mirror of https://gitee.com/openkylin/linux.git
1358 lines
31 KiB
C
1358 lines
31 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 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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struct trace_probe tp;
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};
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#define SIZEOF_TRACE_UPROBE(n) \
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(offsetof(struct trace_uprobe, tp.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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struct uprobe_dispatch_data {
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struct trace_uprobe *tu;
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unsigned long bp_addr;
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};
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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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#ifdef CONFIG_STACK_GROWSUP
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static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
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{
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return addr - (n * sizeof(long));
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}
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#else
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static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
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{
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return addr + (n * sizeof(long));
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}
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#endif
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static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n)
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{
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unsigned long ret;
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unsigned long addr = user_stack_pointer(regs);
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addr = adjust_stack_addr(addr, n);
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if (copy_from_user(&ret, (void __force __user *) addr, sizeof(ret)))
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return 0;
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return ret;
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}
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/*
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* Uprobes-specific fetch functions
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*/
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#define DEFINE_FETCH_stack(type) \
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static void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs, \
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void *offset, void *dest) \
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{ \
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*(type *)dest = (type)get_user_stack_nth(regs, \
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((unsigned long)offset)); \
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}
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DEFINE_BASIC_FETCH_FUNCS(stack)
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/* No string on the stack entry */
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#define fetch_stack_string NULL
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#define fetch_stack_string_size NULL
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#define DEFINE_FETCH_memory(type) \
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static void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs, \
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void *addr, void *dest) \
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{ \
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type retval; \
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void __user *vaddr = (void __force __user *) addr; \
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\
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if (copy_from_user(&retval, vaddr, sizeof(type))) \
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*(type *)dest = 0; \
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else \
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*(type *) dest = retval; \
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}
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DEFINE_BASIC_FETCH_FUNCS(memory)
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/*
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* Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
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* length and relative data location.
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*/
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static void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs,
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void *addr, void *dest)
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{
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long ret;
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u32 rloc = *(u32 *)dest;
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int maxlen = get_rloc_len(rloc);
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u8 *dst = get_rloc_data(dest);
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void __user *src = (void __force __user *) addr;
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if (!maxlen)
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return;
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ret = strncpy_from_user(dst, src, maxlen);
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if (ret < 0) { /* Failed to fetch string */
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((u8 *)get_rloc_data(dest))[0] = '\0';
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*(u32 *)dest = make_data_rloc(0, get_rloc_offs(rloc));
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} else {
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*(u32 *)dest = make_data_rloc(ret, get_rloc_offs(rloc));
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}
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}
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static void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs,
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void *addr, void *dest)
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{
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int len;
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void __user *vaddr = (void __force __user *) addr;
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len = strnlen_user(vaddr, MAX_STRING_SIZE);
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if (len == 0 || len > MAX_STRING_SIZE) /* Failed to check length */
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*(u32 *)dest = 0;
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else
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*(u32 *)dest = len;
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}
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static unsigned long translate_user_vaddr(void *file_offset)
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{
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unsigned long base_addr;
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struct uprobe_dispatch_data *udd;
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udd = (void *) current->utask->vaddr;
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base_addr = udd->bp_addr - udd->tu->offset;
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return base_addr + (unsigned long)file_offset;
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}
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#define DEFINE_FETCH_file_offset(type) \
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static void FETCH_FUNC_NAME(file_offset, type)(struct pt_regs *regs, \
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void *offset, void *dest)\
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{ \
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void *vaddr = (void *)translate_user_vaddr(offset); \
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\
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FETCH_FUNC_NAME(memory, type)(regs, vaddr, dest); \
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}
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DEFINE_BASIC_FETCH_FUNCS(file_offset)
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DEFINE_FETCH_file_offset(string)
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DEFINE_FETCH_file_offset(string_size)
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/* Fetch type information table */
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static const struct fetch_type uprobes_fetch_type_table[] = {
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/* Special types */
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[FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string,
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sizeof(u32), 1, "__data_loc char[]"),
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[FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32,
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string_size, sizeof(u32), 0, "u32"),
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/* Basic types */
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ASSIGN_FETCH_TYPE(u8, u8, 0),
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ASSIGN_FETCH_TYPE(u16, u16, 0),
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ASSIGN_FETCH_TYPE(u32, u32, 0),
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ASSIGN_FETCH_TYPE(u64, u64, 0),
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ASSIGN_FETCH_TYPE(s8, u8, 1),
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ASSIGN_FETCH_TYPE(s16, u16, 1),
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ASSIGN_FETCH_TYPE(s32, u32, 1),
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ASSIGN_FETCH_TYPE(s64, u64, 1),
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ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0),
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ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0),
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ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0),
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ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0),
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ASSIGN_FETCH_TYPE_END
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};
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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->tp.call.class = &tu->tp.class;
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tu->tp.call.name = kstrdup(event, GFP_KERNEL);
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if (!tu->tp.call.name)
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goto error;
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tu->tp.class.system = kstrdup(group, GFP_KERNEL);
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if (!tu->tp.class.system)
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goto error;
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INIT_LIST_HEAD(&tu->list);
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INIT_LIST_HEAD(&tu->tp.files);
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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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return tu;
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error:
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kfree(tu->tp.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->tp.nr_args; i++)
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traceprobe_free_probe_arg(&tu->tp.args[i]);
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iput(tu->inode);
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kfree(tu->tp.call.class->system);
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kfree(tu->tp.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(trace_event_name(&tu->tp.call), event) == 0 &&
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strcmp(tu->tp.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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|
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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_tu;
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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_tu = find_probe_event(trace_event_name(&tu->tp.call),
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tu->tp.call.class->system);
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if (old_tu) {
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/* delete old event */
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ret = unregister_trace_uprobe(old_tu);
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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_warn("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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/*
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* Argument syntax:
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* - Add uprobe: p|r[:[GRP/]EVENT] PATH:OFFSET [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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|
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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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|
|
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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;
|
|
|
|
if (is_delete) {
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|
int ret;
|
|
|
|
if (!event) {
|
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pr_info("Delete command needs an event name.\n");
|
|
return -EINVAL;
|
|
}
|
|
mutex_lock(&uprobe_lock);
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tu = find_probe_event(event, group);
|
|
|
|
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;
|
|
}
|
|
/* 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;
|
|
}
|
|
|
|
if (argc < 2) {
|
|
pr_info("Probe point is not specified.\n");
|
|
return -EINVAL;
|
|
}
|
|
arg = strchr(argv[1], ':');
|
|
if (!arg) {
|
|
ret = -EINVAL;
|
|
goto fail_address_parse;
|
|
}
|
|
|
|
*arg++ = '\0';
|
|
filename = argv[1];
|
|
ret = kern_path(filename, LOOKUP_FOLLOW, &path);
|
|
if (ret)
|
|
goto fail_address_parse;
|
|
|
|
inode = igrab(d_inode(path.dentry));
|
|
path_put(&path);
|
|
|
|
if (!inode || !S_ISREG(inode->i_mode)) {
|
|
ret = -EINVAL;
|
|
goto fail_address_parse;
|
|
}
|
|
|
|
ret = kstrtoul(arg, 0, &offset);
|
|
if (ret)
|
|
goto fail_address_parse;
|
|
|
|
argc -= 2;
|
|
argv += 2;
|
|
|
|
/* setup a probe */
|
|
if (!event) {
|
|
char *tail;
|
|
char *ptr;
|
|
|
|
tail = kstrdup(kbasename(filename), GFP_KERNEL);
|
|
if (!tail) {
|
|
ret = -ENOMEM;
|
|
goto fail_address_parse;
|
|
}
|
|
|
|
ptr = strpbrk(tail, ".-_");
|
|
if (ptr)
|
|
*ptr = '\0';
|
|
|
|
snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset);
|
|
event = buf;
|
|
kfree(tail);
|
|
}
|
|
|
|
tu = alloc_trace_uprobe(group, event, argc, is_return);
|
|
if (IS_ERR(tu)) {
|
|
pr_info("Failed to allocate trace_uprobe.(%d)\n", (int)PTR_ERR(tu));
|
|
ret = PTR_ERR(tu);
|
|
goto fail_address_parse;
|
|
}
|
|
tu->offset = offset;
|
|
tu->inode = inode;
|
|
tu->filename = kstrdup(filename, GFP_KERNEL);
|
|
|
|
if (!tu->filename) {
|
|
pr_info("Failed to allocate filename.\n");
|
|
ret = -ENOMEM;
|
|
goto error;
|
|
}
|
|
|
|
/* parse arguments */
|
|
ret = 0;
|
|
for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
|
|
struct probe_arg *parg = &tu->tp.args[i];
|
|
|
|
/* Increment count for freeing args in error case */
|
|
tu->tp.nr_args++;
|
|
|
|
/* Parse argument name */
|
|
arg = strchr(argv[i], '=');
|
|
if (arg) {
|
|
*arg++ = '\0';
|
|
parg->name = kstrdup(argv[i], GFP_KERNEL);
|
|
} else {
|
|
arg = argv[i];
|
|
/* If argument name is omitted, set "argN" */
|
|
snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1);
|
|
parg->name = kstrdup(buf, GFP_KERNEL);
|
|
}
|
|
|
|
if (!parg->name) {
|
|
pr_info("Failed to allocate argument[%d] name.\n", i);
|
|
ret = -ENOMEM;
|
|
goto error;
|
|
}
|
|
|
|
if (!is_good_name(parg->name)) {
|
|
pr_info("Invalid argument[%d] name: %s\n", i, parg->name);
|
|
ret = -EINVAL;
|
|
goto error;
|
|
}
|
|
|
|
if (traceprobe_conflict_field_name(parg->name, tu->tp.args, i)) {
|
|
pr_info("Argument[%d] name '%s' conflicts with "
|
|
"another field.\n", i, argv[i]);
|
|
ret = -EINVAL;
|
|
goto error;
|
|
}
|
|
|
|
/* Parse fetch argument */
|
|
ret = traceprobe_parse_probe_arg(arg, &tu->tp.size, parg,
|
|
is_return, false,
|
|
uprobes_fetch_type_table);
|
|
if (ret) {
|
|
pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
|
|
goto error;
|
|
}
|
|
}
|
|
|
|
ret = register_trace_uprobe(tu);
|
|
if (ret)
|
|
goto error;
|
|
return 0;
|
|
|
|
error:
|
|
free_trace_uprobe(tu);
|
|
return ret;
|
|
|
|
fail_address_parse:
|
|
iput(inode);
|
|
|
|
pr_info("Failed to parse address or file.\n");
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int cleanup_all_probes(void)
|
|
{
|
|
struct trace_uprobe *tu;
|
|
int ret = 0;
|
|
|
|
mutex_lock(&uprobe_lock);
|
|
while (!list_empty(&uprobe_list)) {
|
|
tu = list_entry(uprobe_list.next, struct trace_uprobe, list);
|
|
ret = unregister_trace_uprobe(tu);
|
|
if (ret)
|
|
break;
|
|
}
|
|
mutex_unlock(&uprobe_lock);
|
|
return ret;
|
|
}
|
|
|
|
/* Probes listing interfaces */
|
|
static void *probes_seq_start(struct seq_file *m, loff_t *pos)
|
|
{
|
|
mutex_lock(&uprobe_lock);
|
|
return seq_list_start(&uprobe_list, *pos);
|
|
}
|
|
|
|
static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos)
|
|
{
|
|
return seq_list_next(v, &uprobe_list, pos);
|
|
}
|
|
|
|
static void probes_seq_stop(struct seq_file *m, void *v)
|
|
{
|
|
mutex_unlock(&uprobe_lock);
|
|
}
|
|
|
|
static int probes_seq_show(struct seq_file *m, void *v)
|
|
{
|
|
struct trace_uprobe *tu = v;
|
|
char c = is_ret_probe(tu) ? 'r' : 'p';
|
|
int i;
|
|
|
|
seq_printf(m, "%c:%s/%s", c, tu->tp.call.class->system,
|
|
trace_event_name(&tu->tp.call));
|
|
seq_printf(m, " %s:", tu->filename);
|
|
|
|
/* Don't print "0x (null)" when offset is 0 */
|
|
if (tu->offset) {
|
|
seq_printf(m, "0x%p", (void *)tu->offset);
|
|
} else {
|
|
switch (sizeof(void *)) {
|
|
case 4:
|
|
seq_printf(m, "0x00000000");
|
|
break;
|
|
case 8:
|
|
default:
|
|
seq_printf(m, "0x0000000000000000");
|
|
break;
|
|
}
|
|
}
|
|
|
|
for (i = 0; i < tu->tp.nr_args; i++)
|
|
seq_printf(m, " %s=%s", tu->tp.args[i].name, tu->tp.args[i].comm);
|
|
|
|
seq_putc(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,
|
|
trace_event_name(&tu->tp.call), 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,
|
|
};
|
|
|
|
struct uprobe_cpu_buffer {
|
|
struct mutex mutex;
|
|
void *buf;
|
|
};
|
|
static struct uprobe_cpu_buffer __percpu *uprobe_cpu_buffer;
|
|
static int uprobe_buffer_refcnt;
|
|
|
|
static int uprobe_buffer_init(void)
|
|
{
|
|
int cpu, err_cpu;
|
|
|
|
uprobe_cpu_buffer = alloc_percpu(struct uprobe_cpu_buffer);
|
|
if (uprobe_cpu_buffer == NULL)
|
|
return -ENOMEM;
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
struct page *p = alloc_pages_node(cpu_to_node(cpu),
|
|
GFP_KERNEL, 0);
|
|
if (p == NULL) {
|
|
err_cpu = cpu;
|
|
goto err;
|
|
}
|
|
per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf = page_address(p);
|
|
mutex_init(&per_cpu_ptr(uprobe_cpu_buffer, cpu)->mutex);
|
|
}
|
|
|
|
return 0;
|
|
|
|
err:
|
|
for_each_possible_cpu(cpu) {
|
|
if (cpu == err_cpu)
|
|
break;
|
|
free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf);
|
|
}
|
|
|
|
free_percpu(uprobe_cpu_buffer);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
static int uprobe_buffer_enable(void)
|
|
{
|
|
int ret = 0;
|
|
|
|
BUG_ON(!mutex_is_locked(&event_mutex));
|
|
|
|
if (uprobe_buffer_refcnt++ == 0) {
|
|
ret = uprobe_buffer_init();
|
|
if (ret < 0)
|
|
uprobe_buffer_refcnt--;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void uprobe_buffer_disable(void)
|
|
{
|
|
int cpu;
|
|
|
|
BUG_ON(!mutex_is_locked(&event_mutex));
|
|
|
|
if (--uprobe_buffer_refcnt == 0) {
|
|
for_each_possible_cpu(cpu)
|
|
free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer,
|
|
cpu)->buf);
|
|
|
|
free_percpu(uprobe_cpu_buffer);
|
|
uprobe_cpu_buffer = NULL;
|
|
}
|
|
}
|
|
|
|
static struct uprobe_cpu_buffer *uprobe_buffer_get(void)
|
|
{
|
|
struct uprobe_cpu_buffer *ucb;
|
|
int cpu;
|
|
|
|
cpu = raw_smp_processor_id();
|
|
ucb = per_cpu_ptr(uprobe_cpu_buffer, cpu);
|
|
|
|
/*
|
|
* Use per-cpu buffers for fastest access, but we might migrate
|
|
* so the mutex makes sure we have sole access to it.
|
|
*/
|
|
mutex_lock(&ucb->mutex);
|
|
|
|
return ucb;
|
|
}
|
|
|
|
static void uprobe_buffer_put(struct uprobe_cpu_buffer *ucb)
|
|
{
|
|
mutex_unlock(&ucb->mutex);
|
|
}
|
|
|
|
static void __uprobe_trace_func(struct trace_uprobe *tu,
|
|
unsigned long func, struct pt_regs *regs,
|
|
struct uprobe_cpu_buffer *ucb, int dsize,
|
|
struct trace_event_file *trace_file)
|
|
{
|
|
struct uprobe_trace_entry_head *entry;
|
|
struct ring_buffer_event *event;
|
|
struct ring_buffer *buffer;
|
|
void *data;
|
|
int size, esize;
|
|
struct trace_event_call *call = &tu->tp.call;
|
|
|
|
WARN_ON(call != trace_file->event_call);
|
|
|
|
if (WARN_ON_ONCE(tu->tp.size + dsize > PAGE_SIZE))
|
|
return;
|
|
|
|
if (trace_trigger_soft_disabled(trace_file))
|
|
return;
|
|
|
|
esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
|
|
size = esize + tu->tp.size + dsize;
|
|
event = trace_event_buffer_lock_reserve(&buffer, trace_file,
|
|
call->event.type, 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);
|
|
}
|
|
|
|
memcpy(data, ucb->buf, tu->tp.size + dsize);
|
|
|
|
event_trigger_unlock_commit(trace_file, buffer, event, entry, 0, 0);
|
|
}
|
|
|
|
/* uprobe handler */
|
|
static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs,
|
|
struct uprobe_cpu_buffer *ucb, int dsize)
|
|
{
|
|
struct event_file_link *link;
|
|
|
|
if (is_ret_probe(tu))
|
|
return 0;
|
|
|
|
rcu_read_lock();
|
|
list_for_each_entry_rcu(link, &tu->tp.files, list)
|
|
__uprobe_trace_func(tu, 0, regs, ucb, dsize, link->file);
|
|
rcu_read_unlock();
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func,
|
|
struct pt_regs *regs,
|
|
struct uprobe_cpu_buffer *ucb, int dsize)
|
|
{
|
|
struct event_file_link *link;
|
|
|
|
rcu_read_lock();
|
|
list_for_each_entry_rcu(link, &tu->tp.files, list)
|
|
__uprobe_trace_func(tu, func, regs, ucb, dsize, link->file);
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
/* 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, tp.call.event);
|
|
|
|
if (is_ret_probe(tu)) {
|
|
trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)",
|
|
trace_event_name(&tu->tp.call),
|
|
entry->vaddr[1], entry->vaddr[0]);
|
|
data = DATAOF_TRACE_ENTRY(entry, true);
|
|
} else {
|
|
trace_seq_printf(s, "%s: (0x%lx)",
|
|
trace_event_name(&tu->tp.call),
|
|
entry->vaddr[0]);
|
|
data = DATAOF_TRACE_ENTRY(entry, false);
|
|
}
|
|
|
|
for (i = 0; i < tu->tp.nr_args; i++) {
|
|
struct probe_arg *parg = &tu->tp.args[i];
|
|
|
|
if (!parg->type->print(s, parg->name, data + parg->offset, entry))
|
|
goto out;
|
|
}
|
|
|
|
trace_seq_putc(s, '\n');
|
|
|
|
out:
|
|
return trace_handle_return(s);
|
|
}
|
|
|
|
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, struct trace_event_file *file,
|
|
filter_func_t filter)
|
|
{
|
|
bool enabled = trace_probe_is_enabled(&tu->tp);
|
|
struct event_file_link *link = NULL;
|
|
int ret;
|
|
|
|
if (file) {
|
|
if (tu->tp.flags & TP_FLAG_PROFILE)
|
|
return -EINTR;
|
|
|
|
link = kmalloc(sizeof(*link), GFP_KERNEL);
|
|
if (!link)
|
|
return -ENOMEM;
|
|
|
|
link->file = file;
|
|
list_add_tail_rcu(&link->list, &tu->tp.files);
|
|
|
|
tu->tp.flags |= TP_FLAG_TRACE;
|
|
} else {
|
|
if (tu->tp.flags & TP_FLAG_TRACE)
|
|
return -EINTR;
|
|
|
|
tu->tp.flags |= TP_FLAG_PROFILE;
|
|
}
|
|
|
|
WARN_ON(!uprobe_filter_is_empty(&tu->filter));
|
|
|
|
if (enabled)
|
|
return 0;
|
|
|
|
ret = uprobe_buffer_enable();
|
|
if (ret)
|
|
goto err_flags;
|
|
|
|
tu->consumer.filter = filter;
|
|
ret = uprobe_register(tu->inode, tu->offset, &tu->consumer);
|
|
if (ret)
|
|
goto err_buffer;
|
|
|
|
return 0;
|
|
|
|
err_buffer:
|
|
uprobe_buffer_disable();
|
|
|
|
err_flags:
|
|
if (file) {
|
|
list_del(&link->list);
|
|
kfree(link);
|
|
tu->tp.flags &= ~TP_FLAG_TRACE;
|
|
} else {
|
|
tu->tp.flags &= ~TP_FLAG_PROFILE;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static void
|
|
probe_event_disable(struct trace_uprobe *tu, struct trace_event_file *file)
|
|
{
|
|
if (!trace_probe_is_enabled(&tu->tp))
|
|
return;
|
|
|
|
if (file) {
|
|
struct event_file_link *link;
|
|
|
|
link = find_event_file_link(&tu->tp, file);
|
|
if (!link)
|
|
return;
|
|
|
|
list_del_rcu(&link->list);
|
|
/* synchronize with u{,ret}probe_trace_func */
|
|
synchronize_sched();
|
|
kfree(link);
|
|
|
|
if (!list_empty(&tu->tp.files))
|
|
return;
|
|
}
|
|
|
|
WARN_ON(!uprobe_filter_is_empty(&tu->filter));
|
|
|
|
uprobe_unregister(tu->inode, tu->offset, &tu->consumer);
|
|
tu->tp.flags &= file ? ~TP_FLAG_TRACE : ~TP_FLAG_PROFILE;
|
|
|
|
uprobe_buffer_disable();
|
|
}
|
|
|
|
static int uprobe_event_define_fields(struct trace_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->tp.nr_args; i++) {
|
|
struct probe_arg *parg = &tu->tp.args[i];
|
|
|
|
ret = trace_define_field(event_call, parg->type->fmttype,
|
|
parg->name, size + parg->offset,
|
|
parg->type->size, parg->type->is_signed,
|
|
FILTER_OTHER);
|
|
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
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.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.target->mm);
|
|
}
|
|
|
|
static int uprobe_perf_close(struct trace_uprobe *tu, struct perf_event *event)
|
|
{
|
|
bool done;
|
|
|
|
write_lock(&tu->filter.rwlock);
|
|
if (event->hw.target) {
|
|
list_del(&event->hw.tp_list);
|
|
done = tu->filter.nr_systemwide ||
|
|
(event->hw.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)
|
|
return uprobe_apply(tu->inode, tu->offset, &tu->consumer, false);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int uprobe_perf_open(struct trace_uprobe *tu, struct perf_event *event)
|
|
{
|
|
bool done;
|
|
int err;
|
|
|
|
write_lock(&tu->filter.rwlock);
|
|
if (event->hw.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);
|
|
|
|
err = 0;
|
|
if (!done) {
|
|
err = uprobe_apply(tu->inode, tu->offset, &tu->consumer, true);
|
|
if (err)
|
|
uprobe_perf_close(tu, event);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
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_func(struct trace_uprobe *tu,
|
|
unsigned long func, struct pt_regs *regs,
|
|
struct uprobe_cpu_buffer *ucb, int dsize)
|
|
{
|
|
struct trace_event_call *call = &tu->tp.call;
|
|
struct uprobe_trace_entry_head *entry;
|
|
struct bpf_prog *prog = call->prog;
|
|
struct hlist_head *head;
|
|
void *data;
|
|
int size, esize;
|
|
int rctx;
|
|
|
|
if (prog && !trace_call_bpf(prog, regs))
|
|
return;
|
|
|
|
esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
|
|
|
|
size = esize + tu->tp.size + dsize;
|
|
size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32);
|
|
if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough"))
|
|
return;
|
|
|
|
preempt_disable();
|
|
head = this_cpu_ptr(call->perf_events);
|
|
if (hlist_empty(head))
|
|
goto out;
|
|
|
|
entry = perf_trace_buf_alloc(size, NULL, &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);
|
|
}
|
|
|
|
memcpy(data, ucb->buf, tu->tp.size + dsize);
|
|
|
|
if (size - esize > tu->tp.size + dsize) {
|
|
int len = tu->tp.size + dsize;
|
|
|
|
memset(data + len, 0, size - esize - len);
|
|
}
|
|
|
|
perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
|
|
head, NULL);
|
|
out:
|
|
preempt_enable();
|
|
}
|
|
|
|
/* uprobe profile handler */
|
|
static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs,
|
|
struct uprobe_cpu_buffer *ucb, int dsize)
|
|
{
|
|
if (!uprobe_perf_filter(&tu->consumer, 0, current->mm))
|
|
return UPROBE_HANDLER_REMOVE;
|
|
|
|
if (!is_ret_probe(tu))
|
|
__uprobe_perf_func(tu, 0, regs, ucb, dsize);
|
|
return 0;
|
|
}
|
|
|
|
static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func,
|
|
struct pt_regs *regs,
|
|
struct uprobe_cpu_buffer *ucb, int dsize)
|
|
{
|
|
__uprobe_perf_func(tu, func, regs, ucb, dsize);
|
|
}
|
|
#endif /* CONFIG_PERF_EVENTS */
|
|
|
|
static int
|
|
trace_uprobe_register(struct trace_event_call *event, enum trace_reg type,
|
|
void *data)
|
|
{
|
|
struct trace_uprobe *tu = event->data;
|
|
struct trace_event_file *file = data;
|
|
|
|
switch (type) {
|
|
case TRACE_REG_REGISTER:
|
|
return probe_event_enable(tu, file, NULL);
|
|
|
|
case TRACE_REG_UNREGISTER:
|
|
probe_event_disable(tu, file);
|
|
return 0;
|
|
|
|
#ifdef CONFIG_PERF_EVENTS
|
|
case TRACE_REG_PERF_REGISTER:
|
|
return probe_event_enable(tu, NULL, uprobe_perf_filter);
|
|
|
|
case TRACE_REG_PERF_UNREGISTER:
|
|
probe_event_disable(tu, NULL);
|
|
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;
|
|
struct uprobe_dispatch_data udd;
|
|
struct uprobe_cpu_buffer *ucb;
|
|
int dsize, esize;
|
|
int ret = 0;
|
|
|
|
|
|
tu = container_of(con, struct trace_uprobe, consumer);
|
|
tu->nhit++;
|
|
|
|
udd.tu = tu;
|
|
udd.bp_addr = instruction_pointer(regs);
|
|
|
|
current->utask->vaddr = (unsigned long) &udd;
|
|
|
|
if (WARN_ON_ONCE(!uprobe_cpu_buffer))
|
|
return 0;
|
|
|
|
dsize = __get_data_size(&tu->tp, regs);
|
|
esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
|
|
|
|
ucb = uprobe_buffer_get();
|
|
store_trace_args(esize, &tu->tp, regs, ucb->buf, dsize);
|
|
|
|
if (tu->tp.flags & TP_FLAG_TRACE)
|
|
ret |= uprobe_trace_func(tu, regs, ucb, dsize);
|
|
|
|
#ifdef CONFIG_PERF_EVENTS
|
|
if (tu->tp.flags & TP_FLAG_PROFILE)
|
|
ret |= uprobe_perf_func(tu, regs, ucb, dsize);
|
|
#endif
|
|
uprobe_buffer_put(ucb);
|
|
return ret;
|
|
}
|
|
|
|
static int uretprobe_dispatcher(struct uprobe_consumer *con,
|
|
unsigned long func, struct pt_regs *regs)
|
|
{
|
|
struct trace_uprobe *tu;
|
|
struct uprobe_dispatch_data udd;
|
|
struct uprobe_cpu_buffer *ucb;
|
|
int dsize, esize;
|
|
|
|
tu = container_of(con, struct trace_uprobe, consumer);
|
|
|
|
udd.tu = tu;
|
|
udd.bp_addr = func;
|
|
|
|
current->utask->vaddr = (unsigned long) &udd;
|
|
|
|
if (WARN_ON_ONCE(!uprobe_cpu_buffer))
|
|
return 0;
|
|
|
|
dsize = __get_data_size(&tu->tp, regs);
|
|
esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
|
|
|
|
ucb = uprobe_buffer_get();
|
|
store_trace_args(esize, &tu->tp, regs, ucb->buf, dsize);
|
|
|
|
if (tu->tp.flags & TP_FLAG_TRACE)
|
|
uretprobe_trace_func(tu, func, regs, ucb, dsize);
|
|
|
|
#ifdef CONFIG_PERF_EVENTS
|
|
if (tu->tp.flags & TP_FLAG_PROFILE)
|
|
uretprobe_perf_func(tu, func, regs, ucb, dsize);
|
|
#endif
|
|
uprobe_buffer_put(ucb);
|
|
return 0;
|
|
}
|
|
|
|
static struct trace_event_functions uprobe_funcs = {
|
|
.trace = print_uprobe_event
|
|
};
|
|
|
|
static int register_uprobe_event(struct trace_uprobe *tu)
|
|
{
|
|
struct trace_event_call *call = &tu->tp.call;
|
|
int ret;
|
|
|
|
/* Initialize trace_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->tp, is_ret_probe(tu)) < 0)
|
|
return -ENOMEM;
|
|
|
|
ret = register_trace_event(&call->event);
|
|
if (!ret) {
|
|
kfree(call->print_fmt);
|
|
return -ENODEV;
|
|
}
|
|
|
|
call->flags = TRACE_EVENT_FL_UPROBE;
|
|
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",
|
|
trace_event_name(call));
|
|
kfree(call->print_fmt);
|
|
unregister_trace_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->tp.call);
|
|
if (ret)
|
|
return ret;
|
|
kfree(tu->tp.call.print_fmt);
|
|
tu->tp.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 (IS_ERR(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);
|