6574658b3b
Signed-off-by: Wenji Huang <wenji.huang@oracle.com> LKML-Reference: <1266997226-6833-1-git-send-email-wenji.huang@oracle.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
632 lines
15 KiB
C
632 lines
15 KiB
C
#include <trace/syscall.h>
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#include <trace/events/syscalls.h>
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#include <linux/kernel.h>
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#include <linux/ftrace.h>
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#include <linux/perf_event.h>
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#include <asm/syscall.h>
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#include "trace_output.h"
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#include "trace.h"
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static DEFINE_MUTEX(syscall_trace_lock);
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static int sys_refcount_enter;
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static int sys_refcount_exit;
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static DECLARE_BITMAP(enabled_enter_syscalls, NR_syscalls);
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static DECLARE_BITMAP(enabled_exit_syscalls, NR_syscalls);
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extern unsigned long __start_syscalls_metadata[];
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extern unsigned long __stop_syscalls_metadata[];
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static struct syscall_metadata **syscalls_metadata;
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static struct syscall_metadata *find_syscall_meta(unsigned long syscall)
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{
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struct syscall_metadata *start;
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struct syscall_metadata *stop;
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char str[KSYM_SYMBOL_LEN];
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start = (struct syscall_metadata *)__start_syscalls_metadata;
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stop = (struct syscall_metadata *)__stop_syscalls_metadata;
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kallsyms_lookup(syscall, NULL, NULL, NULL, str);
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for ( ; start < stop; start++) {
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/*
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* Only compare after the "sys" prefix. Archs that use
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* syscall wrappers may have syscalls symbols aliases prefixed
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* with "SyS" instead of "sys", leading to an unwanted
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* mismatch.
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*/
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if (start->name && !strcmp(start->name + 3, str + 3))
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return start;
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}
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return NULL;
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}
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static struct syscall_metadata *syscall_nr_to_meta(int nr)
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{
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if (!syscalls_metadata || nr >= NR_syscalls || nr < 0)
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return NULL;
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return syscalls_metadata[nr];
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}
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enum print_line_t
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print_syscall_enter(struct trace_iterator *iter, int flags)
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{
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struct trace_seq *s = &iter->seq;
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struct trace_entry *ent = iter->ent;
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struct syscall_trace_enter *trace;
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struct syscall_metadata *entry;
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int i, ret, syscall;
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trace = (typeof(trace))ent;
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syscall = trace->nr;
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entry = syscall_nr_to_meta(syscall);
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if (!entry)
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goto end;
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if (entry->enter_event->id != ent->type) {
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WARN_ON_ONCE(1);
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goto end;
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}
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ret = trace_seq_printf(s, "%s(", entry->name);
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if (!ret)
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return TRACE_TYPE_PARTIAL_LINE;
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for (i = 0; i < entry->nb_args; i++) {
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/* parameter types */
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if (trace_flags & TRACE_ITER_VERBOSE) {
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ret = trace_seq_printf(s, "%s ", entry->types[i]);
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if (!ret)
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return TRACE_TYPE_PARTIAL_LINE;
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}
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/* parameter values */
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ret = trace_seq_printf(s, "%s: %lx%s", entry->args[i],
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trace->args[i],
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i == entry->nb_args - 1 ? "" : ", ");
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if (!ret)
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return TRACE_TYPE_PARTIAL_LINE;
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}
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ret = trace_seq_putc(s, ')');
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if (!ret)
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return TRACE_TYPE_PARTIAL_LINE;
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end:
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ret = trace_seq_putc(s, '\n');
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if (!ret)
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return TRACE_TYPE_PARTIAL_LINE;
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return TRACE_TYPE_HANDLED;
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}
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enum print_line_t
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print_syscall_exit(struct trace_iterator *iter, int flags)
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{
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struct trace_seq *s = &iter->seq;
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struct trace_entry *ent = iter->ent;
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struct syscall_trace_exit *trace;
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int syscall;
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struct syscall_metadata *entry;
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int ret;
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trace = (typeof(trace))ent;
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syscall = trace->nr;
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entry = syscall_nr_to_meta(syscall);
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if (!entry) {
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trace_seq_printf(s, "\n");
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return TRACE_TYPE_HANDLED;
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}
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if (entry->exit_event->id != ent->type) {
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WARN_ON_ONCE(1);
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return TRACE_TYPE_UNHANDLED;
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}
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ret = trace_seq_printf(s, "%s -> 0x%lx\n", entry->name,
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trace->ret);
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if (!ret)
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return TRACE_TYPE_PARTIAL_LINE;
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return TRACE_TYPE_HANDLED;
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}
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extern char *__bad_type_size(void);
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#define SYSCALL_FIELD(type, name) \
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sizeof(type) != sizeof(trace.name) ? \
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__bad_type_size() : \
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#type, #name, offsetof(typeof(trace), name), \
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sizeof(trace.name), is_signed_type(type)
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static
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int __set_enter_print_fmt(struct syscall_metadata *entry, char *buf, int len)
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{
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int i;
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int pos = 0;
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/* When len=0, we just calculate the needed length */
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#define LEN_OR_ZERO (len ? len - pos : 0)
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pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
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for (i = 0; i < entry->nb_args; i++) {
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pos += snprintf(buf + pos, LEN_OR_ZERO, "%s: 0x%%0%zulx%s",
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entry->args[i], sizeof(unsigned long),
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i == entry->nb_args - 1 ? "" : ", ");
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}
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pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
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for (i = 0; i < entry->nb_args; i++) {
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pos += snprintf(buf + pos, LEN_OR_ZERO,
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", ((unsigned long)(REC->%s))", entry->args[i]);
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}
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#undef LEN_OR_ZERO
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/* return the length of print_fmt */
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return pos;
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}
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static int set_syscall_print_fmt(struct ftrace_event_call *call)
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{
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char *print_fmt;
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int len;
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struct syscall_metadata *entry = call->data;
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if (entry->enter_event != call) {
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call->print_fmt = "\"0x%lx\", REC->ret";
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return 0;
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}
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/* First: called with 0 length to calculate the needed length */
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len = __set_enter_print_fmt(entry, NULL, 0);
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print_fmt = kmalloc(len + 1, GFP_KERNEL);
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if (!print_fmt)
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return -ENOMEM;
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/* Second: actually write the @print_fmt */
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__set_enter_print_fmt(entry, print_fmt, len + 1);
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call->print_fmt = print_fmt;
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return 0;
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}
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static void free_syscall_print_fmt(struct ftrace_event_call *call)
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{
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struct syscall_metadata *entry = call->data;
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if (entry->enter_event == call)
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kfree(call->print_fmt);
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}
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int syscall_enter_define_fields(struct ftrace_event_call *call)
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{
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struct syscall_trace_enter trace;
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struct syscall_metadata *meta = call->data;
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int ret;
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int i;
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int offset = offsetof(typeof(trace), args);
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ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER);
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if (ret)
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return ret;
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for (i = 0; i < meta->nb_args; i++) {
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ret = trace_define_field(call, meta->types[i],
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meta->args[i], offset,
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sizeof(unsigned long), 0,
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FILTER_OTHER);
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offset += sizeof(unsigned long);
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}
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return ret;
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}
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int syscall_exit_define_fields(struct ftrace_event_call *call)
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{
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struct syscall_trace_exit trace;
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int ret;
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ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER);
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if (ret)
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return ret;
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ret = trace_define_field(call, SYSCALL_FIELD(long, ret),
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FILTER_OTHER);
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return ret;
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}
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void ftrace_syscall_enter(struct pt_regs *regs, long id)
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{
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struct syscall_trace_enter *entry;
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struct syscall_metadata *sys_data;
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struct ring_buffer_event *event;
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struct ring_buffer *buffer;
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int size;
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int syscall_nr;
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syscall_nr = syscall_get_nr(current, regs);
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if (syscall_nr < 0)
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return;
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if (!test_bit(syscall_nr, enabled_enter_syscalls))
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return;
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sys_data = syscall_nr_to_meta(syscall_nr);
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if (!sys_data)
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return;
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size = sizeof(*entry) + sizeof(unsigned long) * sys_data->nb_args;
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event = trace_current_buffer_lock_reserve(&buffer,
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sys_data->enter_event->id, size, 0, 0);
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if (!event)
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return;
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entry = ring_buffer_event_data(event);
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entry->nr = syscall_nr;
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syscall_get_arguments(current, regs, 0, sys_data->nb_args, entry->args);
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if (!filter_current_check_discard(buffer, sys_data->enter_event,
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entry, event))
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trace_current_buffer_unlock_commit(buffer, event, 0, 0);
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}
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void ftrace_syscall_exit(struct pt_regs *regs, long ret)
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{
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struct syscall_trace_exit *entry;
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struct syscall_metadata *sys_data;
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struct ring_buffer_event *event;
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struct ring_buffer *buffer;
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int syscall_nr;
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syscall_nr = syscall_get_nr(current, regs);
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if (syscall_nr < 0)
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return;
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if (!test_bit(syscall_nr, enabled_exit_syscalls))
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return;
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sys_data = syscall_nr_to_meta(syscall_nr);
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if (!sys_data)
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return;
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event = trace_current_buffer_lock_reserve(&buffer,
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sys_data->exit_event->id, sizeof(*entry), 0, 0);
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if (!event)
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return;
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entry = ring_buffer_event_data(event);
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entry->nr = syscall_nr;
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entry->ret = syscall_get_return_value(current, regs);
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if (!filter_current_check_discard(buffer, sys_data->exit_event,
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entry, event))
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trace_current_buffer_unlock_commit(buffer, event, 0, 0);
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}
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int reg_event_syscall_enter(struct ftrace_event_call *call)
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{
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int ret = 0;
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int num;
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num = ((struct syscall_metadata *)call->data)->syscall_nr;
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if (num < 0 || num >= NR_syscalls)
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return -ENOSYS;
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mutex_lock(&syscall_trace_lock);
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if (!sys_refcount_enter)
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ret = register_trace_sys_enter(ftrace_syscall_enter);
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if (!ret) {
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set_bit(num, enabled_enter_syscalls);
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sys_refcount_enter++;
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}
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mutex_unlock(&syscall_trace_lock);
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return ret;
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}
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void unreg_event_syscall_enter(struct ftrace_event_call *call)
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{
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int num;
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num = ((struct syscall_metadata *)call->data)->syscall_nr;
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if (num < 0 || num >= NR_syscalls)
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return;
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mutex_lock(&syscall_trace_lock);
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sys_refcount_enter--;
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clear_bit(num, enabled_enter_syscalls);
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if (!sys_refcount_enter)
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unregister_trace_sys_enter(ftrace_syscall_enter);
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mutex_unlock(&syscall_trace_lock);
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}
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int reg_event_syscall_exit(struct ftrace_event_call *call)
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{
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int ret = 0;
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int num;
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num = ((struct syscall_metadata *)call->data)->syscall_nr;
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if (num < 0 || num >= NR_syscalls)
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return -ENOSYS;
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mutex_lock(&syscall_trace_lock);
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if (!sys_refcount_exit)
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ret = register_trace_sys_exit(ftrace_syscall_exit);
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if (!ret) {
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set_bit(num, enabled_exit_syscalls);
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sys_refcount_exit++;
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}
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mutex_unlock(&syscall_trace_lock);
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return ret;
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}
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void unreg_event_syscall_exit(struct ftrace_event_call *call)
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{
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int num;
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num = ((struct syscall_metadata *)call->data)->syscall_nr;
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if (num < 0 || num >= NR_syscalls)
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return;
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mutex_lock(&syscall_trace_lock);
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sys_refcount_exit--;
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clear_bit(num, enabled_exit_syscalls);
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if (!sys_refcount_exit)
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unregister_trace_sys_exit(ftrace_syscall_exit);
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mutex_unlock(&syscall_trace_lock);
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}
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int init_syscall_trace(struct ftrace_event_call *call)
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{
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int id;
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if (set_syscall_print_fmt(call) < 0)
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return -ENOMEM;
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id = trace_event_raw_init(call);
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if (id < 0) {
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free_syscall_print_fmt(call);
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return id;
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}
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return id;
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}
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int __init init_ftrace_syscalls(void)
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{
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struct syscall_metadata *meta;
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unsigned long addr;
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int i;
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syscalls_metadata = kzalloc(sizeof(*syscalls_metadata) *
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NR_syscalls, GFP_KERNEL);
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if (!syscalls_metadata) {
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WARN_ON(1);
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return -ENOMEM;
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}
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for (i = 0; i < NR_syscalls; i++) {
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addr = arch_syscall_addr(i);
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meta = find_syscall_meta(addr);
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if (!meta)
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continue;
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meta->syscall_nr = i;
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syscalls_metadata[i] = meta;
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}
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return 0;
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}
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core_initcall(init_ftrace_syscalls);
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#ifdef CONFIG_EVENT_PROFILE
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static DECLARE_BITMAP(enabled_prof_enter_syscalls, NR_syscalls);
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static DECLARE_BITMAP(enabled_prof_exit_syscalls, NR_syscalls);
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static int sys_prof_refcount_enter;
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static int sys_prof_refcount_exit;
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static void prof_syscall_enter(struct pt_regs *regs, long id)
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{
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struct syscall_metadata *sys_data;
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struct syscall_trace_enter *rec;
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unsigned long flags;
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char *trace_buf;
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char *raw_data;
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int syscall_nr;
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int rctx;
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int size;
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int cpu;
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syscall_nr = syscall_get_nr(current, regs);
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if (!test_bit(syscall_nr, enabled_prof_enter_syscalls))
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return;
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sys_data = syscall_nr_to_meta(syscall_nr);
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if (!sys_data)
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return;
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/* get the size after alignment with the u32 buffer size field */
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size = sizeof(unsigned long) * sys_data->nb_args + sizeof(*rec);
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size = ALIGN(size + sizeof(u32), sizeof(u64));
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size -= sizeof(u32);
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if (WARN_ONCE(size > FTRACE_MAX_PROFILE_SIZE,
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"profile buffer not large enough"))
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return;
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/* Protect the per cpu buffer, begin the rcu read side */
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local_irq_save(flags);
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rctx = perf_swevent_get_recursion_context();
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if (rctx < 0)
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goto end_recursion;
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cpu = smp_processor_id();
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trace_buf = rcu_dereference(perf_trace_buf);
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if (!trace_buf)
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goto end;
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raw_data = per_cpu_ptr(trace_buf, cpu);
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/* zero the dead bytes from align to not leak stack to user */
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*(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
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rec = (struct syscall_trace_enter *) raw_data;
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tracing_generic_entry_update(&rec->ent, 0, 0);
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rec->ent.type = sys_data->enter_event->id;
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rec->nr = syscall_nr;
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syscall_get_arguments(current, regs, 0, sys_data->nb_args,
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(unsigned long *)&rec->args);
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perf_tp_event(sys_data->enter_event->id, 0, 1, rec, size);
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end:
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perf_swevent_put_recursion_context(rctx);
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end_recursion:
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local_irq_restore(flags);
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}
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int prof_sysenter_enable(struct ftrace_event_call *call)
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{
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int ret = 0;
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int num;
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num = ((struct syscall_metadata *)call->data)->syscall_nr;
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mutex_lock(&syscall_trace_lock);
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if (!sys_prof_refcount_enter)
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ret = register_trace_sys_enter(prof_syscall_enter);
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if (ret) {
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pr_info("event trace: Could not activate"
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"syscall entry trace point");
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} else {
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set_bit(num, enabled_prof_enter_syscalls);
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sys_prof_refcount_enter++;
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}
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mutex_unlock(&syscall_trace_lock);
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return ret;
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}
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void prof_sysenter_disable(struct ftrace_event_call *call)
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{
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int num;
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num = ((struct syscall_metadata *)call->data)->syscall_nr;
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mutex_lock(&syscall_trace_lock);
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sys_prof_refcount_enter--;
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clear_bit(num, enabled_prof_enter_syscalls);
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if (!sys_prof_refcount_enter)
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unregister_trace_sys_enter(prof_syscall_enter);
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mutex_unlock(&syscall_trace_lock);
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}
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static void prof_syscall_exit(struct pt_regs *regs, long ret)
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{
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struct syscall_metadata *sys_data;
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struct syscall_trace_exit *rec;
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unsigned long flags;
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int syscall_nr;
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char *trace_buf;
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char *raw_data;
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int rctx;
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int size;
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int cpu;
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syscall_nr = syscall_get_nr(current, regs);
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if (!test_bit(syscall_nr, enabled_prof_exit_syscalls))
|
|
return;
|
|
|
|
sys_data = syscall_nr_to_meta(syscall_nr);
|
|
if (!sys_data)
|
|
return;
|
|
|
|
/* 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);
|
|
|
|
rctx = perf_swevent_get_recursion_context();
|
|
if (rctx < 0)
|
|
goto end_recursion;
|
|
|
|
cpu = smp_processor_id();
|
|
|
|
trace_buf = rcu_dereference(perf_trace_buf);
|
|
|
|
if (!trace_buf)
|
|
goto end;
|
|
|
|
raw_data = per_cpu_ptr(trace_buf, 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;
|
|
|
|
tracing_generic_entry_update(&rec->ent, 0, 0);
|
|
rec->ent.type = sys_data->exit_event->id;
|
|
rec->nr = syscall_nr;
|
|
rec->ret = syscall_get_return_value(current, regs);
|
|
|
|
perf_tp_event(sys_data->exit_event->id, 0, 1, rec, size);
|
|
|
|
end:
|
|
perf_swevent_put_recursion_context(rctx);
|
|
end_recursion:
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
int prof_sysexit_enable(struct ftrace_event_call *call)
|
|
{
|
|
int ret = 0;
|
|
int num;
|
|
|
|
num = ((struct syscall_metadata *)call->data)->syscall_nr;
|
|
|
|
mutex_lock(&syscall_trace_lock);
|
|
if (!sys_prof_refcount_exit)
|
|
ret = register_trace_sys_exit(prof_syscall_exit);
|
|
if (ret) {
|
|
pr_info("event trace: Could not activate"
|
|
"syscall exit trace point");
|
|
} else {
|
|
set_bit(num, enabled_prof_exit_syscalls);
|
|
sys_prof_refcount_exit++;
|
|
}
|
|
mutex_unlock(&syscall_trace_lock);
|
|
return ret;
|
|
}
|
|
|
|
void prof_sysexit_disable(struct ftrace_event_call *call)
|
|
{
|
|
int num;
|
|
|
|
num = ((struct syscall_metadata *)call->data)->syscall_nr;
|
|
|
|
mutex_lock(&syscall_trace_lock);
|
|
sys_prof_refcount_exit--;
|
|
clear_bit(num, enabled_prof_exit_syscalls);
|
|
if (!sys_prof_refcount_exit)
|
|
unregister_trace_sys_exit(prof_syscall_exit);
|
|
mutex_unlock(&syscall_trace_lock);
|
|
}
|
|
|
|
#endif
|
|
|
|
|