[S390] ftrace: add system call tracer support
System call tracer support for s390.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/kernel/ftrace.c b/arch/s390/kernel/ftrace.c
index c92a109..82ddfd3 100644
--- a/arch/s390/kernel/ftrace.c
+++ b/arch/s390/kernel/ftrace.c
@@ -12,6 +12,7 @@
#include <linux/ftrace.h>
#include <linux/kernel.h>
#include <linux/types.h>
+#include <trace/syscall.h>
#include <asm/lowcore.h>
#ifdef CONFIG_DYNAMIC_FTRACE
@@ -202,3 +203,58 @@
return parent;
}
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
+#ifdef CONFIG_FTRACE_SYSCALLS
+
+extern unsigned long __start_syscalls_metadata[];
+extern unsigned long __stop_syscalls_metadata[];
+extern unsigned int sys_call_table[];
+
+static struct syscall_metadata **syscalls_metadata;
+
+struct syscall_metadata *syscall_nr_to_meta(int nr)
+{
+ if (!syscalls_metadata || nr >= NR_syscalls || nr < 0)
+ return NULL;
+
+ return syscalls_metadata[nr];
+}
+
+static struct syscall_metadata *find_syscall_meta(unsigned long syscall)
+{
+ struct syscall_metadata *start;
+ struct syscall_metadata *stop;
+ char str[KSYM_SYMBOL_LEN];
+
+ start = (struct syscall_metadata *)__start_syscalls_metadata;
+ stop = (struct syscall_metadata *)__stop_syscalls_metadata;
+ kallsyms_lookup(syscall, NULL, NULL, NULL, str);
+
+ for ( ; start < stop; start++) {
+ if (start->name && !strcmp(start->name + 3, str + 3))
+ return start;
+ }
+ return NULL;
+}
+
+void arch_init_ftrace_syscalls(void)
+{
+ struct syscall_metadata *meta;
+ int i;
+ static atomic_t refs;
+
+ if (atomic_inc_return(&refs) != 1)
+ goto out;
+ syscalls_metadata = kzalloc(sizeof(*syscalls_metadata) * NR_syscalls,
+ GFP_KERNEL);
+ if (!syscalls_metadata)
+ goto out;
+ for (i = 0; i < NR_syscalls; i++) {
+ meta = find_syscall_meta((unsigned long)sys_call_table[i]);
+ syscalls_metadata[i] = meta;
+ }
+ return;
+out:
+ atomic_dec(&refs);
+}
+#endif