ACPI/Panic 2.6.8-rc3

Reported this a while ago, but tried it again, still getting oops when doing an rmmod of the ACPI processor module.

Hardware: IBM T30, P4 2.4GHz, 256MiB, Debian/stable, did an rmmod processor.

Note: Oops below was copied by hand, so may not be fully reliable. Also, EIP was screwy, so no idea what was executing.

100% reproducible.

ramune@hasenpfeffer:linux-2.6: ./scripts/ver_linux
If some fields are empty or look unusual you may have an old version. Compare to the current minimal requirements in Documentation/Changes.

Linux hasenpfeffer 2.6.8-rc3 #25 Tue Aug 3 20:28:47 PDT 2004 i686 unknown

Gnu C                  2.95.4
Gnu make               3.79.1
binutils               2.12.90.0.1
util-linux             2.11n
mount                  2.11n
module-init-tools      3.0-pre7
e2fsprogs              1.27
pcmcia-cs              3.1.33
nfs-utils              1.0
Linux C Library        2.2.5
Dynamic linker (ldd)   2.2.5
Procps                 2.0.7
Net-tools              1.60
Console-tools          0.2.3
Sh-utils               2.0.11

ksymoops 2.4.9 on i686 2.6.8-rc3. Options used
-v /home/ramune/src/kernel-stuff/linux-2.6/vmlinux (specified) -K (specified)
-l /proc/modules (specified)
-o /lib/modules/2.6.8-rc3 (specified)
-m /boot/System.map-2.6.8-rc3 (specified)

No modules in ksyms, skipping objects
No ksyms, skipping lsmod
eip: d0a42294
*pde = 012c5067

Oops: 0000 [#1]
CPU: 0

EIP: 0060:[<d0a42294>] Not tainted
Using defaults from ksymoops -t elf32-i386 -a i386
EFLAGS: 00010216 (2.6.8-rc3)
eax: 00000000 ebx: 002bef05 ecx: 00000008 edx: 00001020
esi: cff346f8 edi: 002beb87 ebp: cff34600 esp: c02fbfd4
ds: 007b es: 007b ss: 0068

Stack: 0009ef00 00000000 c0fb0000 0009ef00 c031a120 00388007 c010208c c02fc5d3
       c031abe0 0001080e c010019f
Call Trace:
  [<c010208c>]
  [<c02fc5d3>]
Code: Bad EIP value

Trace; c010208c <cpu_idle+1f/34>
Trace; c02fc5d3 <start_kernel+145/148>

It should be fixed before 2.6.8, a patch has already been sent to the big wigs.

Index: linux-2.6.8-rc1-mm1/drivers/acpi/processor.c
===================================================================
RCS file: /home/cvsroot/linux-2.6.8-rc1-mm1/drivers/acpi/processor.c,v retrieving revision 1.1.1.1

diff -u -p -B -r1.1.1.1 processor.c
@@ -2372,8 +2372,10 @@ acpi_processor_remove (
 	pr = (struct acpi_processor *) acpi_driver_data(device);
 
 	/* Unregister the idle handler when processor #0 is removed. */
-	if (pr->id == 0)
+	if (pr->id == 0) {
 		pm_idle = pm_idle_save;
+		synchronize_kernel();
+	}
 
 	status = acpi_remove_notify_handler(pr->handle, ACPI_DEVICE_NOTIFY,
 		acpi_processor_notify);