> -----Original Message----- > From: owner-linux-mm@xxxxxxxxx [mailto:owner-linux-mm@xxxxxxxxx] On > Behalf Of Dexuan Cui > Sent: Wednesday, October 29, 2014 18:54 PM > To: gregkh@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; linux- > mm@xxxxxxxxx; x86@xxxxxxxxxx; olaf@xxxxxxxxx; apw@xxxxxxxxxxxxx; > jasowang@xxxxxxxxxx; tglx@xxxxxxxxxxxxx; mingo@xxxxxxxxxx; > hpa@xxxxxxxxx; dave.hansen@xxxxxxxxx; riel@xxxxxxxxxx > Cc: KY Srinivasan; Haiyang Zhang > Subject: [PATCH] x86, pageattr: fix slow_virt_to_phys() for X86_PAE > > pte_pfn() returns a PFN of long (32 bits in 32-PAE), then > "long << PAGE_SHIFT" will overflow for PFNs above 4GB. > > Due to this issue, some Linux 32-PAE distros, running as guests on Hyper-V, > with 5GB memory assigned, can't load the netvsc driver successfully and > hence the synthetic network device can't work (we can use the kernel > parameter > mem=3000M to work around the issue). > > Cc: K. Y. Srinivasan <kys@xxxxxxxxxxxxx> > Cc: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx> > Signed-off-by: Dexuan Cui <decui@xxxxxxxxxxxxx> > --- > arch/x86/mm/pageattr.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c > index ae242a7..36de293 100644 > --- a/arch/x86/mm/pageattr.c > +++ b/arch/x86/mm/pageattr.c > @@ -409,7 +409,7 @@ phys_addr_t slow_virt_to_phys(void *__virt_addr) > psize = page_level_size(level); > pmask = page_level_mask(level); > offset = virt_addr & ~pmask; > - phys_addr = pte_pfn(*pte) << PAGE_SHIFT; > + phys_addr = (phys_addr_t)pte_pfn(*pte) << PAGE_SHIFT; > return (phys_addr | offset); > } > EXPORT_SYMBOL_GPL(slow_virt_to_phys); Sorry for sending the same patch twice due to my silly typing! Thanks, -- Dexuan -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href