The pcb_gs32p should be per-cpu, not per-thread pointer. This is

location in GDT where the segment descriptor from pcb_gs32sd is
copied, and the location is in GDT local to CPU.

Noted and reviewed by:	peter
MFC after:	1 week

7 files changed, 8 insertions, 8 deletions

diff --git a/sys/amd64/amd64/cpu_switch.S b/sys/amd64/amd64/cpu_switch.S
index a0b11f8..99d6716 100644
--- a/sys/amd64/amd64/cpu_switch.S
+++ b/sys/amd64/amd64/cpu_switch.S
@@ -266,7 +266,7 @@ store_seg:
 	movl	%es,PCB_ES(%r8)
 	movl	%fs,PCB_FS(%r8)
 	jmp	done_store_seg
-2:	movq	PCB_GS32P(%r8),%rax
+2:	movq	PCPU(GS32P),%rax
 	movq	(%rax),%rax
 	movq	%rax,PCB_GS32SD(%r8)
 	jmp	1b
@@ -283,7 +283,7 @@ load_seg:
 	movl	PCB_FS(%r8),%fs
 	jmp	done_load_seg
 	/* Restore userland %gs while preserving kernel gsbase */
-2:	movq	PCB_GS32P(%r8),%rax
+2:	movq	PCPU(GS32P),%rax
 	movq	PCB_GS32SD(%r8),%rcx
 	movq	%rcx,(%rax)
 	jmp	1b
diff --git a/sys/amd64/amd64/genassym.c b/sys/amd64/amd64/genassym.c
index fec0380..f749dd6 100644
--- a/sys/amd64/amd64/genassym.c
+++ b/sys/amd64/amd64/genassym.c
@@ -147,7 +147,6 @@ ASSYM(PCB_FLAGS, offsetof(struct pcb, pcb_flags));
 ASSYM(PCB_SAVEFPU, offsetof(struct pcb, pcb_save));
 ASSYM(PCB_SAVEFPU_SIZE, sizeof(struct savefpu));
 ASSYM(PCB_ONFAULT, offsetof(struct pcb, pcb_onfault));
-ASSYM(PCB_GS32P, offsetof(struct pcb, pcb_gs32p));
 ASSYM(PCB_GS32SD, offsetof(struct pcb, pcb_gs32sd));
 
 ASSYM(PCB_SIZE, sizeof(struct pcb));
@@ -199,6 +198,7 @@ ASSYM(PC_SCRATCH_RSP, offsetof(struct pcpu, pc_scratch_rsp));
 ASSYM(PC_CURPMAP, offsetof(struct pcpu, pc_curpmap));
 ASSYM(PC_TSSP, offsetof(struct pcpu, pc_tssp));
 ASSYM(PC_RSP0, offsetof(struct pcpu, pc_rsp0));
+ASSYM(PC_GS32P, offsetof(struct pcpu, pc_gs32p));
  
 ASSYM(LA_VER, offsetof(struct LAPIC, version));
 ASSYM(LA_TPR, offsetof(struct LAPIC, tpr));
diff --git a/sys/amd64/amd64/machdep.c b/sys/amd64/amd64/machdep.c
index 2280ee9..988b039 100644
--- a/sys/amd64/amd64/machdep.c
+++ b/sys/amd64/amd64/machdep.c
@@ -1347,6 +1347,7 @@ hammer_time(u_int64_t modulep, u_int64_t physfree)
 	PCPU_SET(curthread, &thread0);
 	PCPU_SET(curpcb, thread0.td_pcb);
 	PCPU_SET(tssp, &common_tss[0]);
+	PCPU_SET(gs32p, &gdt[GUGS32_SEL]);
 
 	/*
 	 * Initialize mutexes.
diff --git a/sys/amd64/amd64/mp_machdep.c b/sys/amd64/amd64/mp_machdep.c
index 5dc3228..2de63e3 100644
--- a/sys/amd64/amd64/mp_machdep.c
+++ b/sys/amd64/amd64/mp_machdep.c
@@ -470,6 +470,7 @@ init_secondary(void)
 	pc->pc_curthread = 0;
 	pc->pc_tssp = &common_tss[cpu];
 	pc->pc_rsp0 = 0;
+	pc->pc_gs32p = &gdt[NGDT * cpu + GUGS32_SEL];
 
 	wrmsr(MSR_FSBASE, 0);		/* User value */
 	wrmsr(MSR_GSBASE, (u_int64_t)pc);
diff --git a/sys/amd64/include/pcb.h b/sys/amd64/include/pcb.h
index 647d5c9..43b59e5 100644
--- a/sys/amd64/include/pcb.h
+++ b/sys/amd64/include/pcb.h
@@ -77,7 +77,6 @@ struct pcb {
 	caddr_t	pcb_onfault;	/* copyin/out fault recovery */
 
 	/* 32-bit segment descriptor */
-	struct user_segment_descriptor	*pcb_gs32p;
 	struct user_segment_descriptor	pcb_gs32sd;
 };
 
diff --git a/sys/amd64/include/pcpu.h b/sys/amd64/include/pcpu.h
index fe811c5..e9faf28 100644
--- a/sys/amd64/include/pcpu.h
+++ b/sys/amd64/include/pcpu.h
@@ -48,7 +48,8 @@
 	register_t pc_rsp0;						\
 	register_t pc_scratch_rsp;	/* User %rsp in syscall */	\
 	u_int	pc_apic_id;						\
-	u_int   pc_acpi_id		/* ACPI CPU id */
+	u_int   pc_acpi_id;		/* ACPI CPU id */		\
+	struct user_segment_descriptor	*pc_gs32p
 
 #ifdef _KERNEL
 
diff --git a/sys/amd64/linux32/linux32_machdep.c b/sys/amd64/linux32/linux32_machdep.c
index ceba561..aecf869 100644
--- a/sys/amd64/linux32/linux32_machdep.c
+++ b/sys/amd64/linux32/linux32_machdep.c
@@ -694,7 +694,6 @@ linux_clone(struct thread *td, struct linux_clone_args *args)
 #endif
 			td2->td_pcb->pcb_gsbase = (register_t)info.base_addr;
 			td2->td_pcb->pcb_gs32sd = sd;
-			td2->td_pcb->pcb_gs32p = &gdt[GUGS32_SEL];
 			td2->td_pcb->pcb_gs = GSEL(GUGS32_SEL, SEL_UPL);
 			td2->td_pcb->pcb_flags |= PCB_GS32BIT | PCB_32BIT;
 		}
@@ -1352,8 +1351,7 @@ linux_set_thread_area(struct thread *td,
 
 	critical_enter();
 	td->td_pcb->pcb_gsbase = (register_t)info.base_addr;
-	td->td_pcb->pcb_gs32sd = gdt[GUGS32_SEL] = sd;
-	td->td_pcb->pcb_gs32p = &gdt[GUGS32_SEL];
+	td->td_pcb->pcb_gs32sd = *PCPU_GET(gs32p) = sd;
 	td->td_pcb->pcb_flags |= PCB_32BIT | PCB_GS32BIT;
 	wrmsr(MSR_KGSBASE, td->td_pcb->pcb_gsbase);
 	critical_exit();