From: Christoph Hellwig hch@lst.de
mainline inclusion from mainline-v5.8-rc1 commit b607e6d17db5b91e6a807b4f9a2e849219d720a0 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I4EUVI CVE: NA
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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 hch@lst.de Signed-off-by: Andrew Morton akpm@linux-foundation.org Acked-by: Peter Zijlstra (Intel) peterz@infradead.org Cc: Christian Borntraeger borntraeger@de.ibm.com Cc: Christophe Leroy christophe.leroy@c-s.fr Cc: Daniel Vetter daniel.vetter@ffwll.ch Cc: David Airlie airlied@linux.ie Cc: Gao Xiang xiang@kernel.org Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: Haiyang Zhang haiyangz@microsoft.com Cc: Johannes Weiner hannes@cmpxchg.org Cc: "K. Y. Srinivasan" kys@microsoft.com Cc: Laura Abbott labbott@redhat.com Cc: Mark Rutland mark.rutland@arm.com Cc: Michael Kelley mikelley@microsoft.com Cc: Minchan Kim minchan@kernel.org Cc: Nitin Gupta ngupta@vflare.org Cc: Robin Murphy robin.murphy@arm.com Cc: Sakari Ailus sakari.ailus@linux.intel.com Cc: Stephen Hemminger sthemmin@microsoft.com Cc: Sumit Semwal sumit.semwal@linaro.org Cc: Wei Liu wei.liu@kernel.org Cc: Benjamin Herrenschmidt benh@kernel.crashing.org Cc: Catalin Marinas catalin.marinas@arm.com Cc: Heiko Carstens heiko.carstens@de.ibm.com Cc: Paul Mackerras paulus@ozlabs.org Cc: Vasily Gorbik gor@linux.ibm.com Cc: Will Deacon will@kernel.org Link: http://lkml.kernel.org/r/20200414131348.444715-12-hch@lst.de Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Rui Xiang rui.xiang@huawei.com Reviewed-by: Ding Tianhong dingtianhong@huawei.com Reviewed-by: Zefan Li lizefan@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- mm/Kconfig | 2 +- mm/vmalloc.c | 2 -- 2 files changed, 1 insertion(+), 3 deletions(-)
diff --git a/mm/Kconfig b/mm/Kconfig index 7edf3c4c1252b..0434aef47b44c 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -638,7 +638,7 @@ 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 1648d7f14a475..1f6a8b1eae5fe 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)