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-rw-r--r--init/Kconfig65
1 files changed, 65 insertions, 0 deletions
diff --git a/init/Kconfig b/init/Kconfig
index 0dfd09d54c65..f755a602d4a1 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -862,6 +862,28 @@ config LOG_CPU_MAX_BUF_SHIFT
13 => 8 KB for each CPU
12 => 4 KB for each CPU
+config NMI_LOG_BUF_SHIFT
+ int "Temporary per-CPU NMI log buffer size (12 => 4KB, 13 => 8KB)"
+ range 10 21
+ default 13
+ depends on PRINTK_NMI
+ help
+ Select the size of a per-CPU buffer where NMI messages are temporary
+ stored. They are copied to the main log buffer in a safe context
+ to avoid a deadlock. The value defines the size as a power of 2.
+
+ NMI messages are rare and limited. The largest one is when
+ a backtrace is printed. It usually fits into 4KB. Select
+ 8KB if you want to be on the safe side.
+
+ Examples:
+ 17 => 128 KB for each CPU
+ 16 => 64 KB for each CPU
+ 15 => 32 KB for each CPU
+ 14 => 16 KB for each CPU
+ 13 => 8 KB for each CPU
+ 12 => 4 KB for each CPU
+
#
# Architectures with an unreliable sched_clock() should select this:
#
@@ -1284,6 +1306,17 @@ source "usr/Kconfig"
endif
+choice
+ prompt "Compiler optimization level"
+ default CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
+
+config CC_OPTIMIZE_FOR_PERFORMANCE
+ bool "Optimize for performance"
+ help
+ This is the default optimization level for the kernel, building
+ with the "-O2" compiler flag for best performance and most
+ helpful compile-time warnings.
+
config CC_OPTIMIZE_FOR_SIZE
bool "Optimize for size"
help
@@ -1292,6 +1325,8 @@ config CC_OPTIMIZE_FOR_SIZE
If unsure, say N.
+endchoice
+
config SYSCTL
bool
@@ -1454,6 +1489,11 @@ config PRINTK
very difficult to diagnose system problems, saying N here is
strongly discouraged.
+config PRINTK_NMI
+ def_bool y
+ depends on PRINTK
+ depends on HAVE_NMI
+
config BUG
bool "BUG() support" if EXPERT
default y
@@ -1742,6 +1782,15 @@ config SLOB
endchoice
+config SLAB_FREELIST_RANDOM
+ default n
+ depends on SLAB
+ bool "SLAB freelist randomization"
+ help
+ Randomizes the freelist order used on creating new SLABs. This
+ security feature reduces the predictability of the kernel slab
+ allocator against heap overflows.
+
config SLUB_CPU_PARTIAL
default y
depends on SLUB && SMP
@@ -2013,6 +2062,22 @@ config MODULE_COMPRESS_XZ
endchoice
+config TRIM_UNUSED_KSYMS
+ bool "Trim unused exported kernel symbols"
+ depends on MODULES && !UNUSED_SYMBOLS
+ help
+ The kernel and some modules make many symbols available for
+ other modules to use via EXPORT_SYMBOL() and variants. Depending
+ on the set of modules being selected in your kernel configuration,
+ many of those exported symbols might never be used.
+
+ This option allows for unused exported symbols to be dropped from
+ the build. In turn, this provides the compiler more opportunities
+ (especially when using LTO) for optimizing the code and reducing
+ binary size. This might have some security advantages as well.
+
+ If unsure say N.
+
endif # MODULES
config MODULES_TREE_LOOKUP