* [PATCH 008/216] x86, pageattr: Prevent overflow in slow_virt_to_phys() for X86_PAE [not found] <1543404768-89470-1-git-send-email-alex.shi@linux.alibaba.com> @ 2018-11-28 11:29 ` Alex Shi 2018-11-28 12:14 ` Alex Shi 0 siblings, 1 reply; 2+ messages in thread From: Alex Shi @ 2018-11-28 11:29 UTC (permalink / raw) To: Yang Shi, Michael Wang, Xunlei Pang Cc: Dexuan Cui, K. Y. Srinivasan, Haiyang Zhang, gregkh, linux-mm, olaf, apw, jasowang, dave.hansen, riel, stable, Thomas Gleixner, Alex Shi From: Dexuan Cui <decui@microsoft.com> commit d1cd1210834649ce1ca6bafe5ac25d2f40331343 upstream. pte_pfn() returns a PFN of long (32 bits in 32-PAE), so "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). Cast pte_pfn() to phys_addr_t before shifting. Fixes: "commit d76565344512: x86, mm: Create slow_virt_to_phys()" Signed-off-by: Dexuan Cui <decui@microsoft.com> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: gregkh@linuxfoundation.org Cc: linux-mm@kvack.org Cc: olaf@aepfle.de Cc: apw@canonical.com Cc: jasowang@redhat.com Cc: dave.hansen@intel.com Cc: riel@redhat.com Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1414580017-27444-1-git-send-email-decui@microsoft.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com> --- 7u/arch/x86/mm/pageattr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/7u/arch/x86/mm/pageattr.c b/7u/arch/x86/mm/pageattr.c index 4ed2b2d..81b82f4 100644 --- a/7u/arch/x86/mm/pageattr.c +++ b/7u/arch/x86/mm/pageattr.c @@ -405,7 +405,7 @@ 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); -- 1.8.3.1 ^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH 008/216] x86, pageattr: Prevent overflow in slow_virt_to_phys() for X86_PAE 2018-11-28 11:29 ` [PATCH 008/216] x86, pageattr: Prevent overflow in slow_virt_to_phys() for X86_PAE Alex Shi @ 2018-11-28 12:14 ` Alex Shi 0 siblings, 0 replies; 2+ messages in thread From: Alex Shi @ 2018-11-28 12:14 UTC (permalink / raw) To: Yang Shi, Michael Wang, Xunlei Pang Cc: Dexuan Cui, K. Y. Srinivasan, Haiyang Zhang, gregkh, linux-mm, olaf, apw, jasowang, dave.hansen, riel, stable, Thomas Gleixner Hi, All, Please ignore this stupid email thread. I thought I had suppressed cc in gitconfig. But I am wrong... Very very sorry! Thanks Alex On 2018/11/28 7:29 PM, Alex Shi wrote: > From: Dexuan Cui <decui@microsoft.com> > > commit d1cd1210834649ce1ca6bafe5ac25d2f40331343 upstream. > > pte_pfn() returns a PFN of long (32 bits in 32-PAE), so "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). > > Cast pte_pfn() to phys_addr_t before shifting. > > Fixes: "commit d76565344512: x86, mm: Create slow_virt_to_phys()" > Signed-off-by: Dexuan Cui <decui@microsoft.com> > Cc: K. Y. Srinivasan <kys@microsoft.com> > Cc: Haiyang Zhang <haiyangz@microsoft.com> > Cc: gregkh@linuxfoundation.org > Cc: linux-mm@kvack.org > Cc: olaf@aepfle.de > Cc: apw@canonical.com > Cc: jasowang@redhat.com > Cc: dave.hansen@intel.com > Cc: riel@redhat.com > Cc: stable@vger.kernel.org > Link: http://lkml.kernel.org/r/1414580017-27444-1-git-send-email-decui@microsoft.com > Signed-off-by: Thomas Gleixner <tglx@linutronix.de> > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com> > --- > 7u/arch/x86/mm/pageattr.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/7u/arch/x86/mm/pageattr.c b/7u/arch/x86/mm/pageattr.c > index 4ed2b2d..81b82f4 100644 > --- a/7u/arch/x86/mm/pageattr.c > +++ b/7u/arch/x86/mm/pageattr.c > @@ -405,7 +405,7 @@ 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); ^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2018-11-28 12:14 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
[not found] <1543404768-89470-1-git-send-email-alex.shi@linux.alibaba.com>
2018-11-28 11:29 ` [PATCH 008/216] x86, pageattr: Prevent overflow in slow_virt_to_phys() for X86_PAE Alex Shi
2018-11-28 12:14 ` Alex Shi
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox