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 | |
Arjan van de Ven | ae531c2 | 2008-04-24 23:40:47 +0200 | [diff] [blame] | 8 | config NONPROMISC_DEVMEM |
| 9 | bool "Disable promiscuous /dev/mem" |
Arjan van de Ven | ae531c2 | 2008-04-24 23:40:47 +0200 | [diff] [blame] | 10 | help |
| 11 | The /dev/mem file by default only allows userspace access to PCI |
| 12 | space and the BIOS code and data regions. This is sufficient for |
| 13 | dosemu and X and all common users of /dev/mem. With this config |
| 14 | option, you allow userspace access to all of memory, including |
| 15 | kernel and userspace memory. Accidental access to this is |
| 16 | obviously disasterous, but specific access can be used by people |
| 17 | debugging the kernel. |
| 18 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 19 | config EARLY_PRINTK |
Ingo Molnar | 076f977 | 2008-01-30 13:33:06 +0100 | [diff] [blame] | 20 | bool "Early printk" if EMBEDDED |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 21 | default y |
| 22 | help |
| 23 | Write kernel log output directly into the VGA buffer or to a serial |
| 24 | port. |
| 25 | |
| 26 | This is useful for kernel debugging when your machine crashes very |
| 27 | early before the console code is initialized. For normal operation |
| 28 | it is not recommended because it looks ugly and doesn't cooperate |
| 29 | with klogd/syslogd or the X server. You should normally N here, |
| 30 | unless you want to debug such a crash. |
| 31 | |
| 32 | config DEBUG_STACKOVERFLOW |
| 33 | bool "Check for stack overflows" |
| 34 | depends on DEBUG_KERNEL |
Adrian Bunk | dab175f | 2005-07-27 11:44:23 -0700 | [diff] [blame] | 35 | help |
| 36 | This option will cause messages to be printed if free stack space |
| 37 | drops below a certain limit. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 39 | config DEBUG_STACK_USAGE |
| 40 | bool "Stack utilization instrumentation" |
| 41 | depends on DEBUG_KERNEL |
| 42 | help |
| 43 | Enables the display of the minimum amount of free stack which each |
| 44 | task has ever had available in the sysrq-T and sysrq-P debug output. |
| 45 | |
| 46 | This option will slow down process creation somewhat. |
| 47 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | config DEBUG_PAGEALLOC |
Andrew Morton | 4a2f0ac | 2006-03-25 03:07:22 -0800 | [diff] [blame] | 49 | bool "Debug page memory allocations" |
Thomas Gleixner | b1d95f4 | 2008-02-09 23:24:09 +0100 | [diff] [blame] | 50 | depends on DEBUG_KERNEL |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 51 | help |
| 52 | Unmap pages from the kernel linear mapping after free_pages(). |
| 53 | This results in a large slowdown, but helps to find certain types |
| 54 | of memory corruptions. |
| 55 | |
travis@sgi.com | c49a495 | 2008-01-30 13:33:22 +0100 | [diff] [blame] | 56 | config DEBUG_PER_CPU_MAPS |
| 57 | bool "Debug access to per_cpu maps" |
| 58 | depends on DEBUG_KERNEL |
| 59 | depends on X86_64_SMP |
| 60 | default n |
| 61 | help |
| 62 | Say Y to verify that the per_cpu map being accessed has |
| 63 | been setup. Adds a fair amount of code to kernel memory |
| 64 | and decreases performance. |
| 65 | |
| 66 | Say N if unsure. |
| 67 | |
Arjan van de Ven | 926e539 | 2008-04-17 17:40:45 +0200 | [diff] [blame] | 68 | config X86_PTDUMP |
| 69 | bool "Export kernel pagetable layout to userspace via debugfs" |
H. Peter Anvin | fe770bf0 | 2008-04-17 17:40:45 +0200 | [diff] [blame] | 70 | depends on DEBUG_KERNEL |
Arjan van de Ven | 926e539 | 2008-04-17 17:40:45 +0200 | [diff] [blame] | 71 | select DEBUG_FS |
| 72 | help |
| 73 | Say Y here if you want to show the kernel pagetable layout in a |
| 74 | debugfs file. This information is only useful for kernel developers |
| 75 | who are working in architecture specific areas of the kernel. |
| 76 | It is probably not a good idea to enable this feature in a production |
| 77 | kernel. |
| 78 | If in doubt, say "N" |
| 79 | |
Arjan van de Ven | 63aaf30 | 2006-01-06 00:12:02 -0800 | [diff] [blame] | 80 | config DEBUG_RODATA |
| 81 | bool "Write protect kernel read-only data structures" |
Ingo Molnar | 11201e6 | 2008-01-30 13:33:32 +0100 | [diff] [blame] | 82 | default y |
Arjan van de Ven | 63aaf30 | 2006-01-06 00:12:02 -0800 | [diff] [blame] | 83 | depends on DEBUG_KERNEL |
| 84 | help |
| 85 | Mark the kernel read-only data as write-protected in the pagetables, |
| 86 | in order to catch accidental (and incorrect) writes to such const |
Ingo Molnar | 11201e6 | 2008-01-30 13:33:32 +0100 | [diff] [blame] | 87 | data. This is recommended so that we can catch kernel bugs sooner. |
| 88 | If in doubt, say "Y". |
Arjan van de Ven | 63aaf30 | 2006-01-06 00:12:02 -0800 | [diff] [blame] | 89 | |
Ingo Molnar | 00d1c5e | 2008-04-17 17:40:45 +0200 | [diff] [blame] | 90 | config DIRECT_GBPAGES |
| 91 | bool "Enable gbpages-mapped kernel pagetables" |
| 92 | depends on DEBUG_KERNEL && EXPERIMENTAL && X86_64 |
| 93 | help |
| 94 | Enable gigabyte pages support (if the CPU supports it). This can |
| 95 | improve the kernel's performance a tiny bit by reducing TLB |
| 96 | pressure. |
| 97 | |
| 98 | This is experimental code. |
| 99 | |
| 100 | If in doubt, say "N". |
| 101 | |
Ingo Molnar | aba8391 | 2008-01-30 13:34:09 +0100 | [diff] [blame] | 102 | config DEBUG_RODATA_TEST |
| 103 | bool "Testcase for the DEBUG_RODATA feature" |
| 104 | depends on DEBUG_RODATA |
| 105 | help |
| 106 | This option enables a testcase for the DEBUG_RODATA |
| 107 | feature as well as for the change_page_attr() infrastructure. |
| 108 | If in doubt, say "N" |
| 109 | |
| 110 | config DEBUG_NX_TEST |
| 111 | tristate "Testcase for the NX non-executable stack feature" |
| 112 | depends on DEBUG_KERNEL && m |
| 113 | help |
| 114 | This option enables a testcase for the CPU NX capability |
| 115 | and the software setup of this feature. |
| 116 | If in doubt, say "N" |
| 117 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 118 | config 4KSTACKS |
| 119 | bool "Use 4Kb for kernel stacks instead of 8Kb" |
Randy Dunlap | d013a27 | 2007-10-24 15:50:43 -0700 | [diff] [blame] | 120 | depends on X86_32 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 121 | help |
| 122 | If you say Y here the kernel will use a 4Kb stacksize for the |
| 123 | kernel stack attached to each process/thread. This facilitates |
| 124 | running more threads on a system and also reduces the pressure |
| 125 | on the VM subsystem for higher order allocations. This option |
| 126 | will also use IRQ stacks to compensate for the reduced stackspace. |
| 127 | |
| 128 | config X86_FIND_SMP_CONFIG |
Randy Dunlap | d013a27 | 2007-10-24 15:50:43 -0700 | [diff] [blame] | 129 | def_bool y |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 130 | depends on X86_LOCAL_APIC || X86_VOYAGER |
Randy Dunlap | d013a27 | 2007-10-24 15:50:43 -0700 | [diff] [blame] | 131 | depends on X86_32 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 132 | |
| 133 | config X86_MPPARSE |
Randy Dunlap | d013a27 | 2007-10-24 15:50:43 -0700 | [diff] [blame] | 134 | def_bool y |
Sam Ravnborg | 6b0c3d4 | 2008-01-30 13:32:27 +0100 | [diff] [blame] | 135 | depends on (X86_32 && (X86_LOCAL_APIC && !X86_VISWS)) || X86_64 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 136 | |
Andi Kleen | 102e41f | 2006-04-18 12:35:22 +0200 | [diff] [blame] | 137 | config DOUBLEFAULT |
| 138 | default y |
| 139 | bool "Enable doublefault exception handler" if EMBEDDED |
Randy Dunlap | d013a27 | 2007-10-24 15:50:43 -0700 | [diff] [blame] | 140 | depends on X86_32 |
Andi Kleen | 102e41f | 2006-04-18 12:35:22 +0200 | [diff] [blame] | 141 | help |
Randy Dunlap | d013a27 | 2007-10-24 15:50:43 -0700 | [diff] [blame] | 142 | This option allows trapping of rare doublefault exceptions that |
| 143 | would otherwise cause a system to silently reboot. Disabling this |
| 144 | option saves about 4k and might cause you much additional grey |
| 145 | hair. |
| 146 | |
| 147 | config IOMMU_DEBUG |
| 148 | bool "Enable IOMMU debugging" |
Joerg Roedel | 966396d | 2007-10-24 12:49:48 +0200 | [diff] [blame] | 149 | depends on GART_IOMMU && DEBUG_KERNEL |
Randy Dunlap | d013a27 | 2007-10-24 15:50:43 -0700 | [diff] [blame] | 150 | depends on X86_64 |
| 151 | help |
| 152 | Force the IOMMU to on even when you have less than 4GB of |
| 153 | memory and add debugging code. On overflow always panic. And |
| 154 | allow to enable IOMMU leak tracing. Can be disabled at boot |
| 155 | time with iommu=noforce. This will also enable scatter gather |
| 156 | list merging. Currently not recommended for production |
| 157 | code. When you use it make sure you have a big enough |
| 158 | IOMMU/AGP aperture. Most of the options enabled by this can |
| 159 | be set more finegrained using the iommu= command line |
| 160 | options. See Documentation/x86_64/boot-options.txt for more |
| 161 | details. |
| 162 | |
| 163 | config IOMMU_LEAK |
| 164 | bool "IOMMU leak tracing" |
| 165 | depends on DEBUG_KERNEL |
| 166 | depends on IOMMU_DEBUG |
| 167 | help |
| 168 | Add a simple leak tracer to the IOMMU code. This is useful when you |
| 169 | are debugging a buggy device driver that leaks IOMMU mappings. |
| 170 | |
Ingo Molnar | 6e7c402 | 2008-01-30 13:30:05 +0100 | [diff] [blame] | 171 | # |
| 172 | # IO delay types: |
| 173 | # |
| 174 | |
| 175 | config IO_DELAY_TYPE_0X80 |
| 176 | int |
| 177 | default "0" |
| 178 | |
| 179 | config IO_DELAY_TYPE_0XED |
| 180 | int |
| 181 | default "1" |
| 182 | |
| 183 | config IO_DELAY_TYPE_UDELAY |
| 184 | int |
| 185 | default "2" |
| 186 | |
| 187 | config IO_DELAY_TYPE_NONE |
| 188 | int |
| 189 | default "3" |
| 190 | |
| 191 | choice |
| 192 | prompt "IO delay type" |
Ingo Molnar | fd59e9e | 2008-02-17 20:20:24 +0100 | [diff] [blame] | 193 | default IO_DELAY_0X80 |
Ingo Molnar | 6e7c402 | 2008-01-30 13:30:05 +0100 | [diff] [blame] | 194 | |
| 195 | config IO_DELAY_0X80 |
| 196 | bool "port 0x80 based port-IO delay [recommended]" |
Rene Herman | b02aae9 | 2008-01-30 13:30:05 +0100 | [diff] [blame] | 197 | help |
Ingo Molnar | 6e7c402 | 2008-01-30 13:30:05 +0100 | [diff] [blame] | 198 | This is the traditional Linux IO delay used for in/out_p. |
| 199 | It is the most tested hence safest selection here. |
| 200 | |
| 201 | config IO_DELAY_0XED |
| 202 | bool "port 0xed based port-IO delay" |
| 203 | help |
| 204 | Use port 0xed as the IO delay. This frees up port 0x80 which is |
| 205 | often used as a hardware-debug port. |
| 206 | |
| 207 | config IO_DELAY_UDELAY |
| 208 | bool "udelay based port-IO delay" |
| 209 | help |
| 210 | Use udelay(2) as the IO delay method. This provides the delay |
| 211 | while not having any side-effect on the IO port space. |
| 212 | |
| 213 | config IO_DELAY_NONE |
| 214 | bool "no port-IO delay" |
| 215 | help |
| 216 | No port-IO delay. Will break on old boxes that require port-IO |
| 217 | delay for certain operations. Should work on most new machines. |
| 218 | |
| 219 | endchoice |
| 220 | |
| 221 | if IO_DELAY_0X80 |
| 222 | config DEFAULT_IO_DELAY_TYPE |
| 223 | int |
| 224 | default IO_DELAY_TYPE_0X80 |
| 225 | endif |
| 226 | |
| 227 | if IO_DELAY_0XED |
| 228 | config DEFAULT_IO_DELAY_TYPE |
| 229 | int |
| 230 | default IO_DELAY_TYPE_0XED |
| 231 | endif |
| 232 | |
| 233 | if IO_DELAY_UDELAY |
| 234 | config DEFAULT_IO_DELAY_TYPE |
| 235 | int |
| 236 | default IO_DELAY_TYPE_UDELAY |
| 237 | endif |
| 238 | |
| 239 | if IO_DELAY_NONE |
| 240 | config DEFAULT_IO_DELAY_TYPE |
| 241 | int |
| 242 | default IO_DELAY_TYPE_NONE |
| 243 | endif |
Rene Herman | b02aae9 | 2008-01-30 13:30:05 +0100 | [diff] [blame] | 244 | |
Huang, Ying | 6d7d743 | 2008-01-30 13:32:51 +0100 | [diff] [blame] | 245 | config DEBUG_BOOT_PARAMS |
| 246 | bool "Debug boot parameters" |
| 247 | depends on DEBUG_KERNEL |
| 248 | depends on DEBUG_FS |
| 249 | help |
| 250 | This option will cause struct boot_params to be exported via debugfs. |
| 251 | |
Andi Kleen | 0c42f39 | 2008-01-30 13:33:42 +0100 | [diff] [blame] | 252 | config CPA_DEBUG |
Ingo Molnar | 971a52d | 2008-02-06 22:39:45 +0100 | [diff] [blame] | 253 | bool "CPA self-test code" |
Ingo Molnar | f316fe6 | 2008-01-30 13:34:04 +0100 | [diff] [blame] | 254 | depends on DEBUG_KERNEL |
Andi Kleen | 0c42f39 | 2008-01-30 13:33:42 +0100 | [diff] [blame] | 255 | help |
Ingo Molnar | 971a52d | 2008-02-06 22:39:45 +0100 | [diff] [blame] | 256 | Do change_page_attr() self-tests every 30 seconds. |
Andi Kleen | 0c42f39 | 2008-01-30 13:33:42 +0100 | [diff] [blame] | 257 | |
Ingo Molnar | 60a3cdd | 2008-03-03 12:38:52 +0100 | [diff] [blame] | 258 | config OPTIMIZE_INLINING |
| 259 | bool "Allow gcc to uninline functions marked 'inline'" |
Linus Torvalds | 6d98ca7 | 2008-04-30 19:50:03 -0700 | [diff] [blame^] | 260 | depends on BROKEN |
Ingo Molnar | 60a3cdd | 2008-03-03 12:38:52 +0100 | [diff] [blame] | 261 | help |
| 262 | This option determines if the kernel forces gcc to inline the functions |
| 263 | developers have marked 'inline'. Doing so takes away freedom from gcc to |
| 264 | do what it thinks is best, which is desirable for the gcc 3.x series of |
| 265 | compilers. The gcc 4.x series have a rewritten inlining algorithm and |
| 266 | disabling this option will generate a smaller kernel there. Hopefully |
| 267 | this algorithm is so good that allowing gcc4 to make the decision can |
| 268 | become the default in the future, until then this option is there to |
| 269 | test gcc for this. |
Ingo Molnar | c9af1e3 | 2008-04-30 08:48:45 +0200 | [diff] [blame] | 270 | |
| 271 | endmenu |
| 272 | |