From: Keir Fraser Date: Thu, 27 Dec 2007 21:55:38 +0000 (+0000) Subject: hvm: Register fields CS,DS,ES,FS,GS,SS,etc. are all undefined during X-Git-Tag: 3.1.3-rc1~41 X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=ad23e8e549c468d36a2151c594cbb790641e745f;p=people%2Fvhanquez%2Fxen.git hvm: Register fields CS,DS,ES,FS,GS,SS,etc. are all undefined during HVM execution as they are not saved/restore on vmexit/vmentry. To prevent accidental usage of these fields, poison them with 16-bit value 0xbeef (debug builds only). Signed-off-by: Keir Fraser xen-unstable changeset: 16660:2324110ef2c6 xen-unstable date: Thu Dec 27 10:39:04 2007 +0000 --- diff --git a/xen/arch/x86/hvm/svm/x86_32/exits.S b/xen/arch/x86/hvm/svm/x86_32/exits.S index ba5c064b6..7bef7b48a 100644 --- a/xen/arch/x86/hvm/svm/x86_32/exits.S +++ b/xen/arch/x86/hvm/svm/x86_32/exits.S @@ -82,6 +82,22 @@ svm_trace_done: movl VMCB_rax(%ecx),%eax movl %eax,UREGS_eax(%esp) +#ifndef NDEBUG + movl $0xdeadbeef,%eax + movw %ax,UREGS_error_code(%esp) + movw %ax,UREGS_entry_vector(%esp) + movw %ax,UREGS_saved_upcall_mask(%esp) + movw %ax,UREGS_cs(%esp) + movw %ax,UREGS_ds(%esp) + movw %ax,UREGS_es(%esp) + movw %ax,UREGS_fs(%esp) + movw %ax,UREGS_gs(%esp) + movw %ax,UREGS_ss(%esp) + movl %eax,UREGS_eflags(%esp) + movl %eax,UREGS_eip(%esp) + movl %eax,UREGS_esp(%esp) +#endif + STGI .globl svm_stgi_label; svm_stgi_label: diff --git a/xen/arch/x86/hvm/svm/x86_64/exits.S b/xen/arch/x86/hvm/svm/x86_64/exits.S index e991bb4cd..93d23483e 100644 --- a/xen/arch/x86/hvm/svm/x86_64/exits.S +++ b/xen/arch/x86/hvm/svm/x86_64/exits.S @@ -101,6 +101,22 @@ svm_trace_done: movq VMCB_rax(%rcx),%rax movq %rax,UREGS_rax(%rsp) +#ifndef NDEBUG + movl $0xdeadbeef,%eax + movw %ax,UREGS_error_code(%rsp) + movw %ax,UREGS_entry_vector(%rsp) + movw %ax,UREGS_saved_upcall_mask(%rsp) + movw %ax,UREGS_cs(%rsp) + movw %ax,UREGS_ds(%rsp) + movw %ax,UREGS_es(%rsp) + movw %ax,UREGS_fs(%rsp) + movw %ax,UREGS_gs(%rsp) + movw %ax,UREGS_ss(%rsp) + movq %rax,UREGS_eflags(%rsp) + movq %rax,UREGS_rip(%rsp) + movq %rax,UREGS_rsp(%rsp) +#endif + STGI .globl svm_stgi_label; svm_stgi_label: diff --git a/xen/arch/x86/hvm/vmx/x86_32/exits.S b/xen/arch/x86/hvm/vmx/x86_32/exits.S index ef24dce0e..c21059061 100644 --- a/xen/arch/x86/hvm/vmx/x86_32/exits.S +++ b/xen/arch/x86/hvm/vmx/x86_32/exits.S @@ -30,7 +30,6 @@ movl (reg),reg; #define HVM_SAVE_ALL_NOSEGREGS \ - movl $0, 0xc(%esp); /* XXX why do we need to force eflags==0 ?? */ \ pushl %eax; \ pushl %ebp; \ pushl %edi; \ @@ -51,6 +50,23 @@ ALIGN ENTRY(vmx_asm_vmexit_handler) HVM_SAVE_ALL_NOSEGREGS + +#ifndef NDEBUG + movl $0xdeadbeef,%eax + movw %ax,UREGS_error_code(%esp) + movw %ax,UREGS_entry_vector(%esp) + movw %ax,UREGS_saved_upcall_mask(%esp) + movw %ax,UREGS_cs(%esp) + movw %ax,UREGS_ds(%esp) + movw %ax,UREGS_es(%esp) + movw %ax,UREGS_fs(%esp) + movw %ax,UREGS_gs(%esp) + movw %ax,UREGS_ss(%esp) + movl %eax,UREGS_eflags(%esp) + movl %eax,UREGS_eip(%esp) + movl %eax,UREGS_esp(%esp) +#endif + movl %esp,%eax push %eax call vmx_vmexit_handler diff --git a/xen/arch/x86/hvm/vmx/x86_64/exits.S b/xen/arch/x86/hvm/vmx/x86_64/exits.S index 0bebeb6ec..e2a2c2d3d 100644 --- a/xen/arch/x86/hvm/vmx/x86_64/exits.S +++ b/xen/arch/x86/hvm/vmx/x86_64/exits.S @@ -66,6 +66,23 @@ ALIGN ENTRY(vmx_asm_vmexit_handler) HVM_SAVE_ALL_NOSEGREGS + +#ifndef NDEBUG + movl $0xdeadbeef,%eax + movw %ax,UREGS_error_code(%rsp) + movw %ax,UREGS_entry_vector(%rsp) + movw %ax,UREGS_saved_upcall_mask(%rsp) + movw %ax,UREGS_cs(%rsp) + movw %ax,UREGS_ds(%rsp) + movw %ax,UREGS_es(%rsp) + movw %ax,UREGS_fs(%rsp) + movw %ax,UREGS_gs(%rsp) + movw %ax,UREGS_ss(%rsp) + movq %rax,UREGS_eflags(%rsp) + movq %rax,UREGS_rip(%rsp) + movq %rax,UREGS_rsp(%rsp) +#endif + movq %rsp,%rdi call vmx_vmexit_handler jmp vmx_asm_do_vmentry diff --git a/xen/arch/x86/x86_32/asm-offsets.c b/xen/arch/x86/x86_32/asm-offsets.c index 2d6b47de2..83b50434e 100644 --- a/xen/arch/x86/x86_32/asm-offsets.c +++ b/xen/arch/x86/x86_32/asm-offsets.c @@ -44,6 +44,7 @@ void __dummy__(void) OFFSET(UREGS_eflags, struct cpu_user_regs, eflags); OFFSET(UREGS_error_code, struct cpu_user_regs, error_code); OFFSET(UREGS_entry_vector, struct cpu_user_regs, entry_vector); + OFFSET(UREGS_saved_upcall_mask, struct cpu_user_regs, saved_upcall_mask); OFFSET(UREGS_kernel_sizeof, struct cpu_user_regs, esp); DEFINE(UREGS_user_sizeof, sizeof(struct cpu_user_regs)); BLANK(); diff --git a/xen/arch/x86/x86_64/asm-offsets.c b/xen/arch/x86/x86_64/asm-offsets.c index 836ce6a05..a09dc444a 100644 --- a/xen/arch/x86/x86_64/asm-offsets.c +++ b/xen/arch/x86/x86_64/asm-offsets.c @@ -46,11 +46,16 @@ void __dummy__(void) OFFSET(UREGS_rdi, struct cpu_user_regs, rdi); OFFSET(UREGS_error_code, struct cpu_user_regs, error_code); OFFSET(UREGS_entry_vector, struct cpu_user_regs, entry_vector); + OFFSET(UREGS_saved_upcall_mask, struct cpu_user_regs, saved_upcall_mask); OFFSET(UREGS_rip, struct cpu_user_regs, rip); OFFSET(UREGS_cs, struct cpu_user_regs, cs); OFFSET(UREGS_eflags, struct cpu_user_regs, eflags); OFFSET(UREGS_rsp, struct cpu_user_regs, rsp); OFFSET(UREGS_ss, struct cpu_user_regs, ss); + OFFSET(UREGS_ds, struct cpu_user_regs, ds); + OFFSET(UREGS_es, struct cpu_user_regs, es); + OFFSET(UREGS_fs, struct cpu_user_regs, fs); + OFFSET(UREGS_gs, struct cpu_user_regs, gs); OFFSET(UREGS_kernel_sizeof, struct cpu_user_regs, es); DEFINE(UREGS_user_sizeof, sizeof(struct cpu_user_regs)); BLANK();