From 90edaac62729d3b9cbb97756261a0049a7fdd6a0 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Fri, 27 Oct 2017 10:03:13 +0200 Subject: [PATCH] Revert "x86/mm: Limit mmap() of /dev/mem to valid physical addresses" This reverts commit ce56a86e2ade45d052b3228cdfebe913a1ae7381. There's unanticipated interaction with some boot parameters like 'mem=', which now cause the new checks via valid_mmap_phys_addr_range() to be too restrictive, crashing a Qemu bootup in fact, as reported by Fengguang Wu. So while the motivation of the change is still entirely valid, we need a few more rounds of testing to get it right - it's way too late after -rc6, so revert it for now. Reported-by: Fengguang Wu Signed-off-by: Ingo Molnar Acked-by: Craig Bergstrom Cc: Andrew Morton Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Luis R. Rodriguez Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Toshi Kani Cc: dsafonov@virtuozzo.com Cc: kirill.shutemov@linux.intel.com Cc: mhocko@suse.com Cc: oleg@redhat.com Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar --- arch/x86/include/asm/io.h | 4 ---- arch/x86/mm/mmap.c | 12 ------------ 2 files changed, 16 deletions(-) diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h index 322d25ae23ab..c40a95c33bb8 100644 --- a/arch/x86/include/asm/io.h +++ b/arch/x86/include/asm/io.h @@ -110,10 +110,6 @@ build_mmio_write(__writeq, "q", unsigned long, "r", ) #endif -#define ARCH_HAS_VALID_PHYS_ADDR_RANGE -extern int valid_phys_addr_range(phys_addr_t addr, size_t size); -extern int valid_mmap_phys_addr_range(unsigned long pfn, size_t size); - /** * virt_to_phys - map virtual addresses to physical * @address: address to remap diff --git a/arch/x86/mm/mmap.c b/arch/x86/mm/mmap.c index 320c6237e1d1..a99679826846 100644 --- a/arch/x86/mm/mmap.c +++ b/arch/x86/mm/mmap.c @@ -174,15 +174,3 @@ const char *arch_vma_name(struct vm_area_struct *vma) return "[mpx]"; return NULL; } - -int valid_phys_addr_range(phys_addr_t addr, size_t count) -{ - return addr + count <= __pa(high_memory); -} - -int valid_mmap_phys_addr_range(unsigned long pfn, size_t count) -{ - phys_addr_t addr = (phys_addr_t)pfn << PAGE_SHIFT; - - return valid_phys_addr_range(addr, count); -} -- 2.20.1