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authorFrederic Weisbecker <fweisbec@gmail.com>2009-09-19 06:50:42 +0200
committerFrederic Weisbecker <fweisbec@gmail.com>2009-10-14 09:53:56 +0200
commitc44fc770845163f8d9e573f37f92a7b7a7ade14e (patch)
treedac4327b1454b73cefe7ffb2ef28cc67ea878f2b /kernel
parent4d8289494a37e19cd7f3beacea9c957ad3debad6 (diff)
tracing: Move syscalls metadata handling from arch to core
Most of the syscalls metadata processing is done from arch. But these operations are mostly generic accross archs. Especially now that we have a common variable name that expresses the number of syscalls supported by an arch: NR_syscalls, the only remaining bits that need to reside in arch is the syscall nr to addr translation. v2: Compare syscalls symbols only after the "sys" prefix so that we avoid spurious mismatches with archs that have syscalls wrappers, in which case syscalls symbols have "SyS" prefixed aliases. (Reported by: Heiko Carstens) Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Masami Hiramatsu <mhiramat@redhat.com> Cc: Jason Baron <jbaron@redhat.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/trace/trace_syscalls.c86
1 files changed, 86 insertions, 0 deletions
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 9fbce6c9d2e..8bda4bff228 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -14,6 +14,69 @@ static int sys_refcount_exit;
static DECLARE_BITMAP(enabled_enter_syscalls, NR_syscalls);
static DECLARE_BITMAP(enabled_exit_syscalls, NR_syscalls);
+extern unsigned long __start_syscalls_metadata[];
+extern unsigned long __stop_syscalls_metadata[];
+
+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(syscall, NULL, NULL, NULL, str);
+
+ for ( ; start < stop; start++) {
+ /*
+ * Only compare after the "sys" prefix. Archs that use
+ * syscall wrappers may have syscalls symbols aliases prefixed
+ * with "SyS" instead of "sys", leading to an unwanted
+ * mismatch.
+ */
+ if (start->name && !strcmp(start->name + 3, str + 3))
+ return start;
+ }
+ return NULL;
+}
+
+static struct syscall_metadata *syscall_nr_to_meta(int nr)
+{
+ if (!syscalls_metadata || nr >= NR_syscalls || nr < 0)
+ return NULL;
+
+ return syscalls_metadata[nr];
+}
+
+int syscall_name_to_nr(char *name)
+{
+ int i;
+
+ if (!syscalls_metadata)
+ return -1;
+
+ for (i = 0; i < NR_syscalls; i++) {
+ if (syscalls_metadata[i]) {
+ if (!strcmp(syscalls_metadata[i]->name, name))
+ return i;
+ }
+ }
+ return -1;
+}
+
+void set_syscall_enter_id(int num, int id)
+{
+ syscalls_metadata[num]->enter_id = id;
+}
+
+void set_syscall_exit_id(int num, int id)
+{
+ syscalls_metadata[num]->exit_id = id;
+}
+
enum print_line_t
print_syscall_enter(struct trace_iterator *iter, int flags)
{
@@ -375,6 +438,29 @@ struct trace_event event_syscall_exit = {
.trace = print_syscall_exit,
};
+int __init init_ftrace_syscalls(void)
+{
+ struct syscall_metadata *meta;
+ unsigned long addr;
+ int i;
+
+ syscalls_metadata = kzalloc(sizeof(*syscalls_metadata) *
+ NR_syscalls, GFP_KERNEL);
+ if (!syscalls_metadata) {
+ WARN_ON(1);
+ return -ENOMEM;
+ }
+
+ for (i = 0; i < NR_syscalls; i++) {
+ addr = arch_syscall_addr(i);
+ meta = find_syscall_meta(addr);
+ syscalls_metadata[i] = meta;
+ }
+
+ return 0;
+}
+core_initcall(init_ftrace_syscalls);
+
#ifdef CONFIG_EVENT_PROFILE
static DECLARE_BITMAP(enabled_prof_enter_syscalls, NR_syscalls);