diff options
| author | Chengming Zhou <zhouchengming@bytedance.com> | 2022-04-21 00:00:06 +0800 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2022-04-29 19:21:12 +0100 |
| commit | c4a0ebf87cebbfa28d56e7d93b2536e2311e30c9 (patch) | |
| tree | 4bac1e78233bb63eebbc32430d88feac9326e2c7 /arch/arm64/kernel/ftrace.c | |
| parent | e999995c84c3abb6dcae83f8c35942a8d4ee0451 (diff) | |
arm64/ftrace: Make function graph use ftrace directly
As we do in commit 0c0593b45c9b ("x86/ftrace: Make function graph
use ftrace directly"), we don't need special hook for graph tracer,
but instead we use graph_ops:func function to install return_hooker.
Since commit 3b23e4991fb6 ("arm64: implement ftrace with regs") add
implementation for FTRACE_WITH_REGS on arm64, we can easily adopt
the same cleanup on arm64.
And this cleanup only changes the FTRACE_WITH_REGS implementation,
so the mcount-based implementation is unaffected.
While in theory it would be possible to make a similar cleanup for
!FTRACE_WITH_REGS, this will require rework of the core code, and
so for now we only change the FTRACE_WITH_REGS implementation.
Tested-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Link: https://lore.kernel.org/r/20220420160006.17880-2-zhouchengming@bytedance.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kernel/ftrace.c')
| -rw-r--r-- | arch/arm64/kernel/ftrace.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/arch/arm64/kernel/ftrace.c b/arch/arm64/kernel/ftrace.c index 4506c4a90ac1..f447c4a36f69 100644 --- a/arch/arm64/kernel/ftrace.c +++ b/arch/arm64/kernel/ftrace.c @@ -268,6 +268,22 @@ void prepare_ftrace_return(unsigned long self_addr, unsigned long *parent, } #ifdef CONFIG_DYNAMIC_FTRACE + +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS +void ftrace_graph_func(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op, struct ftrace_regs *fregs) +{ + /* + * When DYNAMIC_FTRACE_WITH_REGS is selected, `fregs` can never be NULL + * and arch_ftrace_get_regs(fregs) will always give a non-NULL pt_regs + * in which we can safely modify the LR. + */ + struct pt_regs *regs = arch_ftrace_get_regs(fregs); + unsigned long *parent = (unsigned long *)&procedure_link_pointer(regs); + + prepare_ftrace_return(ip, parent, frame_pointer(regs)); +} +#else /* * Turn on/off the call to ftrace_graph_caller() in ftrace_caller() * depending on @enable. @@ -297,5 +313,6 @@ int ftrace_disable_ftrace_graph_caller(void) { return ftrace_modify_graph_caller(false); } +#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ #endif /* CONFIG_DYNAMIC_FTRACE */ #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |