diff options
Diffstat (limited to 'arch/s390/kernel/ftrace.c')
| -rw-r--r-- | arch/s390/kernel/ftrace.c | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/arch/s390/kernel/ftrace.c b/arch/s390/kernel/ftrace.c index c92a1095327..82ddfd3a75a 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 @@ out: 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 |