[PATCH] pci_alloc_consistent() crash

[Geert Uytterhoeven <geert@linux-m68k.org>]

        Hi Ralf,

Avoid a NULL-pointer dereference when using pci_alloc_consistent() for PCI-like
buses (i.e. hwdev = NULL).

--- linux-mips-2.4.x/arch/mips/kernel/pci-dma.c Tue Apr  1 16:21:18 2003
+++ linux/arch/mips/kernel/pci-dma.c    Thu May 15 18:17:35 2003
@@ -21,6 +21,7 @@
 {
        void *ret;
        int gfp = GFP_ATOMIC;
+       struct pci_bus *bus = NULL;
 
 #ifdef CONFIG_ISA
        if (hwdev == NULL || hwdev->dma_mask != 0xffffffff)
@@ -30,7 +31,9 @@
 
        if (ret != NULL) {
                memset(ret, 0, size);
-               *dma_handle = bus_to_baddr(hwdev->bus, __pa(ret));
+               if (hwdev)
+                       bus = hwdev->bus;
+               *dma_handle = bus_to_baddr(bus, __pa(ret));
 #ifdef CONFIG_NONCOHERENT_IO
                dma_cache_wback_inv((unsigned long) ret, size);
                ret = UNCAC_ADDR(ret);

Gr{oetje,eeting}s,

                                                Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                                            -- Linus Torvalds