 != pmap->pm_cr3) {
+ } else {
load_cr3(pmap->pm_cr3);
PCPU_SET(curpmap, pmap);
if (pti) {
@@ -7557,6 +7555,26 @@ pmap_activate(struct thread *td)
critical_enter();
pmap_activate_sw(td);
critical_exit();
+}
+
+void
+pmap_activate_boot(pmap_t pmap)
+{
+ u_int cpuid;
+
+ /*
+ * kernel_pmap must be never deactivated, and we ensure that
+ * by never activating it at all.
+ */
+ MPASS(pmap != kernel_pmap);
+
+ cpuid = PCPU_GET(cpuid);
+#ifdef SMP
+ CPU_SET_ATOMIC(cpuid, &pmap->pm_active);
+#else
+ CPU_SET(cpuid, &pmap->pm_active);
+#endif
+ PCPU_SET(curpmap, pmap);
}
void
Modified: head/sys/amd64/include/pmap.h
==============================================================================
--- head/sys/amd64/include/pmap.h Tue Aug 14 16:33:30 2018 (r337772)
+++ head/sys/amd64/include/pmap.h Tue Aug 14 16:37:14 2018 (r337773)
@@ -407,6 +407,7 @@ extern int invpcid_works;
struct thread;
+void pmap_activate_boot(pmap_t pmap);
void pmap_activate_sw(struct thread *);
void pmap_bootstrap(vm_paddr_t *);
int pmap_cache_bits(pmap_t pmap, int mode, boolean_t is_pde);
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