Re: swsusp regression [Was: 2.6.17-mm1]

[Andrew Morton <akpm@osdl.org>]

On Fri, 23 Jun 2006 14:57:01 +0200
Pavel Machek <pavel@ucw.cz> wrote:

> > Stack: c0229b71 00000046 00000000 00000286 c0383ca7 f6cb9ecc c013b242 00000003
> >         00000000 00000003 f6cb9ee0 c013b2e8 00000003 c0436890 f6c9a003 f6cb9f08
> >         c013b481 00000003 00000003 00000246 c1788b00 00000003 c04368a0 c043692c
> > Call Trace:
> >  <c0103eea> show_stack_log_lvl+0x92/0xb7  <c0104100> show_registers+0x1a3/0x21b
> >  <c0104319> die+0x117/0x230  <c03627a6> do_page_fault+0x39c/0x72a
> >  <c0103b2f> error_code+0x4f/0x54  <c013b242> suspend_enter+0x2f/0x52
> >  <c013b2e8> enter_state+0x4b/0x8d  <c013b481> state_store+0xa0/0xa2
> >  <c01a5151> subsys_attr_store+0x37/0x41  <c01a53d2> flush_write_buffer+0x3c/0x46
> >  <c01a5443> sysfs_write_file+0x67/0x8b  <c0166bb6> vfs_write+0x1b9/0x1be
> >  <c0166c7b> sys_write+0x4b/0x75  <c010300f> sysenter_past_esp+0x54/0x75
> > 
> > Code: 05 c4 42 43 c0 31 43 43 c0 c3 8b 2d 68 6e 54 c0 8b 1d 60 6e 54 c0 8b 35 6c 6e 54 c0 8b 3d 70 6d 54 c0 ff 35 74 6e 54 c0 9d c3 90 <e8> 6d 38 ea ff e8 a2 ff ff ff 6a 03 e8 ec b6 de ff 83 c4 04 c3
> > EIP: [c043431c>] do_suspend_lowlevel+0x0/0x15 SS:ESP 0068:f6cb6ea4
>   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> Ha, wait a moment, this is interesting line. Can you trace down which
> instruction causes this?
> 
> We recently changed pagetable handling during swsusp, perhaps thats
> it? It went to Linus few minutes ago...

That's a good possibility.  It does appear to be oopsing at the first
instruction of arch/i386/kernel/acpi/wakeup.S:do_suspend_lowlevel(). 
Perhaps there's enough info in that oops trace to tell us whether it was
the instruction fetch which oopsed.

One wonders whether this will help...

--- a/arch/i386/kernel/acpi/wakeup.S~a
+++ a/arch/i386/kernel/acpi/wakeup.S
@@ -270,6 +270,7 @@ ALIGN
 ENTRY(saved_magic)	.long	0
 ENTRY(saved_eip)	.long	0
 
+.text
 save_registers:
 	leal	4(%esp), %eax
 	movl	%eax, saved_context_esp
@@ -304,6 +305,7 @@ ret_point:
 	call	restore_processor_state
 	ret
 
+.data
 ALIGN
 # saved registers
 saved_gdt:	.long	0,0
_