[PATCH] i386: Abstract sensitive instructions
Abstract sensitive instructions in assembler code, replacing them with macros (which currently are #defined to the native versions). We use long names: assembler is case-insensitive, so if something goes wrong and macros do not expand, it would assemble anyway. Resulting object files are exactly the same as before. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Andi Kleen <ak@suse.de>
This commit is contained in:
Rusty Russell
Andi Kleen
parent
7b0bda74f7
commit
0da5db3133
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@ -76,8 +76,15 @@ DF_MASK = 0x00000400
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NT_MASK = 0x00004000
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VM_MASK = 0x00020000
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/* These are replaces for paravirtualization */
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#define DISABLE_INTERRUPTS cli
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#define ENABLE_INTERRUPTS sti
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#define ENABLE_INTERRUPTS_SYSEXIT sti; sysexit
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#define INTERRUPT_RETURN iret
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#define GET_CR0_INTO_EAX movl %cr0, %eax
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#ifdef CONFIG_PREEMPT
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#define preempt_stop cli; TRACE_IRQS_OFF
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#define preempt_stop DISABLE_INTERRUPTS; TRACE_IRQS_OFF
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#else
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#define preempt_stop
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#define resume_kernel restore_nocheck
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@ -236,7 +243,7 @@ check_userspace:
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testl $(VM_MASK | 3), %eax
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jz resume_kernel
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ENTRY(resume_userspace)
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cli # make sure we don't miss an interrupt
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DISABLE_INTERRUPTS # make sure we don't miss an interrupt
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# setting need_resched or sigpending
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# between sampling and the iret
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movl TI_flags(%ebp), %ecx
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@ -247,7 +254,7 @@ ENTRY(resume_userspace)
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#ifdef CONFIG_PREEMPT
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ENTRY(resume_kernel)
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cli
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DISABLE_INTERRUPTS
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cmpl $0,TI_preempt_count(%ebp) # non-zero preempt_count ?
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jnz restore_nocheck
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need_resched:
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@ -275,7 +282,7 @@ sysenter_past_esp:
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* No need to follow this irqs on/off section: the syscall
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* disabled irqs and here we enable it straight after entry:
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*/
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sti
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ENABLE_INTERRUPTS
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pushl $(__USER_DS)
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CFI_ADJUST_CFA_OFFSET 4
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/*CFI_REL_OFFSET ss, 0*/
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@ -320,7 +327,7 @@ sysenter_past_esp:
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jae syscall_badsys
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call *sys_call_table(,%eax,4)
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movl %eax,EAX(%esp)
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cli
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DISABLE_INTERRUPTS
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TRACE_IRQS_OFF
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movl TI_flags(%ebp), %ecx
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testw $_TIF_ALLWORK_MASK, %cx
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@ -330,8 +337,7 @@ sysenter_past_esp:
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movl OLDESP(%esp), %ecx
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xorl %ebp,%ebp
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TRACE_IRQS_ON
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sti
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sysexit
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ENABLE_INTERRUPTS_SYSEXIT
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CFI_ENDPROC
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@ -356,7 +362,7 @@ syscall_call:
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call *sys_call_table(,%eax,4)
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movl %eax,EAX(%esp) # store the return value
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syscall_exit:
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cli # make sure we don't miss an interrupt
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DISABLE_INTERRUPTS # make sure we don't miss an interrupt
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# setting need_resched or sigpending
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# between sampling and the iret
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TRACE_IRQS_OFF
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@ -381,11 +387,11 @@ restore_nocheck_notrace:
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RESTORE_REGS
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addl $4, %esp
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CFI_ADJUST_CFA_OFFSET -4
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1: iret
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1: INTERRUPT_RETURN
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.section .fixup,"ax"
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iret_exc:
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TRACE_IRQS_ON
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sti
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ENABLE_INTERRUPTS
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pushl $0 # no error code
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pushl $do_iret_error
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jmp error_code
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@ -409,7 +415,7 @@ ldt_ss:
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* dosemu and wine happy. */
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subl $8, %esp # reserve space for switch16 pointer
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CFI_ADJUST_CFA_OFFSET 8
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cli
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DISABLE_INTERRUPTS
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TRACE_IRQS_OFF
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movl %esp, %eax
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/* Set up the 16bit stack frame with switch32 pointer on top,
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@ -419,7 +425,7 @@ ldt_ss:
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TRACE_IRQS_IRET
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RESTORE_REGS
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lss 20+4(%esp), %esp # switch to 16bit stack
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1: iret
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1: INTERRUPT_RETURN
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.section __ex_table,"a"
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.align 4
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.long 1b,iret_exc
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@ -434,7 +440,7 @@ work_pending:
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jz work_notifysig
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work_resched:
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call schedule
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cli # make sure we don't miss an interrupt
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DISABLE_INTERRUPTS # make sure we don't miss an interrupt
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# setting need_resched or sigpending
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# between sampling and the iret
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TRACE_IRQS_OFF
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@ -490,7 +496,7 @@ syscall_exit_work:
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testb $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP), %cl
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jz work_pending
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TRACE_IRQS_ON
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sti # could let do_syscall_trace() call
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ENABLE_INTERRUPTS # could let do_syscall_trace() call
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# schedule() instead
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movl %esp, %eax
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movl $1, %edx
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@ -668,7 +674,7 @@ ENTRY(device_not_available)
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pushl $-1 # mark this as an int
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CFI_ADJUST_CFA_OFFSET 4
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SAVE_ALL
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movl %cr0, %eax
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GET_CR0_INTO_EAX
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testl $0x4, %eax # EM (math emulation bit)
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jne device_not_available_emulate
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preempt_stop
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@ -811,7 +817,7 @@ nmi_16bit_stack:
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call do_nmi
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RESTORE_REGS
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lss 12+4(%esp), %esp # back to 16bit stack
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1: iret
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1: INTERRUPT_RETURN
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CFI_ENDPROC
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.section __ex_table,"a"
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.align 4
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@ -7,6 +7,9 @@
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#include <asm/processor.h>
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#include <linux/compiler.h>
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#define CLI_STRING "cli"
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#define STI_STRING "sti"
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/*
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* Your basic SMP spinlocks, allowing only a single CPU anywhere
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*
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@ -55,12 +58,12 @@ static inline void __raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long fla
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"2:\t"
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"testl $0x200, %1\n\t"
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"jz 4f\n\t"
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"sti\n"
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STI_STRING "\n"
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"3:\t"
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"rep;nop\n\t"
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"cmpb $0, %0\n\t"
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"jle 3b\n\t"
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"cli\n\t"
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CLI_STRING "\n\t"
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"jmp 1b\n"
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"4:\t"
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"rep;nop\n\t"
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