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![Tom Zanussi](/assets/img/avatar_default.png)
The trace event filters are still tied to event calls rather than event files, which means you don't get what you'd expect when using filters in the multibuffer case: Before: # echo 'bytes_alloc > 8192' > /sys/kernel/debug/tracing/events/kmem/kmalloc/filter # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/filter bytes_alloc > 8192 # mkdir /sys/kernel/debug/tracing/instances/test1 # echo 'bytes_alloc > 2048' > /sys/kernel/debug/tracing/instances/test1/events/kmem/kmalloc/filter # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/filter bytes_alloc > 2048 # cat /sys/kernel/debug/tracing/instances/test1/events/kmem/kmalloc/filter bytes_alloc > 2048 Setting the filter in tracing/instances/test1/events shouldn't affect the same event in tracing/events as it does above. After: # echo 'bytes_alloc > 8192' > /sys/kernel/debug/tracing/events/kmem/kmalloc/filter # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/filter bytes_alloc > 8192 # mkdir /sys/kernel/debug/tracing/instances/test1 # echo 'bytes_alloc > 2048' > /sys/kernel/debug/tracing/instances/test1/events/kmem/kmalloc/filter # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/filter bytes_alloc > 8192 # cat /sys/kernel/debug/tracing/instances/test1/events/kmem/kmalloc/filter bytes_alloc > 2048 We'd like to just move the filter directly from ftrace_event_call to ftrace_event_file, but there are a couple cases that don't yet have multibuffer support and therefore have to continue using the current event_call-based filters. For those cases, a new USE_CALL_FILTER bit is added to the event_call flags, whose main purpose is to keep the old behavior for those cases until they can be updated with multibuffer support; at that point, the USE_CALL_FILTER flag (and the new associated call_filter_check_discard() function) can go away. The multibuffer support also made filter_current_check_discard() redundant, so this change removes that function as well and replaces it with filter_check_discard() (or call_filter_check_discard() as appropriate). Link: http://lkml.kernel.org/r/f16e9ce4270c62f46b2e966119225e1c3cca7e60.1382620672.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
1022 lines
23 KiB
C
1022 lines
23 KiB
C
/*
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* uprobes-based tracing events
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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* Copyright (C) IBM Corporation, 2010-2012
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* Author: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
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*/
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#include <linux/module.h>
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#include <linux/uaccess.h>
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#include <linux/uprobes.h>
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#include <linux/namei.h>
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#include <linux/string.h>
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#include "trace_probe.h"
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#define UPROBE_EVENT_SYSTEM "uprobes"
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struct uprobe_trace_entry_head {
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struct trace_entry ent;
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unsigned long vaddr[];
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};
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#define SIZEOF_TRACE_ENTRY(is_return) \
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(sizeof(struct uprobe_trace_entry_head) + \
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sizeof(unsigned long) * (is_return ? 2 : 1))
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#define DATAOF_TRACE_ENTRY(entry, is_return) \
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((void*)(entry) + SIZEOF_TRACE_ENTRY(is_return))
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struct trace_uprobe_filter {
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rwlock_t rwlock;
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int nr_systemwide;
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struct list_head perf_events;
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};
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/*
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* uprobe event core functions
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*/
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struct trace_uprobe {
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struct list_head list;
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struct ftrace_event_class class;
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struct ftrace_event_call call;
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struct trace_uprobe_filter filter;
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struct uprobe_consumer consumer;
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struct inode *inode;
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char *filename;
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unsigned long offset;
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unsigned long nhit;
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unsigned int flags; /* For TP_FLAG_* */
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ssize_t size; /* trace entry size */
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unsigned int nr_args;
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struct probe_arg args[];
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};
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#define SIZEOF_TRACE_UPROBE(n) \
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(offsetof(struct trace_uprobe, args) + \
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(sizeof(struct probe_arg) * (n)))
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static int register_uprobe_event(struct trace_uprobe *tu);
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static int unregister_uprobe_event(struct trace_uprobe *tu);
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static DEFINE_MUTEX(uprobe_lock);
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static LIST_HEAD(uprobe_list);
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static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs);
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static int uretprobe_dispatcher(struct uprobe_consumer *con,
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unsigned long func, struct pt_regs *regs);
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static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter)
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{
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rwlock_init(&filter->rwlock);
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filter->nr_systemwide = 0;
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INIT_LIST_HEAD(&filter->perf_events);
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}
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static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter)
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{
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return !filter->nr_systemwide && list_empty(&filter->perf_events);
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}
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static inline bool is_ret_probe(struct trace_uprobe *tu)
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{
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return tu->consumer.ret_handler != NULL;
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}
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/*
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* Allocate new trace_uprobe and initialize it (including uprobes).
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*/
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static struct trace_uprobe *
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alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret)
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{
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struct trace_uprobe *tu;
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if (!event || !is_good_name(event))
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return ERR_PTR(-EINVAL);
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if (!group || !is_good_name(group))
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return ERR_PTR(-EINVAL);
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tu = kzalloc(SIZEOF_TRACE_UPROBE(nargs), GFP_KERNEL);
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if (!tu)
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return ERR_PTR(-ENOMEM);
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tu->call.class = &tu->class;
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tu->call.name = kstrdup(event, GFP_KERNEL);
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if (!tu->call.name)
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goto error;
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tu->class.system = kstrdup(group, GFP_KERNEL);
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if (!tu->class.system)
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goto error;
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INIT_LIST_HEAD(&tu->list);
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tu->consumer.handler = uprobe_dispatcher;
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if (is_ret)
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tu->consumer.ret_handler = uretprobe_dispatcher;
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init_trace_uprobe_filter(&tu->filter);
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tu->call.flags |= TRACE_EVENT_FL_USE_CALL_FILTER;
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return tu;
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error:
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kfree(tu->call.name);
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kfree(tu);
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return ERR_PTR(-ENOMEM);
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}
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static void free_trace_uprobe(struct trace_uprobe *tu)
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{
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int i;
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for (i = 0; i < tu->nr_args; i++)
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traceprobe_free_probe_arg(&tu->args[i]);
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iput(tu->inode);
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kfree(tu->call.class->system);
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kfree(tu->call.name);
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kfree(tu->filename);
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kfree(tu);
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}
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static struct trace_uprobe *find_probe_event(const char *event, const char *group)
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{
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struct trace_uprobe *tu;
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list_for_each_entry(tu, &uprobe_list, list)
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if (strcmp(tu->call.name, event) == 0 &&
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strcmp(tu->call.class->system, group) == 0)
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return tu;
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return NULL;
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}
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/* Unregister a trace_uprobe and probe_event: call with locking uprobe_lock */
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static int unregister_trace_uprobe(struct trace_uprobe *tu)
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{
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int ret;
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ret = unregister_uprobe_event(tu);
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if (ret)
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return ret;
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list_del(&tu->list);
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free_trace_uprobe(tu);
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return 0;
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}
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/* Register a trace_uprobe and probe_event */
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static int register_trace_uprobe(struct trace_uprobe *tu)
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{
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struct trace_uprobe *old_tp;
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int ret;
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mutex_lock(&uprobe_lock);
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/* register as an event */
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old_tp = find_probe_event(tu->call.name, tu->call.class->system);
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if (old_tp) {
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/* delete old event */
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ret = unregister_trace_uprobe(old_tp);
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if (ret)
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goto end;
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}
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ret = register_uprobe_event(tu);
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if (ret) {
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pr_warning("Failed to register probe event(%d)\n", ret);
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goto end;
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}
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list_add_tail(&tu->list, &uprobe_list);
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end:
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mutex_unlock(&uprobe_lock);
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return ret;
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}
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/*
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* Argument syntax:
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* - Add uprobe: p|r[:[GRP/]EVENT] PATH:SYMBOL [FETCHARGS]
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*
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* - Remove uprobe: -:[GRP/]EVENT
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*/
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static int create_trace_uprobe(int argc, char **argv)
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{
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struct trace_uprobe *tu;
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struct inode *inode;
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char *arg, *event, *group, *filename;
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char buf[MAX_EVENT_NAME_LEN];
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struct path path;
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unsigned long offset;
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bool is_delete, is_return;
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int i, ret;
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inode = NULL;
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ret = 0;
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is_delete = false;
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is_return = false;
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event = NULL;
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group = NULL;
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/* argc must be >= 1 */
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if (argv[0][0] == '-')
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is_delete = true;
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else if (argv[0][0] == 'r')
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is_return = true;
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else if (argv[0][0] != 'p') {
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pr_info("Probe definition must be started with 'p', 'r' or '-'.\n");
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return -EINVAL;
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}
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if (argv[0][1] == ':') {
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event = &argv[0][2];
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arg = strchr(event, '/');
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if (arg) {
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group = event;
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event = arg + 1;
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event[-1] = '\0';
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if (strlen(group) == 0) {
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pr_info("Group name is not specified\n");
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return -EINVAL;
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}
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}
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if (strlen(event) == 0) {
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pr_info("Event name is not specified\n");
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return -EINVAL;
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}
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}
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if (!group)
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group = UPROBE_EVENT_SYSTEM;
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if (is_delete) {
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int ret;
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if (!event) {
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pr_info("Delete command needs an event name.\n");
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return -EINVAL;
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}
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mutex_lock(&uprobe_lock);
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tu = find_probe_event(event, group);
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if (!tu) {
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mutex_unlock(&uprobe_lock);
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pr_info("Event %s/%s doesn't exist.\n", group, event);
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return -ENOENT;
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}
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/* delete an event */
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ret = unregister_trace_uprobe(tu);
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mutex_unlock(&uprobe_lock);
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return ret;
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}
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if (argc < 2) {
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pr_info("Probe point is not specified.\n");
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return -EINVAL;
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}
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if (isdigit(argv[1][0])) {
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pr_info("probe point must be have a filename.\n");
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return -EINVAL;
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}
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arg = strchr(argv[1], ':');
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if (!arg) {
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ret = -EINVAL;
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goto fail_address_parse;
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}
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*arg++ = '\0';
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filename = argv[1];
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ret = kern_path(filename, LOOKUP_FOLLOW, &path);
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if (ret)
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goto fail_address_parse;
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inode = igrab(path.dentry->d_inode);
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path_put(&path);
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if (!inode || !S_ISREG(inode->i_mode)) {
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ret = -EINVAL;
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goto fail_address_parse;
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}
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ret = kstrtoul(arg, 0, &offset);
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if (ret)
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goto fail_address_parse;
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argc -= 2;
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argv += 2;
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/* setup a probe */
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if (!event) {
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char *tail;
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char *ptr;
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tail = kstrdup(kbasename(filename), GFP_KERNEL);
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if (!tail) {
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ret = -ENOMEM;
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goto fail_address_parse;
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}
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ptr = strpbrk(tail, ".-_");
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if (ptr)
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*ptr = '\0';
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snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset);
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event = buf;
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kfree(tail);
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}
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tu = alloc_trace_uprobe(group, event, argc, is_return);
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if (IS_ERR(tu)) {
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pr_info("Failed to allocate trace_uprobe.(%d)\n", (int)PTR_ERR(tu));
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ret = PTR_ERR(tu);
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goto fail_address_parse;
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}
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tu->offset = offset;
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tu->inode = inode;
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tu->filename = kstrdup(filename, GFP_KERNEL);
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if (!tu->filename) {
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pr_info("Failed to allocate filename.\n");
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ret = -ENOMEM;
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goto error;
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}
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/* parse arguments */
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ret = 0;
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for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
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/* Increment count for freeing args in error case */
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tu->nr_args++;
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/* Parse argument name */
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arg = strchr(argv[i], '=');
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if (arg) {
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*arg++ = '\0';
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tu->args[i].name = kstrdup(argv[i], GFP_KERNEL);
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} else {
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arg = argv[i];
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/* If argument name is omitted, set "argN" */
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snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1);
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tu->args[i].name = kstrdup(buf, GFP_KERNEL);
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}
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if (!tu->args[i].name) {
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pr_info("Failed to allocate argument[%d] name.\n", i);
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ret = -ENOMEM;
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goto error;
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}
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if (!is_good_name(tu->args[i].name)) {
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pr_info("Invalid argument[%d] name: %s\n", i, tu->args[i].name);
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ret = -EINVAL;
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goto error;
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}
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if (traceprobe_conflict_field_name(tu->args[i].name, tu->args, i)) {
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pr_info("Argument[%d] name '%s' conflicts with "
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"another field.\n", i, argv[i]);
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ret = -EINVAL;
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goto error;
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}
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/* Parse fetch argument */
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ret = traceprobe_parse_probe_arg(arg, &tu->size, &tu->args[i], false, false);
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if (ret) {
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pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
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goto error;
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}
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}
|
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ret = register_trace_uprobe(tu);
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if (ret)
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goto error;
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return 0;
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error:
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free_trace_uprobe(tu);
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return ret;
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fail_address_parse:
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if (inode)
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iput(inode);
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pr_info("Failed to parse address or file.\n");
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return ret;
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}
|
|
|
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static int cleanup_all_probes(void)
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{
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struct trace_uprobe *tu;
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int ret = 0;
|
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|
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mutex_lock(&uprobe_lock);
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while (!list_empty(&uprobe_list)) {
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tu = list_entry(uprobe_list.next, struct trace_uprobe, list);
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ret = unregister_trace_uprobe(tu);
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if (ret)
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break;
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}
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mutex_unlock(&uprobe_lock);
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return ret;
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}
|
|
|
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/* Probes listing interfaces */
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static void *probes_seq_start(struct seq_file *m, loff_t *pos)
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{
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mutex_lock(&uprobe_lock);
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return seq_list_start(&uprobe_list, *pos);
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}
|
|
|
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static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos)
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{
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return seq_list_next(v, &uprobe_list, pos);
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}
|
|
|
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static void probes_seq_stop(struct seq_file *m, void *v)
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{
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mutex_unlock(&uprobe_lock);
|
|
}
|
|
|
|
static int probes_seq_show(struct seq_file *m, void *v)
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|
{
|
|
struct trace_uprobe *tu = v;
|
|
char c = is_ret_probe(tu) ? 'r' : 'p';
|
|
int i;
|
|
|
|
seq_printf(m, "%c:%s/%s", c, tu->call.class->system, tu->call.name);
|
|
seq_printf(m, " %s:0x%p", tu->filename, (void *)tu->offset);
|
|
|
|
for (i = 0; i < tu->nr_args; i++)
|
|
seq_printf(m, " %s=%s", tu->args[i].name, tu->args[i].comm);
|
|
|
|
seq_printf(m, "\n");
|
|
return 0;
|
|
}
|
|
|
|
static const struct seq_operations probes_seq_op = {
|
|
.start = probes_seq_start,
|
|
.next = probes_seq_next,
|
|
.stop = probes_seq_stop,
|
|
.show = probes_seq_show
|
|
};
|
|
|
|
static int probes_open(struct inode *inode, struct file *file)
|
|
{
|
|
int ret;
|
|
|
|
if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
|
|
ret = cleanup_all_probes();
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
return seq_open(file, &probes_seq_op);
|
|
}
|
|
|
|
static ssize_t probes_write(struct file *file, const char __user *buffer,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
return traceprobe_probes_write(file, buffer, count, ppos, create_trace_uprobe);
|
|
}
|
|
|
|
static const struct file_operations uprobe_events_ops = {
|
|
.owner = THIS_MODULE,
|
|
.open = probes_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = seq_release,
|
|
.write = probes_write,
|
|
};
|
|
|
|
/* Probes profiling interfaces */
|
|
static int probes_profile_seq_show(struct seq_file *m, void *v)
|
|
{
|
|
struct trace_uprobe *tu = v;
|
|
|
|
seq_printf(m, " %s %-44s %15lu\n", tu->filename, tu->call.name, tu->nhit);
|
|
return 0;
|
|
}
|
|
|
|
static const struct seq_operations profile_seq_op = {
|
|
.start = probes_seq_start,
|
|
.next = probes_seq_next,
|
|
.stop = probes_seq_stop,
|
|
.show = probes_profile_seq_show
|
|
};
|
|
|
|
static int profile_open(struct inode *inode, struct file *file)
|
|
{
|
|
return seq_open(file, &profile_seq_op);
|
|
}
|
|
|
|
static const struct file_operations uprobe_profile_ops = {
|
|
.owner = THIS_MODULE,
|
|
.open = profile_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = seq_release,
|
|
};
|
|
|
|
static void uprobe_trace_print(struct trace_uprobe *tu,
|
|
unsigned long func, struct pt_regs *regs)
|
|
{
|
|
struct uprobe_trace_entry_head *entry;
|
|
struct ring_buffer_event *event;
|
|
struct ring_buffer *buffer;
|
|
void *data;
|
|
int size, i;
|
|
struct ftrace_event_call *call = &tu->call;
|
|
|
|
size = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
|
|
event = trace_current_buffer_lock_reserve(&buffer, call->event.type,
|
|
size + tu->size, 0, 0);
|
|
if (!event)
|
|
return;
|
|
|
|
entry = ring_buffer_event_data(event);
|
|
if (is_ret_probe(tu)) {
|
|
entry->vaddr[0] = func;
|
|
entry->vaddr[1] = instruction_pointer(regs);
|
|
data = DATAOF_TRACE_ENTRY(entry, true);
|
|
} else {
|
|
entry->vaddr[0] = instruction_pointer(regs);
|
|
data = DATAOF_TRACE_ENTRY(entry, false);
|
|
}
|
|
|
|
for (i = 0; i < tu->nr_args; i++)
|
|
call_fetch(&tu->args[i].fetch, regs, data + tu->args[i].offset);
|
|
|
|
if (!call_filter_check_discard(call, entry, buffer, event))
|
|
trace_buffer_unlock_commit(buffer, event, 0, 0);
|
|
}
|
|
|
|
/* uprobe handler */
|
|
static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs)
|
|
{
|
|
if (!is_ret_probe(tu))
|
|
uprobe_trace_print(tu, 0, regs);
|
|
return 0;
|
|
}
|
|
|
|
static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func,
|
|
struct pt_regs *regs)
|
|
{
|
|
uprobe_trace_print(tu, func, regs);
|
|
}
|
|
|
|
/* Event entry printers */
|
|
static enum print_line_t
|
|
print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event)
|
|
{
|
|
struct uprobe_trace_entry_head *entry;
|
|
struct trace_seq *s = &iter->seq;
|
|
struct trace_uprobe *tu;
|
|
u8 *data;
|
|
int i;
|
|
|
|
entry = (struct uprobe_trace_entry_head *)iter->ent;
|
|
tu = container_of(event, struct trace_uprobe, call.event);
|
|
|
|
if (is_ret_probe(tu)) {
|
|
if (!trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)", tu->call.name,
|
|
entry->vaddr[1], entry->vaddr[0]))
|
|
goto partial;
|
|
data = DATAOF_TRACE_ENTRY(entry, true);
|
|
} else {
|
|
if (!trace_seq_printf(s, "%s: (0x%lx)", tu->call.name,
|
|
entry->vaddr[0]))
|
|
goto partial;
|
|
data = DATAOF_TRACE_ENTRY(entry, false);
|
|
}
|
|
|
|
for (i = 0; i < tu->nr_args; i++) {
|
|
if (!tu->args[i].type->print(s, tu->args[i].name,
|
|
data + tu->args[i].offset, entry))
|
|
goto partial;
|
|
}
|
|
|
|
if (trace_seq_puts(s, "\n"))
|
|
return TRACE_TYPE_HANDLED;
|
|
|
|
partial:
|
|
return TRACE_TYPE_PARTIAL_LINE;
|
|
}
|
|
|
|
static inline bool is_trace_uprobe_enabled(struct trace_uprobe *tu)
|
|
{
|
|
return tu->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE);
|
|
}
|
|
|
|
typedef bool (*filter_func_t)(struct uprobe_consumer *self,
|
|
enum uprobe_filter_ctx ctx,
|
|
struct mm_struct *mm);
|
|
|
|
static int
|
|
probe_event_enable(struct trace_uprobe *tu, int flag, filter_func_t filter)
|
|
{
|
|
int ret = 0;
|
|
|
|
if (is_trace_uprobe_enabled(tu))
|
|
return -EINTR;
|
|
|
|
WARN_ON(!uprobe_filter_is_empty(&tu->filter));
|
|
|
|
tu->flags |= flag;
|
|
tu->consumer.filter = filter;
|
|
ret = uprobe_register(tu->inode, tu->offset, &tu->consumer);
|
|
if (ret)
|
|
tu->flags &= ~flag;
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void probe_event_disable(struct trace_uprobe *tu, int flag)
|
|
{
|
|
if (!is_trace_uprobe_enabled(tu))
|
|
return;
|
|
|
|
WARN_ON(!uprobe_filter_is_empty(&tu->filter));
|
|
|
|
uprobe_unregister(tu->inode, tu->offset, &tu->consumer);
|
|
tu->flags &= ~flag;
|
|
}
|
|
|
|
static int uprobe_event_define_fields(struct ftrace_event_call *event_call)
|
|
{
|
|
int ret, i, size;
|
|
struct uprobe_trace_entry_head field;
|
|
struct trace_uprobe *tu = event_call->data;
|
|
|
|
if (is_ret_probe(tu)) {
|
|
DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0);
|
|
DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0);
|
|
size = SIZEOF_TRACE_ENTRY(true);
|
|
} else {
|
|
DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0);
|
|
size = SIZEOF_TRACE_ENTRY(false);
|
|
}
|
|
/* Set argument names as fields */
|
|
for (i = 0; i < tu->nr_args; i++) {
|
|
ret = trace_define_field(event_call, tu->args[i].type->fmttype,
|
|
tu->args[i].name,
|
|
size + tu->args[i].offset,
|
|
tu->args[i].type->size,
|
|
tu->args[i].type->is_signed,
|
|
FILTER_OTHER);
|
|
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
#define LEN_OR_ZERO (len ? len - pos : 0)
|
|
static int __set_print_fmt(struct trace_uprobe *tu, char *buf, int len)
|
|
{
|
|
const char *fmt, *arg;
|
|
int i;
|
|
int pos = 0;
|
|
|
|
if (is_ret_probe(tu)) {
|
|
fmt = "(%lx <- %lx)";
|
|
arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP;
|
|
} else {
|
|
fmt = "(%lx)";
|
|
arg = "REC->" FIELD_STRING_IP;
|
|
}
|
|
|
|
/* When len=0, we just calculate the needed length */
|
|
|
|
pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt);
|
|
|
|
for (i = 0; i < tu->nr_args; i++) {
|
|
pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%s",
|
|
tu->args[i].name, tu->args[i].type->fmt);
|
|
}
|
|
|
|
pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg);
|
|
|
|
for (i = 0; i < tu->nr_args; i++) {
|
|
pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s",
|
|
tu->args[i].name);
|
|
}
|
|
|
|
return pos; /* return the length of print_fmt */
|
|
}
|
|
#undef LEN_OR_ZERO
|
|
|
|
static int set_print_fmt(struct trace_uprobe *tu)
|
|
{
|
|
char *print_fmt;
|
|
int len;
|
|
|
|
/* First: called with 0 length to calculate the needed length */
|
|
len = __set_print_fmt(tu, NULL, 0);
|
|
print_fmt = kmalloc(len + 1, GFP_KERNEL);
|
|
if (!print_fmt)
|
|
return -ENOMEM;
|
|
|
|
/* Second: actually write the @print_fmt */
|
|
__set_print_fmt(tu, print_fmt, len + 1);
|
|
tu->call.print_fmt = print_fmt;
|
|
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_PERF_EVENTS
|
|
static bool
|
|
__uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm)
|
|
{
|
|
struct perf_event *event;
|
|
|
|
if (filter->nr_systemwide)
|
|
return true;
|
|
|
|
list_for_each_entry(event, &filter->perf_events, hw.tp_list) {
|
|
if (event->hw.tp_target->mm == mm)
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
static inline bool
|
|
uprobe_filter_event(struct trace_uprobe *tu, struct perf_event *event)
|
|
{
|
|
return __uprobe_perf_filter(&tu->filter, event->hw.tp_target->mm);
|
|
}
|
|
|
|
static int uprobe_perf_open(struct trace_uprobe *tu, struct perf_event *event)
|
|
{
|
|
bool done;
|
|
|
|
write_lock(&tu->filter.rwlock);
|
|
if (event->hw.tp_target) {
|
|
/*
|
|
* event->parent != NULL means copy_process(), we can avoid
|
|
* uprobe_apply(). current->mm must be probed and we can rely
|
|
* on dup_mmap() which preserves the already installed bp's.
|
|
*
|
|
* attr.enable_on_exec means that exec/mmap will install the
|
|
* breakpoints we need.
|
|
*/
|
|
done = tu->filter.nr_systemwide ||
|
|
event->parent || event->attr.enable_on_exec ||
|
|
uprobe_filter_event(tu, event);
|
|
list_add(&event->hw.tp_list, &tu->filter.perf_events);
|
|
} else {
|
|
done = tu->filter.nr_systemwide;
|
|
tu->filter.nr_systemwide++;
|
|
}
|
|
write_unlock(&tu->filter.rwlock);
|
|
|
|
if (!done)
|
|
uprobe_apply(tu->inode, tu->offset, &tu->consumer, true);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int uprobe_perf_close(struct trace_uprobe *tu, struct perf_event *event)
|
|
{
|
|
bool done;
|
|
|
|
write_lock(&tu->filter.rwlock);
|
|
if (event->hw.tp_target) {
|
|
list_del(&event->hw.tp_list);
|
|
done = tu->filter.nr_systemwide ||
|
|
(event->hw.tp_target->flags & PF_EXITING) ||
|
|
uprobe_filter_event(tu, event);
|
|
} else {
|
|
tu->filter.nr_systemwide--;
|
|
done = tu->filter.nr_systemwide;
|
|
}
|
|
write_unlock(&tu->filter.rwlock);
|
|
|
|
if (!done)
|
|
uprobe_apply(tu->inode, tu->offset, &tu->consumer, false);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static bool uprobe_perf_filter(struct uprobe_consumer *uc,
|
|
enum uprobe_filter_ctx ctx, struct mm_struct *mm)
|
|
{
|
|
struct trace_uprobe *tu;
|
|
int ret;
|
|
|
|
tu = container_of(uc, struct trace_uprobe, consumer);
|
|
read_lock(&tu->filter.rwlock);
|
|
ret = __uprobe_perf_filter(&tu->filter, mm);
|
|
read_unlock(&tu->filter.rwlock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void uprobe_perf_print(struct trace_uprobe *tu,
|
|
unsigned long func, struct pt_regs *regs)
|
|
{
|
|
struct ftrace_event_call *call = &tu->call;
|
|
struct uprobe_trace_entry_head *entry;
|
|
struct hlist_head *head;
|
|
void *data;
|
|
int size, rctx, i;
|
|
|
|
size = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
|
|
size = ALIGN(size + tu->size + sizeof(u32), sizeof(u64)) - sizeof(u32);
|
|
|
|
preempt_disable();
|
|
head = this_cpu_ptr(call->perf_events);
|
|
if (hlist_empty(head))
|
|
goto out;
|
|
|
|
entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx);
|
|
if (!entry)
|
|
goto out;
|
|
|
|
if (is_ret_probe(tu)) {
|
|
entry->vaddr[0] = func;
|
|
entry->vaddr[1] = instruction_pointer(regs);
|
|
data = DATAOF_TRACE_ENTRY(entry, true);
|
|
} else {
|
|
entry->vaddr[0] = instruction_pointer(regs);
|
|
data = DATAOF_TRACE_ENTRY(entry, false);
|
|
}
|
|
|
|
for (i = 0; i < tu->nr_args; i++)
|
|
call_fetch(&tu->args[i].fetch, regs, data + tu->args[i].offset);
|
|
|
|
perf_trace_buf_submit(entry, size, rctx, 0, 1, regs, head, NULL);
|
|
out:
|
|
preempt_enable();
|
|
}
|
|
|
|
/* uprobe profile handler */
|
|
static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs)
|
|
{
|
|
if (!uprobe_perf_filter(&tu->consumer, 0, current->mm))
|
|
return UPROBE_HANDLER_REMOVE;
|
|
|
|
if (!is_ret_probe(tu))
|
|
uprobe_perf_print(tu, 0, regs);
|
|
return 0;
|
|
}
|
|
|
|
static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func,
|
|
struct pt_regs *regs)
|
|
{
|
|
uprobe_perf_print(tu, func, regs);
|
|
}
|
|
#endif /* CONFIG_PERF_EVENTS */
|
|
|
|
static
|
|
int trace_uprobe_register(struct ftrace_event_call *event, enum trace_reg type, void *data)
|
|
{
|
|
struct trace_uprobe *tu = event->data;
|
|
|
|
switch (type) {
|
|
case TRACE_REG_REGISTER:
|
|
return probe_event_enable(tu, TP_FLAG_TRACE, NULL);
|
|
|
|
case TRACE_REG_UNREGISTER:
|
|
probe_event_disable(tu, TP_FLAG_TRACE);
|
|
return 0;
|
|
|
|
#ifdef CONFIG_PERF_EVENTS
|
|
case TRACE_REG_PERF_REGISTER:
|
|
return probe_event_enable(tu, TP_FLAG_PROFILE, uprobe_perf_filter);
|
|
|
|
case TRACE_REG_PERF_UNREGISTER:
|
|
probe_event_disable(tu, TP_FLAG_PROFILE);
|
|
return 0;
|
|
|
|
case TRACE_REG_PERF_OPEN:
|
|
return uprobe_perf_open(tu, data);
|
|
|
|
case TRACE_REG_PERF_CLOSE:
|
|
return uprobe_perf_close(tu, data);
|
|
|
|
#endif
|
|
default:
|
|
return 0;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
|
|
{
|
|
struct trace_uprobe *tu;
|
|
int ret = 0;
|
|
|
|
tu = container_of(con, struct trace_uprobe, consumer);
|
|
tu->nhit++;
|
|
|
|
if (tu->flags & TP_FLAG_TRACE)
|
|
ret |= uprobe_trace_func(tu, regs);
|
|
|
|
#ifdef CONFIG_PERF_EVENTS
|
|
if (tu->flags & TP_FLAG_PROFILE)
|
|
ret |= uprobe_perf_func(tu, regs);
|
|
#endif
|
|
return ret;
|
|
}
|
|
|
|
static int uretprobe_dispatcher(struct uprobe_consumer *con,
|
|
unsigned long func, struct pt_regs *regs)
|
|
{
|
|
struct trace_uprobe *tu;
|
|
|
|
tu = container_of(con, struct trace_uprobe, consumer);
|
|
|
|
if (tu->flags & TP_FLAG_TRACE)
|
|
uretprobe_trace_func(tu, func, regs);
|
|
|
|
#ifdef CONFIG_PERF_EVENTS
|
|
if (tu->flags & TP_FLAG_PROFILE)
|
|
uretprobe_perf_func(tu, func, regs);
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
static struct trace_event_functions uprobe_funcs = {
|
|
.trace = print_uprobe_event
|
|
};
|
|
|
|
static int register_uprobe_event(struct trace_uprobe *tu)
|
|
{
|
|
struct ftrace_event_call *call = &tu->call;
|
|
int ret;
|
|
|
|
/* Initialize ftrace_event_call */
|
|
INIT_LIST_HEAD(&call->class->fields);
|
|
call->event.funcs = &uprobe_funcs;
|
|
call->class->define_fields = uprobe_event_define_fields;
|
|
|
|
if (set_print_fmt(tu) < 0)
|
|
return -ENOMEM;
|
|
|
|
ret = register_ftrace_event(&call->event);
|
|
if (!ret) {
|
|
kfree(call->print_fmt);
|
|
return -ENODEV;
|
|
}
|
|
call->flags = 0;
|
|
call->class->reg = trace_uprobe_register;
|
|
call->data = tu;
|
|
ret = trace_add_event_call(call);
|
|
|
|
if (ret) {
|
|
pr_info("Failed to register uprobe event: %s\n", call->name);
|
|
kfree(call->print_fmt);
|
|
unregister_ftrace_event(&call->event);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int unregister_uprobe_event(struct trace_uprobe *tu)
|
|
{
|
|
int ret;
|
|
|
|
/* tu->event is unregistered in trace_remove_event_call() */
|
|
ret = trace_remove_event_call(&tu->call);
|
|
if (ret)
|
|
return ret;
|
|
kfree(tu->call.print_fmt);
|
|
tu->call.print_fmt = NULL;
|
|
return 0;
|
|
}
|
|
|
|
/* Make a trace interface for controling probe points */
|
|
static __init int init_uprobe_trace(void)
|
|
{
|
|
struct dentry *d_tracer;
|
|
|
|
d_tracer = tracing_init_dentry();
|
|
if (!d_tracer)
|
|
return 0;
|
|
|
|
trace_create_file("uprobe_events", 0644, d_tracer,
|
|
NULL, &uprobe_events_ops);
|
|
/* Profile interface */
|
|
trace_create_file("uprobe_profile", 0444, d_tracer,
|
|
NULL, &uprobe_profile_ops);
|
|
return 0;
|
|
}
|
|
|
|
fs_initcall(init_uprobe_trace);
|