[patch 099/128] mm: only allow page table mappings for built-in zsmalloc

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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)
_




[Index of Archives]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [IETF Annouce]     [Bugtraq]     [Linux OMAP]     [Linux MIPS]     [eCos]     [Asterisk Internet PBX]     [Linux API]

  Powered by Linux