Linux/mm/Kconfig.debug

Version: ~ [ linux-6.11.5 ] ~ [ linux-6.10.14 ] ~ [ linux-6.9.12 ] ~ [ linux-6.8.12 ] ~ [ linux-6.7.12 ] ~ [ linux-6.6.58 ] ~ [ linux-6.5.13 ] ~ [ linux-6.4.16 ] ~ [ linux-6.3.13 ] ~ [ linux-6.2.16 ] ~ [ linux-6.1.114 ] ~ [ linux-6.0.19 ] ~ [ linux-5.19.17 ] ~ [ linux-5.18.19 ] ~ [ linux-5.17.15 ] ~ [ linux-5.16.20 ] ~ [ linux-5.15.169 ] ~ [ linux-5.14.21 ] ~ [ linux-5.13.19 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.228 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.284 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.322 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.336 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.337 ] ~ [ linux-4.4.302 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.9 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

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1 # SPDX-License-Identifier: GPL-2.0-only 1 # SPDX-License-Identifier: GPL-2.0-only 2 config PAGE_EXTENSION 2 config PAGE_EXTENSION 3 bool "Extend memmap on extra space for 3 bool "Extend memmap on extra space for more information on page" 4 help 4 help 5 Extend memmap on extra space for mor 5 Extend memmap on extra space for more information on page. This 6 could be used for debugging features 6 could be used for debugging features that need to insert extra 7 field for every page. This extension 7 field for every page. This extension enables us to save memory 8 by not allocating this extra memory 8 by not allocating this extra memory according to boottime 9 configuration. 9 configuration. 10 10 11 config DEBUG_PAGEALLOC 11 config DEBUG_PAGEALLOC 12 bool "Debug page memory allocations" 12 bool "Debug page memory allocations" 13 depends on DEBUG_KERNEL 13 depends on DEBUG_KERNEL 14 depends on !HIBERNATION || ARCH_SUPPOR 14 depends on !HIBERNATION || ARCH_SUPPORTS_DEBUG_PAGEALLOC && !PPC && !SPARC 15 select PAGE_POISONING if !ARCH_SUPPORT 15 select PAGE_POISONING if !ARCH_SUPPORTS_DEBUG_PAGEALLOC 16 help 16 help 17 Unmap pages from the kernel linear m 17 Unmap pages from the kernel linear mapping after free_pages(). 18 Depending on runtime enablement, thi 18 Depending on runtime enablement, this results in a small or large 19 slowdown, but helps to find certain 19 slowdown, but helps to find certain types of memory corruption. 20 20 21 Also, the state of page tracking str 21 Also, the state of page tracking structures is checked more often as 22 pages are being allocated and freed, 22 pages are being allocated and freed, as unexpected state changes 23 often happen for same reasons as mem 23 often happen for same reasons as memory corruption (e.g. double free, 24 use-after-free). The error reports f 24 use-after-free). The error reports for these checks can be augmented 25 with stack traces of last allocation 25 with stack traces of last allocation and freeing of the page, when 26 PAGE_OWNER is also selected and enab 26 PAGE_OWNER is also selected and enabled on boot. 27 27 28 For architectures which don't enable 28 For architectures which don't enable ARCH_SUPPORTS_DEBUG_PAGEALLOC, 29 fill the pages with poison patterns 29 fill the pages with poison patterns after free_pages() and verify 30 the patterns before alloc_pages(). A 30 the patterns before alloc_pages(). Additionally, this option cannot 31 be enabled in combination with hiber 31 be enabled in combination with hibernation as that would result in 32 incorrect warnings of memory corrupt 32 incorrect warnings of memory corruption after a resume because free 33 pages are not saved to the suspend i 33 pages are not saved to the suspend image. 34 34 35 By default this option will have a s 35 By default this option will have a small overhead, e.g. by not 36 allowing the kernel mapping to be ba 36 allowing the kernel mapping to be backed by large pages on some 37 architectures. Even bigger overhead 37 architectures. Even bigger overhead comes when the debugging is 38 enabled by DEBUG_PAGEALLOC_ENABLE_DE 38 enabled by DEBUG_PAGEALLOC_ENABLE_DEFAULT or the debug_pagealloc 39 command line parameter. 39 command line parameter. 40 40 41 config DEBUG_PAGEALLOC_ENABLE_DEFAULT 41 config DEBUG_PAGEALLOC_ENABLE_DEFAULT 42 bool "Enable debug page memory allocat 42 bool "Enable debug page memory allocations by default?" 43 depends on DEBUG_PAGEALLOC 43 depends on DEBUG_PAGEALLOC 44 help 44 help 45 Enable debug page memory allocations 45 Enable debug page memory allocations by default? This value 46 can be overridden by debug_pagealloc 46 can be overridden by debug_pagealloc=off|on. 47 47 48 config SLUB_DEBUG << 49 default y << 50 bool "Enable SLUB debugging support" i << 51 depends on SYSFS && !SLUB_TINY << 52 select STACKDEPOT if STACKTRACE_SUPPOR << 53 help << 54 SLUB has extensive debug support fea << 55 result in significant savings in cod << 56 will still exist (with SYSFS enabled << 57 validation. << 58 << 59 config SLUB_DEBUG_ON << 60 bool "SLUB debugging on by default" << 61 depends on SLUB_DEBUG << 62 select STACKDEPOT_ALWAYS_INIT if STACK << 63 default n << 64 help << 65 Boot with debugging on by default. S << 66 the runtime debug capabilities switc << 67 equivalent to specifying the "slab_d << 68 There is no support for more fine gr << 69 possible with slab_debug=xxx. SLUB d << 70 off in a kernel built with CONFIG_SL << 71 "slab_debug=-". << 72 << 73 config PAGE_OWNER 48 config PAGE_OWNER 74 bool "Track page owner" 49 bool "Track page owner" 75 depends on DEBUG_KERNEL && STACKTRACE_ 50 depends on DEBUG_KERNEL && STACKTRACE_SUPPORT 76 select DEBUG_FS 51 select DEBUG_FS 77 select STACKTRACE 52 select STACKTRACE 78 select STACKDEPOT 53 select STACKDEPOT 79 select PAGE_EXTENSION 54 select PAGE_EXTENSION 80 help 55 help 81 This keeps track of what call chain 56 This keeps track of what call chain is the owner of a page, may 82 help to find bare alloc_page(s) leak 57 help to find bare alloc_page(s) leaks. Even if you include this 83 feature on your build, it is disable 58 feature on your build, it is disabled in default. You should pass 84 "page_owner=on" to boot parameter in 59 "page_owner=on" to boot parameter in order to enable it. Eats 85 a fair amount of memory if enabled. !! 60 a fair amount of memory if enabled. See tools/vm/page_owner_sort.c 86 for user-space helper. 61 for user-space helper. 87 62 88 If unsure, say N. 63 If unsure, say N. 89 64 90 config PAGE_TABLE_CHECK << 91 bool "Check for invalid mappings in us << 92 depends on ARCH_SUPPORTS_PAGE_TABLE_CH << 93 depends on EXCLUSIVE_SYSTEM_RAM << 94 select PAGE_EXTENSION << 95 help << 96 Check that anonymous page is not bei << 97 permissions. Check that anonymous an << 98 erroneously shared. Since the checki << 99 entries are added and removed to use << 100 and double mapping problems are dete << 101 << 102 If unsure say "n". << 103 << 104 config PAGE_TABLE_CHECK_ENFORCED << 105 bool "Enforce the page table checking << 106 depends on PAGE_TABLE_CHECK << 107 help << 108 Always enable page table checking. << 109 is disabled, and can be optionally e << 110 kernel parameter. This config enforc << 111 enabled. << 112 << 113 If unsure say "n". << 114 << 115 config PAGE_POISONING 65 config PAGE_POISONING 116 bool "Poison pages after freeing" 66 bool "Poison pages after freeing" >> 67 select PAGE_POISONING_NO_SANITY if HIBERNATION 117 help 68 help 118 Fill the pages with poison patterns 69 Fill the pages with poison patterns after free_pages() and verify 119 the patterns before alloc_pages. The 70 the patterns before alloc_pages. The filling of the memory helps 120 reduce the risk of information leaks 71 reduce the risk of information leaks from freed data. This does 121 have a potential performance impact 72 have a potential performance impact if enabled with the 122 "page_poison=1" kernel boot option. 73 "page_poison=1" kernel boot option. 123 74 124 Note that "poison" here is not the s 75 Note that "poison" here is not the same thing as the "HWPoison" 125 for CONFIG_MEMORY_FAILURE. This is s 76 for CONFIG_MEMORY_FAILURE. This is software poisoning only. 126 77 127 If you are only interested in saniti << 128 checking the poison pattern on alloc << 129 "init_on_free=1" instead of enabling << 130 << 131 If unsure, say N 78 If unsure, say N 132 79 >> 80 config PAGE_POISONING_NO_SANITY >> 81 depends on PAGE_POISONING >> 82 bool "Only poison, don't sanity check" >> 83 help >> 84 Skip the sanity checking on alloc, only fill the pages with >> 85 poison on free. This reduces some of the overhead of the >> 86 poisoning feature. >> 87 >> 88 If you are only interested in sanitization, say Y. Otherwise >> 89 say N. >> 90 >> 91 config PAGE_POISONING_ZERO >> 92 bool "Use zero for poisoning instead of debugging value" >> 93 depends on PAGE_POISONING >> 94 help >> 95 Instead of using the existing poison value, fill the pages with >> 96 zeros. This makes it harder to detect when errors are occurring >> 97 due to sanitization but the zeroing at free means that it is >> 98 no longer necessary to write zeros when GFP_ZERO is used on >> 99 allocation. >> 100 >> 101 If unsure, say N >> 102 133 config DEBUG_PAGE_REF 103 config DEBUG_PAGE_REF 134 bool "Enable tracepoint to track down 104 bool "Enable tracepoint to track down page reference manipulation" 135 depends on DEBUG_KERNEL 105 depends on DEBUG_KERNEL 136 depends on TRACEPOINTS 106 depends on TRACEPOINTS 137 help 107 help 138 This is a feature to add tracepoint 108 This is a feature to add tracepoint for tracking down page reference 139 manipulation. This tracking is usefu 109 manipulation. This tracking is useful to diagnose functional failure 140 due to migration failures caused by 110 due to migration failures caused by page reference mismatches. Be 141 careful when enabling this feature b 111 careful when enabling this feature because it adds about 30 KB to the 142 kernel code. However the runtime pe 112 kernel code. However the runtime performance overhead is virtually 143 nil until the tracepoints are actual 113 nil until the tracepoints are actually enabled. 144 114 145 config DEBUG_RODATA_TEST 115 config DEBUG_RODATA_TEST 146 bool "Testcase for the marking rodata read 116 bool "Testcase for the marking rodata read-only" 147 depends on STRICT_KERNEL_RWX 117 depends on STRICT_KERNEL_RWX 148 help 118 help 149 This option enables a testcase for the s 119 This option enables a testcase for the setting rodata read-only. 150 120 151 config ARCH_HAS_DEBUG_WX 121 config ARCH_HAS_DEBUG_WX 152 bool 122 bool 153 123 154 config DEBUG_WX 124 config DEBUG_WX 155 bool "Warn on W+X mappings at boot" 125 bool "Warn on W+X mappings at boot" 156 depends on ARCH_HAS_DEBUG_WX 126 depends on ARCH_HAS_DEBUG_WX 157 depends on MMU 127 depends on MMU 158 select PTDUMP_CORE 128 select PTDUMP_CORE 159 help 129 help 160 Generate a warning if any W+X mappin 130 Generate a warning if any W+X mappings are found at boot. 161 131 162 This is useful for discovering cases 132 This is useful for discovering cases where the kernel is leaving W+X 163 mappings after applying NX, as such 133 mappings after applying NX, as such mappings are a security risk. 164 134 165 Look for a message in dmesg output l 135 Look for a message in dmesg output like this: 166 136 167 <arch>/mm: Checked W+X mappings: p 137 <arch>/mm: Checked W+X mappings: passed, no W+X pages found. 168 138 169 or like this, if the check failed: 139 or like this, if the check failed: 170 140 171 <arch>/mm: Checked W+X mappings: f 141 <arch>/mm: Checked W+X mappings: failed, <N> W+X pages found. 172 142 173 Note that even if the check fails, y 143 Note that even if the check fails, your kernel is possibly 174 still fine, as W+X mappings are not 144 still fine, as W+X mappings are not a security hole in 175 themselves, what they do is that the 145 themselves, what they do is that they make the exploitation 176 of other unfixed kernel bugs easier. 146 of other unfixed kernel bugs easier. 177 147 178 There is no runtime or memory usage 148 There is no runtime or memory usage effect of this option 179 once the kernel has booted up - it's 149 once the kernel has booted up - it's a one time check. 180 150 181 If in doubt, say "Y". 151 If in doubt, say "Y". 182 152 183 config GENERIC_PTDUMP 153 config GENERIC_PTDUMP 184 bool 154 bool 185 155 186 config PTDUMP_CORE 156 config PTDUMP_CORE 187 bool 157 bool 188 158 189 config PTDUMP_DEBUGFS 159 config PTDUMP_DEBUGFS 190 bool "Export kernel pagetable layout t 160 bool "Export kernel pagetable layout to userspace via debugfs" 191 depends on DEBUG_KERNEL 161 depends on DEBUG_KERNEL 192 depends on DEBUG_FS 162 depends on DEBUG_FS 193 depends on GENERIC_PTDUMP 163 depends on GENERIC_PTDUMP 194 select PTDUMP_CORE 164 select PTDUMP_CORE 195 help 165 help 196 Say Y here if you want to show the k 166 Say Y here if you want to show the kernel pagetable layout in a 197 debugfs file. This information is on 167 debugfs file. This information is only useful for kernel developers 198 who are working in architecture spec 168 who are working in architecture specific areas of the kernel. 199 It is probably not a good idea to en 169 It is probably not a good idea to enable this feature in a production 200 kernel. 170 kernel. 201 << 202 If in doubt, say N. << 203 << 204 config HAVE_DEBUG_KMEMLEAK << 205 bool << 206 << 207 config DEBUG_KMEMLEAK << 208 bool "Kernel memory leak detector" << 209 depends on DEBUG_KERNEL && HAVE_DEBUG_ << 210 select DEBUG_FS << 211 select STACKTRACE if STACKTRACE_SUPPOR << 212 select KALLSYMS << 213 select CRC32 << 214 select STACKDEPOT << 215 select STACKDEPOT_ALWAYS_INIT if !DEBU << 216 help << 217 Say Y here if you want to enable the << 218 detector. The memory allocation/free << 219 similar to the Boehm's conservative << 220 difference being that the orphan obj << 221 only shown in /sys/kernel/debug/kmem << 222 feature will introduce an overhead t << 223 allocations. See Documentation/dev-t << 224 details. << 225 << 226 Enabling SLUB_DEBUG may increase the << 227 due to the slab objects poisoning. << 228 << 229 In order to access the kmemleak file << 230 mounted (usually at /sys/kernel/debu << 231 << 232 config DEBUG_KMEMLEAK_MEM_POOL_SIZE << 233 int "Kmemleak memory pool size" << 234 depends on DEBUG_KMEMLEAK << 235 range 200 1000000 << 236 default 16000 << 237 help << 238 Kmemleak must track all the memory a << 239 reporting false positives. Since mem << 240 freed before kmemleak is fully initi << 241 of metadata objects to track such ca << 242 fully initialised, this memory pool << 243 if slab allocations fail. << 244 << 245 config DEBUG_KMEMLEAK_DEFAULT_OFF << 246 bool "Default kmemleak to off" << 247 depends on DEBUG_KMEMLEAK << 248 help << 249 Say Y here to disable kmemleak by de << 250 on the command line via kmemleak=on. << 251 << 252 config DEBUG_KMEMLEAK_AUTO_SCAN << 253 bool "Enable kmemleak auto scan thread << 254 default y << 255 depends on DEBUG_KMEMLEAK << 256 help << 257 Depending on the cpu, kmemleak scan << 258 stall user tasks at times. This opti << 259 kmemleak scan at boot up. << 260 << 261 Say N here to disable kmemleak auto << 262 scanning. Disabling this option disa << 263 memory leaks. << 264 << 265 If unsure, say Y. << 266 << 267 config PER_VMA_LOCK_STATS << 268 bool "Statistics for per-vma locks" << 269 depends on PER_VMA_LOCK << 270 help << 271 Say Y here to enable success, retry << 272 faults handled under protection of p << 273 counters are exposed in /proc/vmstat << 274 kernel developers to evaluate effect << 275 identify pathological cases. Countin << 276 overhead in the page fault path. << 277 171 278 If in doubt, say N. 172 If in doubt, say N.

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TOMOYO Linux Cross Reference
Linux/mm/Kconfig.debug

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Differences between /mm/Kconfig.debug (Version linux-6.11.5) and /mm/Kconfig.debug (Version linux-5.9.16)

TOMOYO Linux Cross Reference Linux/mm/Kconfig.debug

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Differences between /mm/Kconfig.debug (Version linux-6.11.5) and /mm/Kconfig.debug (Version linux-5.9.16)

TOMOYO Linux Cross Reference
Linux/mm/Kconfig.debug