diff options
Diffstat (limited to 'system/xen/xsa/xsa202.patch')
| -rw-r--r-- | system/xen/xsa/xsa202.patch | 75 |
1 files changed, 0 insertions, 75 deletions
diff --git a/system/xen/xsa/xsa202.patch b/system/xen/xsa/xsa202.patch deleted file mode 100644 index 51d38dcba5..0000000000 --- a/system/xen/xsa/xsa202.patch +++ /dev/null @@ -1,75 +0,0 @@ -From: Jan Beulich <jbeulich@suse.com> -Subject: x86: force EFLAGS.IF on when exiting to PV guests - -Guest kernels modifying instructions in the process of being emulated -for another of their vCPU-s may effect EFLAGS.IF to be cleared upon -next exiting to guest context, by converting the being emulated -instruction to CLI (at the right point in time). Prevent any such bad -effects by always forcing EFLAGS.IF on. And to cover hypothetical other -similar issues, also force EFLAGS.{IOPL,NT,VM} to zero. - -This is XSA-202. - -Signed-off-by: Jan Beulich <jbeulich@suse.com> -Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> ---- - ---- a/xen/arch/x86/x86_64/compat/entry.S -+++ b/xen/arch/x86/x86_64/compat/entry.S -@@ -109,6 +109,8 @@ compat_process_trap: - /* %rbx: struct vcpu, interrupts disabled */ - ENTRY(compat_restore_all_guest) - ASSERT_INTERRUPTS_DISABLED -+ mov $~(X86_EFLAGS_IOPL|X86_EFLAGS_NT|X86_EFLAGS_VM),%r11d -+ and UREGS_eflags(%rsp),%r11d - .Lcr4_orig: - .skip .Lcr4_alt_end - .Lcr4_alt, 0x90 - .Lcr4_orig_end: -@@ -144,6 +146,8 @@ ENTRY(compat_restore_all_guest) - (.Lcr4_orig_end - .Lcr4_orig), \ - (.Lcr4_alt_end - .Lcr4_alt) - .popsection -+ or $X86_EFLAGS_IF,%r11 -+ mov %r11d,UREGS_eflags(%rsp) - RESTORE_ALL adj=8 compat=1 - .Lft0: iretq - _ASM_PRE_EXTABLE(.Lft0, handle_exception) ---- a/xen/arch/x86/x86_64/entry.S -+++ b/xen/arch/x86/x86_64/entry.S -@@ -40,28 +40,29 @@ restore_all_guest: - testw $TRAP_syscall,4(%rsp) - jz iret_exit_to_guest - -+ movq 24(%rsp),%r11 # RFLAGS -+ andq $~(X86_EFLAGS_IOPL|X86_EFLAGS_NT|X86_EFLAGS_VM),%r11 -+ orq $X86_EFLAGS_IF,%r11 -+ - /* Don't use SYSRET path if the return address is not canonical. */ - movq 8(%rsp),%rcx - sarq $47,%rcx - incl %ecx - cmpl $1,%ecx -- ja .Lforce_iret -+ movq 8(%rsp),%rcx # RIP -+ ja iret_exit_to_guest - - cmpw $FLAT_USER_CS32,16(%rsp)# CS -- movq 8(%rsp),%rcx # RIP -- movq 24(%rsp),%r11 # RFLAGS - movq 32(%rsp),%rsp # RSP - je 1f - sysretq - 1: sysretl - --.Lforce_iret: -- /* Mimic SYSRET behavior. */ -- movq 8(%rsp),%rcx # RIP -- movq 24(%rsp),%r11 # RFLAGS - ALIGN - /* No special register assumptions. */ - iret_exit_to_guest: -+ andl $~(X86_EFLAGS_IOPL|X86_EFLAGS_NT|X86_EFLAGS_VM),24(%rsp) -+ orl $X86_EFLAGS_IF,24(%rsp) - addq $8,%rsp - .Lft0: iretq - _ASM_PRE_EXTABLE(.Lft0, handle_exception) |