Fix stack handling in acpi_wakeup.S

Fix stack handling in acpi_wakeup.S

[Pavel Machek]

Hi!

This fixes stack handling in acpi_wakeup.S, and makes stack smaller so
that wakeup code actually fits inside memory allocated for it. Plus
someone renamed .L1432 to something meaningfull. Please apply,
								Pavel

--- clean/arch/i386/kernel/acpi_wakeup.S	2003-02-11 17:40:33.000000000 +0100
+++ linux/arch/i386/kernel/acpi_wakeup.S	2003-02-11 12:51:03.000000000 +0100
@@ -31,7 +31,7 @@
 	movw	%cs, %ax
 	movw	%ax, %ds					# Make ds:0 point to wakeup_start
 	movw	%ax, %ss
-	mov	wakeup_stack - wakeup_code, %sp			# Private stack is needed for ASUS board
+	mov	$(wakeup_stack - wakeup_code), %sp		# Private stack is needed for ASUS board
 	movw	$0x0e00 + 'S', %fs:(0x12)
 
 	pushl	$0						# Kill any dangerous flags
@@ -159,12 +159,14 @@
 	.code32
 	ALIGN
 
+.org	0x800
+wakeup_stack_begin:	# Stack grows down
 
-.org	0x2000
+.org	0xff0		# Just below end of page
 wakeup_stack:
-.org	0x3000
 ENTRY(wakeup_end)
-.org	0x4000
+	
+.org	0x1000
 
 wakeup_pmode_return:
 	movl	$__KERNEL_DS, %eax
@@ -274,7 +276,7 @@
 
 ENTRY(do_suspend_lowlevel)
 	cmpl $0,4(%esp)
-	jne .L1432
+	jne ret_point
 	call save_processor_state
 
 	movl %esp, saved_context_esp
@@ -287,7 +289,7 @@
 	movl %edi, saved_context_edi
 	pushfl ; popl saved_context_eflags
 
-	movl $.L1432,saved_eip
+	movl $ret_point,saved_eip
 	movl %esp,saved_esp
 	movl %ebp,saved_ebp
 	movl %ebx,saved_ebx
@@ -299,7 +301,7 @@
 	addl $4,%esp
 	ret
 	.p2align 4,,7
-.L1432:
+ret_point:
 	movl $__KERNEL_DS,%eax
 	movw %ax, %ds
 	movl saved_context_esp, %esp

-- 
When do you have a heart between your knees?
[Johanka's followup: and *two* hearts?]

Re: Fix stack handling in acpi_wakeup.S

[David Woodhouse]

On Tue, 2003-02-11 at 18:44, Pavel Machek wrote:
> Hi!
> 
> This fixes stack handling in acpi_wakeup.S, and makes stack smaller so
> that wakeup code actually fits inside memory allocated for it. Plus
> someone renamed .L1432 to something meaningfull. Please apply,

I am confused. If I apply your patch, I get a failure to resume (precise
symptoms below) on both boards I've tried it on. Applying this obviously
broken patch 'fixes' it:

--- arch/i386/kernel/acpi.c.orig        Thu Feb 13 19:07:34 2003
+++ arch/i386/kernel/acpi.c     Thu Feb 13 19:07:36 2003
@@ -483,6 +483,7 @@
        if (!acpi_wakeup_address)
                return 1;
        init_low_mapping(swapper_pg_dir, USER_PTRS_PER_PGD);
+       memset((void *)acpi_wakeup_address, 0, 0x3000);
        memcpy((void *) acpi_wakeup_address, &wakeup_start, &wakeup_end
- &wakeup_start);
        acpi_copy_wakeup_routine(acpi_wakeup_address);
  

If I reserve the whole three pages I scribble on in the above patch (and
which we used to scribble on), by calling alloc_bootmem_low(3*PAGE_SIZE)
in acpi_reserve_bootmem(), then the failure to resume returns. I _need_
to scribble on whatever's after us :)

Failure mode is as follows:

Upon resume, _all_ processes with a userspace VM will oops on being
rescheduled. In every case, %eip is zero and %esp is the very top of the
8KiB area allocated for the task structure and stack. For example:

 portmap left refrigerator
Unable to handle kernel NULL pointer dereference at virtual address
00000000
 printing eip:
00000000
*pde = 00000000
Oops: 0000
CPU:    0
EIP:    0060:[<00000000>]    Not tainted
EFLAGS: 00010046
EIP is at 0x0
eax: 000000a8   ebx: 08054db0   ecx: 00000003   edx: ffffffff
esi: 08054db0   edi: 08054db0   ebp: bffffd3c   esp: ce14e000
ds: 007b   es: 007b   ss: 0068
Process portmap (pid: 550, threadinfo=ce14c000 task=ce4f80a0)
Stack:
Call Trace:
                                                                                                                                                      
Code:  Bad EIP value.

-- 
dwmw2

Re: Fix stack handling in acpi_wakeup.S

[Alfred E. Heggestad]

Hi Pavel

I applied this patch to 2.5.60 and when doing the
software suspend it did manage to start the freezing
process (process X into refrigerator etc...) but crashed
once in ide.c - apologies I do not have any more details
and I cannot reproduce that one.

Doing software suspend now will freeze all procs and
hang on the last one:

# echo 4 > /proc/acpi/sleep

...
=<proc> entered refrigerator
=| entered refrigerator

-> hang

This happens both with 2.5.60 plus Pavel acpi_wakeup.S patch
and vanilla 2.5.61, also with or withour X running.

My machine is a Sony Vaio VX71P, details can be found here:

http://lamis.wyrdweb.com/~alfredh/vaio_vx71p/

/alfred

On Tue, 2003-02-11 at 19:44, Pavel Machek wrote:
> Hi!
> 
> This fixes stack handling in acpi_wakeup.S, and makes stack smaller so
> that wakeup code actually fits inside memory allocated for it. Plus
> someone renamed .L1432 to something meaningfull. Please apply,
> 								Pavel
> 
> --- clean/arch/i386/kernel/acpi_wakeup.S	2003-02-11 17:40:33.000000000 +0100
> +++ linux/arch/i386/kernel/acpi_wakeup.S	2003-02-11 12:51:03.000000000 +0100
> @@ -31,7 +31,7 @@
>  	movw	%cs, %ax
>  	movw	%ax, %ds					# Make ds:0 point to wakeup_start
>  	movw	%ax, %ss
> -	mov	wakeup_stack - wakeup_code, %sp			# Private stack is needed for ASUS board
> +	mov	$(wakeup_stack - wakeup_code), %sp		# Private stack is needed for ASUS board
>  	movw	$0x0e00 + 'S', %fs:(0x12)
>  
>  	pushl	$0						# Kill any dangerous flags
> @@ -159,12 +159,14 @@
>  	.code32
>  	ALIGN
>  
> +.org	0x800
> +wakeup_stack_begin:	# Stack grows down
>  
> -.org	0x2000
> +.org	0xff0		# Just below end of page
>  wakeup_stack:
> -.org	0x3000
>  ENTRY(wakeup_end)
> -.org	0x4000
> +	
> +.org	0x1000
>  
>  wakeup_pmode_return:
>  	movl	$__KERNEL_DS, %eax
> @@ -274,7 +276,7 @@
>  
>  ENTRY(do_suspend_lowlevel)
>  	cmpl $0,4(%esp)
> -	jne .L1432
> +	jne ret_point
>  	call save_processor_state
>  
>  	movl %esp, saved_context_esp
> @@ -287,7 +289,7 @@
>  	movl %edi, saved_context_edi
>  	pushfl ; popl saved_context_eflags
>  
> -	movl $.L1432,saved_eip
> +	movl $ret_point,saved_eip
>  	movl %esp,saved_esp
>  	movl %ebp,saved_ebp
>  	movl %ebx,saved_ebx
> @@ -299,7 +301,7 @@
>  	addl $4,%esp
>  	ret
>  	.p2align 4,,7
> -.L1432:
> +ret_point:
>  	movl $__KERNEL_DS,%eax
>  	movw %ax, %ds
>  	movl saved_context_esp, %esp
-- 
Alfred E. Heggestad <linuxedmund@home.no>

Re: Fix stack handling in acpi_wakeup.S

[Pavel Machek]

Hi!

> I applied this patch to 2.5.60 and when doing the
> software suspend it did manage to start the freezing
> process (process X into refrigerator etc...) but crashed
> once in ide.c - apologies I do not have any more details
> and I cannot reproduce that one.

this patch has nothing to do with swsusp. I do not know what goes
wrong in ide.c, but this patch is for orthogonal issue.
-- 
Casualities in World Trade Center: ~3k dead inside the building,
cryptography in U.S.A. and free speech in Czech Republic.