Author: kib
Date: Tue Jul 31 10:18:30 2018
New Revision: 336963
URL: https://svnweb.freebsd.org/changeset/base/336963
Log:
MFC r336683:
Extend ranges of the critical sections to ensure that context switch
code never sees FPU pcb flags not consistent with the hardware state.
Modified:
stable/11/sys/amd64/amd64/fpu.c
stable/11/sys/amd64/amd64/machdep.c
stable/11/sys/i386/i386/machdep.c
stable/11/sys/i386/isa/npx.c
Directory Properties:
stable/11/ (props changed)
Modified: stable/11/sys/amd64/amd64/fpu.c
==============================================================================
--- stable/11/sys/amd64/amd64/fpu.c Tue Jul 31 06:27:05 2018
(r336962)
+++ stable/11/sys/amd64/amd64/fpu.c Tue Jul 31 10:18:30 2018
(r336963)
@@ -744,22 +744,22 @@ fpugetregs(struct thread *td)
int max_ext_n, i, owned;
pcb = td->td_pcb;
+ critical_enter();
if ((pcb->pcb_flags & PCB_USERFPUINITDONE) == 0) {
bcopy(fpu_initialstate, get_pcb_user_save_pcb(pcb),
cpu_max_ext_state_size);
get_pcb_user_save_pcb(pcb)->sv_env.en_cw =
pcb->pcb_initial_fpucw;
fpuuserinited(td);
+ critical_exit();
return (_MC_FPOWNED_PCB);
}
- critical_enter();
if (td == PCPU_GET(fpcurthread) && PCB_USER_FPU(pcb)) {
fpusave(get_pcb_user_save_pcb(pcb));
owned = _MC_FPOWNED_FPU;
} else {
owned = _MC_FPOWNED_PCB;
}
- critical_exit();
if (use_xsave) {
/*
* Handle partially saved state.
@@ -779,6 +779,7 @@ fpugetregs(struct thread *td)
*xstate_bv |= bit;
}
}
+ critical_exit();
return (owned);
}
@@ -787,6 +788,7 @@ fpuuserinited(struct thread *td)
{
struct pcb *pcb;
+ CRITICAL_ASSERT(td);
pcb = td->td_pcb;
if (PCB_USER_FPU(pcb))
set_pcb_flags(pcb,
@@ -845,26 +847,25 @@ fpusetregs(struct thread *td, struct savefpu *addr, ch
addr->sv_env.en_mxcsr &= cpu_mxcsr_mask;
pcb = td->td_pcb;
+ error = 0;
critical_enter();
if (td == PCPU_GET(fpcurthread) && PCB_USER_FPU(pcb)) {
error = fpusetxstate(td, xfpustate, xfpustate_size);
- if (error != 0) {
- critical_exit();
- return (error);
+ if (error == 0) {
+ bcopy(addr, get_pcb_user_save_td(td), sizeof(*addr));
+ fpurestore(get_pcb_user_save_td(td));
+ set_pcb_flags(pcb, PCB_FPUINITDONE |
+ PCB_USERFPUINITDONE);
}
- bcopy(addr, get_pcb_user_save_td(td), sizeof(*addr));
- fpurestore(get_pcb_user_save_td(td));
- critical_exit();
- set_pcb_flags(pcb, PCB_FPUINITDONE | PCB_USERFPUINITDONE);
} else {
- critical_exit();
error = fpusetxstate(td, xfpustate, xfpustate_size);
- if (error != 0)
- return (error);
- bcopy(addr, get_pcb_user_save_td(td), sizeof(*addr));
- fpuuserinited(td);
+ if (error == 0) {
+ bcopy(addr, get_pcb_user_save_td(td), sizeof(*addr));
+ fpuuserinited(td);
+ }
}
- return (0);
+ critical_exit();
+ return (error);
}
/*
@@ -1037,6 +1038,7 @@ fpu_kern_enter(struct thread *td, struct fpu_kern_ctx
ctx->flags = FPU_KERN_CTX_DUMMY | FPU_KERN_CTX_INUSE;
return (0);
}
+ critical_enter();
KASSERT(!PCB_USER_FPU(pcb) || pcb->pcb_save ==
get_pcb_user_save_pcb(pcb), ("mangled pcb_save"));
ctx->flags = FPU_KERN_CTX_INUSE;
@@ -1047,6 +1049,7 @@ fpu_kern_enter(struct thread *td, struct fpu_kern_ctx
pcb->pcb_save = fpu_kern_ctx_savefpu(ctx);
set_pcb_flags(pcb, PCB_KERNFPU);
clear_pcb_flags(pcb, PCB_FPUINITDONE);
+ critical_exit();
return (0);
}
@@ -1065,7 +1068,6 @@ fpu_kern_leave(struct thread *td, struct fpu_kern_ctx
clear_pcb_flags(pcb, PCB_FPUNOSAVE | PCB_FPUINITDONE);
start_emulating();
- critical_exit();
} else {
KASSERT((ctx->flags & FPU_KERN_CTX_INUSE) != 0,
("leaving not inuse ctx"));
@@ -1079,7 +1081,6 @@ fpu_kern_leave(struct thread *td, struct fpu_kern_ctx
critical_enter();
if (curthread == PCPU_GET(fpcurthread))
fpudrop();
- critical_exit();
pcb->pcb_save = ctx->prev;
}
@@ -1096,6 +1097,7 @@ fpu_kern_leave(struct thread *td, struct fpu_kern_ctx
clear_pcb_flags(pcb, PCB_FPUINITDONE);
KASSERT(!PCB_USER_FPU(pcb), ("unpaired fpu_kern_leave"));
}
+ critical_exit();
return (0);
}
Modified: stable/11/sys/amd64/amd64/machdep.c
==============================================================================
--- stable/11/sys/amd64/amd64/machdep.c Tue Jul 31 06:27:05 2018
(r336962)
+++ stable/11/sys/amd64/amd64/machdep.c Tue Jul 31 10:18:30 2018
(r336963)
@@ -2158,8 +2158,10 @@ int
set_fpregs(struct thread *td, struct fpreg *fpregs)
{
+ critical_enter();
set_fpregs_xmm(fpregs, get_pcb_user_save_td(td));
fpuuserinited(td);
+ critical_exit();
return (0);
}
Modified: stable/11/sys/i386/i386/machdep.c
==============================================================================
--- stable/11/sys/i386/i386/machdep.c Tue Jul 31 06:27:05 2018
(r336962)
+++ stable/11/sys/i386/i386/machdep.c Tue Jul 31 10:18:30 2018
(r336963)
@@ -3004,6 +3004,7 @@ int
set_fpregs(struct thread *td, struct fpreg *fpregs)
{
+ critical_enter();
if (cpu_fxsr)
npx_set_fpregs_xmm((struct save87 *)fpregs,
&get_pcb_user_save_td(td)->sv_xmm);
@@ -3011,6 +3012,7 @@ set_fpregs(struct thread *td, struct fpreg *fpregs)
bcopy(fpregs, &get_pcb_user_save_td(td)->sv_87,
sizeof(*fpregs));
npxuserinited(td);
+ critical_exit();
return (0);
}
Modified: stable/11/sys/i386/isa/npx.c
==============================================================================
--- stable/11/sys/i386/isa/npx.c Tue Jul 31 06:27:05 2018
(r336962)
+++ stable/11/sys/i386/isa/npx.c Tue Jul 31 10:18:30 2018
(r336963)
@@ -974,14 +974,15 @@ npxgetregs(struct thread *td)
return (_MC_FPOWNED_NONE);
pcb = td->td_pcb;
+ critical_enter();
if ((pcb->pcb_flags & PCB_NPXINITDONE) == 0) {
bcopy(npx_initialstate, get_pcb_user_save_pcb(pcb),
cpu_max_ext_state_size);
SET_FPU_CW(get_pcb_user_save_pcb(pcb), pcb->pcb_initial_npxcw);
npxuserinited(td);
+ critical_exit();
return (_MC_FPOWNED_PCB);
}
- critical_enter();
if (td == PCPU_GET(fpcurthread)) {
fpusave(get_pcb_user_save_pcb(pcb));
if (!cpu_fxsr)
@@ -995,7 +996,6 @@ npxgetregs(struct thread *td)
} else {
owned = _MC_FPOWNED_PCB;
}
- critical_exit();
if (use_xsave) {
/*
* Handle partially saved state.
@@ -1018,6 +1018,7 @@ npxgetregs(struct thread *td)
*xstate_bv |= bit;
}
}
+ critical_exit();
return (owned);
}
@@ -1026,6 +1027,7 @@ npxuserinited(struct thread *td)
{
struct pcb *pcb;
+ CRITICAL_ASSERT(td);
pcb = td->td_pcb;
if (PCB_USER_FPU(pcb))
pcb->pcb_flags |= PCB_NPXINITDONE;
@@ -1083,28 +1085,26 @@ npxsetregs(struct thread *td, union savefpu *addr, cha
if (cpu_fxsr)
addr->sv_xmm.sv_env.en_mxcsr &= cpu_mxcsr_mask;
pcb = td->td_pcb;
+ error = 0;
critical_enter();
if (td == PCPU_GET(fpcurthread) && PCB_USER_FPU(pcb)) {
error = npxsetxstate(td, xfpustate, xfpustate_size);
- if (error != 0) {
- critical_exit();
- return (error);
+ if (error == 0) {
+ if (!cpu_fxsr)
+ fnclex(); /* As in npxdrop(). */
+ bcopy(addr, get_pcb_user_save_td(td), sizeof(*addr));
+ fpurstor(get_pcb_user_save_td(td));
+ pcb->pcb_flags |= PCB_NPXUSERINITDONE | PCB_NPXINITDONE;
}
- if (!cpu_fxsr)
- fnclex(); /* As in npxdrop(). */
- bcopy(addr, get_pcb_user_save_td(td), sizeof(*addr));
- fpurstor(get_pcb_user_save_td(td));
- critical_exit();
- pcb->pcb_flags |= PCB_NPXUSERINITDONE | PCB_NPXINITDONE;
} else {
- critical_exit();
error = npxsetxstate(td, xfpustate, xfpustate_size);
- if (error != 0)
- return (error);
- bcopy(addr, get_pcb_user_save_td(td), sizeof(*addr));
- npxuserinited(td);
+ if (error == 0) {
+ bcopy(addr, get_pcb_user_save_td(td), sizeof(*addr));
+ npxuserinited(td);
+ }
}
- return (0);
+ critical_exit();
+ return (error);
}
static void
@@ -1373,6 +1373,7 @@ fpu_kern_enter(struct thread *td, struct fpu_kern_ctx
return (0);
}
pcb = td->td_pcb;
+ critical_enter();
KASSERT(!PCB_USER_FPU(pcb) || pcb->pcb_save ==
get_pcb_user_save_pcb(pcb), ("mangled pcb_save"));
ctx->flags = FPU_KERN_CTX_INUSE;
@@ -1383,6 +1384,7 @@ fpu_kern_enter(struct thread *td, struct fpu_kern_ctx
pcb->pcb_save = fpu_kern_ctx_savefpu(ctx);
pcb->pcb_flags |= PCB_KERNNPX;
pcb->pcb_flags &= ~PCB_NPXINITDONE;
+ critical_exit();
return (0);
}
@@ -1401,7 +1403,6 @@ fpu_kern_leave(struct thread *td, struct fpu_kern_ctx
critical_enter();
if (curthread == PCPU_GET(fpcurthread))
npxdrop();
- critical_exit();
pcb->pcb_save = ctx->prev;
if (pcb->pcb_save == get_pcb_user_save_pcb(pcb)) {
if ((pcb->pcb_flags & PCB_NPXUSERINITDONE) != 0)
@@ -1416,6 +1417,7 @@ fpu_kern_leave(struct thread *td, struct fpu_kern_ctx
pcb->pcb_flags &= ~PCB_NPXINITDONE;
KASSERT(!PCB_USER_FPU(pcb), ("unpaired fpu_kern_leave"));
}
+ critical_exit();
return (0);
}
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