Re: [PATCH] of: Use proper types for checking memory overflow

[Grant Likely]

On Tue, 8 Jul 2014 09:24:08 +0200 (CEST), Nicolas Pitre <nicolas.pitre@xxxxxxxxxx> wrote:
> On Mon, 7 Jul 2014, Laura Abbott wrote:
> 
> > Commit a67a6ed15513541579d38bcbd127e7be170710e5
> > (of: Check for phys_addr_t overflows in early_init_dt_add_memory_arch)
> > corrected early_init_dt_add_memory_arch to account for overflows
> > but did so in an unclean way using ULONG_MAX. There is no
> > guarantee that sizeof(unsigned long) == sizeof(phys_addr_t).
> > Check against phys_addr_t instead.
> > 
> > Signed-off-by: Laura Abbott <lauraa@xxxxxxxxxxxxxx>
> 
> Acked-by: Nicolas Pitre <nico@xxxxxxxxxx>

Applied, thanks.

g.

> 
> > ---
> >  drivers/of/fdt.c | 22 +++++++++++-----------
> >  1 file changed, 11 insertions(+), 11 deletions(-)
> > 
> > diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
> > index b777d8f..b88a68e 100644
> > --- a/drivers/of/fdt.c
> > +++ b/drivers/of/fdt.c
> > @@ -875,24 +875,24 @@ int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
> >  }
> >  
> >  #ifdef CONFIG_HAVE_MEMBLOCK
> > +#define MAX_PHYS_ADDR	((phys_addr_t)~0)
> > +
> >  void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
> >  {
> >  	const u64 phys_offset = __pa(PAGE_OFFSET);
> >  	base &= PAGE_MASK;
> >  	size &= PAGE_MASK;
> >  
> > -	if (sizeof(phys_addr_t) < sizeof(u64)) {
> > -		if (base > ULONG_MAX) {
> > -			pr_warning("Ignoring memory block 0x%llx - 0x%llx\n",
> > -					base, base + size);
> > -			return;
> > -		}
> > +	if (base > MAX_PHYS_ADDR) {
> > +		pr_warning("Ignoring memory block 0x%llx - 0x%llx\n",
> > +				base, base + size);
> > +		return;
> > +	}
> >  
> > -		if (base + size > ULONG_MAX) {
> > -			pr_warning("Ignoring memory range 0x%lx - 0x%llx\n",
> > -					ULONG_MAX, base + size);
> > -			size = ULONG_MAX - base;
> > -		}
> > +	if (base + size > MAX_PHYS_ADDR) {
> > +		pr_warning("Ignoring memory range 0x%lx - 0x%llx\n",
> > +				ULONG_MAX, base + size);
> > +		size = MAX_PHYS_ADDR - base;
> >  	}
> >  
> >  	if (base + size < phys_offset) {
> > -- 
> > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> > hosted by The Linux Foundation
> > 
> > 

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