Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | menu "Kernel hacking" |
| 2 | |
Ingo Molnar | 55f327f | 2006-07-03 00:24:43 -0700 | [diff] [blame] | 3 | config TRACE_IRQFLAGS_SUPPORT |
Randy Dunlap | d013a27 | 2007-10-24 15:50:43 -0700 | [diff] [blame] | 4 | def_bool y |
Ingo Molnar | 55f327f | 2006-07-03 00:24:43 -0700 | [diff] [blame] | 5 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 6 | source "lib/Kconfig.debug" |
| 7 | |
Ingo Molnar | d092633 | 2008-07-18 00:26:59 +0200 | [diff] [blame] | 8 | config STRICT_DEVMEM |
Stefan Richter | 16104b55 | 2008-06-05 22:47:13 +0200 | [diff] [blame] | 9 | bool "Filter access to /dev/mem" |
Arjan van de Ven | ae531c2 | 2008-04-24 23:40:47 +0200 | [diff] [blame] | 10 | help |
Linus Torvalds | f2d0f1d | 2008-07-21 13:04:08 -0700 | [diff] [blame] | 11 | If this option is disabled, you allow userspace (root) access to all |
Stefan Richter | 16104b55 | 2008-06-05 22:47:13 +0200 | [diff] [blame] | 12 | of memory, including kernel and userspace memory. Accidental |
| 13 | access to this is obviously disastrous, but specific access can |
Ingo Molnar | d092633 | 2008-07-18 00:26:59 +0200 | [diff] [blame] | 14 | be used by people debugging the kernel. Note that with PAT support |
| 15 | enabled, even in this case there are restrictions on /dev/mem |
| 16 | use due to the cache aliasing requirements. |
Stefan Richter | 16104b55 | 2008-06-05 22:47:13 +0200 | [diff] [blame] | 17 | |
| 18 | If this option is switched on, the /dev/mem file only allows |
| 19 | userspace access to PCI space and the BIOS code and data regions. |
| 20 | This is sufficient for dosemu and X and all common users of |
| 21 | /dev/mem. |
| 22 | |
| 23 | If in doubt, say Y. |
Arjan van de Ven | ae531c2 | 2008-04-24 23:40:47 +0200 | [diff] [blame] | 24 | |
Ben Collins | 6bcb13b | 2008-06-18 14:04:35 -0400 | [diff] [blame] | 25 | config X86_VERBOSE_BOOTUP |
| 26 | bool "Enable verbose x86 bootup info messages" |
| 27 | default y |
| 28 | help |
| 29 | Enables the informational output from the decompression stage |
| 30 | (e.g. bzImage) of the boot. If you disable this you will still |
| 31 | see errors. Disable this if you want silent bootup. |
| 32 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 33 | config EARLY_PRINTK |
Ingo Molnar | 076f977 | 2008-01-30 13:33:06 +0100 | [diff] [blame] | 34 | bool "Early printk" if EMBEDDED |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | default y |
| 36 | help |
| 37 | Write kernel log output directly into the VGA buffer or to a serial |
| 38 | port. |
| 39 | |
| 40 | This is useful for kernel debugging when your machine crashes very |
| 41 | early before the console code is initialized. For normal operation |
| 42 | it is not recommended because it looks ugly and doesn't cooperate |
| 43 | with klogd/syslogd or the X server. You should normally N here, |
| 44 | unless you want to debug such a crash. |
| 45 | |
Yinghai Lu | 5c05917 | 2008-07-24 17:29:40 -0700 | [diff] [blame] | 46 | config EARLY_PRINTK_DBGP |
| 47 | bool "Early printk via EHCI debug port" |
| 48 | default n |
Ingo Molnar | 9749986 | 2008-07-26 17:28:11 +0200 | [diff] [blame] | 49 | depends on EARLY_PRINTK && PCI |
Yinghai Lu | 5c05917 | 2008-07-24 17:29:40 -0700 | [diff] [blame] | 50 | help |
| 51 | Write kernel log output directly into the EHCI debug port. |
| 52 | |
| 53 | This is useful for kernel debugging when your machine crashes very |
| 54 | early before the console code is initialized. For normal operation |
| 55 | it is not recommended because it looks ugly and doesn't cooperate |
| 56 | with klogd/syslogd or the X server. You should normally N here, |
| 57 | unless you want to debug such a crash. You need usb debug device. |
| 58 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 59 | config DEBUG_STACKOVERFLOW |
| 60 | bool "Check for stack overflows" |
| 61 | depends on DEBUG_KERNEL |
Adrian Bunk | dab175f | 2005-07-27 11:44:23 -0700 | [diff] [blame] | 62 | help |
| 63 | This option will cause messages to be printed if free stack space |
| 64 | drops below a certain limit. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 65 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 66 | config DEBUG_STACK_USAGE |
| 67 | bool "Stack utilization instrumentation" |
| 68 | depends on DEBUG_KERNEL |
| 69 | help |
| 70 | Enables the display of the minimum amount of free stack which each |
| 71 | task has ever had available in the sysrq-T and sysrq-P debug output. |
| 72 | |
| 73 | This option will slow down process creation somewhat. |
| 74 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 75 | config DEBUG_PAGEALLOC |
Andrew Morton | 4a2f0ac | 2006-03-25 03:07:22 -0800 | [diff] [blame] | 76 | bool "Debug page memory allocations" |
Thomas Gleixner | b1d95f4 | 2008-02-09 23:24:09 +0100 | [diff] [blame] | 77 | depends on DEBUG_KERNEL |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 78 | help |
| 79 | Unmap pages from the kernel linear mapping after free_pages(). |
| 80 | This results in a large slowdown, but helps to find certain types |
| 81 | of memory corruptions. |
| 82 | |
travis@sgi.com | c49a495 | 2008-01-30 13:33:22 +0100 | [diff] [blame] | 83 | config DEBUG_PER_CPU_MAPS |
| 84 | bool "Debug access to per_cpu maps" |
| 85 | depends on DEBUG_KERNEL |
Mike Travis | 23ca4bb | 2008-05-12 21:21:12 +0200 | [diff] [blame] | 86 | depends on X86_SMP |
travis@sgi.com | c49a495 | 2008-01-30 13:33:22 +0100 | [diff] [blame] | 87 | default n |
| 88 | help |
| 89 | Say Y to verify that the per_cpu map being accessed has |
| 90 | been setup. Adds a fair amount of code to kernel memory |
| 91 | and decreases performance. |
| 92 | |
| 93 | Say N if unsure. |
| 94 | |
Arjan van de Ven | 926e539 | 2008-04-17 17:40:45 +0200 | [diff] [blame] | 95 | config X86_PTDUMP |
| 96 | bool "Export kernel pagetable layout to userspace via debugfs" |
H. Peter Anvin | fe770bf0 | 2008-04-17 17:40:45 +0200 | [diff] [blame] | 97 | depends on DEBUG_KERNEL |
Arjan van de Ven | 926e539 | 2008-04-17 17:40:45 +0200 | [diff] [blame] | 98 | select DEBUG_FS |
| 99 | help |
| 100 | Say Y here if you want to show the kernel pagetable layout in a |
| 101 | debugfs file. This information is only useful for kernel developers |
| 102 | who are working in architecture specific areas of the kernel. |
| 103 | It is probably not a good idea to enable this feature in a production |
| 104 | kernel. |
| 105 | If in doubt, say "N" |
| 106 | |
Arjan van de Ven | 63aaf30 | 2006-01-06 00:12:02 -0800 | [diff] [blame] | 107 | config DEBUG_RODATA |
| 108 | bool "Write protect kernel read-only data structures" |
Ingo Molnar | 11201e6 | 2008-01-30 13:33:32 +0100 | [diff] [blame] | 109 | default y |
Arjan van de Ven | 63aaf30 | 2006-01-06 00:12:02 -0800 | [diff] [blame] | 110 | depends on DEBUG_KERNEL |
| 111 | help |
| 112 | Mark the kernel read-only data as write-protected in the pagetables, |
| 113 | in order to catch accidental (and incorrect) writes to such const |
Ingo Molnar | 11201e6 | 2008-01-30 13:33:32 +0100 | [diff] [blame] | 114 | data. This is recommended so that we can catch kernel bugs sooner. |
| 115 | If in doubt, say "Y". |
Arjan van de Ven | 63aaf30 | 2006-01-06 00:12:02 -0800 | [diff] [blame] | 116 | |
Ingo Molnar | aba8391 | 2008-01-30 13:34:09 +0100 | [diff] [blame] | 117 | config DEBUG_RODATA_TEST |
| 118 | bool "Testcase for the DEBUG_RODATA feature" |
| 119 | depends on DEBUG_RODATA |
Ingo Molnar | 72370f2 | 2008-02-13 16:15:34 +0100 | [diff] [blame] | 120 | default y |
Ingo Molnar | aba8391 | 2008-01-30 13:34:09 +0100 | [diff] [blame] | 121 | help |
| 122 | This option enables a testcase for the DEBUG_RODATA |
| 123 | feature as well as for the change_page_attr() infrastructure. |
| 124 | If in doubt, say "N" |
| 125 | |
| 126 | config DEBUG_NX_TEST |
| 127 | tristate "Testcase for the NX non-executable stack feature" |
| 128 | depends on DEBUG_KERNEL && m |
| 129 | help |
| 130 | This option enables a testcase for the CPU NX capability |
| 131 | and the software setup of this feature. |
| 132 | If in doubt, say "N" |
| 133 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 134 | config 4KSTACKS |
| 135 | bool "Use 4Kb for kernel stacks instead of 8Kb" |
Randy Dunlap | d013a27 | 2007-10-24 15:50:43 -0700 | [diff] [blame] | 136 | depends on X86_32 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 137 | help |
| 138 | If you say Y here the kernel will use a 4Kb stacksize for the |
| 139 | kernel stack attached to each process/thread. This facilitates |
| 140 | running more threads on a system and also reduces the pressure |
| 141 | on the VM subsystem for higher order allocations. This option |
| 142 | will also use IRQ stacks to compensate for the reduced stackspace. |
| 143 | |
Andi Kleen | 102e41f | 2006-04-18 12:35:22 +0200 | [diff] [blame] | 144 | config DOUBLEFAULT |
| 145 | default y |
| 146 | bool "Enable doublefault exception handler" if EMBEDDED |
Randy Dunlap | d013a27 | 2007-10-24 15:50:43 -0700 | [diff] [blame] | 147 | depends on X86_32 |
Andi Kleen | 102e41f | 2006-04-18 12:35:22 +0200 | [diff] [blame] | 148 | help |
Randy Dunlap | d013a27 | 2007-10-24 15:50:43 -0700 | [diff] [blame] | 149 | This option allows trapping of rare doublefault exceptions that |
| 150 | would otherwise cause a system to silently reboot. Disabling this |
| 151 | option saves about 4k and might cause you much additional grey |
| 152 | hair. |
| 153 | |
| 154 | config IOMMU_DEBUG |
| 155 | bool "Enable IOMMU debugging" |
Joerg Roedel | 966396d | 2007-10-24 12:49:48 +0200 | [diff] [blame] | 156 | depends on GART_IOMMU && DEBUG_KERNEL |
Randy Dunlap | d013a27 | 2007-10-24 15:50:43 -0700 | [diff] [blame] | 157 | depends on X86_64 |
| 158 | help |
| 159 | Force the IOMMU to on even when you have less than 4GB of |
| 160 | memory and add debugging code. On overflow always panic. And |
| 161 | allow to enable IOMMU leak tracing. Can be disabled at boot |
| 162 | time with iommu=noforce. This will also enable scatter gather |
| 163 | list merging. Currently not recommended for production |
| 164 | code. When you use it make sure you have a big enough |
| 165 | IOMMU/AGP aperture. Most of the options enabled by this can |
| 166 | be set more finegrained using the iommu= command line |
| 167 | options. See Documentation/x86_64/boot-options.txt for more |
| 168 | details. |
| 169 | |
| 170 | config IOMMU_LEAK |
| 171 | bool "IOMMU leak tracing" |
| 172 | depends on DEBUG_KERNEL |
| 173 | depends on IOMMU_DEBUG |
| 174 | help |
| 175 | Add a simple leak tracer to the IOMMU code. This is useful when you |
| 176 | are debugging a buggy device driver that leaks IOMMU mappings. |
| 177 | |
Pekka Paalanen | 8b7d89d | 2008-05-12 21:20:56 +0200 | [diff] [blame] | 178 | config MMIOTRACE |
Pekka Paalanen | d61fc44 | 2008-05-12 21:20:57 +0200 | [diff] [blame] | 179 | bool "Memory mapped IO tracing" |
Randy Dunlap | 37b36192 | 2008-05-12 21:20:59 +0200 | [diff] [blame] | 180 | depends on DEBUG_KERNEL && PCI |
Pekka Paalanen | f984b51 | 2008-05-12 21:20:57 +0200 | [diff] [blame] | 181 | select TRACING |
Pekka Paalanen | 8b7d89d | 2008-05-12 21:20:56 +0200 | [diff] [blame] | 182 | help |
Pekka Paalanen | d61fc44 | 2008-05-12 21:20:57 +0200 | [diff] [blame] | 183 | Mmiotrace traces Memory Mapped I/O access and is meant for |
| 184 | debugging and reverse engineering. It is called from the ioremap |
Pekka Paalanen | c6c67c1 | 2008-05-12 21:20:59 +0200 | [diff] [blame] | 185 | implementation and works via page faults. Tracing is disabled by |
Randy Dunlap | 37b36192 | 2008-05-12 21:20:59 +0200 | [diff] [blame] | 186 | default and can be enabled at run-time. |
Pekka Paalanen | 8b7d89d | 2008-05-12 21:20:56 +0200 | [diff] [blame] | 187 | |
Pekka Paalanen | c6c67c1 | 2008-05-12 21:20:59 +0200 | [diff] [blame] | 188 | See Documentation/tracers/mmiotrace.txt. |
Pekka Paalanen | 8b7d89d | 2008-05-12 21:20:56 +0200 | [diff] [blame] | 189 | If you are not helping to develop drivers, say N. |
| 190 | |
| 191 | config MMIOTRACE_TEST |
| 192 | tristate "Test module for mmiotrace" |
| 193 | depends on MMIOTRACE && m |
Pekka Paalanen | 8b7d89d | 2008-05-12 21:20:56 +0200 | [diff] [blame] | 194 | help |
| 195 | This is a dumb module for testing mmiotrace. It is very dangerous |
| 196 | as it will write garbage to IO memory starting at a given address. |
| 197 | However, it should be safe to use on e.g. unused portion of VRAM. |
| 198 | |
| 199 | Say N, unless you absolutely know what you are doing. |
| 200 | |
Ingo Molnar | 6e7c402 | 2008-01-30 13:30:05 +0100 | [diff] [blame] | 201 | # |
| 202 | # IO delay types: |
| 203 | # |
| 204 | |
| 205 | config IO_DELAY_TYPE_0X80 |
| 206 | int |
| 207 | default "0" |
| 208 | |
| 209 | config IO_DELAY_TYPE_0XED |
| 210 | int |
| 211 | default "1" |
| 212 | |
| 213 | config IO_DELAY_TYPE_UDELAY |
| 214 | int |
| 215 | default "2" |
| 216 | |
| 217 | config IO_DELAY_TYPE_NONE |
| 218 | int |
| 219 | default "3" |
| 220 | |
| 221 | choice |
| 222 | prompt "IO delay type" |
Ingo Molnar | fd59e9e | 2008-02-17 20:20:24 +0100 | [diff] [blame] | 223 | default IO_DELAY_0X80 |
Ingo Molnar | 6e7c402 | 2008-01-30 13:30:05 +0100 | [diff] [blame] | 224 | |
| 225 | config IO_DELAY_0X80 |
| 226 | bool "port 0x80 based port-IO delay [recommended]" |
Rene Herman | b02aae9 | 2008-01-30 13:30:05 +0100 | [diff] [blame] | 227 | help |
Ingo Molnar | 6e7c402 | 2008-01-30 13:30:05 +0100 | [diff] [blame] | 228 | This is the traditional Linux IO delay used for in/out_p. |
| 229 | It is the most tested hence safest selection here. |
| 230 | |
| 231 | config IO_DELAY_0XED |
| 232 | bool "port 0xed based port-IO delay" |
| 233 | help |
| 234 | Use port 0xed as the IO delay. This frees up port 0x80 which is |
| 235 | often used as a hardware-debug port. |
| 236 | |
| 237 | config IO_DELAY_UDELAY |
| 238 | bool "udelay based port-IO delay" |
| 239 | help |
| 240 | Use udelay(2) as the IO delay method. This provides the delay |
| 241 | while not having any side-effect on the IO port space. |
| 242 | |
| 243 | config IO_DELAY_NONE |
| 244 | bool "no port-IO delay" |
| 245 | help |
| 246 | No port-IO delay. Will break on old boxes that require port-IO |
| 247 | delay for certain operations. Should work on most new machines. |
| 248 | |
| 249 | endchoice |
| 250 | |
| 251 | if IO_DELAY_0X80 |
| 252 | config DEFAULT_IO_DELAY_TYPE |
| 253 | int |
| 254 | default IO_DELAY_TYPE_0X80 |
| 255 | endif |
| 256 | |
| 257 | if IO_DELAY_0XED |
| 258 | config DEFAULT_IO_DELAY_TYPE |
| 259 | int |
| 260 | default IO_DELAY_TYPE_0XED |
| 261 | endif |
| 262 | |
| 263 | if IO_DELAY_UDELAY |
| 264 | config DEFAULT_IO_DELAY_TYPE |
| 265 | int |
| 266 | default IO_DELAY_TYPE_UDELAY |
| 267 | endif |
| 268 | |
| 269 | if IO_DELAY_NONE |
| 270 | config DEFAULT_IO_DELAY_TYPE |
| 271 | int |
| 272 | default IO_DELAY_TYPE_NONE |
| 273 | endif |
Rene Herman | b02aae9 | 2008-01-30 13:30:05 +0100 | [diff] [blame] | 274 | |
Huang, Ying | 6d7d743 | 2008-01-30 13:32:51 +0100 | [diff] [blame] | 275 | config DEBUG_BOOT_PARAMS |
| 276 | bool "Debug boot parameters" |
| 277 | depends on DEBUG_KERNEL |
| 278 | depends on DEBUG_FS |
| 279 | help |
| 280 | This option will cause struct boot_params to be exported via debugfs. |
| 281 | |
Andi Kleen | 0c42f39 | 2008-01-30 13:33:42 +0100 | [diff] [blame] | 282 | config CPA_DEBUG |
Ingo Molnar | 971a52d | 2008-02-06 22:39:45 +0100 | [diff] [blame] | 283 | bool "CPA self-test code" |
Ingo Molnar | f316fe6 | 2008-01-30 13:34:04 +0100 | [diff] [blame] | 284 | depends on DEBUG_KERNEL |
Andi Kleen | 0c42f39 | 2008-01-30 13:33:42 +0100 | [diff] [blame] | 285 | help |
Ingo Molnar | 971a52d | 2008-02-06 22:39:45 +0100 | [diff] [blame] | 286 | Do change_page_attr() self-tests every 30 seconds. |
Andi Kleen | 0c42f39 | 2008-01-30 13:33:42 +0100 | [diff] [blame] | 287 | |
Ingo Molnar | 60a3cdd | 2008-03-03 12:38:52 +0100 | [diff] [blame] | 288 | config OPTIMIZE_INLINING |
| 289 | bool "Allow gcc to uninline functions marked 'inline'" |
Ingo Molnar | 60a3cdd | 2008-03-03 12:38:52 +0100 | [diff] [blame] | 290 | help |
| 291 | This option determines if the kernel forces gcc to inline the functions |
| 292 | developers have marked 'inline'. Doing so takes away freedom from gcc to |
| 293 | do what it thinks is best, which is desirable for the gcc 3.x series of |
| 294 | compilers. The gcc 4.x series have a rewritten inlining algorithm and |
Sitsofe Wheeler | 63fb708 | 2008-10-11 20:27:53 +0100 | [diff] [blame] | 295 | enabling this option will generate a smaller kernel there. Hopefully |
| 296 | this algorithm is so good that allowing gcc 4.x and above to make the |
| 297 | decision will become the default in the future. Until then this option |
| 298 | is there to test gcc for this. |
Ingo Molnar | c9af1e3 | 2008-04-30 08:48:45 +0200 | [diff] [blame] | 299 | |
Ingo Molnar | 3f9b5cc | 2008-07-18 16:30:05 +0200 | [diff] [blame] | 300 | If unsure, say N. |
| 301 | |
Ingo Molnar | c9af1e3 | 2008-04-30 08:48:45 +0200 | [diff] [blame] | 302 | endmenu |
| 303 | |