Messages in this thread Patch in this message |  | | | Date | Wed, 1 Jul 2009 22:46:27 -0700 | | From | Andrew Morton <> | | Subject | Re: [PATCH] Fix virt_to_phys() warnings |
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On Fri, 26 Jun 2009 17:13:20 -0700 Kevin Cernekee <cernekee@gmail.com> wrote:
> These warnings were observed on MIPS32 using 2.6.31-rc1 and gcc-4.2.0: > > mm/page_alloc.c: In function 'alloc_pages_exact': > mm/page_alloc.c:1986: warning: passing argument 1 of 'virt_to_phys' makes pointer from integer without a cast > > drivers/usb/mon/mon_bin.c: In function 'mon_alloc_buff': > drivers/usb/mon/mon_bin.c:1264: warning: passing argument 1 of 'virt_to_phys' makes pointer from integer without a cast > > Signed-off-by: Kevin Cernekee <cernekee@gmail.com> > --- > diff --git a/drivers/usb/mon/mon_bin.c b/drivers/usb/mon/mon_bin.c > index f8d9045..0f7a30b 100644 > --- a/drivers/usb/mon/mon_bin.c > +++ b/drivers/usb/mon/mon_bin.c > @@ -1261,7 +1261,7 @@ static int mon_alloc_buff(struct mon_pgmap *map, int npages) > return -ENOMEM; > } > map[n].ptr = (unsigned char *) vaddr; > - map[n].pg = virt_to_page(vaddr); > + map[n].pg = virt_to_page((void *) vaddr); > } > return 0; > } > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 5d714f8..f6180db 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -1983,7 +1983,7 @@ void *alloc_pages_exact(size_t size, gfp_t gfp_mask) > unsigned long alloc_end = addr + (PAGE_SIZE << order); > unsigned long used = addr + PAGE_ALIGN(size); > > - split_page(virt_to_page(addr), order); > + split_page(virt_to_page((void *)addr), order); > while (used < alloc_end) { > free_page(used); > used += PAGE_SIZE;
The virt_to_foo() functions were written back in the Linux dark ages and they're horrid. A byzantine mixture of macros and typecasts which make it really hard to work out what type their argument actually should be.
virt_to_page() takes an argument of type `unsigned long'. (except for the include/asm-generic/page.h version which takes any damn type at all).
virt_to_phys() takes an argument of `const void *' (weird, huh?)
But arch/mips/include/asm/page.h does
#define virt_to_page(kaddr) pfn_to_page(PFN_DOWN(virt_to_phys(kaddr)))
thereby passing an `unsigned long' where a void* was expected.
So perhaps something along these lines:
--- a/arch/mips/include/asm/page.h~a +++ a/arch/mips/include/asm/page.h @@ -184,7 +184,11 @@ typedef struct { unsigned long pgprot; } #endif -#define virt_to_page(kaddr) pfn_to_page(PFN_DOWN(virt_to_phys(kaddr))) +static inline struct page *virt_to_page(unsigned long kaddr) +{ + return pfn_to_page(PFN_DOWN(virt_to_phys((void *)kaddr))); +} + #define virt_addr_valid(kaddr) pfn_valid(PFN_DOWN(virt_to_phys(kaddr))) #define VM_DATA_DEFAULT_FLAGS (VM_READ | VM_WRITE | VM_EXEC | \ _
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