Setting ->owner as done currently (pde->owner = THIS_MODULE) is racy
as correctly noted at bug #12454. Someone can lookup entry with NULL
->owner, thus not pinning enything, and release it later resulting
in module refcount underflow.
We can keep ->owner and supply it at registration time like ->proc_fops
and ->data.
But this leaves ->owner as easy-manipulative field (just one C assignment)
and somebody will forget to unpin previous/pin current module when
switching ->owner. ->proc_fops is declared as "const" which should give
some thoughts.
->read_proc/->write_proc were just fixed to not require ->owner for
protection.
rmmod'ed directories will be empty and return "." and ".." -- no harm.
And directories with tricky enough readdir and lookup shouldn't be modular.
We definitely don't want such modular code.
Removing ->owner will also make PDE smaller.
So, let's nuke it.
Kudos to Jeff Layton for reminding about this, let's say, oversight.
http://bugzilla.kernel.org/show_bug.cgi?id=12454
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (422 commits)
[ARM] 5435/1: fix compile warning in sanity_check_meminfo()
[ARM] 5434/1: ARM: OMAP: Fix mailbox compile for 24xx
[ARM] pxa: fix the bad assumption that PCMCIA sockets always start with 0
[ARM] pxa: fix Colibri PXA300 and PXA320 LCD backlight pins
imxfb: Fix TFT mode
i.MX21/27: remove ifdef CONFIG_FB_IMX
imxfb: add clock support
mxc: add arch_reset() function
clkdev: add possibility to get a clock based on the device name
i.MX1: remove fb support from mach-imx
[ARM] pxa: build arch/arm/plat-pxa/mfp.c only when PXA3xx or ARCH_MMP defined
Gemini: Add support for Teltonika RUT100
Gemini: gpiolib based GPIO support v2
MAINTAINERS: add myself as Gemini architecture maintainer
ARM: Add Gemini architecture v3
[ARM] OMAP: Fix compile for omap2_init_common_hw()
MAINTAINERS: Add myself as Faraday ARM core variant maintainer
ARM: Add support for FA526 v2
[ARM] acorn,ebsa110,footbridge,integrator,sa1100: Convert asm/io.h to linux/io.h
[ARM] collie: fix two minor formatting nits
...
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k:
m68k: irq_node.handler() should return irqreturn_t
m68k: section mismatch fixes: Atari SCSI
m68k: section mismatch fixes: DMAsound for Atari
MAINTAINERS: Replace dead link to m68k CVS repository by link to new git repository
m68k: mac - Add SWIM floppy support
m68k: mac - Add a new entry in mac_model to identify the floppy controller type.
m68k: Add install target
* 'bkl-removal' of git://git.lwn.net/linux-2.6:
Rationalize fasync return values
Move FASYNC bit handling to f_op->fasync()
Use f_lock to protect f_flags
Rename struct file->f_ep_lock
* git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6: (96 commits)
sh: add support for SMSC Polaris platform
sh: fix the HD64461 level-triggered interrupts handling
sh: sh-rtc wakeup support
sh: sh-rtc invalid time rework
sh: sh-rtc carry interrupt rework
sh: disallow kexec virtual entry
sh: kexec jump: fix for ftrace.
sh: kexec: Drop SR.BL bit toggling.
sh: add kexec jump support
sh: rework kexec segment code
sh: simplify kexec vbr code
sh: Flush only the needed range when unmapping a VMA.
sh: Update debugfs ASID dumping for 16-bit ASID support.
sh: tlb-pteaex: Kill off legacy PTEA updates.
sh: Support for extended ASIDs on PTEAEX-capable SH-X3 cores.
sh: sh7763rdp: Change IRQ number for sh_eth of sh7763rdp
sh: espt-giga board support
sh: dma: Make G2 DMA configurable.
sh: dma: Make PVR2 DMA configurable.
sh: Move IRQ multi definition of DMAC to defconfig
...
Alexey Dobriyan
Mauro Carvalho Chehab
Linus Torvalds
Russell King
Ingo Molnar
Michael Schmitz
Takashi Iwai