From 85dfb79a22409f563fce918e99632db00d6d98fa Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 19 Oct 2020 21:03:20 +0800 Subject: [PATCH] mm: only allow page table mappings for built-in zsmalloc mainline inclusion from mainline-v5.8-rc1 commit b607e6d17db5b91e6a807b4f9a2e849219d720a0 category: feature bugzilla: NA CVE: NA --------------------------- This allows to unexport map_vm_area and unmap_kernel_range, which are rather deep internal and should not be available to modules, as they for example allow fine grained control of mapping permissions, and also allow splitting the setup of a vmalloc area and the actual mapping and thus expose vmalloc internals. zsmalloc is typically built-in and continues to work (just like the percpu-vm code using a similar patter), while modular zsmalloc also continues to work, but must use copies. Signed-off-by: Christoph Hellwig Signed-off-by: Andrew Morton Acked-by: Peter Zijlstra (Intel) Cc: Christian Borntraeger Cc: Christophe Leroy Cc: Daniel Vetter Cc: David Airlie Cc: Gao Xiang Cc: Greg Kroah-Hartman Cc: Haiyang Zhang Cc: Johannes Weiner Cc: "K. Y. Srinivasan" Cc: Laura Abbott Cc: Mark Rutland Cc: Michael Kelley Cc: Minchan Kim Cc: Nitin Gupta Cc: Robin Murphy Cc: Sakari Ailus Cc: Stephen Hemminger Cc: Sumit Semwal Cc: Wei Liu Cc: Benjamin Herrenschmidt Cc: Catalin Marinas Cc: Heiko Carstens Cc: Paul Mackerras Cc: Vasily Gorbik Cc: Will Deacon Link: http://lkml.kernel.org/r/20200414131348.444715-12-hch@lst.de Signed-off-by: Linus Torvalds Signed-off-by: Rui Xiang Reviewed-by: Ding Tianhong Reviewed-by: Zefan Li Signed-off-by: Yang Yingliang --- mm/Kconfig | 2 +- mm/vmalloc.c | 2 -- 2 files changed, 1 insertion(+), 3 deletions(-) diff --git a/mm/Kconfig b/mm/Kconfig index 7ebd52dc1e40..dddeb30d645e 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -617,7 +617,7 @@ config ZSMALLOC config PGTABLE_MAPPING bool "Use page table mapping to access object in zsmalloc" - depends on ZSMALLOC + depends on ZSMALLOC=y help By default, zsmalloc uses a copy-based object mapping method to access allocations that span two pages. However, if a particular diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 5f14a7d294cf..66b0a7d03b28 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1927,7 +1927,6 @@ void unmap_kernel_range(unsigned long addr, unsigned long size) vunmap_page_range(addr, end); flush_tlb_kernel_range(addr, end); } -EXPORT_SYMBOL_GPL(unmap_kernel_range); int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page **pages) { @@ -1939,7 +1938,6 @@ int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page **pages) return err > 0 ? 0 : err; } -EXPORT_SYMBOL_GPL(map_vm_area); static void setup_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va, unsigned long flags, const void *caller) -- GitLab