Date: Fri, 12 Mar 2021 17:49:25 GMT From: John Baldwin <jhb@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: 755efb8d8fca - main - x86: Copy the FPU/XSAVE state from the creating thread to new threads. Message-ID: <202103121749.12CHnPuc066672@gitrepo.freebsd.org>
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The branch main has been updated by jhb: URL: https://cgit.FreeBSD.org/src/commit/?id=755efb8d8fcacc6607bc46469750d78497f89378 commit 755efb8d8fcacc6607bc46469750d78497f89378 Author: John Baldwin <jhb@FreeBSD.org> AuthorDate: 2021-03-12 17:47:41 +0000 Commit: John Baldwin <jhb@FreeBSD.org> CommitDate: 2021-03-12 17:47:41 +0000 x86: Copy the FPU/XSAVE state from the creating thread to new threads. POSIX states that new threads created via pthread_create() should inherit the "floating point environment" from the creating thread. Discussed with: kib MFC after: 1 week Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D29204 --- sys/amd64/amd64/vm_machdep.c | 10 ++++++---- sys/i386/i386/vm_machdep.c | 12 +++++++++--- 2 files changed, 15 insertions(+), 7 deletions(-) diff --git a/sys/amd64/amd64/vm_machdep.c b/sys/amd64/amd64/vm_machdep.c index 76f7f400dd9c..f10d0339a65a 100644 --- a/sys/amd64/amd64/vm_machdep.c +++ b/sys/amd64/amd64/vm_machdep.c @@ -564,16 +564,18 @@ cpu_copy_thread(struct thread *td, struct thread *td0) pcb2 = td->td_pcb; + /* Ensure that td0's pcb is up to date. */ + fpuexit(td0); + if (td0 == curthread) + update_pcb_bases(td0->td_pcb); + /* * Copy the upcall pcb. This loads kernel regs. * Those not loaded individually below get their default * values here. */ - if (td0 == curthread) - update_pcb_bases(td0->td_pcb); bcopy(td0->td_pcb, pcb2, sizeof(*pcb2)); - clear_pcb_flags(pcb2, PCB_FPUINITDONE | PCB_USERFPUINITDONE | - PCB_KERNFPU); + clear_pcb_flags(pcb2, PCB_KERNFPU); pcb2->pcb_save = get_pcb_user_save_pcb(pcb2); bcopy(get_pcb_user_save_td(td0), pcb2->pcb_save, cpu_max_ext_state_size); diff --git a/sys/i386/i386/vm_machdep.c b/sys/i386/i386/vm_machdep.c index d3182cb224bf..502de6e7f38f 100644 --- a/sys/i386/i386/vm_machdep.c +++ b/sys/i386/i386/vm_machdep.c @@ -428,14 +428,21 @@ cpu_copy_thread(struct thread *td, struct thread *td0) /* Point the pcb to the top of the stack. */ pcb2 = td->td_pcb; + /* Ensure that td0's pcb is up to date. */ + if (td0 == curthread) + td0->td_pcb->pcb_gs = rgs(); + critical_enter(); + if (PCPU_GET(fpcurthread) == td0) + npxsave(td0->td_pcb->pcb_save); + critical_exit(); + /* * Copy the upcall pcb. This loads kernel regs. * Those not loaded individually below get their default * values here. */ bcopy(td0->td_pcb, pcb2, sizeof(*pcb2)); - pcb2->pcb_flags &= ~(PCB_NPXINITDONE | PCB_NPXUSERINITDONE | - PCB_KERNNPX); + pcb2->pcb_flags &= ~PCB_KERNNPX; pcb2->pcb_save = get_pcb_user_save_pcb(pcb2); bcopy(get_pcb_user_save_td(td0), pcb2->pcb_save, cpu_max_ext_state_size); @@ -463,7 +470,6 @@ cpu_copy_thread(struct thread *td, struct thread *td0) pcb2->pcb_esp = (int)td->td_frame - sizeof(void *); /* trampoline arg */ pcb2->pcb_ebx = (int)td; /* trampoline arg */ pcb2->pcb_eip = (int)fork_trampoline + setidt_disp; - pcb2->pcb_gs = rgs(); /* * If we didn't copy the pcb, we'd need to do the following registers: * pcb2->pcb_cr3: cloned above.
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