Commit f58ba100 authored by Frederic Weisbecker's avatar Frederic Weisbecker Committed by Ingo Molnar

tracing/syscalls: support for syscalls tracing on x86

Extend x86 architecture syscall tracing support with syscall
metadata table details.

(The upcoming core syscall tracing modifications rely on this.)
Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1236955332-10133-3-git-send-email-fweisbec@gmail.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 1b3fa2ce
......@@ -28,6 +28,13 @@
#endif
/* FIXME: I don't want to stay hardcoded */
#ifdef CONFIG_X86_64
# define FTRACE_SYSCALL_MAX 296
#else
# define FTRACE_SYSCALL_MAX 333
#endif
#ifdef CONFIG_FUNCTION_TRACER
#define MCOUNT_ADDR ((long)(mcount))
#define MCOUNT_INSN_SIZE 5 /* sizeof mcount call */
......
......@@ -453,3 +453,66 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
}
}
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
#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;
}
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
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