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-rw-r--r--arch/x86/kernel/entry_32.S5
-rw-r--r--arch/x86/kernel/ftrace.c48
-rw-r--r--include/linux/ftrace.h5
-rw-r--r--kernel/trace/ftrace.c35
4 files changed, 72 insertions, 21 deletions
diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index 7def9fd5c1e..958af86186c 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -1174,6 +1174,11 @@ ftrace_call:
popl %edx
popl %ecx
popl %eax
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+.globl ftrace_graph_call
+ftrace_graph_call:
+ jmp ftrace_stub
+#endif
.globl ftrace_stub
ftrace_stub:
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 26b2d92d48b..7ef914e6a2f 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -111,7 +111,6 @@ static void ftrace_mod_code(void)
*/
mod_code_status = probe_kernel_write(mod_code_ip, mod_code_newcode,
MCOUNT_INSN_SIZE);
-
}
void ftrace_nmi_enter(void)
@@ -325,7 +324,51 @@ int __init ftrace_dyn_arch_init(void *data)
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
-#ifndef CONFIG_DYNAMIC_FTRACE
+#ifdef CONFIG_DYNAMIC_FTRACE
+extern void ftrace_graph_call(void);
+
+static int ftrace_mod_jmp(unsigned long ip,
+ int old_offset, int new_offset)
+{
+ unsigned char code[MCOUNT_INSN_SIZE];
+
+ if (probe_kernel_read(code, (void *)ip, MCOUNT_INSN_SIZE))
+ return -EFAULT;
+
+ if (code[0] != 0xe9 || old_offset != *(int *)(&code[1]))
+ return -EINVAL;
+
+ *(int *)(&code[1]) = new_offset;
+
+ if (do_ftrace_mod_code(ip, &code))
+ return -EPERM;
+
+ return 0;
+}
+
+int ftrace_enable_ftrace_graph_caller(void)
+{
+ unsigned long ip = (unsigned long)(&ftrace_graph_call);
+ int old_offset, new_offset;
+
+ old_offset = (unsigned long)(&ftrace_stub) - (ip + MCOUNT_INSN_SIZE);
+ new_offset = (unsigned long)(&ftrace_graph_caller) - (ip + MCOUNT_INSN_SIZE);
+
+ return ftrace_mod_jmp(ip, old_offset, new_offset);
+}
+
+int ftrace_disable_ftrace_graph_caller(void)
+{
+ unsigned long ip = (unsigned long)(&ftrace_graph_call);
+ int old_offset, new_offset;
+
+ old_offset = (unsigned long)(&ftrace_graph_caller) - (ip + MCOUNT_INSN_SIZE);
+ new_offset = (unsigned long)(&ftrace_stub) - (ip + MCOUNT_INSN_SIZE);
+
+ return ftrace_mod_jmp(ip, old_offset, new_offset);
+}
+
+#else /* CONFIG_DYNAMIC_FTRACE */
/*
* These functions are picked from those used on
@@ -343,6 +386,7 @@ void ftrace_nmi_exit(void)
{
atomic_dec(&in_nmi);
}
+
#endif /* !CONFIG_DYNAMIC_FTRACE */
/* Add a function return address to the trace stack on thread info.*/
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index fc2d5498719..f9792c0d73f 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -117,6 +117,11 @@ extern void ftrace_call(void);
extern void mcount_call(void);
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
extern void ftrace_graph_caller(void);
+extern int ftrace_enable_ftrace_graph_caller(void);
+extern int ftrace_disable_ftrace_graph_caller(void);
+#else
+static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; }
+static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; }
#endif
/**
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 00d98c65fad..5f7c8642d58 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -281,6 +281,8 @@ enum {
FTRACE_UPDATE_TRACE_FUNC = (1 << 2),
FTRACE_ENABLE_MCOUNT = (1 << 3),
FTRACE_DISABLE_MCOUNT = (1 << 4),
+ FTRACE_START_FUNC_RET = (1 << 5),
+ FTRACE_STOP_FUNC_RET = (1 << 6),
};
static int ftrace_filtered;
@@ -465,14 +467,7 @@ __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
unsigned long ip, fl;
unsigned long ftrace_addr;
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
- if (ftrace_tracing_type == FTRACE_TYPE_ENTER)
- ftrace_addr = (unsigned long)ftrace_caller;
- else
- ftrace_addr = (unsigned long)ftrace_graph_caller;
-#else
ftrace_addr = (unsigned long)ftrace_caller;
-#endif
ip = rec->ip;
@@ -605,6 +600,11 @@ static int __ftrace_modify_code(void *data)
if (*command & FTRACE_UPDATE_TRACE_FUNC)
ftrace_update_ftrace_func(ftrace_trace_function);
+ if (*command & FTRACE_START_FUNC_RET)
+ ftrace_enable_ftrace_graph_caller();
+ else if (*command & FTRACE_STOP_FUNC_RET)
+ ftrace_disable_ftrace_graph_caller();
+
return 0;
}
@@ -629,10 +629,8 @@ static void ftrace_startup_enable(int command)
ftrace_run_update_code(command);
}
-static void ftrace_startup(void)
+static void ftrace_startup(int command)
{
- int command = 0;
-
if (unlikely(ftrace_disabled))
return;
@@ -645,10 +643,8 @@ static void ftrace_startup(void)
mutex_unlock(&ftrace_start_lock);
}
-static void ftrace_shutdown(void)
+static void ftrace_shutdown(int command)
{
- int command = 0;
-
if (unlikely(ftrace_disabled))
return;
@@ -1453,8 +1449,9 @@ device_initcall(ftrace_nodyn_init);
static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; }
static inline void ftrace_startup_enable(int command) { }
-# define ftrace_startup() do { } while (0)
-# define ftrace_shutdown() do { } while (0)
+/* Keep as macros so we do not need to define the commands */
+# define ftrace_startup(command) do { } while (0)
+# define ftrace_shutdown(command) do { } while (0)
# define ftrace_startup_sysctl() do { } while (0)
# define ftrace_shutdown_sysctl() do { } while (0)
#endif /* CONFIG_DYNAMIC_FTRACE */
@@ -1585,7 +1582,7 @@ int register_ftrace_function(struct ftrace_ops *ops)
}
ret = __register_ftrace_function(ops);
- ftrace_startup();
+ ftrace_startup(0);
out:
mutex_unlock(&ftrace_sysctl_lock);
@@ -1604,7 +1601,7 @@ int unregister_ftrace_function(struct ftrace_ops *ops)
mutex_lock(&ftrace_sysctl_lock);
ret = __unregister_ftrace_function(ops);
- ftrace_shutdown();
+ ftrace_shutdown(0);
mutex_unlock(&ftrace_sysctl_lock);
return ret;
@@ -1751,7 +1748,7 @@ int register_ftrace_graph(trace_func_graph_ret_t retfunc,
ftrace_tracing_type = FTRACE_TYPE_RETURN;
ftrace_graph_return = retfunc;
ftrace_graph_entry = entryfunc;
- ftrace_startup();
+ ftrace_startup(FTRACE_START_FUNC_RET);
out:
mutex_unlock(&ftrace_sysctl_lock);
@@ -1765,7 +1762,7 @@ void unregister_ftrace_graph(void)
atomic_dec(&ftrace_graph_active);
ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
ftrace_graph_entry = (trace_func_graph_ent_t)ftrace_stub;
- ftrace_shutdown();
+ ftrace_shutdown(FTRACE_STOP_FUNC_RET);
/* Restore normal tracing type */
ftrace_tracing_type = FTRACE_TYPE_ENTER;
generated by cgit v1.2.3 (git 2.25.1) at 2024-08-05 05:11:46 +0000