consolidate per-arch stack overflow debugging options

Original posting:

	http://lkml.kernel.org/r/[email protected]

Several architectures have similar stack debugging config options.
They all pretty much do the same thing, some with slightly
differing help text.

This patch changes the architectures to instead enable a Kconfig
boolean, and then use that boolean in the generic Kconfig.debug
to present the actual menu option.  This removes a bunch of
duplication and adds consistency across arches.

Signed-off-by: Dave Hansen <[email protected]>
Reviewed-by: H. Peter Anvin <[email protected]>
Reviewed-by: James Hogan <[email protected]>
Acked-by: Chris Metcalf <[email protected]> [for tile]
Signed-off-by: Dave Hansen <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Author: Dave Hansen

arch/arc/Kconfig

@@ -34,6 +34,7 @@ config ARC
 	select OF
 	select OF_EARLY_FLATTREE
 	select PERF_USE_VMALLOC
+	select HAVE_DEBUG_STACKOVERFLOW
 
 config SCHED_OMIT_FRAME_POINTER
 	def_bool y

arch/arc/Kconfig.debug

@@ -15,13 +15,6 @@ config EARLY_PRINTK
 	  with klogd/syslogd or the X server. You should normally N here,
 	  unless you want to debug such a crash.
 
-config DEBUG_STACKOVERFLOW
-	bool "Check for stack overflows"
-	depends on DEBUG_KERNEL
-	help
-	  This option will cause messages to be printed if free stack space
-	  drops below a certain limit.
-
 config 16KSTACKS
 	bool "Use 16Kb for kernel stacks instead of 8Kb"
 	help

arch/blackfin/Kconfig

@@ -41,6 +41,7 @@ config BLACKFIN
 	select ARCH_USES_GETTIMEOFFSET if !GENERIC_CLOCKEVENTS
 	select HAVE_MOD_ARCH_SPECIFIC
 	select MODULES_USE_ELF_RELA
+	select HAVE_DEBUG_STACKOVERFLOW
 
 config GENERIC_CSUM
 	def_bool y

arch/blackfin/Kconfig.debug

@@ -2,13 +2,6 @@ menu "Kernel hacking"
 
 source "lib/Kconfig.debug"
 
-config DEBUG_STACKOVERFLOW
-	bool "Check for stack overflows"
-	depends on DEBUG_KERNEL
-	help
-	  This option will cause messages to be printed if free stack space
-	  drops below a certain limit.
-
 config DEBUG_VERBOSE
 	bool "Verbose fault messages"
 	default y

arch/frv/Kconfig

@@ -14,6 +14,7 @@ config FRV
 	select ARCH_WANT_IPC_PARSE_VERSION
 	select OLD_SIGSUSPEND3
 	select OLD_SIGACTION
+	select HAVE_DEBUG_STACKOVERFLOW
 
 config ZONE_DMA
 	bool

arch/frv/Kconfig.debug

@@ -2,10 +2,6 @@ menu "Kernel hacking"
 
 source "lib/Kconfig.debug"
 
-config DEBUG_STACKOVERFLOW
-	bool "Check for stack overflows"
-	depends on DEBUG_KERNEL
-
 config GDBSTUB
 	bool "Remote GDB kernel debugging"
 	depends on DEBUG_KERNEL

arch/m32r/Kconfig

@@ -16,6 +16,7 @@ config M32R
 	select GENERIC_ATOMIC64
 	select ARCH_USES_GETTIMEOFFSET
 	select MODULES_USE_ELF_RELA
+	select HAVE_DEBUG_STACKOVERFLOW
 
 config SBUS
 	bool

arch/m32r/Kconfig.debug

@@ -2,13 +2,6 @@ menu "Kernel hacking"
 
 source "lib/Kconfig.debug"
 
-config DEBUG_STACKOVERFLOW
-	bool "Check for stack overflows"
-	depends on DEBUG_KERNEL
-	help
-	  This option will cause messages to be printed if free stack space
-	  drops below a certain limit.
-
 config DEBUG_PAGEALLOC
 	bool "Debug page memory allocations"
 	depends on DEBUG_KERNEL && BROKEN

arch/metag/Kconfig

@@ -30,6 +30,7 @@ config METAG
 	select OF
 	select OF_EARLY_FLATTREE
 	select SPARSE_IRQ
+	select HAVE_DEBUG_STACKOVERFLOW
 
 config STACKTRACE_SUPPORT
 	def_bool y

arch/metag/Kconfig.debug

@@ -6,13 +6,6 @@ config TRACE_IRQFLAGS_SUPPORT
 
 source "lib/Kconfig.debug"
 
-config DEBUG_STACKOVERFLOW
-	bool "Check for stack overflows"
-	depends on DEBUG_KERNEL
-	help
-	  This option will cause messages to be printed if free stack space
-	  drops below a certain limit.
-
 config 4KSTACKS
 	bool "Use 4Kb for kernel stacks instead of 8Kb"
 	depends on DEBUG_KERNEL

arch/mips/Kconfig

@@ -42,6 +42,7 @@ config MIPS
 	select MODULES_USE_ELF_REL if MODULES
 	select MODULES_USE_ELF_RELA if MODULES && 64BIT
 	select CLONE_BACKWARDS
+	select HAVE_DEBUG_STACKOVERFLOW
 
 menu "Machine selection"
 

arch/mips/Kconfig.debug

@@ -67,15 +67,6 @@ config CMDLINE_OVERRIDE
 
 	  Normally, you will choose 'N' here.
 
-config DEBUG_STACKOVERFLOW
-	bool "Check for stack overflows"
-	depends on DEBUG_KERNEL
-	help
-	  This option will cause messages to be printed if free stack space
-	  drops below a certain limit(2GB on MIPS). The debugging option
-	  provides another way to check stack overflow happened on kernel mode
-	  stack usually caused by nested interruption.
-
 config SMTC_IDLE_HOOK_DEBUG
 	bool "Enable additional debug checks before going into CPU idle loop"
 	depends on DEBUG_KERNEL && MIPS_MT_SMTC

arch/mn10300/Kconfig

@@ -13,6 +13,7 @@ config MN10300
 	select MODULES_USE_ELF_RELA
 	select OLD_SIGSUSPEND3
 	select OLD_SIGACTION
+	select HAVE_DEBUG_STACKOVERFLOW
 
 config AM33_2
 	def_bool n

arch/mn10300/Kconfig.debug

@@ -2,10 +2,6 @@ menu "Kernel hacking"
 
 source "lib/Kconfig.debug"
 
-config DEBUG_STACKOVERFLOW
-	bool "Check for stack overflows"
-	depends on DEBUG_KERNEL
-
 config DEBUG_DECOMPRESS_KERNEL
 	bool "Using serial port during decompressing kernel"
 	depends on DEBUG_KERNEL

arch/openrisc/Kconfig

@@ -22,6 +22,7 @@ config OPENRISC
 	select GENERIC_STRNCPY_FROM_USER
 	select GENERIC_STRNLEN_USER
 	select MODULES_USE_ELF_RELA
+	select HAVE_DEBUG_STACKOVERFLOW
 
 config MMU
 	def_bool y
@@ -128,16 +129,6 @@ config CMDLINE
 
 menu "Debugging options"
 
-config DEBUG_STACKOVERFLOW
-	bool "Check for kernel stack overflow"
-	default y
-	help
-	  Make extra checks for space available on stack in some
-          critical functions. This will cause kernel to run a bit slower,
-	  but will catch most of kernel stack overruns and exit gracefully.
-
-	  Say Y if you are unsure.
-
 config JUMP_UPON_UNHANDLED_EXCEPTION
 	bool "Try to die gracefully"
 	default y

arch/parisc/Kconfig

@@ -27,6 +27,7 @@ config PARISC
 	select MODULES_USE_ELF_RELA
 	select CLONE_BACKWARDS
 	select TTY # Needed for pdc_cons.c
+	select HAVE_DEBUG_STACKOVERFLOW
 
 	help
 	  The PA-RISC microprocessor is designed by Hewlett-Packard and used

arch/parisc/Kconfig.debug

@@ -13,14 +13,3 @@ config DEBUG_RODATA
          If in doubt, say "N".
 
 endmenu
-
-config DEBUG_STACKOVERFLOW
-	bool "Check for stack overflows"
-	default y
-	depends on DEBUG_KERNEL
-	---help---
-	  Say Y here if you want to check the overflows of kernel, IRQ
-	  and exception stacks. This option will cause messages of the
-	  stacks in detail when free stack space drops below a certain
-	  limit.
-	  If in doubt, say "N".

arch/powerpc/Kconfig

@@ -138,6 +138,7 @@ config PPC
 	select ARCH_USE_BUILTIN_BSWAP
 	select OLD_SIGSUSPEND
 	select OLD_SIGACTION if PPC32
+	select HAVE_DEBUG_STACKOVERFLOW
 
 config EARLY_PRINTK
 	bool

arch/powerpc/Kconfig.debug

@@ -28,13 +28,6 @@ config PRINT_STACK_DEPTH
 	  too small and stack traces cause important information to
 	  scroll off the screen.
 
-config DEBUG_STACKOVERFLOW
-	bool "Check for stack overflows"
-	depends on DEBUG_KERNEL
-	help
-	  This option will cause messages to be printed if free stack space
-	  drops below a certain limit.
-
 config HCALL_STATS
 	bool "Hypervisor call instrumentation"
 	depends on PPC_PSERIES && DEBUG_FS && TRACEPOINTS

arch/tile/Kconfig

@@ -25,6 +25,7 @@ config TILE
 	select HAVE_ARCH_TRACEHOOK
 	select HAVE_SYSCALL_TRACEPOINTS
 	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
+	select HAVE_DEBUG_STACKOVERFLOW
 
 # FIXME: investigate whether we need/want these options.
 #	select HAVE_IOREMAP_PROT

arch/tile/Kconfig.debug

@@ -14,13 +14,6 @@ config EARLY_PRINTK
 	  with klogd/syslogd. You should normally N here,
 	  unless you want to debug such a crash.
 
-config DEBUG_STACKOVERFLOW
-	bool "Check for stack overflows"
-	depends on DEBUG_KERNEL
-	help
-	  This option will cause messages to be printed if free stack space
-	  drops below a certain limit.
-
 config DEBUG_EXTRA_FLAGS
 	string "Additional compiler arguments when building with '-g'"
 	depends on DEBUG_INFO

arch/x86/Kconfig

@@ -121,6 +121,7 @@ config X86
 	select OLD_SIGACTION if X86_32
 	select COMPAT_OLD_SIGACTION if IA32_EMULATION
 	select RTC_LIB
+	select HAVE_DEBUG_STACKOVERFLOW
 
 config INSTRUCTION_DECODER
 	def_bool y

arch/x86/Kconfig.debug

@@ -59,16 +59,6 @@ config EARLY_PRINTK_DBGP
 	  with klogd/syslogd or the X server. You should normally N here,
 	  unless you want to debug such a crash. You need usb debug device.
 
-config DEBUG_STACKOVERFLOW
-	bool "Check for stack overflows"
-	depends on DEBUG_KERNEL
-	---help---
-	  Say Y here if you want to check the overflows of kernel, IRQ
-	  and exception stacks. This option will cause messages of the
-	  stacks in detail when free stack space drops below a certain
-	  limit.
-	  If in doubt, say "N".
-
 config X86_PTDUMP
 	bool "Export kernel pagetable layout to userspace via debugfs"
 	depends on DEBUG_KERNEL

lib/Kconfig.debug

@@ -1475,6 +1475,27 @@ config ASYNC_RAID6_TEST
 
 	  If unsure, say N.
 
+config HAVE_DEBUG_STACKOVERFLOW
+	bool
+
+config DEBUG_STACKOVERFLOW
+	bool "Check for stack overflows"
+	depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW
+	---help---
+	  Say Y here if you want to check for overflows of kernel, IRQ
+	  and exception stacks (if your archicture uses them). This
+	  option will show detailed messages if free stack space drops
+	  below a certain limit.
+
+	  These kinds of bugs usually occur when call-chains in the
+	  kernel get too deep, especially when interrupts are
+	  involved.
+
+	  Use this in cases where you see apparently random memory
+	  corruption, especially if it appears in 'struct thread_info'
+
+	  If in doubt, say "N".
+
 source "samples/Kconfig"
 
 source "lib/Kconfig.kgdb"