diff options
Diffstat (limited to 'mm/Kconfig.debug')
| -rw-r--r-- | mm/Kconfig.debug | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug index fa6d79281368..82b6a20898bd 100644 --- a/mm/Kconfig.debug +++ b/mm/Kconfig.debug @@ -12,19 +12,23 @@ 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. + Also, the state of page tracking structures is checked more often as + pages are being allocated and freed, as unexpected state changes + often happen for same reasons as memory corruption (e.g. double free, + use-after-free). + 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. + 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 |