2 * This file is part of ltrace.
3 * Copyright (C) 2011,2012,2013 Petr Machata, Red Hat Inc.
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation; either version 2 of the
8 * License, or (at your option) any later version.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
21 #ifndef _LTRACE_LINUX_TRACE_H_
22 #define _LTRACE_LINUX_TRACE_H_
26 /* This publishes some Linux-specific data structures used for process
30 * This is used for bookkeeping related to PIDs that the event
34 pid_t pid; /* This may be 0 for tasks that exited
44 struct pid_task *tasks;
50 * Breakpoint re-enablement. When we hit a breakpoint, we must
51 * disable it, single-step, and re-enable it. That single-step can be
52 * done only by one task in a task group, while others are stopped,
53 * otherwise the processes would race for who sees the breakpoint
54 * disabled and who doesn't. The following is to keep track of it
57 struct process_stopping_handler
59 struct event_handler super;
61 /* The task that is doing the re-enablement. */
62 struct process *task_enabling_breakpoint;
64 /* The pointer being re-enabled. */
65 struct breakpoint *breakpoint_being_enabled;
67 /* Software singlestep breakpoints, if any needed. */
68 struct breakpoint *sws_bps[2];
70 /* When all tasks are stopped, this callback gets called. */
71 void (*on_all_stopped)(struct process_stopping_handler *);
73 /* When we get a singlestep event, this is called to decide
74 * whether to stop stepping, or whether to enable the
75 * brakpoint, sink remaining signals, and continue
77 enum callback_status (*keep_stepping_p)
78 (struct process_stopping_handler *);
80 /* Whether we need to use ugly workaround to get around
81 * various problems with singlestepping. */
82 enum callback_status (*ugly_workaround_p)
83 (struct process_stopping_handler *);
86 /* We are waiting for everyone to land in t/T. */
89 /* We are doing the PTRACE_SINGLESTEP. */
92 /* We are waiting for all the SIGSTOPs to arrive so
93 * that we can sink them. */
96 /* This is for tracking the ugly workaround. */
105 /* Allocate a process stopping handler, initialize it and install it.
106 * Return 0 on success or a negative value on failure. Pass NULL for
107 * each callback to use a default instead. The default for
108 * ON_ALL_STOPPED is LINUX_PTRACE_DISABLE_AND_SINGLESTEP, the default
109 * for KEEP_STEPPING_P and UGLY_WORKAROUND_P is "no". */
110 int process_install_stopping_handler
111 (struct process *proc, struct breakpoint *sbp,
112 void (*on_all_stopped)(struct process_stopping_handler *),
113 enum callback_status (*keep_stepping_p)
114 (struct process_stopping_handler *),
115 enum callback_status (*ugly_workaround_p)
116 (struct process_stopping_handler *));
118 void linux_ptrace_disable_and_singlestep(struct process_stopping_handler *self);
119 void linux_ptrace_disable_and_continue(struct process_stopping_handler *self);
121 /* When main binary needs to call an IFUNC function defined in the
122 * binary itself, a PLT entry is set up so that dynamic linker can get
123 * involved and resolve the symbol. But unlike other PLT relocation,
124 * this one can't rely on symbol table being available. So it doesn't
125 * reference the symbol by its name, but by its address, and
126 * correspondingly, has another type. When arch backend wishes to
127 * support these IRELATIVE relocations, it should override
128 * arch_elf_add_plt_entry and dispatch to this function for IRELATIVE
131 * This function behaves as arch_elf_add_plt_entry, except that it
132 * doesn't take name for a parameter, but instead looks up the name in
133 * symbol tables in LTE. */
134 enum plt_status linux_elf_add_plt_entry_irelative(struct process *proc,
136 GElf_Rela *rela, size_t ndx,
137 struct library_symbol **ret);
139 /* Service routine of the above. Determines a name corresponding to
140 * ADDR, or invents a new one. Returns NULL on failures, otherwise it
141 * returns a malloc'd pointer that the caller is responsible for
143 char *linux_elf_find_irelative_name(struct ltelf *lte, GElf_Addr addr);
145 /* Returns ${NAME}.IFUNC in a newly-malloc'd block, or NULL on
147 char *linux_append_IFUNC_to_name(const char *name);
149 /* Returns a statically allocated prototype that represents the
150 * prototype "void *()". Never fails. */
151 struct prototype *linux_IFUNC_prototype(void);
154 #endif /* _LTRACE_LINUX_TRACE_H_ */