Date: Sun, 22 Mar 2009 02:33:48 +0000 (UTC) From: Alan Cox <alc@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r190237 - in head/sys: amd64/amd64 i386/i386 Message-ID: <200903220233.n2M2Xmxu054201@svn.freebsd.org>
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Author: alc Date: Sun Mar 22 02:33:48 2009 New Revision: 190237 URL: http://svn.freebsd.org/changeset/base/190237 Log: Eliminate the recomputation of pcb_cr3 from cpu_set_upcall(). The bcopy()ed value from the old thread is the correct value because the new thread and the old thread will share a page table. Modified: head/sys/amd64/amd64/vm_machdep.c head/sys/i386/i386/vm_machdep.c Modified: head/sys/amd64/amd64/vm_machdep.c ============================================================================== --- head/sys/amd64/amd64/vm_machdep.c Sun Mar 22 01:24:32 2009 (r190236) +++ head/sys/amd64/amd64/vm_machdep.c Sun Mar 22 02:33:48 2009 (r190237) @@ -287,7 +287,6 @@ cpu_set_upcall(struct thread *td, struct * Set registers for trampoline to user mode. Leave space for the * return address on stack. These are the kernel mode register values. */ - pcb2->pcb_cr3 = vtophys(vmspace_pmap(td->td_proc->p_vmspace)->pm_pml4); pcb2->pcb_r12 = (register_t)fork_return; /* trampoline arg */ pcb2->pcb_rbp = 0; pcb2->pcb_rsp = (register_t)td->td_frame - sizeof(void *); /* trampoline arg */ @@ -295,6 +294,7 @@ cpu_set_upcall(struct thread *td, struct pcb2->pcb_rip = (register_t)fork_trampoline; /* * If we didn't copy the pcb, we'd need to do the following registers: + * pcb2->pcb_cr3: cloned above. * pcb2->pcb_dr*: cloned above. * pcb2->pcb_savefpu: cloned above. * pcb2->pcb_onfault: cloned above (always NULL here?). Modified: head/sys/i386/i386/vm_machdep.c ============================================================================== --- head/sys/i386/i386/vm_machdep.c Sun Mar 22 01:24:32 2009 (r190236) +++ head/sys/i386/i386/vm_machdep.c Sun Mar 22 02:33:48 2009 (r190237) @@ -424,11 +424,6 @@ cpu_set_upcall(struct thread *td, struct * Set registers for trampoline to user mode. Leave space for the * return address on stack. These are the kernel mode register values. */ -#ifdef PAE - pcb2->pcb_cr3 = vtophys(vmspace_pmap(td->td_proc->p_vmspace)->pm_pdpt); -#else - pcb2->pcb_cr3 = vtophys(vmspace_pmap(td->td_proc->p_vmspace)->pm_pdir); -#endif pcb2->pcb_edi = 0; pcb2->pcb_esi = (int)fork_return; /* trampoline arg */ pcb2->pcb_ebp = 0; @@ -439,6 +434,7 @@ cpu_set_upcall(struct thread *td, struct pcb2->pcb_gs = rgs(); /* * If we didn't copy the pcb, we'd need to do the following registers: + * pcb2->pcb_cr3: cloned above. * pcb2->pcb_dr*: cloned above. * pcb2->pcb_savefpu: cloned above. * pcb2->pcb_flags: cloned above.
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