ARM: 8800/1: use choice for kernel unwinders
commit f9b58e8c7d031b0daa5c9a9ee27f5a4028ba53ac upstream.
While in theory multiple unwinders could be compiled in, it does
not make sense in practise. Use a choice to make the unwinder
selection mutually exclusive and mandatory.
Already before this commit it has not been possible to deselect
FRAME_POINTER. Remove the obsolete comment.
Furthermore, to produce a meaningful backtrace with FRAME_POINTER
enabled the kernel needs a specific function prologue:
mov ip, sp
stmfd sp!, {fp, ip, lr, pc}
sub fp, ip, #4
To get to the required prologue gcc uses apcs and no-sched-prolog.
This compiler options are not available on clang, and clang is not
able to generate the required prologue. Make the FRAME_POINTER
config symbol depending on !clang.
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Stefan Agner <stefan@agner.ch>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index bc5ff3a..e7addfc 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1091,7 +1091,7 @@
bool
depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
select STACKTRACE
- select FRAME_POINTER if !MIPS && !PPC && !ARM_UNWIND && !S390 && !MICROBLAZE && !ARC && !SCORE
+ select FRAME_POINTER if !MIPS && !PPC && !ARM && !S390 && !MICROBLAZE && !ARC && !SCORE
select KALLSYMS
select KALLSYMS_ALL
@@ -1670,7 +1670,7 @@
depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
depends on !X86_64
select STACKTRACE
- select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM_UNWIND && !ARC && !SCORE
+ select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !SCORE
help
Provide stacktrace filter for fault-injection capabilities
@@ -1679,7 +1679,7 @@
depends on DEBUG_KERNEL
depends on STACKTRACE_SUPPORT
depends on PROC_FS
- select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM_UNWIND && !ARC
+ select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC
select KALLSYMS
select KALLSYMS_ALL
select STACKTRACE