[PATCH] i386: Use asm-offsets for the offsets of registers into the pt_regs struct

Use asm-offsets for the offsets of registers into the pt_regs struct, rather
than having hard-coded constants

I left the constants in the comments of entry.S because they're useful for
reference; the code in entry.S is very dependent on the layout of pt_regs,
even when using asm-offsets.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Keith Owens <kaos@ocs.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>

diff --git a/arch/i386/kernel/asm-offsets.c b/arch/i386/kernel/asm-offsets.c
index e94d910..70b1980 100644 (file)
--- a/arch/i386/kernel/asm-offsets.c
+++ b/arch/i386/kernel/asm-offsets.c
@@ -63,6 +63,23 @@ void foo(void)
        OFFSET(GDS_pad, Xgt_desc_struct, pad);
        BLANK();
 
+       OFFSET(PT_EBX, pt_regs, ebx);
+       OFFSET(PT_ECX, pt_regs, ecx);
+       OFFSET(PT_EDX, pt_regs, edx);
+       OFFSET(PT_ESI, pt_regs, esi);
+       OFFSET(PT_EDI, pt_regs, edi);
+       OFFSET(PT_EBP, pt_regs, ebp);
+       OFFSET(PT_EAX, pt_regs, eax);
+       OFFSET(PT_DS,  pt_regs, xds);
+       OFFSET(PT_ES,  pt_regs, xes);
+       OFFSET(PT_ORIG_EAX, pt_regs, orig_eax);
+       OFFSET(PT_EIP, pt_regs, eip);
+       OFFSET(PT_CS,  pt_regs, xcs);
+       OFFSET(PT_EFLAGS, pt_regs, eflags);
+       OFFSET(PT_OLDESP, pt_regs, esp);
+       OFFSET(PT_OLDSS,  pt_regs, xss);
+       BLANK();
+
        OFFSET(EXEC_DOMAIN_handler, exec_domain, handler);
        OFFSET(RT_SIGFRAME_sigcontext, rt_sigframe, uc.uc_mcontext);
        BLANK();

diff --git a/arch/i386/kernel/entry.S b/arch/i386/kernel/entry.S
index c38d801..0069bf0 100644 (file)
--- a/arch/i386/kernel/entry.S
+++ b/arch/i386/kernel/entry.S
@@ -54,22 +54,6 @@
 
 #define nr_syscalls ((syscall_table_size)/4)
 
-EBX            = 0x00
-ECX            = 0x04
-EDX            = 0x08
-ESI            = 0x0C
-EDI            = 0x10
-EBP            = 0x14
-EAX            = 0x18
-DS             = 0x1C
-ES             = 0x20
-ORIG_EAX       = 0x24
-EIP            = 0x28
-CS             = 0x2C
-EFLAGS         = 0x30
-OLDESP         = 0x34
-OLDSS          = 0x38
-
 CF_MASK                = 0x00000001
 TF_MASK                = 0x00000100
 IF_MASK                = 0x00000200
@@ -93,7 +77,7 @@ VM_MASK               = 0x00020000
 
 .macro TRACE_IRQS_IRET
 #ifdef CONFIG_TRACE_IRQFLAGS
-       testl $IF_MASK,EFLAGS(%esp)     # interrupts off?
+       testl $IF_MASK,PT_EFLAGS(%esp)     # interrupts off?
        jz 1f
        TRACE_IRQS_ON
 1:
@@ -199,18 +183,18 @@ VM_MASK           = 0x00020000
 #define RING0_PTREGS_FRAME \
        CFI_STARTPROC simple;\
        CFI_SIGNAL_FRAME;\
-       CFI_DEF_CFA esp, OLDESP-EBX;\
-       /*CFI_OFFSET cs, CS-OLDESP;*/\
-       CFI_OFFSET eip, EIP-OLDESP;\
-       /*CFI_OFFSET es, ES-OLDESP;*/\
-       /*CFI_OFFSET ds, DS-OLDESP;*/\
-       CFI_OFFSET eax, EAX-OLDESP;\
-       CFI_OFFSET ebp, EBP-OLDESP;\
-       CFI_OFFSET edi, EDI-OLDESP;\
-       CFI_OFFSET esi, ESI-OLDESP;\
-       CFI_OFFSET edx, EDX-OLDESP;\
-       CFI_OFFSET ecx, ECX-OLDESP;\
-       CFI_OFFSET ebx, EBX-OLDESP
+       CFI_DEF_CFA esp, PT_OLDESP-PT_EBX;\
+       /*CFI_OFFSET cs, PT_CS-PT_OLDESP;*/\
+       CFI_OFFSET eip, PT_EIP-PT_OLDESP;\
+       /*CFI_OFFSET es, PT_ES-PT_OLDESP;*/\
+       /*CFI_OFFSET ds, PT_DS-PT_OLDESP;*/\
+       CFI_OFFSET eax, PT_EAX-PT_OLDESP;\
+       CFI_OFFSET ebp, PT_EBP-PT_OLDESP;\
+       CFI_OFFSET edi, PT_EDI-PT_OLDESP;\
+       CFI_OFFSET esi, PT_ESI-PT_OLDESP;\
+       CFI_OFFSET edx, PT_EDX-PT_OLDESP;\
+       CFI_OFFSET ecx, PT_ECX-PT_OLDESP;\
+       CFI_OFFSET ebx, PT_EBX-PT_OLDESP
 
 ENTRY(ret_from_fork)
        CFI_STARTPROC
@@ -242,8 +226,8 @@ ret_from_exception:
 ret_from_intr:
        GET_THREAD_INFO(%ebp)
 check_userspace:
-       movl EFLAGS(%esp), %eax         # mix EFLAGS and CS
-       movb CS(%esp), %al
+       movl PT_EFLAGS(%esp), %eax      # mix EFLAGS and CS
+       movb PT_CS(%esp), %al
        andl $(VM_MASK | SEGMENT_RPL_MASK), %eax
        cmpl $USER_RPL, %eax
        jb resume_kernel                # not returning to v8086 or userspace
@@ -266,7 +250,7 @@ need_resched:
        movl TI_flags(%ebp), %ecx       # need_resched set ?
        testb $_TIF_NEED_RESCHED, %cl
        jz restore_all
-       testl $IF_MASK,EFLAGS(%esp)     # interrupts off (exception path) ?
+       testl $IF_MASK,PT_EFLAGS(%esp)  # interrupts off (exception path) ?
        jz restore_all
        call preempt_schedule_irq
        jmp need_resched
@@ -332,15 +316,15 @@ sysenter_past_esp:
        cmpl $(nr_syscalls), %eax
        jae syscall_badsys
        call *sys_call_table(,%eax,4)
-       movl %eax,EAX(%esp)
+       movl %eax,PT_EAX(%esp)
        DISABLE_INTERRUPTS
        TRACE_IRQS_OFF
        movl TI_flags(%ebp), %ecx
        testw $_TIF_ALLWORK_MASK, %cx
        jne syscall_exit_work
 /* if something modifies registers it must also disable sysexit */
-       movl EIP(%esp), %edx
-       movl OLDESP(%esp), %ecx
+       movl PT_EIP(%esp), %edx
+       movl PT_OLDESP(%esp), %ecx
        xorl %ebp,%ebp
        TRACE_IRQS_ON
        ENABLE_INTERRUPTS_SYSEXIT
@@ -354,7 +338,7 @@ ENTRY(system_call)
        CFI_ADJUST_CFA_OFFSET 4
        SAVE_ALL
        GET_THREAD_INFO(%ebp)
-       testl $TF_MASK,EFLAGS(%esp)
+       testl $TF_MASK,PT_EFLAGS(%esp)
        jz no_singlestep
        orl $_TIF_SINGLESTEP,TI_flags(%ebp)
 no_singlestep:
@@ -366,7 +350,7 @@ no_singlestep:
        jae syscall_badsys
 syscall_call:
        call *sys_call_table(,%eax,4)
-       movl %eax,EAX(%esp)             # store the return value
+       movl %eax,PT_EAX(%esp)          # store the return value
 syscall_exit:
        DISABLE_INTERRUPTS              # make sure we don't miss an interrupt
                                        # setting need_resched or sigpending
@@ -377,12 +361,12 @@ syscall_exit:
        jne syscall_exit_work
 
 restore_all:
-       movl EFLAGS(%esp), %eax         # mix EFLAGS, SS and CS
-       # Warning: OLDSS(%esp) contains the wrong/random values if we
+       movl PT_EFLAGS(%esp), %eax      # mix EFLAGS, SS and CS
+       # Warning: PT_OLDSS(%esp) contains the wrong/random values if we
        # are returning to the kernel.
        # See comments in process.c:copy_thread() for details.
-       movb OLDSS(%esp), %ah
-       movb CS(%esp), %al
+       movb PT_OLDSS(%esp), %ah
+       movb PT_CS(%esp), %al
        andl $(VM_MASK | (SEGMENT_TI_MASK << 8) | SEGMENT_RPL_MASK), %eax
        cmpl $((SEGMENT_LDT << 8) | USER_RPL), %eax
        CFI_REMEMBER_STATE
@@ -409,7 +393,7 @@ iret_exc:
 
        CFI_RESTORE_STATE
 ldt_ss:
-       larl OLDSS(%esp), %eax
+       larl PT_OLDSS(%esp), %eax
        jnz restore_nocheck
        testl $0x00400000, %eax         # returning to 32bit stack?
        jnz restore_nocheck             # allright, normal return
@@ -419,7 +403,7 @@ ldt_ss:
         * This is an "official" bug of all the x86-compatible
         * CPUs, which we can try to work around to make
         * dosemu and wine happy. */
-       movl OLDESP(%esp), %eax
+       movl PT_OLDESP(%esp), %eax
        movl %esp, %edx
        call patch_espfix_desc
        pushl $__ESPFIX_SS
@@ -454,7 +438,7 @@ work_resched:
 
 work_notifysig:                                # deal with pending signals and
                                        # notify-resume requests
-       testl $VM_MASK, EFLAGS(%esp)
+       testl $VM_MASK, PT_EFLAGS(%esp)
        movl %esp, %eax
        jne work_notifysig_v86          # returning to kernel-space or
                                        # vm86-space
@@ -479,14 +463,14 @@ work_notifysig_v86:
        # perform syscall exit tracing
        ALIGN
 syscall_trace_entry:
-       movl $-ENOSYS,EAX(%esp)
+       movl $-ENOSYS,PT_EAX(%esp)
        movl %esp, %eax
        xorl %edx,%edx
        call do_syscall_trace
        cmpl $0, %eax
        jne resume_userspace            # ret != 0 -> running under PTRACE_SYSEMU,
                                        # so must skip actual syscall
-       movl ORIG_EAX(%esp), %eax
+       movl PT_ORIG_EAX(%esp), %eax
        cmpl $(nr_syscalls), %eax
        jnae syscall_call
        jmp syscall_exit
@@ -511,11 +495,11 @@ syscall_fault:
        CFI_ADJUST_CFA_OFFSET 4
        SAVE_ALL
        GET_THREAD_INFO(%ebp)
-       movl $-EFAULT,EAX(%esp)
+       movl $-EFAULT,PT_EAX(%esp)
        jmp resume_userspace
 
 syscall_badsys:
-       movl $-ENOSYS,EAX(%esp)
+       movl $-ENOSYS,PT_EAX(%esp)
        jmp resume_userspace
        CFI_ENDPROC
 
@@ -636,10 +620,10 @@ error_code:
        popl %ecx
        CFI_ADJUST_CFA_OFFSET -4
        /*CFI_REGISTER es, ecx*/
-       movl ES(%esp), %edi             # get the function address
-       movl ORIG_EAX(%esp), %edx       # get the error code
-       movl $-1, ORIG_EAX(%esp)
-       movl %ecx, ES(%esp)
+       movl PT_ES(%esp), %edi          # get the function address
+       movl PT_ORIG_EAX(%esp), %edx    # get the error code
+       movl $-1, PT_ORIG_EAX(%esp)
+       movl %ecx, PT_ES(%esp)
        /*CFI_REL_OFFSET es, ES*/
        movl $(__USER_DS), %ecx
        movl %ecx, %ds
@@ -942,26 +926,26 @@ ENTRY(arch_unwind_init_running)
        movl    4(%esp), %edx
        movl    (%esp), %ecx
        leal    4(%esp), %eax
-       movl    %ebx, EBX(%edx)
+       movl    %ebx, PT_EBX(%edx)
        xorl    %ebx, %ebx
-       movl    %ebx, ECX(%edx)
-       movl    %ebx, EDX(%edx)
-       movl    %esi, ESI(%edx)
-       movl    %edi, EDI(%edx)
-       movl    %ebp, EBP(%edx)
-       movl    %ebx, EAX(%edx)
-       movl    $__USER_DS, DS(%edx)
-       movl    $__USER_DS, ES(%edx)
-       movl    %ebx, ORIG_EAX(%edx)
-       movl    %ecx, EIP(%edx)
+       movl    %ebx, PT_ECX(%edx)
+       movl    %ebx, PT_EDX(%edx)
+       movl    %esi, PT_ESI(%edx)
+       movl    %edi, PT_EDI(%edx)
+       movl    %ebp, PT_EBP(%edx)
+       movl    %ebx, PT_EAX(%edx)
+       movl    $__USER_DS, PT_DS(%edx)
+       movl    $__USER_DS, PT_ES(%edx)
+       movl    %ebx, PT_ORIG_EAX(%edx)
+       movl    %ecx, PT_EIP(%edx)
        movl    12(%esp), %ecx
-       movl    $__KERNEL_CS, CS(%edx)
-       movl    %ebx, EFLAGS(%edx)
-       movl    %eax, OLDESP(%edx)
+       movl    $__KERNEL_CS, PT_CS(%edx)
+       movl    %ebx, PT_EFLAGS(%edx)
+       movl    %eax, PT_OLDESP(%edx)
        movl    8(%esp), %eax
        movl    %ecx, 8(%esp)
-       movl    EBX(%edx), %ebx
-       movl    $__KERNEL_DS, OLDSS(%edx)
+       movl    PT_EBX(%edx), %ebx
+       movl    $__KERNEL_DS, PT_OLDSS(%edx)
        jmpl    *%eax
        CFI_ENDPROC
 ENDPROC(arch_unwind_init_running)