diff options
| -rw-r--r-- | arch/arm/Kconfig.debug | 5 | ||||
| -rw-r--r-- | arch/arm/kernel/armksyms.c | 2 | ||||
| -rw-r--r-- | arch/arm/kernel/entry-common.S | 14 | ||||
| -rw-r--r-- | kernel/trace/Kconfig | 2 |
4 files changed, 22 insertions, 1 deletions
diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug index 91344af75f3..4dbce538fec 100644 --- a/arch/arm/Kconfig.debug +++ b/arch/arm/Kconfig.debug @@ -27,6 +27,11 @@ config ARM_UNWIND the performance is not affected. Currently, this feature only works with EABI compilers. If unsure say Y. +config OLD_MCOUNT + bool + depends on FUNCTION_TRACER && FRAME_POINTER + default y + config DEBUG_USER bool "Verbose user fault messages" help diff --git a/arch/arm/kernel/armksyms.c b/arch/arm/kernel/armksyms.c index 8214bfebfac..e5e1e538767 100644 --- a/arch/arm/kernel/armksyms.c +++ b/arch/arm/kernel/armksyms.c @@ -165,6 +165,8 @@ EXPORT_SYMBOL(_find_next_bit_be); #endif #ifdef CONFIG_FUNCTION_TRACER +#ifdef CONFIG_OLD_MCOUNT EXPORT_SYMBOL(mcount); +#endif EXPORT_SYMBOL(__gnu_mcount_nc); #endif diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index f05a35a5969..6805a7216bf 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -128,6 +128,13 @@ ENDPROC(ret_from_fork) * allows it to be clobbered in subroutines and doesn't use it to hold * parameters.) */ + +#ifndef CONFIG_OLD_MCOUNT +#if (__GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 4)) +#error Ftrace requires CONFIG_FRAME_POINTER=y with GCC older than 4.4.0. +#endif +#endif + #ifdef CONFIG_DYNAMIC_FTRACE ENTRY(mcount) stmdb sp!, {r0-r3, lr} @@ -173,6 +180,12 @@ gnu_trace: ldmia sp!, {r0-r3, ip, lr} mov pc, ip +#ifdef CONFIG_OLD_MCOUNT +/* + * This is under an ifdef in order to force link-time errors for people trying + * to build with !FRAME_POINTER with a GCC which doesn't use the new-style + * mcount. + */ ENTRY(mcount) stmdb sp!, {r0-r3, lr} ldr r0, =ftrace_trace_function @@ -191,6 +204,7 @@ trace: mov pc, r2 ldr lr, [fp, #-4] @ restore lr ldmia sp!, {r0-r3, pc} +#endif #endif /* CONFIG_DYNAMIC_FTRACE */ diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 538501c6ea5..6329d063b5e 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -121,7 +121,7 @@ if FTRACE config FUNCTION_TRACER bool "Kernel Function Tracer" depends on HAVE_FUNCTION_TRACER - select FRAME_POINTER + select FRAME_POINTER if (!ARM_UNWIND) select KALLSYMS select GENERIC_TRACER select CONTEXT_SWITCH_TRACER |