consolidate per-arch stack overflow debugging options

Original posting:

	http://lkml.kernel.org/r/20121214184202.F54094D9@kernel.stglabs.ibm.com

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 <dave@linux.vnet.ibm.com>
Reviewed-by: H. Peter Anvin <hpa@zytor.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Chris Metcalf <cmetcalf@tilera.com> [for tile]
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

24 files changed, 33 insertions, 90 deletions

diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index 5917099470ea..cff2aad31041 100644
--- a/arch/arc/Kconfig
+++ b/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
diff --git a/arch/arc/Kconfig.debug b/arch/arc/Kconfig.debug
index 962c6099659e..a7fc0da25650 100644
--- a/arch/arc/Kconfig.debug
+++ b/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
diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig
index a117652b5fea..82707a77aa73 100644
--- a/arch/blackfin/Kconfig
+++ b/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
diff --git a/arch/blackfin/Kconfig.debug b/arch/blackfin/Kconfig.debug
index 79594694ee90..f3337ee03621 100644
--- a/arch/blackfin/Kconfig.debug
+++ b/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
diff --git a/arch/frv/Kconfig b/arch/frv/Kconfig
index 2ce731f9aa4d..4b6628ea381e 100644
--- a/arch/frv/Kconfig
+++ b/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
diff --git a/arch/frv/Kconfig.debug b/arch/frv/Kconfig.debug
index 211f01bc4caa..98c99a3ed2be 100644
--- a/arch/frv/Kconfig.debug
+++ b/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
diff --git a/arch/m32r/Kconfig b/arch/m32r/Kconfig
index bcd17b206571..29a7ef4e448b 100644
--- a/arch/m32r/Kconfig
+++ b/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
diff --git a/arch/m32r/Kconfig.debug b/arch/m32r/Kconfig.debug
index bb1afc1a31cc..6c612b7691b0 100644
--- a/arch/m32r/Kconfig.debug
+++ b/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
diff --git a/arch/metag/Kconfig b/arch/metag/Kconfig
index dcd94406030e..cfd831c29824 100644
--- a/arch/metag/Kconfig
+++ b/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
diff --git a/arch/metag/Kconfig.debug b/arch/metag/Kconfig.debug
index e45bbf6a7a5d..cb5c92860540 100644
--- a/arch/metag/Kconfig.debug
+++ b/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
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 7a58ab933b20..7aae1ef096ea 100644
--- a/arch/mips/Kconfig
+++ b/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"
 
diff --git a/arch/mips/Kconfig.debug b/arch/mips/Kconfig.debug
index 5a43aa0798ca..37871f0de15e 100644
--- a/arch/mips/Kconfig.debug
+++ b/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
diff --git a/arch/mn10300/Kconfig b/arch/mn10300/Kconfig
index 428da175d073..70e4f663ebd2 100644
--- a/arch/mn10300/Kconfig
+++ b/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
diff --git a/arch/mn10300/Kconfig.debug b/arch/mn10300/Kconfig.debug
index bdbfd444a9ff..94efb3ed223f 100644
--- a/arch/mn10300/Kconfig.debug
+++ b/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
diff --git a/arch/openrisc/Kconfig b/arch/openrisc/Kconfig
index 1072bfd18c50..99dbab1c59ac 100644
--- a/arch/openrisc/Kconfig
+++ b/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
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index 6507dabdd5dd..ffcd557f8cfd 100644
--- a/arch/parisc/Kconfig
+++ b/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
diff --git a/arch/parisc/Kconfig.debug b/arch/parisc/Kconfig.debug
index 08a332f6ee87..bc989e522a04 100644
--- a/arch/parisc/Kconfig.debug
+++ b/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".
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index c33e3ad2c8fd..a4f5959ed9b0 100644
--- a/arch/powerpc/Kconfig
+++ b/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
diff --git a/arch/powerpc/Kconfig.debug b/arch/powerpc/Kconfig.debug
index 863d877e0b5f..a4914f373958 100644
--- a/arch/powerpc/Kconfig.debug
+++ b/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
diff --git a/arch/tile/Kconfig b/arch/tile/Kconfig
index 3aa37669ff8c..24565a7ffe6d 100644
--- a/arch/tile/Kconfig
+++ b/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
diff --git a/arch/tile/Kconfig.debug b/arch/tile/Kconfig.debug
index ddbfc3322d7f..9165ea979e85 100644
--- a/arch/tile/Kconfig.debug
+++ b/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
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index fe120da25625..22f30337a18e 100644
--- a/arch/x86/Kconfig
+++ b/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
diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
index c198b7e13e7b..c1665a8989da 100644
--- a/arch/x86/Kconfig.debug
+++ b/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
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 566cf2bc08ea..cc443bc6edfc 100644
--- a/lib/Kconfig.debug
+++ b/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"