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[Xen-changelog] More code cleanups, mainly to do_iret() implementations.

From: Xen patchbot -unstable <patchbot-unstable@xxxxxxxxxxxxxxxxxxx>

Date: Wed, 11 Jan 2006 21:36:12 +0000

Delivery-date: Wed, 11 Jan 2006 21:43:48 +0000

List-id: BK change log <xen-changelog.lists.xensource.com>

# HG changeset patch # User kaf24@xxxxxxxxxxxxxxxxxxxx # Node ID b7e88c83b2a0991590e5d46531d487a3356cd4fb # Parent c96ea9ebcd298c30bc251cce14b78ca8cb3dd69e More code cleanups, mainly to do_iret() implementations. Signed-off-by: Keir Fraser <keir@xxxxxxxxxxxxx> diff -r c96ea9ebcd29 -r b7e88c83b2a0 xen/arch/x86/domain.c --- a/xen/arch/x86/domain.c Wed Jan 11 18:26:03 2006 +++ b/xen/arch/x86/domain.c Wed Jan 11 18:44:54 2006 @@ -480,14 +480,6 @@ #ifdef __x86_64__ -void toggle_guest_mode(struct vcpu *v) -{ - v->arch.flags ^= TF_kernel_mode; - __asm__ __volatile__ ( "swapgs" ); - update_pagetables(v); - write_ptbase(v); -} - #define loadsegment(seg,value) ({ \ int __r = 1; \ __asm__ __volatile__ ( \ diff -r c96ea9ebcd29 -r b7e88c83b2a0 xen/arch/x86/mm.c --- a/xen/arch/x86/mm.c Wed Jan 11 18:26:03 2006 +++ b/xen/arch/x86/mm.c Wed Jan 11 18:44:54 2006 @@ -297,7 +297,6 @@ #if defined(__x86_64__) /* If in user mode, switch to kernel mode just to read LDT mapping. */ - extern void toggle_guest_mode(struct vcpu *); int user_mode = !(v->arch.flags & TF_kernel_mode); #define TOGGLE_MODE() if ( user_mode ) toggle_guest_mode(v) #elif defined(__i386__) @@ -2971,7 +2970,6 @@ #ifdef CONFIG_X86_64 struct vcpu *v = current; - extern void toggle_guest_mode(struct vcpu *); int user_mode = !(v->arch.flags & TF_kernel_mode); #endif diff -r c96ea9ebcd29 -r b7e88c83b2a0 xen/arch/x86/traps.c --- a/xen/arch/x86/traps.c Wed Jan 11 18:26:03 2006 +++ b/xen/arch/x86/traps.c Wed Jan 11 18:44:54 2006 @@ -596,7 +596,6 @@ u16 x; #if defined(__x86_64__) /* If in user mode, switch to kernel mode just to read I/O bitmap. */ - extern void toggle_guest_mode(struct vcpu *); int user_mode = !(v->arch.flags & TF_kernel_mode); #define TOGGLE_MODE() if ( user_mode ) toggle_guest_mode(v) #elif defined(__i386__) diff -r c96ea9ebcd29 -r b7e88c83b2a0 xen/arch/x86/x86_32/traps.c --- a/xen/arch/x86/x86_32/traps.c Wed Jan 11 18:26:03 2006 +++ b/xen/arch/x86/x86_32/traps.c Wed Jan 11 18:44:54 2006 @@ -157,38 +157,37 @@ __asm__ __volatile__ ( "hlt" ); } +static inline void pop_from_guest_stack( + void *dst, struct cpu_user_regs *regs, unsigned int bytes) +{ + if ( unlikely(copy_from_user(dst, (void __user *)regs->esp, bytes)) ) + domain_crash_synchronous(); + regs->esp += bytes; +} + asmlinkage unsigned long do_iret(void) { struct cpu_user_regs *regs = guest_cpu_user_regs(); - /* Restore EAX (clobbered by hypercall). */ - if ( copy_from_user(&regs->eax, (void __user *)regs->esp, 4) ) + /* Pop and restore EAX (clobbered by hypercall). */ + pop_from_guest_stack(&regs->eax, regs, 4); + + /* Pop and restore EFLAGS, CS and EIP. */ + pop_from_guest_stack(&regs->eip, regs, 12); + + if ( VM86_MODE(regs) ) + { + /* Return to VM86 mode: pop and restore ESP,SS,ES,DS,FS and GS. */ + pop_from_guest_stack(&regs->esp, regs, 24); + } + else if ( RING_0(regs) ) + { domain_crash_synchronous(); - regs->esp += 4; - - /* Restore EFLAGS, CS and EIP. */ - if ( copy_from_user(&regs->eip, (void __user *)regs->esp, 12) ) - domain_crash_synchronous(); - - if ( VM86_MODE(regs) ) - { - /* Return to VM86 mode: restore ESP,SS,ES,DS,FS and GS. */ - if(copy_from_user(&regs->esp, (void __user *)(regs->esp+12), 24)) - domain_crash_synchronous(); - } - else if ( RING_0(regs) ) - { - domain_crash_synchronous(); - } - else if ( RING_1(regs) ) { - /* Return to ring 1: pop EFLAGS,CS and EIP. */ - regs->esp += 12; - } - else - { - /* Return to ring 2/3: restore ESP and SS. */ - if ( copy_from_user(&regs->esp, (void __user *)(regs->esp+12), 8) ) - domain_crash_synchronous(); + } + else if ( !RING_1(regs) ) + { + /* Return to ring 2/3: pop and restore ESP and SS. */ + pop_from_guest_stack(&regs->esp, regs, 8); } /* Fixup EFLAGS. */ diff -r c96ea9ebcd29 -r b7e88c83b2a0 xen/arch/x86/x86_64/traps.c --- a/xen/arch/x86/x86_64/traps.c Wed Jan 11 18:26:03 2006 +++ b/xen/arch/x86/x86_64/traps.c Wed Jan 11 18:44:54 2006 @@ -114,7 +114,13 @@ __asm__ __volatile__ ( "hlt" ); } -extern void toggle_guest_mode(struct vcpu *); +void toggle_guest_mode(struct vcpu *v) +{ + v->arch.flags ^= TF_kernel_mode; + __asm__ __volatile__ ( "swapgs" ); + update_pagetables(v); + write_ptbase(v); +} long do_iret(void) { @@ -122,13 +128,17 @@ struct iret_context iret_saved; struct vcpu *v = current; - if ( unlikely(copy_from_user(&iret_saved, (void *)regs->rsp, sizeof(iret_saved))) || - unlikely(pagetable_get_paddr(v->arch.guest_table_user) == 0) ) - return -EFAULT; - - /* Returning to user mode. */ - if ( (iret_saved.cs & 0x03) == 3 ) + if ( unlikely(copy_from_user(&iret_saved, (void *)regs->rsp, + sizeof(iret_saved))) ) + domain_crash_synchronous(); + + /* Returning to user mode? */ + if ( (iret_saved.cs & 3) == 3 ) + { + if ( unlikely(pagetable_get_paddr(v->arch.guest_table_user) == 0) ) + return -EFAULT; toggle_guest_mode(v); + } regs->rip = iret_saved.rip; regs->cs = iret_saved.cs | 3; /* force guest privilege */ diff -r c96ea9ebcd29 -r b7e88c83b2a0 xen/include/asm-x86/domain.h --- a/xen/include/asm-x86/domain.h Wed Jan 11 18:26:03 2006 +++ b/xen/include/asm-x86/domain.h Wed Jan 11 18:44:54 2006 @@ -46,7 +46,10 @@ struct vcpu_maphash vcpu_maphash[MAX_VIRT_CPUS]; }; -extern void mapcache_init(struct domain *d); +extern void mapcache_init(struct domain *); + +/* x86/64: toggle guest between kernel and user modes. */ +extern void toggle_guest_mode(struct vcpu *); struct arch_domain { _______________________________________________ Xen-changelog mailing list Xen-changelog@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-changelog

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