diff options
| author | Sven Schnelle <svens@stackframe.org> | 2021-10-23 20:21:01 +0200 |
|---|---|---|
| committer | Helge Deller <deller@gmx.de> | 2021-11-01 07:36:01 +0100 |
| commit | 98f2926171aea858b074b714bb6e111d51fa747d (patch) | |
| tree | 766d1b877a34a33c17bb3f41cdfb8bd79832926a /arch | |
| parent | 44382af89346d612c8d5b88cd0a48895f9863ee9 (diff) | |
| download | linux-98f2926171aea858b074b714bb6e111d51fa747d.tar.gz | |
parisc/ftrace: use static key to enable/disable function graph tracer
This avoids using dereference_function_descriptor in the ftrace code path, and it's also faster. Signed-off-by: Sven Schnelle <svens@stackframe.org> Signed-off-by: Helge Deller <deller@gmx.de>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/parisc/kernel/ftrace.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/arch/parisc/kernel/ftrace.c b/arch/parisc/kernel/ftrace.c index 3a577186f71b..2a1f826b3def 100644 --- a/arch/parisc/kernel/ftrace.c +++ b/arch/parisc/kernel/ftrace.c @@ -15,6 +15,7 @@ #include <linux/uaccess.h> #include <linux/kprobes.h> #include <linux/ptrace.h> +#include <linux/jump_label.h> #include <asm/assembly.h> #include <asm/sections.h> @@ -24,6 +25,8 @@ #define __hot __section(".text.hot") #ifdef CONFIG_FUNCTION_GRAPH_TRACER +static DEFINE_STATIC_KEY_FALSE(ftrace_graph_enable); + /* * Hook the return address and push it in the stack of return addrs * in current thread info. @@ -60,9 +63,7 @@ void notrace __hot ftrace_function_trampoline(unsigned long parent, ftrace_func(self_addr, parent, function_trace_op, fregs); #ifdef CONFIG_FUNCTION_GRAPH_TRACER - if (dereference_function_descriptor(ftrace_graph_return) != - dereference_function_descriptor(ftrace_stub) || - ftrace_graph_entry != ftrace_graph_entry_stub) { + if (static_branch_unlikely(&ftrace_graph_enable)) { unsigned long *parent_rp; /* calculate pointer to %rp in stack */ @@ -80,11 +81,13 @@ void notrace __hot ftrace_function_trampoline(unsigned long parent, #ifdef CONFIG_FUNCTION_GRAPH_TRACER int ftrace_enable_ftrace_graph_caller(void) { + static_key_enable(&ftrace_graph_enable.key); return 0; } int ftrace_disable_ftrace_graph_caller(void) { + static_key_enable(&ftrace_graph_enable.key); return 0; } #endif |