From: Christoph Hellwig <hch@xxxxxx> Subject: mm: only allow page table mappings for built-in zsmalloc 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. Link: http://lkml.kernel.org/r/20200414131348.444715-12-hch@xxxxxx Signed-off-by: Christoph Hellwig <hch@xxxxxx> Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Cc: Christian Borntraeger <borntraeger@xxxxxxxxxx> Cc: Christophe Leroy <christophe.leroy@xxxxxx> Cc: Daniel Vetter <daniel@xxxxxxxx> Cc: Daniel Vetter <daniel.vetter@xxxxxxxx> Cc: David Airlie <airlied@xxxxxxxx> Cc: Gao Xiang <xiang@xxxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: "K. Y. Srinivasan" <kys@xxxxxxxxxxxxx> Cc: Laura Abbott <labbott@xxxxxxxxxx> Cc: Mark Rutland <mark.rutland@xxxxxxx> Cc: Michael Kelley <mikelley@xxxxxxxxxxxxx> Cc: Minchan Kim <minchan@xxxxxxxxxx> Cc: Nitin Gupta <ngupta@xxxxxxxxxx> Cc: Robin Murphy <robin.murphy@xxxxxxx> Cc: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx> Cc: Stephen Hemminger <sthemmin@xxxxxxxxxxxxx> Cc: Sumit Semwal <sumit.semwal@xxxxxxxxxx> Cc: Wei Liu <wei.liu@xxxxxxxxxx> Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx> Cc: Paul Mackerras <paulus@xxxxxxxxxx> Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx> Cc: Will Deacon <will@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/Kconfig | 2 +- mm/vmalloc.c | 2 -- 2 files changed, 1 insertion(+), 3 deletions(-) --- a/mm/Kconfig~mm-only-allow-page-table-mappings-for-built-in-zsmalloc +++ a/mm/Kconfig @@ -707,7 +707,7 @@ config ZSMALLOC config ZSMALLOC_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 --- a/mm/vmalloc.c~mm-only-allow-page-table-mappings-for-built-in-zsmalloc +++ a/mm/vmalloc.c @@ -2047,7 +2047,6 @@ void unmap_kernel_range(unsigned long ad 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) { @@ -2059,7 +2058,6 @@ int map_vm_area(struct vm_struct *area, return err > 0 ? 0 : err; } -EXPORT_SYMBOL_GPL(map_vm_area); static inline void setup_vmalloc_vm_locked(struct vm_struct *vm, struct vmap_area *va, unsigned long flags, const void *caller) _
