diff options
Diffstat (limited to 'mm/Kconfig.debug')
| -rw-r--r-- | mm/Kconfig.debug | 153 |
1 files changed, 144 insertions, 9 deletions
diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug index 5bd5bb097252..7638d75b27db 100644 --- a/mm/Kconfig.debug +++ b/mm/Kconfig.debug @@ -45,6 +45,63 @@ config DEBUG_PAGEALLOC_ENABLE_DEFAULT Enable debug page memory allocations by default? This value can be overridden by debug_pagealloc=off|on. +config SLUB_DEBUG + default y + bool "Enable SLUB debugging support" if EXPERT + depends on SYSFS && !SLUB_TINY + select STACKDEPOT if STACKTRACE_SUPPORT + help + SLUB has extensive debug support features. Disabling these can + result in significant savings in code size. While /sys/kernel/slab + will still exist (with SYSFS enabled), it will not provide e.g. cache + validation. + +config SLUB_DEBUG_ON + bool "SLUB debugging on by default" + depends on SLUB_DEBUG + select STACKDEPOT_ALWAYS_INIT if STACKTRACE_SUPPORT + default n + help + Boot with debugging on by default. SLUB boots by default with + the runtime debug capabilities switched off. Enabling this is + equivalent to specifying the "slab_debug" parameter on boot. + There is no support for more fine grained debug control like + possible with slab_debug=xxx. SLUB debugging may be switched + off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying + "slab_debug=-". + +config SLUB_RCU_DEBUG + bool "Enable UAF detection in TYPESAFE_BY_RCU caches (for KASAN)" + depends on SLUB_DEBUG + # SLUB_RCU_DEBUG should build fine without KASAN, but is currently useless + # without KASAN, so mark it as a dependency of KASAN for now. + depends on KASAN + default KASAN_GENERIC || KASAN_SW_TAGS + help + Make SLAB_TYPESAFE_BY_RCU caches behave approximately as if the cache + was not marked as SLAB_TYPESAFE_BY_RCU and every caller used + kfree_rcu() instead. + + This is intended for use in combination with KASAN, to enable KASAN to + detect use-after-free accesses in such caches. + (KFENCE is able to do that independent of this flag.) + + This might degrade performance. + Unfortunately this also prevents a very specific bug pattern from + triggering (insufficient checks against an object being recycled + within the RCU grace period); so this option can be turned off even on + KASAN builds, in case you want to test for such a bug. + + If you're using this for testing bugs / fuzzing and care about + catching all the bugs WAY more than performance, you might want to + also turn on CONFIG_RCU_STRICT_GRACE_PERIOD. + + WARNING: + This is designed as a debugging feature, not a security feature. + Objects are sometimes recycled without RCU delay under memory pressure. + + If unsure, say N. + config PAGE_OWNER bool "Track page owner" depends on DEBUG_KERNEL && STACKTRACE_SUPPORT @@ -57,7 +114,7 @@ config PAGE_OWNER help to find bare alloc_page(s) leaks. Even if you include this feature on your build, it is disabled in default. You should pass "page_owner=on" to boot parameter in order to enable it. Eats - a fair amount of memory if enabled. See tools/vm/page_owner_sort.c + a fair amount of memory if enabled. See tools/mm/page_owner_sort.c for user-space helper. If unsure, say N. @@ -65,6 +122,7 @@ config PAGE_OWNER config PAGE_TABLE_CHECK bool "Check for invalid mappings in user page tables" depends on ARCH_SUPPORTS_PAGE_TABLE_CHECK + depends on EXCLUSIVE_SYSTEM_RAM select PAGE_EXTENSION help Check that anonymous page is not being mapped twice with read write @@ -117,10 +175,10 @@ config DEBUG_PAGE_REF nil until the tracepoints are actually enabled. config DEBUG_RODATA_TEST - bool "Testcase for the marking rodata read-only" - depends on STRICT_KERNEL_RWX + 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. + This option enables a testcase for the setting rodata read-only. config ARCH_HAS_DEBUG_WX bool @@ -128,8 +186,9 @@ config ARCH_HAS_DEBUG_WX config DEBUG_WX bool "Warn on W+X mappings at boot" depends on ARCH_HAS_DEBUG_WX + depends on ARCH_HAS_PTDUMP depends on MMU - select PTDUMP_CORE + select PTDUMP help Generate a warning if any W+X mappings are found at boot. @@ -154,18 +213,18 @@ config DEBUG_WX If in doubt, say "Y". -config GENERIC_PTDUMP +config ARCH_HAS_PTDUMP bool -config PTDUMP_CORE +config PTDUMP bool config PTDUMP_DEBUGFS bool "Export kernel pagetable layout to userspace via debugfs" depends on DEBUG_KERNEL depends on DEBUG_FS - depends on GENERIC_PTDUMP - select PTDUMP_CORE + depends on ARCH_HAS_PTDUMP + select PTDUMP help Say Y here if you want to show the kernel pagetable layout in a debugfs file. This information is only useful for kernel developers @@ -174,3 +233,79 @@ config PTDUMP_DEBUGFS kernel. If in doubt, say N. + +config HAVE_DEBUG_KMEMLEAK + bool + +config DEBUG_KMEMLEAK + bool "Kernel memory leak detector" + depends on DEBUG_KERNEL && HAVE_DEBUG_KMEMLEAK + select DEBUG_FS + select STACKTRACE if STACKTRACE_SUPPORT + select KALLSYMS + select CRC32 + select STACKDEPOT + select STACKDEPOT_ALWAYS_INIT if !DEBUG_KMEMLEAK_DEFAULT_OFF + help + Say Y here if you want to enable the memory leak + detector. The memory allocation/freeing is traced in a way + similar to the Boehm's conservative garbage collector, the + difference being that the orphan objects are not freed but + only shown in /sys/kernel/debug/kmemleak. Enabling this + feature will introduce an overhead to memory + allocations. See Documentation/dev-tools/kmemleak.rst for more + details. + + Enabling SLUB_DEBUG may increase the chances of finding leaks + due to the slab objects poisoning. + + In order to access the kmemleak file, debugfs needs to be + mounted (usually at /sys/kernel/debug). + +config DEBUG_KMEMLEAK_MEM_POOL_SIZE + int "Kmemleak memory pool size" + depends on DEBUG_KMEMLEAK + range 200 1000000 + default 16000 + help + Kmemleak must track all the memory allocations to avoid + reporting false positives. Since memory may be allocated or + freed before kmemleak is fully initialised, use a static pool + of metadata objects to track such callbacks. After kmemleak is + fully initialised, this memory pool acts as an emergency one + if slab allocations fail. + +config DEBUG_KMEMLEAK_DEFAULT_OFF + bool "Default kmemleak to off" + depends on DEBUG_KMEMLEAK + help + Say Y here to disable kmemleak by default. It can then be enabled + on the command line via kmemleak=on. + +config DEBUG_KMEMLEAK_AUTO_SCAN + bool "Enable kmemleak auto scan thread on boot up" + default y + depends on DEBUG_KMEMLEAK + help + Depending on the cpu, kmemleak scan may be cpu intensive and can + stall user tasks at times. This option enables/disables automatic + kmemleak scan at boot up. + + Say N here to disable kmemleak auto scan thread to stop automatic + scanning. Disabling this option disables automatic reporting of + memory leaks. + + If unsure, say Y. + +config PER_VMA_LOCK_STATS + bool "Statistics for per-vma locks" + depends on PER_VMA_LOCK + help + Say Y here to enable success, retry and failure counters of page + faults handled under protection of per-vma locks. When enabled, the + counters are exposed in /proc/vmstat. This information is useful for + kernel developers to evaluate effectiveness of per-vma locks and to + identify pathological cases. Counting these events introduces a small + overhead in the page fault path. + + If in doubt, say N. |