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-rw-r--r--include/asm-generic/vmlinux.lds.h11
-rw-r--r--include/linux/ftrace.h14
-rw-r--r--include/linux/syscalls.h60
-rw-r--r--kernel/trace/trace.h17
-rw-r--r--kernel/trace/trace_syscalls.c146
5 files changed, 234 insertions, 14 deletions
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 0e0f39be6c8b..d3bc3c86df6a 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -77,6 +77,14 @@
#define TRACE_PRINTKS()
#endif
+#ifdef CONFIG_FTRACE_SYSCALLS
+#define TRACE_SYSCALLS() VMLINUX_SYMBOL(__start_syscalls_metadata) = .; \
+ *(__syscalls_metadata) \
+ VMLINUX_SYMBOL(__stop_syscalls_metadata) = .;
+#else
+#define TRACE_SYSCALLS()
+#endif
+
/* .data section */
#define DATA_DATA \
*(.data) \
@@ -99,7 +107,8 @@
LIKELY_PROFILE() \
BRANCH_PROFILE() \
TRACE_PRINTKS() \
- FTRACE_EVENTS()
+ FTRACE_EVENTS() \
+ TRACE_SYSCALLS()
#define RO_DATA(align) \
. = ALIGN((align)); \
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index c146c1021a29..6dc1c652447e 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -506,13 +506,21 @@ static inline void trace_hw_branch_oops(void) {}
/*
* A syscall entry in the ftrace syscalls array.
*
- * @syscall_nr: syscall number
+ * @name: name of the syscall
+ * @nb_args: number of parameters it takes
+ * @types: list of types as strings
+ * @args: list of args as strings (args[i] matches types[i])
*/
-struct syscall_trace_entry {
- int syscall_nr;
+struct syscall_metadata {
+ const char *name;
+ int nb_args;
+ const char **types;
+ const char **args;
};
#ifdef CONFIG_FTRACE_SYSCALLS
+extern void arch_init_ftrace_syscalls(void);
+extern struct syscall_metadata *syscall_nr_to_meta(int nr);
extern void start_ftrace_syscalls(void);
extern void stop_ftrace_syscalls(void);
extern void ftrace_syscall_enter(struct pt_regs *regs);
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index f9f900cfd066..0cff9bb80b02 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -65,6 +65,7 @@ struct old_linux_dirent;
#include <asm/signal.h>
#include <linux/quota.h>
#include <linux/key.h>
+#include <linux/ftrace.h>
#define __SC_DECL1(t1, a1) t1 a1
#define __SC_DECL2(t2, a2, ...) t2 a2, __SC_DECL1(__VA_ARGS__)
@@ -95,7 +96,46 @@ struct old_linux_dirent;
#define __SC_TEST5(t5, a5, ...) __SC_TEST(t5); __SC_TEST4(__VA_ARGS__)
#define __SC_TEST6(t6, a6, ...) __SC_TEST(t6); __SC_TEST5(__VA_ARGS__)
+#ifdef CONFIG_FTRACE_SYSCALLS
+#define __SC_STR_ADECL1(t, a) #a
+#define __SC_STR_ADECL2(t, a, ...) #a, __SC_STR_ADECL1(__VA_ARGS__)
+#define __SC_STR_ADECL3(t, a, ...) #a, __SC_STR_ADECL2(__VA_ARGS__)
+#define __SC_STR_ADECL4(t, a, ...) #a, __SC_STR_ADECL3(__VA_ARGS__)
+#define __SC_STR_ADECL5(t, a, ...) #a, __SC_STR_ADECL4(__VA_ARGS__)
+#define __SC_STR_ADECL6(t, a, ...) #a, __SC_STR_ADECL5(__VA_ARGS__)
+
+#define __SC_STR_TDECL1(t, a) #t
+#define __SC_STR_TDECL2(t, a, ...) #t, __SC_STR_TDECL1(__VA_ARGS__)
+#define __SC_STR_TDECL3(t, a, ...) #t, __SC_STR_TDECL2(__VA_ARGS__)
+#define __SC_STR_TDECL4(t, a, ...) #t, __SC_STR_TDECL3(__VA_ARGS__)
+#define __SC_STR_TDECL5(t, a, ...) #t, __SC_STR_TDECL4(__VA_ARGS__)
+#define __SC_STR_TDECL6(t, a, ...) #t, __SC_STR_TDECL5(__VA_ARGS__)
+
+#define SYSCALL_METADATA(sname, nb) \
+ static const struct syscall_metadata __used \
+ __attribute__((__aligned__(4))) \
+ __attribute__((section("__syscalls_metadata"))) \
+ __syscall_meta_##sname = { \
+ .name = "sys"#sname, \
+ .nb_args = nb, \
+ .types = types_##sname, \
+ .args = args_##sname, \
+ }
+
+#define SYSCALL_DEFINE0(sname) \
+ static const struct syscall_metadata __used \
+ __attribute__((__aligned__(4))) \
+ __attribute__((section("__syscalls_metadata"))) \
+ __syscall_meta_##sname = { \
+ .name = "sys_"#sname, \
+ .nb_args = 0, \
+ }; \
+ asmlinkage long sys_##sname(void)
+
+#else
#define SYSCALL_DEFINE0(name) asmlinkage long sys_##name(void)
+#endif
+
#define SYSCALL_DEFINE1(name, ...) SYSCALL_DEFINEx(1, _##name, __VA_ARGS__)
#define SYSCALL_DEFINE2(name, ...) SYSCALL_DEFINEx(2, _##name, __VA_ARGS__)
#define SYSCALL_DEFINE3(name, ...) SYSCALL_DEFINEx(3, _##name, __VA_ARGS__)
@@ -117,10 +157,26 @@ struct old_linux_dirent;
#endif
#endif
+#ifdef CONFIG_FTRACE_SYSCALLS
+#define SYSCALL_DEFINEx(x, sname, ...) \
+ static const char *types_##sname[] = { \
+ __SC_STR_TDECL##x(__VA_ARGS__) \
+ }; \
+ static const char *args_##sname[] = { \
+ __SC_STR_ADECL##x(__VA_ARGS__) \
+ }; \
+ SYSCALL_METADATA(sname, x); \
+ __SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
+#else
+#define SYSCALL_DEFINEx(x, sname, ...) \
+ __SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
+#endif
+
#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
#define SYSCALL_DEFINE(name) static inline long SYSC_##name
-#define SYSCALL_DEFINEx(x, name, ...) \
+
+#define __SYSCALL_DEFINEx(x, name, ...) \
asmlinkage long sys##name(__SC_DECL##x(__VA_ARGS__)); \
static inline long SYSC##name(__SC_DECL##x(__VA_ARGS__)); \
asmlinkage long SyS##name(__SC_LONG##x(__VA_ARGS__)) \
@@ -134,7 +190,7 @@ struct old_linux_dirent;
#else /* CONFIG_HAVE_SYSCALL_WRAPPERS */
#define SYSCALL_DEFINE(name) asmlinkage long sys_##name
-#define SYSCALL_DEFINEx(x, name, ...) \
+#define __SYSCALL_DEFINEx(x, name, ...) \
asmlinkage long sys##name(__SC_DECL##x(__VA_ARGS__))
#endif /* CONFIG_HAVE_SYSCALL_WRAPPERS */
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 3d49daae47dc..d80ca0d464d9 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -194,6 +194,19 @@ struct kmemtrace_free_entry {
const void *ptr;
};
+struct syscall_trace_enter {
+ struct trace_entry ent;
+ int nr;
+ unsigned long args[];
+};
+
+struct syscall_trace_exit {
+ struct trace_entry ent;
+ int nr;
+ unsigned long ret;
+};
+
+
/*
* trace_flag_type is an enumeration that holds different
* states when a trace occurs. These are:
@@ -306,6 +319,10 @@ extern void __ftrace_bad_type(void);
TRACE_KMEM_ALLOC); \
IF_ASSIGN(var, ent, struct kmemtrace_free_entry, \
TRACE_KMEM_FREE); \
+ IF_ASSIGN(var, ent, struct syscall_trace_enter, \
+ TRACE_SYSCALL_ENTER); \
+ IF_ASSIGN(var, ent, struct syscall_trace_exit, \
+ TRACE_SYSCALL_EXIT); \
__ftrace_bad_type(); \
} while (0)
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 66cf97449af3..c72e599230ff 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -1,6 +1,5 @@
-#include <linux/ftrace.h>
#include <linux/kernel.h>
-
+#include <linux/ftrace.h>
#include <asm/syscall.h>
#include "trace_output.h"
@@ -8,6 +7,90 @@
static atomic_t refcount;
+/* Our two options */
+enum {
+ TRACE_SYSCALLS_OPT_TYPES = 0x1,
+};
+
+static struct tracer_opt syscalls_opts[] = {
+ { TRACER_OPT(syscall_arg_type, TRACE_SYSCALLS_OPT_TYPES) },
+ { }
+};
+
+static struct tracer_flags syscalls_flags = {
+ .val = 0, /* By default: no args types */
+ .opts = syscalls_opts
+};
+
+enum print_line_t
+print_syscall_enter(struct trace_iterator *iter, int flags)
+{
+ struct trace_seq *s = &iter->seq;
+ struct trace_entry *ent = iter->ent;
+ struct syscall_trace_enter *trace;
+ struct syscall_metadata *entry;
+ int i, ret, syscall;
+
+ trace_assign_type(trace, ent);
+
+ syscall = trace->nr;
+
+ entry = syscall_nr_to_meta(syscall);
+ if (!entry)
+ goto end;
+
+ ret = trace_seq_printf(s, "%s(", entry->name);
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+
+ for (i = 0; i < entry->nb_args; i++) {
+ /* parameter types */
+ if (syscalls_flags.val & TRACE_SYSCALLS_OPT_TYPES) {
+ ret = trace_seq_printf(s, "%s ", entry->types[i]);
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+ }
+ /* parameter values */
+ ret = trace_seq_printf(s, "%s: %lx%s ", entry->args[i],
+ trace->args[i],
+ i == entry->nb_args - 1 ? ")" : ",");
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+ }
+
+end:
+ trace_seq_printf(s, "\n");
+ return TRACE_TYPE_HANDLED;
+}
+
+enum print_line_t
+print_syscall_exit(struct trace_iterator *iter, int flags)
+{
+ struct trace_seq *s = &iter->seq;
+ struct trace_entry *ent = iter->ent;
+ struct syscall_trace_exit *trace;
+ int syscall;
+ struct syscall_metadata *entry;
+ int ret;
+
+ trace_assign_type(trace, ent);
+
+ syscall = trace->nr;
+
+ entry = syscall_nr_to_meta(syscall);
+ if (!entry) {
+ trace_seq_printf(s, "\n");
+ return TRACE_TYPE_HANDLED;
+ }
+
+ ret = trace_seq_printf(s, "%s -> 0x%lx\n", entry->name,
+ trace->ret);
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+
+ return TRACE_TYPE_HANDLED;
+}
+
void start_ftrace_syscalls(void)
{
unsigned long flags;
@@ -16,6 +99,7 @@ void start_ftrace_syscalls(void)
if (atomic_inc_return(&refcount) != 1)
goto out;
+ arch_init_ftrace_syscalls();
read_lock_irqsave(&tasklist_lock, flags);
do_each_thread(g, t) {
@@ -48,20 +132,63 @@ out:
void ftrace_syscall_enter(struct pt_regs *regs)
{
+ struct syscall_trace_enter *entry;
+ struct syscall_metadata *sys_data;
+ struct ring_buffer_event *event;
+ int size;
int syscall_nr;
+ int cpu;
syscall_nr = syscall_get_nr(current, regs);
- trace_printk("syscall %d enter\n", syscall_nr);
+ cpu = raw_smp_processor_id();
+
+ sys_data = syscall_nr_to_meta(syscall_nr);
+ if (!sys_data)
+ return;
+
+ size = sizeof(*entry) + sizeof(unsigned long) * sys_data->nb_args;
+
+ event = trace_current_buffer_lock_reserve(TRACE_SYSCALL_ENTER, size,
+ 0, 0);
+ if (!event)
+ return;
+
+ entry = ring_buffer_event_data(event);
+ entry->nr = syscall_nr;
+ syscall_get_arguments(current, regs, 0, sys_data->nb_args, entry->args);
+
+ trace_current_buffer_unlock_commit(event, 0, 0);
+ trace_wake_up();
}
void ftrace_syscall_exit(struct pt_regs *regs)
{
+ struct syscall_trace_exit *entry;
+ struct syscall_metadata *sys_data;
+ struct ring_buffer_event *event;
int syscall_nr;
+ int cpu;
syscall_nr = syscall_get_nr(current, regs);
- trace_printk("syscall %d exit\n", syscall_nr);
+ cpu = raw_smp_processor_id();
+
+ sys_data = syscall_nr_to_meta(syscall_nr);
+ if (!sys_data)
+ return;
+
+ event = trace_current_buffer_lock_reserve(TRACE_SYSCALL_EXIT,
+ sizeof(*entry), 0, 0);
+ if (!event)
+ return;
+
+ entry = ring_buffer_event_data(event);
+ entry->nr = syscall_nr;
+ entry->ret = syscall_get_return_value(current, regs);
+
+ trace_current_buffer_unlock_commit(event, 0, 0);
+ trace_wake_up();
}
static int init_syscall_tracer(struct trace_array *tr)
@@ -77,17 +204,20 @@ static void reset_syscall_tracer(struct trace_array *tr)
}
static struct trace_event syscall_enter_event = {
- .type = TRACE_SYSCALL_ENTER,
+ .type = TRACE_SYSCALL_ENTER,
+ .trace = print_syscall_enter,
};
static struct trace_event syscall_exit_event = {
- .type = TRACE_SYSCALL_EXIT,
+ .type = TRACE_SYSCALL_EXIT,
+ .trace = print_syscall_exit,
};
static struct tracer syscall_tracer __read_mostly = {
- .name = "syscall",
+ .name = "syscall",
.init = init_syscall_tracer,
- .reset = reset_syscall_tracer
+ .reset = reset_syscall_tracer,
+ .flags = &syscalls_flags,
};
__init int register_ftrace_syscalls(void)
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.