On Tue, Aug 05, 2008 at 12:39:31PM +0200, Sven Wegener wrote:
> On Tue, 5 Aug 2008, Simon Horman wrote:
>
> > Check the return value of device_create_bin_file in pci_create_bus,
> > unwind if neccessary, and propogate any errors to the caller.
> >
> > Signed-off-by: Simon Horman <horms@xxxxxxxxxxxx>
> >
> > ---
> >
> > drivers/pci/probe.c: In function `pci_create_bus':
> > drivers/pci/probe.c:66: warning: ignoring return value of `device_create_bin_file', declared with attribute warn_unused_result
> > drivers/pci/probe.c:74: warning: ignoring return value of `device_create_bin_file', declared with attribute warn_unused_result
> >
> > # ia64-unknown-linux-gnu-gcc --version
> > ia64-unknown-linux-gnu-gcc (GCC) 3.4.5
> > Copyright (C) 2004 Free Software Foundation, Inc.
> > This is free software; see the source for copying conditions. There is NO
> > warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
> >
> > Index: linux-2.6/drivers/pci/probe.c
> > ===================================================================
> > --- linux-2.6.orig/drivers/pci/probe.c 2008-08-05 19:58:43.000000000 +1000
> > +++ linux-2.6/drivers/pci/probe.c 2008-08-05 19:59:15.000000000 +1000
> > @@ -53,26 +53,37 @@ EXPORT_SYMBOL(no_pci_devices);
> > * a per-bus basis. This routine creates the files and ties them into
> > * their associated read, write and mmap files from pci-sysfs.c
> > */
> > -static void pci_create_legacy_files(struct pci_bus *b)
> > +static int pci_create_legacy_files(struct pci_bus *b)
> > {
> > + int error;
> > +
> > b->legacy_io = kzalloc(sizeof(struct bin_attribute) * 2,
> > GFP_ATOMIC);
> > - if (b->legacy_io) {
> > - b->legacy_io->attr.name = "legacy_io";
> > - b->legacy_io->size = 0xffff;
> > - b->legacy_io->attr.mode = S_IRUSR | S_IWUSR;
> > - b->legacy_io->read = pci_read_legacy_io;
> > - b->legacy_io->write = pci_write_legacy_io;
> > - device_create_bin_file(&b->dev, b->legacy_io);
> > -
> > - /* Allocated above after the legacy_io struct */
> > - b->legacy_mem = b->legacy_io + 1;
> > - b->legacy_mem->attr.name = "legacy_mem";
> > - b->legacy_mem->size = 1024*1024;
> > - b->legacy_mem->attr.mode = S_IRUSR | S_IWUSR;
> > - b->legacy_mem->mmap = pci_mmap_legacy_mem;
> > - device_create_bin_file(&b->dev, b->legacy_mem);
> > + if (!b->legacy_io)
> > + return -ENOMEM;
> > +
> > + b->legacy_io->attr.name = "legacy_io";
> > + b->legacy_io->size = 0xffff;
> > + b->legacy_io->attr.mode = S_IRUSR | S_IWUSR;
> > + b->legacy_io->read = pci_read_legacy_io;
> > + b->legacy_io->write = pci_write_legacy_io;
> > + error = device_create_bin_file(&b->dev, b->legacy_io);
> > + if (error)
> > + return error;
>
> I'd release the memory here and NULLify legacy_io.
>
> > +
> > + /* Allocated above after the legacy_io struct */
> > + b->legacy_mem = b->legacy_io + 1;
> > + b->legacy_mem->attr.name = "legacy_mem";
> > + b->legacy_mem->size = 1024*1024;
> > + b->legacy_mem->attr.mode = S_IRUSR | S_IWUSR;
> > + b->legacy_mem->mmap = pci_mmap_legacy_mem;
> > + error = device_create_bin_file(&b->dev, b->legacy_mem);
> > + if (error) {
> > + device_remove_bin_file(&b->dev, b->legacy_io);
> > + return error;
>
> Here too.
>
> Reason: If we fail to create the legacy_io file, legacy_mem will still be
> NULL, because it has been not initialized at that point. But we will try
> to remove it in pci_remove_legacy_files and in sysfs_remove_bin_file
> we're going to derefence it and blow up.
Yes, sorry, my bad.
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