4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dexuan Cui <decui@xxxxxxxxxxxxx> commit bf70e5513dfea29c3682e7eb3dbb45f0723bac09 upstream. "d1cd12108346: x86, pageattr: Prevent overflow in slow_virt_to_phys() for X86_PAE" was unintentionally removed by the recent "34437e67a672: x86/mm: Fix slow_virt_to_phys() to handle large PAT bit". And, the variable 'phys_addr' was defined as "unsigned long" by mistake -- it should be "phys_addr_t". As a result, Hyper-V network driver in 32-PAE Linux guest can't work again. Fixes: commit 34437e67a672: "x86/mm: Fix slow_virt_to_phys() to handle large PAT bit" Signed-off-by: Dexuan Cui <decui@xxxxxxxxxxxxx> Reviewed-by: Toshi Kani <toshi.kani@xxxxxxx> Cc: olaf@xxxxxxxxx Cc: jasowang@xxxxxxxxxx Cc: driverdev-devel@xxxxxxxxxxxxxxxxxxxxxx Cc: linux-mm@xxxxxxxxx Cc: apw@xxxxxxxxxxxxx Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: K. Y. Srinivasan <kys@xxxxxxxxxxxxx> Cc: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx> Link: http://lkml.kernel.org/r/1456394292-9030-1-git-send-email-decui@xxxxxxxxxxxxx Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/x86/mm/pageattr.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -414,24 +414,30 @@ pmd_t *lookup_pmd_address(unsigned long phys_addr_t slow_virt_to_phys(void *__virt_addr) { unsigned long virt_addr = (unsigned long)__virt_addr; - unsigned long phys_addr, offset; + phys_addr_t phys_addr; + unsigned long offset; enum pg_level level; pte_t *pte; pte = lookup_address(virt_addr, &level); BUG_ON(!pte); + /* + * pXX_pfn() returns unsigned long, which must be cast to phys_addr_t + * before being left-shifted PAGE_SHIFT bits -- this trick is to + * make 32-PAE kernel work correctly. + */ switch (level) { case PG_LEVEL_1G: - phys_addr = pud_pfn(*(pud_t *)pte) << PAGE_SHIFT; + phys_addr = (phys_addr_t)pud_pfn(*(pud_t *)pte) << PAGE_SHIFT; offset = virt_addr & ~PUD_PAGE_MASK; break; case PG_LEVEL_2M: - phys_addr = pmd_pfn(*(pmd_t *)pte) << PAGE_SHIFT; + phys_addr = (phys_addr_t)pmd_pfn(*(pmd_t *)pte) << PAGE_SHIFT; offset = virt_addr & ~PMD_PAGE_MASK; break; default: - phys_addr = pte_pfn(*pte) << PAGE_SHIFT; + phys_addr = (phys_addr_t)pte_pfn(*pte) << PAGE_SHIFT; offset = virt_addr & ~PAGE_MASK; } -- 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=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>