Skip to main content

Browse the archive

Revision 7695fb04aca62e2d8a7ca6ede50f6211e1d71e53 authored by Darren Salt on 07 February 2009, 06:02:07 UTC, committed by Len Brown on 07 February 2009, 06:02:07 UTC 
eeepc-laptop: fix oops when changing backlight brightness during eeepc-laptop init
 
I got the following oops while changing the backlight brightness during
startup.  When it happens, it prevents use of the hotkeys, Fn-Fx, and the
lid button.

It's a clear use-before-init, as I verified by testing with an
appropriately-placed "else printk".

BUG: unable to handle kernel NULL pointer dereference at 00000000
*pde = 00000000
Oops: 0002 [#1] PREEMPT SMP
Pid: 160, comm: kacpi_notify Not tainted (2.6.28.1-eee901 #4) 901
EIP: 0060:[<c0264e68>]  [<c0264e68>] eeepc_hotk_notify+26/da
EFLAGS: 00010246 CPU: 1
Using defaults from ksymoops -t elf32-i386 -a i386
EAX: 00000009 EBX: 00000000 ECX: 00000009 EDX: f70dbf64
ESI: 00000029 EDI: f7335188 EBP: c02112c9 ESP: f70dbf80
 DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
 f70731e0 f73acd50 c02164ac f7335180 f70aa040 c02112e6 f733518c c012b62f
 f70aa044 f70aa040 c012bdba f70aa04c 00000000 c012be6e 00000000 f70bdf80
 c012e198 f70dbfc4 f70dbfc4 f70aa040 c012bdba 00000000 c012e0c9 c012e091
Call Trace:
 [<c02164ac>] ? acpi_ev_notify_dispatch+4c/55
 [<c02112e6>] ? acpi_os_execute_deferred+1d/25
 [<c012b62f>] ? run_workqueue+71/f1
 [<c012bdba>] ? worker_thread+0/bf
 [<c012be6e>] ? worker_thread+b4/bf
 [<c012e198>] ? autoremove_wake_function+0/2b
 [<c012bdba>] ? worker_thread+0/bf
 [<c012e0c9>] ? kthread+38/5f
 [<c012e091>] ? kthread+0/5f
 [<c0103abf>] ? kernel_thread_helper+7/10
Code: 00 00 00 00 c3 83 3d 60 5c 50 c0 00 56 89 d6 53 0f 84 c4 00 00 00 8d 42
e0 83 f8 0f 77 0f 8b 1d 68 5c 50 c0 89 d8 e8 a9 fa ff ff <89> 03 8b 1d 60 5c
50 c0 89 f2 83 e2 7f 0f b7 4c 53 10 8d 41 01

Signed-off-by: Darren Salt <linux@youmustbejoking.demon.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
1 parent 386e4a8
Raw File
Kbuild 
#
# Kbuild for top-level directory of the kernel
# This file takes care of the following:
# 1) Generate bounds.h
# 2) Generate asm-offsets.h (may need bounds.h)
# 3) Check for missing system calls

#####
# 1) Generate bounds.h

bounds-file := include/linux/bounds.h

always  := $(bounds-file)
targets := $(bounds-file) kernel/bounds.s

quiet_cmd_bounds = GEN     $@
define cmd_bounds
	(set -e; \
	 echo "#ifndef __LINUX_BOUNDS_H__"; \
	 echo "#define __LINUX_BOUNDS_H__"; \
	 echo "/*"; \
	 echo " * DO NOT MODIFY."; \
	 echo " *"; \
	 echo " * This file was generated by Kbuild"; \
	 echo " *"; \
	 echo " */"; \
	 echo ""; \
	 sed -ne $(sed-y) $<; \
	 echo ""; \
	 echo "#endif" ) > $@
endef

# We use internal kbuild rules to avoid the "is up to date" message from make
kernel/bounds.s: kernel/bounds.c FORCE
	$(Q)mkdir -p $(dir $@)
	$(call if_changed_dep,cc_s_c)

$(obj)/$(bounds-file): kernel/bounds.s Kbuild
	$(Q)mkdir -p $(dir $@)
	$(call cmd,bounds)

#####
# 2) Generate asm-offsets.h
#

offsets-file := include/asm/asm-offsets.h

always  += $(offsets-file)
targets += $(offsets-file)
targets += arch/$(SRCARCH)/kernel/asm-offsets.s


# Default sed regexp - multiline due to syntax constraints
define sed-y
	"/^->/{s:->#\(.*\):/* \1 */:; \
	s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \
	s:->::; p;}"
endef

quiet_cmd_offsets = GEN     $@
define cmd_offsets
	(set -e; \
	 echo "#ifndef __ASM_OFFSETS_H__"; \
	 echo "#define __ASM_OFFSETS_H__"; \
	 echo "/*"; \
	 echo " * DO NOT MODIFY."; \
	 echo " *"; \
	 echo " * This file was generated by Kbuild"; \
	 echo " *"; \
	 echo " */"; \
	 echo ""; \
	 sed -ne $(sed-y) $<; \
	 echo ""; \
	 echo "#endif" ) > $@
endef

# We use internal kbuild rules to avoid the "is up to date" message from make
arch/$(SRCARCH)/kernel/asm-offsets.s: arch/$(SRCARCH)/kernel/asm-offsets.c \
                                      $(obj)/$(bounds-file) FORCE
	$(Q)mkdir -p $(dir $@)
	$(call if_changed_dep,cc_s_c)

$(obj)/$(offsets-file): arch/$(SRCARCH)/kernel/asm-offsets.s Kbuild
	$(call cmd,offsets)

#####
# 3) Check for missing system calls
#

quiet_cmd_syscalls = CALL    $<
      cmd_syscalls = $(CONFIG_SHELL) $< $(CC) $(c_flags)

PHONY += missing-syscalls
missing-syscalls: scripts/checksyscalls.sh FORCE
	$(call cmd,syscalls)

# Delete all targets during make clean
clean-files := $(addprefix $(objtree)/,$(filter-out $(bounds-file) $(offsets-file),$(targets)))
back to top