diff options
Diffstat (limited to 'arch/sh/kernel/ftrace.c')
-rw-r--r-- | arch/sh/kernel/ftrace.c | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/arch/sh/kernel/ftrace.c b/arch/sh/kernel/ftrace.c index 066f37dc32a9..4f62eced0aec 100644 --- a/arch/sh/kernel/ftrace.c +++ b/arch/sh/kernel/ftrace.c @@ -18,6 +18,8 @@ #include <linux/io.h> #include <asm/ftrace.h> #include <asm/cacheflush.h> +#include <asm/unistd.h> +#include <trace/syscall.h> static unsigned char ftrace_replaced_code[MCOUNT_INSN_SIZE]; @@ -131,3 +133,69 @@ int __init ftrace_dyn_arch_init(void *data) return 0; } + +#ifdef CONFIG_FTRACE_SYSCALLS + +extern unsigned long __start_syscalls_metadata[]; +extern unsigned long __stop_syscalls_metadata[]; +extern unsigned long *sys_call_table; + +static struct syscall_metadata **syscalls_metadata; + +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((unsigned long) syscall, NULL, NULL, NULL, str); + + for ( ; start < stop; start++) { + if (start->name && !strcmp(start->name, str)) + return start; + } + + return NULL; +} + +#define FTRACE_SYSCALL_MAX (NR_syscalls - 1) + +struct syscall_metadata *syscall_nr_to_meta(int nr) +{ + if (!syscalls_metadata || nr >= FTRACE_SYSCALL_MAX || nr < 0) + return NULL; + + return syscalls_metadata[nr]; +} + +void arch_init_ftrace_syscalls(void) +{ + int i; + struct syscall_metadata *meta; + unsigned long **psys_syscall_table = &sys_call_table; + static atomic_t refs; + + if (atomic_inc_return(&refs) != 1) + goto end; + + syscalls_metadata = kzalloc(sizeof(*syscalls_metadata) * + FTRACE_SYSCALL_MAX, GFP_KERNEL); + if (!syscalls_metadata) { + WARN_ON(1); + return; + } + + for (i = 0; i < FTRACE_SYSCALL_MAX; i++) { + meta = find_syscall_meta(psys_syscall_table[i]); + syscalls_metadata[i] = meta; + } + return; + + /* Paranoid: avoid overflow */ +end: + atomic_dec(&refs); +} +#endif /* CONFIG_FTRACE_SYSCALLS */ |