Messages in this thread Patch in this message | | | From | Rusty Russell <> | Subject | [PATCH] Get rid of check_resource() before it becomes a problem | Date | Wed, 30 Oct 2002 12:40:14 +1100 |
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AFAICT, it has the same race issues as the old check_region() which is being slowly and painfully eliminated.
Remove the temptation, and open-code the one user (PCMCIA).
Rusty.
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal linux-2.5.44/drivers/pcmcia/rsrc_mgr.c working-2.5.44-proc-register/drivers/pcmcia/rsrc_mgr.c --- linux-2.5.44/drivers/pcmcia/rsrc_mgr.c 2002-10-15 15:29:59.000000000 +1000 +++ working-2.5.44-proc-register/drivers/pcmcia/rsrc_mgr.c 2002-10-30 12:35:20.000000000 +1100 @@ -124,16 +124,36 @@ static struct resource *resource_parent( return &ioport_resource; } +/* FIXME: Fundamentally racy. */ static inline int check_io_resource(unsigned long b, unsigned long n, struct pci_dev *dev) { - return check_resource(resource_parent(b, n, IORESOURCE_IO, dev), b, n); + struct resource *region; + + region = __request_region(resource_parent(b, n, IORESOURCE_IO, dev), + b, n, "check_io_resource"); + if (!region) + return -EBUSY; + + release_resource(region); + kfree(region); + return 0; } +/* FIXME: Fundamentally racy. */ static inline int check_mem_resource(unsigned long b, unsigned long n, struct pci_dev *dev) { - return check_resource(resource_parent(b, n, IORESOURCE_MEM, dev), b, n); + struct resource *region; + + region = __request_region(resource_parent(b, n, IORESOURCE_MEM, dev), + b, n, "check_mem_resource"); + if (!region) + return -EBUSY; + + release_resource(region); + kfree(region); + return 0; } static struct resource *make_resource(unsigned long b, unsigned long n, diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal linux-2.5.44/include/linux/ioport.h working-2.5.44-proc-register/include/linux/ioport.h --- linux-2.5.44/include/linux/ioport.h 2002-05-09 12:40:19.000000000 +1000 +++ working-2.5.44-proc-register/include/linux/ioport.h 2002-10-30 12:25:54.000000000 +1100 @@ -85,7 +85,6 @@ extern struct resource iomem_resource; extern int get_resource_list(struct resource *, char *buf, int size); -extern int check_resource(struct resource *root, unsigned long, unsigned long); extern int request_resource(struct resource *root, struct resource *new); extern int release_resource(struct resource *new); extern int allocate_resource(struct resource *root, struct resource *new, diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal linux-2.5.44/kernel/resource.c working-2.5.44-proc-register/kernel/resource.c --- linux-2.5.44/kernel/resource.c 2002-08-11 15:31:43.000000000 +1000 +++ working-2.5.44-proc-register/kernel/resource.c 2002-10-30 12:26:12.000000000 +1100 @@ -131,20 +131,6 @@ int release_resource(struct resource *ol return retval; } -int check_resource(struct resource *root, unsigned long start, unsigned long len) -{ - struct resource *conflict, tmp; - - tmp.start = start; - tmp.end = start + len - 1; - write_lock(&resource_lock); - conflict = __request_resource(root, &tmp); - if (!conflict) - __release_resource(&tmp); - write_unlock(&resource_lock); - return conflict ? -EBUSY : 0; -} - /* * Find empty slot in the resource tree given range and alignment. */ -- Anyone who quotes me in their sig is an idiot. -- Rusty Russell. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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