Author: kib Date: Wed Oct 14 23:01:41 2020 New Revision: 366713 URL: https://svnweb.freebsd.org/changeset/base/366713
Log: Fix for mis-interpretation of PCB_KERNFPU. RIght now PCB_KERNFPU is used both as indication that kernel prepared hardware FPU context to use and that the thread is fpu-kern thread. This also breaks fpu_kern_enter(FPU_KERN_NOCTX), since fpu_kern_leave() then clears PCB_KERNFPU. Introduce new flag PCB_KERNFPU_THR which indicates that the thread is fpu-kern. Do not clear PCB_KERNFPU if fpu-kern thread leaves noctx fpu region. Reported and tested by: jhb (amd64) Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D25511 Modified: head/sys/amd64/amd64/fpu.c head/sys/amd64/include/pcb.h head/sys/i386/i386/npx.c head/sys/i386/include/pcb.h Modified: head/sys/amd64/amd64/fpu.c ============================================================================== --- head/sys/amd64/amd64/fpu.c Wed Oct 14 22:57:50 2020 (r366712) +++ head/sys/amd64/amd64/fpu.c Wed Oct 14 23:01:41 2020 (r366713) @@ -1230,8 +1230,9 @@ fpu_kern_leave(struct thread *td, struct fpu_kern_ctx if (pcb->pcb_save == get_pcb_user_save_pcb(pcb)) { if ((pcb->pcb_flags & PCB_USERFPUINITDONE) != 0) { set_pcb_flags(pcb, PCB_FPUINITDONE); - clear_pcb_flags(pcb, PCB_KERNFPU); - } else + if ((pcb->pcb_flags & PCB_KERNFPU_THR) == 0) + clear_pcb_flags(pcb, PCB_KERNFPU); + } else if ((pcb->pcb_flags & PCB_KERNFPU_THR) == 0) clear_pcb_flags(pcb, PCB_FPUINITDONE | PCB_KERNFPU); } else { if ((ctx->flags & FPU_KERN_CTX_FPUINITDONE) != 0) @@ -1254,7 +1255,7 @@ fpu_kern_thread(u_int flags) ("mangled pcb_save")); KASSERT(PCB_USER_FPU(curpcb), ("recursive call")); - set_pcb_flags(curpcb, PCB_KERNFPU); + set_pcb_flags(curpcb, PCB_KERNFPU | PCB_KERNFPU_THR); return (0); } @@ -1264,7 +1265,7 @@ is_fpu_kern_thread(u_int flags) if ((curthread->td_pflags & TDP_KTHREAD) == 0) return (0); - return ((curpcb->pcb_flags & PCB_KERNFPU) != 0); + return ((curpcb->pcb_flags & PCB_KERNFPU_THR) != 0); } /* Modified: head/sys/amd64/include/pcb.h ============================================================================== --- head/sys/amd64/include/pcb.h Wed Oct 14 22:57:50 2020 (r366712) +++ head/sys/amd64/include/pcb.h Wed Oct 14 23:01:41 2020 (r366713) @@ -84,6 +84,7 @@ struct pcb { #define PCB_KERNFPU 0x04 /* kernel uses fpu */ #define PCB_FPUINITDONE 0x08 /* fpu state is initialized */ #define PCB_USERFPUINITDONE 0x10 /* fpu user state is initialized */ +#define PCB_KERNFPU_THR 0x20 /* fpu_kern_thread() */ #define PCB_32BIT 0x40 /* process has 32 bit context (segs etc) */ #define PCB_FPUNOSAVE 0x80 /* no save area for current FPU ctx */ Modified: head/sys/i386/i386/npx.c ============================================================================== --- head/sys/i386/i386/npx.c Wed Oct 14 22:57:50 2020 (r366712) +++ head/sys/i386/i386/npx.c Wed Oct 14 23:01:41 2020 (r366713) @@ -1472,11 +1472,12 @@ fpu_kern_leave(struct thread *td, struct fpu_kern_ctx } if (pcb->pcb_save == get_pcb_user_save_pcb(pcb)) { - if ((pcb->pcb_flags & PCB_NPXUSERINITDONE) != 0) + if ((pcb->pcb_flags & PCB_NPXUSERINITDONE) != 0) { pcb->pcb_flags |= PCB_NPXINITDONE; - else - pcb->pcb_flags &= ~PCB_NPXINITDONE; - pcb->pcb_flags &= ~PCB_KERNNPX; + if ((pcb->pcb_flags & PCB_KERNNPX_THR) == 0) + pcb->pcb_flags |= ~PCB_KERNNPX; + } else if ((pcb->pcb_flags & PCB_KERNNPX_THR) == 0) + pcb->pcb_flags &= ~(PCB_NPXINITDONE | PCB_KERNNPX); } else { if ((ctx->flags & FPU_KERN_CTX_NPXINITDONE) != 0) pcb->pcb_flags |= PCB_NPXINITDONE; @@ -1498,7 +1499,7 @@ fpu_kern_thread(u_int flags) ("mangled pcb_save")); KASSERT(PCB_USER_FPU(curpcb), ("recursive call")); - curpcb->pcb_flags |= PCB_KERNNPX; + curpcb->pcb_flags |= PCB_KERNNPX | PCB_KERNNPX_THR; return (0); } @@ -1508,7 +1509,7 @@ is_fpu_kern_thread(u_int flags) if ((curthread->td_pflags & TDP_KTHREAD) == 0) return (0); - return ((curpcb->pcb_flags & PCB_KERNNPX) != 0); + return ((curpcb->pcb_flags & PCB_KERNNPX_THR) != 0); } /* Modified: head/sys/i386/include/pcb.h ============================================================================== --- head/sys/i386/include/pcb.h Wed Oct 14 22:57:50 2020 (r366712) +++ head/sys/i386/include/pcb.h Wed Oct 14 23:01:41 2020 (r366713) @@ -82,6 +82,7 @@ struct pcb { u_int pcb_flags; #define PCB_DBREGS 0x02 /* process using debug registers */ +#define PCB_KERNNPX_THR 0x04 /* fpu_kern_thread() */ #define PCB_NPXINITDONE 0x08 /* fpu state is initialized */ #define PCB_VM86CALL 0x10 /* in vm86 call */ #define PCB_NPXUSERINITDONE 0x20 /* user fpu state is initialized */ _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
