Date: Thu, 10 Sep 2015 17:46:49 +0000 (UTC) From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r287625 - in head/sys: amd64/amd64 arm/arm arm64/arm64 i386/i386 mips/mips powerpc/powerpc sparc64/sparc64 Message-ID: <201509101746.t8AHknft012076@repo.freebsd.org>
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Author: kib Date: Thu Sep 10 17:46:48 2015 New Revision: 287625 URL: https://svnweb.freebsd.org/changeset/base/287625 Log: Do not hold the process around the vm_fault() call from the trap()s. The only operation which is prevented by the hold is the kernel stack swapout for the faulted thread, which should be fine to allow. Remove useless checks for NULL curproc or curproc->p_vmspace from the trap_pfault() wrappers on x86 and powerpc. Reviewed by: alc (previous version) Sponsored by: The FreeBSD Foundation MFC after: 2 weeks Modified: head/sys/amd64/amd64/trap.c head/sys/arm/arm/trap-v6.c head/sys/arm/arm/trap.c head/sys/arm64/arm64/trap.c head/sys/i386/i386/trap.c head/sys/mips/mips/trap.c head/sys/powerpc/powerpc/trap.c head/sys/sparc64/sparc64/trap.c Modified: head/sys/amd64/amd64/trap.c ============================================================================== --- head/sys/amd64/amd64/trap.c Thu Sep 10 16:13:44 2015 (r287624) +++ head/sys/amd64/amd64/trap.c Thu Sep 10 17:46:48 2015 (r287625) @@ -625,7 +625,6 @@ trap_pfault(frame, usermode) int usermode; { vm_offset_t va; - struct vmspace *vm; vm_map_t map; int rv = 0; vm_prot_t ftype; @@ -687,14 +686,7 @@ trap_pfault(frame, usermode) map = kernel_map; } else { - /* - * This is a fault on non-kernel virtual memory. If either - * p or p->p_vmspace is NULL, then the fault is fatal. - */ - if (p == NULL || (vm = p->p_vmspace) == NULL) - goto nogo; - - map = &vm->vm_map; + map = &p->p_vmspace->vm_map; /* * When accessing a usermode address, kernel must be @@ -729,28 +721,8 @@ trap_pfault(frame, usermode) else ftype = VM_PROT_READ; - if (map != kernel_map) { - /* - * Keep swapout from messing with us during this - * critical time. - */ - PROC_LOCK(p); - ++p->p_lock; - PROC_UNLOCK(p); - - /* Fault in the user page: */ - rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL); - - PROC_LOCK(p); - --p->p_lock; - PROC_UNLOCK(p); - } else { - /* - * Don't have to worry about process locking or stacks in the - * kernel. - */ - rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL); - } + /* Fault in the page. */ + rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL); if (rv == KERN_SUCCESS) { #ifdef HWPMC_HOOKS if (ftype == VM_PROT_READ || ftype == VM_PROT_WRITE) { Modified: head/sys/arm/arm/trap-v6.c ============================================================================== --- head/sys/arm/arm/trap-v6.c Thu Sep 10 16:13:44 2015 (r287624) +++ head/sys/arm/arm/trap-v6.c Thu Sep 10 17:46:48 2015 (r287625) @@ -500,28 +500,9 @@ abort_handler(struct trapframe *tf, int onfault = pcb->pcb_onfault; pcb->pcb_onfault = NULL; #endif - if (map != kernel_map) { - /* - * Keep swapout from messing with us during this - * critical time. - */ - PROC_LOCK(p); - ++p->p_lock; - PROC_UNLOCK(p); - - /* Fault in the user page: */ - rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL); - - PROC_LOCK(p); - --p->p_lock; - PROC_UNLOCK(p); - } else { - /* - * Don't have to worry about process locking or stacks in the - * kernel. - */ - rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL); - } + + /* Fault in the page. */ + rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL); #ifdef INVARIANTS pcb->pcb_onfault = onfault; Modified: head/sys/arm/arm/trap.c ============================================================================== --- head/sys/arm/arm/trap.c Thu Sep 10 16:13:44 2015 (r287624) +++ head/sys/arm/arm/trap.c Thu Sep 10 17:46:48 2015 (r287625) @@ -365,19 +365,8 @@ abort_handler(struct trapframe *tf, int onfault = pcb->pcb_onfault; pcb->pcb_onfault = NULL; - if (map != kernel_map) { - PROC_LOCK(p); - p->p_lock++; - PROC_UNLOCK(p); - } error = vm_fault(map, va, ftype, VM_FAULT_NORMAL); pcb->pcb_onfault = onfault; - - if (map != kernel_map) { - PROC_LOCK(p); - p->p_lock--; - PROC_UNLOCK(p); - } if (__predict_true(error == 0)) goto out; fatal_pagefault: @@ -682,20 +671,8 @@ prefetch_abort_handler(struct trapframe if (pmap_fault_fixup(map->pmap, va, VM_PROT_READ, 1)) goto out; - if (map != kernel_map) { - PROC_LOCK(p); - p->p_lock++; - PROC_UNLOCK(p); - } - error = vm_fault(map, va, VM_PROT_READ | VM_PROT_EXECUTE, VM_FAULT_NORMAL); - if (map != kernel_map) { - PROC_LOCK(p); - p->p_lock--; - PROC_UNLOCK(p); - } - if (__predict_true(error == 0)) goto out; Modified: head/sys/arm64/arm64/trap.c ============================================================================== --- head/sys/arm64/arm64/trap.c Thu Sep 10 16:13:44 2015 (r287624) +++ head/sys/arm64/arm64/trap.c Thu Sep 10 17:46:48 2015 (r287625) @@ -190,29 +190,8 @@ data_abort(struct trapframe *frame, uint va = trunc_page(far); ftype = ((esr >> 6) & 1) ? VM_PROT_READ | VM_PROT_WRITE : VM_PROT_READ; - if (map != kernel_map) { - /* - * Keep swapout from messing with us during this - * critical time. - */ - PROC_LOCK(p); - ++p->p_lock; - PROC_UNLOCK(p); - - /* Fault in the user page: */ - error = vm_fault(map, va, ftype, VM_FAULT_NORMAL); - - PROC_LOCK(p); - --p->p_lock; - PROC_UNLOCK(p); - } else { - /* - * Don't have to worry about process locking or stacks in the - * kernel. - */ - error = vm_fault(map, va, ftype, VM_FAULT_NORMAL); - } - + /* Fault in the page. */ + error = vm_fault(map, va, ftype, VM_FAULT_NORMAL); if (error != KERN_SUCCESS) { if (lower) { sig = SIGSEGV; Modified: head/sys/i386/i386/trap.c ============================================================================== --- head/sys/i386/i386/trap.c Thu Sep 10 16:13:44 2015 (r287624) +++ head/sys/i386/i386/trap.c Thu Sep 10 17:46:48 2015 (r287625) @@ -782,7 +782,6 @@ trap_pfault(frame, usermode, eva) vm_offset_t eva; { vm_offset_t va; - struct vmspace *vm; vm_map_t map; int rv = 0; vm_prot_t ftype; @@ -852,14 +851,7 @@ trap_pfault(frame, usermode, eva) map = kernel_map; } else { - /* - * This is a fault on non-kernel virtual memory. If either - * p or p->p_vmspace is NULL, then the fault is fatal. - */ - if (p == NULL || (vm = p->p_vmspace) == NULL) - goto nogo; - - map = &vm->vm_map; + map = &p->p_vmspace->vm_map; /* * When accessing a user-space address, kernel must be @@ -888,28 +880,8 @@ trap_pfault(frame, usermode, eva) else ftype = VM_PROT_READ; - if (map != kernel_map) { - /* - * Keep swapout from messing with us during this - * critical time. - */ - PROC_LOCK(p); - ++p->p_lock; - PROC_UNLOCK(p); - - /* Fault in the user page: */ - rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL); - - PROC_LOCK(p); - --p->p_lock; - PROC_UNLOCK(p); - } else { - /* - * Don't have to worry about process locking or stacks in the - * kernel. - */ - rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL); - } + /* Fault in the page. */ + rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL); if (rv == KERN_SUCCESS) { #ifdef HWPMC_HOOKS if (ftype == VM_PROT_READ || ftype == VM_PROT_WRITE) { Modified: head/sys/mips/mips/trap.c ============================================================================== --- head/sys/mips/mips/trap.c Thu Sep 10 16:13:44 2015 (r287624) +++ head/sys/mips/mips/trap.c Thu Sep 10 17:46:48 2015 (r287625) @@ -714,19 +714,7 @@ dofault: goto nogo; } - /* - * Keep swapout from messing with us during this - * critical time. - */ - PROC_LOCK(p); - ++p->p_lock; - PROC_UNLOCK(p); - rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL); - - PROC_LOCK(p); - --p->p_lock; - PROC_UNLOCK(p); /* * XXXDTRACE: add dtrace_doubletrap_func here? */ Modified: head/sys/powerpc/powerpc/trap.c ============================================================================== --- head/sys/powerpc/powerpc/trap.c Thu Sep 10 16:13:44 2015 (r287624) +++ head/sys/powerpc/powerpc/trap.c Thu Sep 10 17:46:48 2015 (r287625) @@ -704,9 +704,6 @@ trap_pfault(struct trapframe *frame, int #else if ((eva >> ADDR_SR_SHFT) == (USER_ADDR >> ADDR_SR_SHFT)) { #endif - if (p->p_vmspace == NULL) - return (SIGSEGV); - map = &p->p_vmspace->vm_map; #ifdef AIM @@ -720,31 +717,11 @@ trap_pfault(struct trapframe *frame, int } va = trunc_page(eva); - if (map != kernel_map) { - /* - * Keep swapout from messing with us during this - * critical time. - */ - PROC_LOCK(p); - ++p->p_lock; - PROC_UNLOCK(p); - - /* Fault in the user page: */ - rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL); - - PROC_LOCK(p); - --p->p_lock; - PROC_UNLOCK(p); - /* - * XXXDTRACE: add dtrace_doubletrap_func here? - */ - } else { - /* - * Don't have to worry about process locking or stacks in the - * kernel. - */ - rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL); - } + /* Fault in the page. */ + rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL); + /* + * XXXDTRACE: add dtrace_doubletrap_func here? + */ if (rv == KERN_SUCCESS) return (0); Modified: head/sys/sparc64/sparc64/trap.c ============================================================================== --- head/sys/sparc64/sparc64/trap.c Thu Sep 10 16:13:44 2015 (r287624) +++ head/sys/sparc64/sparc64/trap.c Thu Sep 10 17:46:48 2015 (r287625) @@ -441,7 +441,7 @@ trap_cecc(void) static int trap_pfault(struct thread *td, struct trapframe *tf) { - struct vmspace *vm; + vm_map_t map; struct proc *p; vm_offset_t va; vm_prot_t prot; @@ -484,28 +484,8 @@ trap_pfault(struct thread *td, struct tr return (0); } - /* - * This is a fault on non-kernel virtual memory. - */ - vm = p->p_vmspace; - - /* - * Keep swapout from messing with us during this - * critical time. - */ - PROC_LOCK(p); - ++p->p_lock; - PROC_UNLOCK(p); - - /* Fault in the user page. */ - rv = vm_fault(&vm->vm_map, va, prot, VM_FAULT_NORMAL); - - /* - * Now the process can be swapped again. - */ - PROC_LOCK(p); - --p->p_lock; - PROC_UNLOCK(p); + /* This is a fault on non-kernel virtual memory. */ + map = &p->p_vmspace->vm_map; } else { /* * This is a fault on kernel virtual memory. Attempts to @@ -527,14 +507,12 @@ trap_pfault(struct thread *td, struct tr } vm_map_unlock_read(kernel_map); } - - /* - * We don't have to worry about process locking or stacks in - * the kernel. - */ - rv = vm_fault(kernel_map, va, prot, VM_FAULT_NORMAL); + map = kernel_map; } + /* Fault in the page. */ + rv = vm_fault(map, va, prot, VM_FAULT_NORMAL); + CTR3(KTR_TRAP, "trap_pfault: return td=%p va=%#lx rv=%d", td, va, rv); if (rv == KERN_SUCCESS)
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