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Diffstat (limited to 'kernel/trace/trace_syscalls.c')
-rw-r--r--kernel/trace/trace_syscalls.c207
1 files changed, 179 insertions, 28 deletions
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 8712ce3c6a0..d00d1a8f1f2 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -2,7 +2,7 @@
#include <trace/events/syscalls.h>
#include <linux/kernel.h>
#include <linux/ftrace.h>
-#include <linux/perf_counter.h>
+#include <linux/perf_event.h>
#include <asm/syscall.h>
#include "trace_output.h"
@@ -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)
{
@@ -103,7 +166,8 @@ extern char *__bad_type_size(void);
#define SYSCALL_FIELD(type, name) \
sizeof(type) != sizeof(trace.name) ? \
__bad_type_size() : \
- #type, #name, offsetof(typeof(trace), name), sizeof(trace.name)
+ #type, #name, offsetof(typeof(trace), name), \
+ sizeof(trace.name), is_signed_type(type)
int syscall_enter_format(struct ftrace_event_call *call, struct trace_seq *s)
{
@@ -120,7 +184,8 @@ int syscall_enter_format(struct ftrace_event_call *call, struct trace_seq *s)
if (!entry)
return 0;
- ret = trace_seq_printf(s, "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n",
+ ret = trace_seq_printf(s, "\tfield:%s %s;\toffset:%zu;\tsize:%zu;"
+ "\tsigned:%u;\n",
SYSCALL_FIELD(int, nr));
if (!ret)
return 0;
@@ -130,8 +195,10 @@ int syscall_enter_format(struct ftrace_event_call *call, struct trace_seq *s)
entry->args[i]);
if (!ret)
return 0;
- ret = trace_seq_printf(s, "\toffset:%d;\tsize:%zu;\n", offset,
- sizeof(unsigned long));
+ ret = trace_seq_printf(s, "\toffset:%d;\tsize:%zu;"
+ "\tsigned:%u;\n", offset,
+ sizeof(unsigned long),
+ is_signed_type(unsigned long));
if (!ret)
return 0;
offset += sizeof(unsigned long);
@@ -163,10 +230,12 @@ int syscall_exit_format(struct ftrace_event_call *call, struct trace_seq *s)
struct syscall_trace_exit trace;
ret = trace_seq_printf(s,
- "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
- "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n",
+ "\tfield:%s %s;\toffset:%zu;\tsize:%zu;"
+ "\tsigned:%u;\n"
+ "\tfield:%s %s;\toffset:%zu;\tsize:%zu;"
+ "\tsigned:%u;\n",
SYSCALL_FIELD(int, nr),
- SYSCALL_FIELD(unsigned long, ret));
+ SYSCALL_FIELD(long, ret));
if (!ret)
return 0;
@@ -212,7 +281,7 @@ int syscall_exit_define_fields(struct ftrace_event_call *call)
if (ret)
return ret;
- ret = trace_define_field(call, SYSCALL_FIELD(unsigned long, ret), 0,
+ ret = trace_define_field(call, SYSCALL_FIELD(long, ret),
FILTER_OTHER);
return ret;
@@ -375,6 +444,29 @@ 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);
@@ -384,10 +476,13 @@ static int sys_prof_refcount_exit;
static void prof_syscall_enter(struct pt_regs *regs, long id)
{
- struct syscall_trace_enter *rec;
struct syscall_metadata *sys_data;
+ struct syscall_trace_enter *rec;
+ unsigned long flags;
+ char *raw_data;
int syscall_nr;
int size;
+ int cpu;
syscall_nr = syscall_get_nr(current, regs);
if (!test_bit(syscall_nr, enabled_prof_enter_syscalls))
@@ -402,20 +497,38 @@ static void prof_syscall_enter(struct pt_regs *regs, long id)
size = ALIGN(size + sizeof(u32), sizeof(u64));
size -= sizeof(u32);
- do {
- char raw_data[size];
+ if (WARN_ONCE(size > FTRACE_MAX_PROFILE_SIZE,
+ "profile buffer not large enough"))
+ return;
+
+ /* Protect the per cpu buffer, begin the rcu read side */
+ local_irq_save(flags);
- /* zero the dead bytes from align to not leak stack to user */
- *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
+ cpu = smp_processor_id();
- rec = (struct syscall_trace_enter *) raw_data;
- tracing_generic_entry_update(&rec->ent, 0, 0);
- rec->ent.type = sys_data->enter_id;
- rec->nr = syscall_nr;
- syscall_get_arguments(current, regs, 0, sys_data->nb_args,
- (unsigned long *)&rec->args);
- perf_tpcounter_event(sys_data->enter_id, 0, 1, rec, size);
- } while(0);
+ if (in_nmi())
+ raw_data = rcu_dereference(trace_profile_buf_nmi);
+ else
+ raw_data = rcu_dereference(trace_profile_buf);
+
+ if (!raw_data)
+ goto end;
+
+ raw_data = per_cpu_ptr(raw_data, cpu);
+
+ /* zero the dead bytes from align to not leak stack to user */
+ *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
+
+ rec = (struct syscall_trace_enter *) raw_data;
+ tracing_generic_entry_update(&rec->ent, 0, 0);
+ rec->ent.type = sys_data->enter_id;
+ rec->nr = syscall_nr;
+ syscall_get_arguments(current, regs, 0, sys_data->nb_args,
+ (unsigned long *)&rec->args);
+ perf_tp_event(sys_data->enter_id, 0, 1, rec, size);
+
+end:
+ local_irq_restore(flags);
}
int reg_prof_syscall_enter(char *name)
@@ -460,8 +573,12 @@ void unreg_prof_syscall_enter(char *name)
static void prof_syscall_exit(struct pt_regs *regs, long ret)
{
struct syscall_metadata *sys_data;
- struct syscall_trace_exit rec;
+ struct syscall_trace_exit *rec;
+ unsigned long flags;
int syscall_nr;
+ char *raw_data;
+ int size;
+ int cpu;
syscall_nr = syscall_get_nr(current, regs);
if (!test_bit(syscall_nr, enabled_prof_exit_syscalls))
@@ -471,12 +588,46 @@ static void prof_syscall_exit(struct pt_regs *regs, long ret)
if (!sys_data)
return;
- tracing_generic_entry_update(&rec.ent, 0, 0);
- rec.ent.type = sys_data->exit_id;
- rec.nr = syscall_nr;
- rec.ret = syscall_get_return_value(current, regs);
+ /* We can probably do that at build time */
+ size = ALIGN(sizeof(*rec) + sizeof(u32), sizeof(u64));
+ size -= sizeof(u32);
+
+ /*
+ * Impossible, but be paranoid with the future
+ * How to put this check outside runtime?
+ */
+ if (WARN_ONCE(size > FTRACE_MAX_PROFILE_SIZE,
+ "exit event has grown above profile buffer size"))
+ return;
+
+ /* Protect the per cpu buffer, begin the rcu read side */
+ local_irq_save(flags);
+ cpu = smp_processor_id();
+
+ if (in_nmi())
+ raw_data = rcu_dereference(trace_profile_buf_nmi);
+ else
+ raw_data = rcu_dereference(trace_profile_buf);
+
+ if (!raw_data)
+ goto end;
+
+ raw_data = per_cpu_ptr(raw_data, cpu);
+
+ /* zero the dead bytes from align to not leak stack to user */
+ *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
+
+ rec = (struct syscall_trace_exit *)raw_data;
- perf_tpcounter_event(sys_data->exit_id, 0, 1, &rec, sizeof(rec));
+ tracing_generic_entry_update(&rec->ent, 0, 0);
+ rec->ent.type = sys_data->exit_id;
+ rec->nr = syscall_nr;
+ rec->ret = syscall_get_return_value(current, regs);
+
+ perf_tp_event(sys_data->exit_id, 0, 1, rec, size);
+
+end:
+ local_irq_restore(flags);
}
int reg_prof_syscall_exit(char *name)
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-24 08:40:30 +0000