Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 96 insertions, 0 deletions

diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug
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--- /dev/null
+++ b/mm/Kconfig.debug
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+config PAGE_EXTENSION
+	bool "Extend memmap on extra space for more information on page"
+	---help---
+	  Extend memmap on extra space for more information on page. This
+	  could be used for debugging features that need to insert extra
+	  field for every page. This extension enables us to save memory
+	  by not allocating this extra memory according to boottime
+	  configuration.
+
+config DEBUG_PAGEALLOC
+	bool "Debug page memory allocations"
+	depends on DEBUG_KERNEL
+	depends on !HIBERNATION || ARCH_SUPPORTS_DEBUG_PAGEALLOC && !PPC && !SPARC
+	select PAGE_EXTENSION
+	select PAGE_POISONING if !ARCH_SUPPORTS_DEBUG_PAGEALLOC
+	---help---
+	  Unmap pages from the kernel linear mapping after free_pages().
+	  Depending on runtime enablement, this results in a small or large
+	  slowdown, but helps to find certain types of memory corruption.
+
+	  For architectures which don't enable ARCH_SUPPORTS_DEBUG_PAGEALLOC,
+	  fill the pages with poison patterns after free_pages() and verify
+	  the patterns before alloc_pages().  Additionally,
+	  this option cannot be enabled in combination with hibernation as
+	  that would result in incorrect warnings of memory corruption after
+	  a resume because free pages are not saved to the suspend image.
+
+	  By default this option will have a small overhead, e.g. by not
+	  allowing the kernel mapping to be backed by large pages on some
+	  architectures. Even bigger overhead comes when the debugging is
+	  enabled by DEBUG_PAGEALLOC_ENABLE_DEFAULT or the debug_pagealloc
+	  command line parameter.
+
+config DEBUG_PAGEALLOC_ENABLE_DEFAULT
+	bool "Enable debug page memory allocations by default?"
+	default n
+	depends on DEBUG_PAGEALLOC
+	---help---
+	  Enable debug page memory allocations by default? This value
+	  can be overridden by debug_pagealloc=off|on.
+
+config PAGE_POISONING
+	bool "Poison pages after freeing"
+	select PAGE_POISONING_NO_SANITY if HIBERNATION
+	---help---
+	  Fill the pages with poison patterns after free_pages() and verify
+	  the patterns before alloc_pages. The filling of the memory helps
+	  reduce the risk of information leaks from freed data. This does
+	  have a potential performance impact if enabled with the
+	  "page_poison=1" kernel boot option.
+
+	  Note that "poison" here is not the same thing as the "HWPoison"
+	  for CONFIG_MEMORY_FAILURE. This is software poisoning only.
+
+	  If unsure, say N
+
+config PAGE_POISONING_NO_SANITY
+	depends on PAGE_POISONING
+	bool "Only poison, don't sanity check"
+	---help---
+	   Skip the sanity checking on alloc, only fill the pages with
+	   poison on free. This reduces some of the overhead of the
+	   poisoning feature.
+
+	   If you are only interested in sanitization, say Y. Otherwise
+	   say N.
+
+config PAGE_POISONING_ZERO
+	bool "Use zero for poisoning instead of debugging value"
+	depends on PAGE_POISONING
+	---help---
+	   Instead of using the existing poison value, fill the pages with
+	   zeros. This makes it harder to detect when errors are occurring
+	   due to sanitization but the zeroing at free means that it is
+	   no longer necessary to write zeros when GFP_ZERO is used on
+	   allocation.
+
+	   If unsure, say N
+
+config DEBUG_PAGE_REF
+	bool "Enable tracepoint to track down page reference manipulation"
+	depends on DEBUG_KERNEL
+	depends on TRACEPOINTS
+	---help---
+	  This is a feature to add tracepoint for tracking down page reference
+	  manipulation. This tracking is useful to diagnose functional failure
+	  due to migration failures caused by page reference mismatches.  Be
+	  careful when enabling this feature because it adds about 30 KB to the
+	  kernel code.  However the runtime performance overhead is virtually
+	  nil until the tracepoints are actually enabled.
+
+config DEBUG_RODATA_TEST
+    bool "Testcase for the marking rodata read-only"
+    depends on STRICT_KERNEL_RWX
+    ---help---
+      This option enables a testcase for the setting rodata read-only.