[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen-unstable] xen x86/64: Fix int80 direct trap. It must check for events and also
# HG changeset patch # User Keir Fraser <keir@xxxxxxxxxxxxx> # Date 1175868454 -3600 # Node ID f80a97d262769710f9e1612bebc3c1308f947e4e # Parent bd73cb523111dd022d6d1e7de01d1930ed85b307 xen x86/64: Fix int80 direct trap. It must check for events and also disable interrupts before exiting to guest context. Also sprinkle about some assertions about interrupt-enable status. Signed-off-by: Keir Fraser <keir@xxxxxxxxxxxxx> --- xen/arch/x86/x86_32/entry.S | 1 + xen/arch/x86/x86_64/compat/entry.S | 4 +++- xen/arch/x86/x86_64/entry.S | 6 ++++-- xen/arch/x86/x86_64/traps.c | 12 ++++++++---- xen/include/asm-x86/desc.h | 2 +- xen/include/asm-x86/x86_32/asm_defns.h | 10 ++++++++++ xen/include/asm-x86/x86_64/asm_defns.h | 10 ++++++++++ 7 files changed, 37 insertions(+), 8 deletions(-) diff -r bd73cb523111 -r f80a97d26276 xen/arch/x86/x86_32/entry.S --- a/xen/arch/x86/x86_32/entry.S Fri Apr 06 14:35:25 2007 +0100 +++ b/xen/arch/x86/x86_32/entry.S Fri Apr 06 15:07:34 2007 +0100 @@ -283,6 +283,7 @@ bad_hypercall: /* %edx == trap_bounce, %ebx == struct vcpu */ /* %eax,%ecx are clobbered. %gs:%esi contain new UREGS_ss/UREGS_esp. */ create_bounce_frame: + ASSERT_INTERRUPTS_ENABLED movl UREGS_eflags+4(%esp),%ecx movb UREGS_cs+4(%esp),%cl testl $(2|X86_EFLAGS_VM),%ecx diff -r bd73cb523111 -r f80a97d26276 xen/arch/x86/x86_64/compat/entry.S --- a/xen/arch/x86/x86_64/compat/entry.S Fri Apr 06 14:35:25 2007 +0100 +++ b/xen/arch/x86/x86_64/compat/entry.S Fri Apr 06 15:07:34 2007 +0100 @@ -137,6 +137,7 @@ compat_bad_hypercall: /* %rbx: struct vcpu, interrupts disabled */ compat_restore_all_guest: + ASSERT_INTERRUPTS_DISABLED RESTORE_ALL addq $8,%rsp .Lft0: iretq @@ -188,13 +189,14 @@ ENTRY(compat_post_handle_exception) ENTRY(compat_int80_direct_trap) call compat_create_bounce_frame - jmp compat_restore_all_guest + jmp compat_test_all_events /* CREATE A BASIC EXCEPTION FRAME ON GUEST OS (RING-1) STACK: */ /* {[ERRCODE,] EIP, CS, EFLAGS, [ESP, SS]} */ /* %rdx: trap_bounce, %rbx: struct vcpu */ /* On return only %rbx is guaranteed non-clobbered. */ compat_create_bounce_frame: + ASSERT_INTERRUPTS_ENABLED mov %fs,%edi testb $2,UREGS_cs+8(%rsp) jz 1f diff -r bd73cb523111 -r f80a97d26276 xen/arch/x86/x86_64/entry.S --- a/xen/arch/x86/x86_64/entry.S Fri Apr 06 14:35:25 2007 +0100 +++ b/xen/arch/x86/x86_64/entry.S Fri Apr 06 15:07:34 2007 +0100 @@ -38,6 +38,7 @@ 1: call create_bounce_frame /* %rbx: struct vcpu, interrupts disabled */ restore_all_guest: + ASSERT_INTERRUPTS_DISABLED RESTORE_ALL testw $TRAP_syscall,4(%rsp) jz iret_exit_to_guest @@ -230,7 +231,7 @@ ENTRY(int80_direct_trap) /* Check that the callback is non-null. */ leaq VCPU_int80_bounce(%rbx),%rdx - cmp $0, TRAPBOUNCE_flags(%rdx) + cmp $0,TRAPBOUNCE_flags(%rdx) jz int80_slow_path movq VCPU_domain(%rbx),%rax @@ -238,7 +239,7 @@ ENTRY(int80_direct_trap) jnz compat_int80_direct_trap call create_bounce_frame - jmp restore_all_guest + jmp test_all_events int80_slow_path: /* @@ -256,6 +257,7 @@ int80_slow_path: /* %rdx: trap_bounce, %rbx: struct vcpu */ /* On return only %rbx is guaranteed non-clobbered. */ create_bounce_frame: + ASSERT_INTERRUPTS_ENABLED testb $TF_kernel_mode,VCPU_thread_flags(%rbx) jnz 1f /* Push new frame at registered guest-OS stack base. */ diff -r bd73cb523111 -r f80a97d26276 xen/arch/x86/x86_64/traps.c --- a/xen/arch/x86/x86_64/traps.c Fri Apr 06 14:35:25 2007 +0100 +++ b/xen/arch/x86/x86_64/traps.c Fri Apr 06 15:07:34 2007 +0100 @@ -170,7 +170,8 @@ asmlinkage void do_double_fault(struct c regs->r9, regs->r10, regs->r11); printk("r12: %016lx r13: %016lx r14: %016lx\n", regs->r12, regs->r13, regs->r14); - printk("r15: %016lx\n", regs->r15); + printk("r15: %016lx cs: %016lx ss: %016lx\n", + regs->r15, (long)regs->cs, (long)regs->ss); show_stack_overflow(cpu, regs->rsp); panic("DOUBLE FAULT -- system shutdown\n"); @@ -260,11 +261,14 @@ void __init percpu_traps_init(void) idt_table[TRAP_double_fault].a |= 1UL << 32; /* IST1 */ idt_table[TRAP_nmi].a |= 2UL << 32; /* IST2 */ -#ifdef CONFIG_COMPAT - /* The hypercall entry vector is only accessible from ring 1. */ + /* + * The 32-on-64 hypercall entry vector is only accessible from ring 1. + * Also note that this is a trap gate, not an interrupt gate. + */ _set_gate(idt_table+HYPERCALL_VECTOR, 15, 1, &compat_hypercall); + + /* Fast trap for int80 (faster than taking the #GP-fixup path). */ _set_gate(idt_table+0x80, 15, 3, &int80_direct_trap); -#endif } stack_bottom = (char *)get_stack_bottom(); diff -r bd73cb523111 -r f80a97d26276 xen/include/asm-x86/desc.h --- a/xen/include/asm-x86/desc.h Fri Apr 06 14:35:25 2007 +0100 +++ b/xen/include/asm-x86/desc.h Fri Apr 06 15:07:34 2007 +0100 @@ -106,7 +106,7 @@ ((((sel)>>3) < FIRST_RESERVED_GDT_ENTRY) || /* Guest seg? */ \ ((sel) == (!IS_COMPAT(d) ? \ FLAT_KERNEL_CS : /* Xen default seg? */ \ - FLAT_COMPAT_KERNEL_CS)) || /* Xen default compat seg? */ \ + FLAT_COMPAT_KERNEL_CS)) || \ ((sel) & 4)) /* LDT seg? */ #endif /* __ASSEMBLY__ */ diff -r bd73cb523111 -r f80a97d26276 xen/include/asm-x86/x86_32/asm_defns.h --- a/xen/include/asm-x86/x86_32/asm_defns.h Fri Apr 06 14:35:25 2007 +0100 +++ b/xen/include/asm-x86/x86_32/asm_defns.h Fri Apr 06 15:07:34 2007 +0100 @@ -8,9 +8,19 @@ #define SETUP_EXCEPTION_FRAME_POINTER \ movl %esp,%ebp; \ notl %ebp +#define ASSERT_INTERRUPT_STATUS(x) \ + pushf; \ + testb $X86_EFLAGS_IF>>8,1(%esp); \ + j##x 1f; \ + ud2a; \ +1: addl $4,%esp; #else #define SETUP_EXCEPTION_FRAME_POINTER +#define ASSERT_INTERRUPT_STATUS(x) #endif + +#define ASSERT_INTERRUPTS_ENABLED ASSERT_INTERRUPT_STATUS(nz) +#define ASSERT_INTERRUPTS_DISABLED ASSERT_INTERRUPT_STATUS(z) #define __SAVE_ALL_PRE \ cld; \ diff -r bd73cb523111 -r f80a97d26276 xen/include/asm-x86/x86_64/asm_defns.h --- a/xen/include/asm-x86/x86_64/asm_defns.h Fri Apr 06 14:35:25 2007 +0100 +++ b/xen/include/asm-x86/x86_64/asm_defns.h Fri Apr 06 15:07:34 2007 +0100 @@ -8,9 +8,19 @@ #define SETUP_EXCEPTION_FRAME_POINTER \ movq %rsp,%rbp; \ notq %rbp +#define ASSERT_INTERRUPT_STATUS(x) \ + pushf; \ + testb $X86_EFLAGS_IF>>8,1(%rsp); \ + j##x 1f; \ + ud2a; \ +1: addq $8,%rsp; #else #define SETUP_EXCEPTION_FRAME_POINTER +#define ASSERT_INTERRUPT_STATUS(x) #endif + +#define ASSERT_INTERRUPTS_ENABLED ASSERT_INTERRUPT_STATUS(nz) +#define ASSERT_INTERRUPTS_DISABLED ASSERT_INTERRUPT_STATUS(z) #define SAVE_ALL \ cld; \ _______________________________________________ Xen-changelog mailing list Xen-changelog@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-changelog
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