(forgot to send this to lkml before)
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 <[email protected]>
Index: working-2.6.18-rc2-hg-paravirt/arch/i386/kernel/entry.S
===================================================================
--- working-2.6.18-rc2-hg-paravirt.orig/arch/i386/kernel/entry.S 2006-07-21 21:09:22.000000000 +1000
+++ working-2.6.18-rc2-hg-paravirt/arch/i386/kernel/entry.S 2006-07-22 04:32:25.000000000 +1000
@@ -76,8 +76,15 @@
NT_MASK = 0x00004000
VM_MASK = 0x00020000
+/* These are replaces for paravirtualization */
+#define DISABLE_INTERRUPTS cli
+#define ENABLE_INTERRUPTS sti
+#define ENABLE_INTERRUPTS_SYSEXIT sti; sysexit
+#define INTERRUPT_RETURN iret
+#define GET_CR0 movl %cr0, %eax
+
#ifdef CONFIG_PREEMPT
-#define preempt_stop cli; TRACE_IRQS_OFF
+#define preempt_stop DISABLE_INTERRUPTS; TRACE_IRQS_OFF
#else
#define preempt_stop
#define resume_kernel restore_nocheck
@@ -234,7 +241,7 @@
cmpl $SEGMENT_RPL_MASK, %eax
jb resume_kernel # returning to kernel or vm86-space
ENTRY(resume_userspace)
- cli # make sure we don't miss an interrupt
+ DISABLE_INTERRUPTS # make sure we don't miss an interrupt
# setting need_resched or sigpending
# between sampling and the iret
movl TI_flags(%ebp), %ecx
@@ -245,7 +252,7 @@
#ifdef CONFIG_PREEMPT
ENTRY(resume_kernel)
- cli
+ DISABLE_INTERRUPTS
cmpl $0,TI_preempt_count(%ebp) # non-zero preempt_count ?
jnz restore_nocheck
need_resched:
@@ -273,7 +280,7 @@
* No need to follow this irqs on/off section: the syscall
* disabled irqs and here we enable it straight after entry:
*/
- sti
+ ENABLE_INTERRUPTS
pushl $(__USER_DS)
CFI_ADJUST_CFA_OFFSET 4
/*CFI_REL_OFFSET ss, 0*/
@@ -318,7 +325,7 @@
jae syscall_badsys
call *sys_call_table(,%eax,4)
movl %eax,EAX(%esp)
- cli
+ DISABLE_INTERRUPTS
TRACE_IRQS_OFF
movl TI_flags(%ebp), %ecx
testw $_TIF_ALLWORK_MASK, %cx
@@ -328,8 +335,7 @@
movl OLDESP(%esp), %ecx
xorl %ebp,%ebp
TRACE_IRQS_ON
- sti
- sysexit
+ ENABLE_INTERRUPTS_SYSEXIT
CFI_ENDPROC
@@ -354,7 +360,7 @@
call *sys_call_table(,%eax,4)
movl %eax,EAX(%esp) # store the return value
syscall_exit:
- cli # make sure we don't miss an interrupt
+ DISABLE_INTERRUPTS # make sure we don't miss an interrupt
# setting need_resched or sigpending
# between sampling and the iret
TRACE_IRQS_OFF
@@ -379,11 +385,11 @@
RESTORE_REGS
addl $4, %esp
CFI_ADJUST_CFA_OFFSET -4
-1: iret
+1: INTERRUPT_RETURN
.section .fixup,"ax"
iret_exc:
TRACE_IRQS_ON
- sti
+ ENABLE_INTERRUPTS
pushl $0 # no error code
pushl $do_iret_error
jmp error_code
@@ -407,7 +413,7 @@
* dosemu and wine happy. */
subl $8, %esp # reserve space for switch16 pointer
CFI_ADJUST_CFA_OFFSET 8
- cli
+ DISABLE_INTERRUPTS
TRACE_IRQS_OFF
movl %esp, %eax
/* Set up the 16bit stack frame with switch32 pointer on top,
@@ -417,7 +423,7 @@
TRACE_IRQS_IRET
RESTORE_REGS
lss 20+4(%esp), %esp # switch to 16bit stack
-1: iret
+1: INTERRUPT_RETURN
.section __ex_table,"a"
.align 4
.long 1b,iret_exc
@@ -432,7 +438,7 @@
jz work_notifysig
work_resched:
call schedule
- cli # make sure we don't miss an interrupt
+ DISABLE_INTERRUPTS # make sure we don't miss an interrupt
# setting need_resched or sigpending
# between sampling and the iret
TRACE_IRQS_OFF
@@ -488,7 +494,7 @@
testb $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP), %cl
jz work_pending
TRACE_IRQS_ON
- sti # could let do_syscall_trace() call
+ ENABLE_INTERRUPTS # could let do_syscall_trace() call
# schedule() instead
movl %esp, %eax
movl $1, %edx
@@ -667,7 +673,7 @@
pushl $-1 # mark this as an int
CFI_ADJUST_CFA_OFFSET 4
SAVE_ALL
- movl %cr0, %eax
+ GET_CR0
testl $0x4, %eax # EM (math emulation bit)
jne device_not_available_emulate
preempt_stop
@@ -797,7 +803,7 @@
call do_nmi
RESTORE_REGS
lss 12+4(%esp), %esp # back to 16bit stack
-1: iret
+1: INTERRUPT_RETURN
CFI_ENDPROC
.section __ex_table,"a"
.align 4
Index: working-2.6.18-rc2-hg-paravirt/include/asm-i386/spinlock.h
===================================================================
--- working-2.6.18-rc2-hg-paravirt.orig/include/asm-i386/spinlock.h 2006-07-21 20:27:59.000000000 +1000
+++ working-2.6.18-rc2-hg-paravirt/include/asm-i386/spinlock.h 2006-07-22 04:32:51.000000000 +1000
@@ -17,6 +17,9 @@
* (the type definitions are in asm/spinlock_types.h)
*/
+#define CLI_STRING "cli"
+#define STI_STRING "sti"
+
#define __raw_spin_is_locked(x) \
(*(volatile signed char *)(&(x)->slock) <= 0)
@@ -43,12 +46,12 @@
"2:\t" \
"testl $0x200, %1\n\t" \
"jz 4f\n\t" \
- "sti\n" \
+ STI_STRING "\n" \
"3:\t" \
"rep;nop\n\t" \
"cmpb $0, %0\n\t" \
"jle 3b\n\t" \
- "cli\n\t" \
+ CLI_STRING "\n\t" \
"jmp 1b\n" \
"4:\t" \
"rep;nop\n\t" \
--
Help! Save Australia from the worst of the DMCA: http://linux.org.au/law
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
