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| author |   Abel Vesa <abelvesa@linux.com> | 2017-05-26 21:49:47 +0100 |
|---|---|---|
| committer |   Russell King <rmk+kernel@armlinux.org.uk> | 2017-06-18 22:25:16 +0100 |
| commit | 620176f335017fbfcbc79d26a8c9beb6e64f4868 (patch) | |
| tree | e5865d1ab6cfe66b5009ce118c08d4b9cc49a711 /arch/arm/include/asm/ftrace.h | |
| parent | ARM: make configuration of userspace Thumb support an expert option (diff) | |
| download | linux-dev-620176f335017fbfcbc79d26a8c9beb6e64f4868.tar.xz linux-dev-620176f335017fbfcbc79d26a8c9beb6e64f4868.zip | |
ARM: 8678/1: ftrace: Adds support for CONFIG_DYNAMIC_FTRACE_WITH_REGS
The DYNAMIC_FTRACE_WITH_REGS configuration makes it possible for a
ftrace operation to specify if registers need to saved/restored by
the ftrace handler. This is needed by kgraft and possibly other
ftrace-based tools, and the ARM architecture is currently lacking
this feature. It would also be the first step to support the
"Kprobes-on-ftrace" optimization on ARM.
This patch introduces a new ftrace handler that stores the registers
on the stack before calling the next stage. The registers are restored
from the stack before going back to the instrumented function.
A side-effect of this patch is to activate the support for
ftrace_modify_call() as it defines ARCH_SUPPORTS_FTRACE_OPS for the
ARM architecture.
Signed-off-by: Abel Vesa <abelvesa@linux.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Diffstat (limited to 'arch/arm/include/asm/ftrace.h')
| -rw-r--r-- | arch/arm/include/asm/ftrace.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/arm/include/asm/ftrace.h b/arch/arm/include/asm/ftrace.h index 22b73112b75f..f379881d5cc3 100644 --- a/arch/arm/include/asm/ftrace.h +++ b/arch/arm/include/asm/ftrace.h @@ -1,6 +1,10 @@ #ifndef _ASM_ARM_FTRACE #define _ASM_ARM_FTRACE +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS +#define ARCH_SUPPORTS_FTRACE_OPS 1 +#endif + #ifdef CONFIG_FUNCTION_TRACER #define MCOUNT_ADDR ((unsigned long)(__gnu_mcount_nc)) #define MCOUNT_INSN_SIZE 4 /* sizeof mcount call */ |