1 /* -*- mode: C; c-basic-offset: 3; -*- */
2
3 /*--------------------------------------------------------------------*/
4 /*--- Signal frames handling: stuff common to most/all platforms ---*/
5 /*--- ---*/
6 /*--- sigframe-common.c ---*/
7 /*--------------------------------------------------------------------*/
8
9 /*
10 This file is part of Valgrind, a dynamic binary instrumentation
11 framework.
12
13 Copyright (C) 2000-2017 Nicholas Nethercote
14 njn@valgrind.org
15 Copyright (C) 2006-2017 OpenWorks Ltd
16 info@open-works.co.uk
17
18 This program is free software; you can redistribute it and/or
19 modify it under the terms of the GNU General Public License as
20 published by the Free Software Foundation; either version 2 of the
21 License, or (at your option) any later version.
22
23 This program is distributed in the hope that it will be useful, but
24 WITHOUT ANY WARRANTY; without even the implied warranty of
25 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
26 General Public License for more details.
27
28 You should have received a copy of the GNU General Public License
29 along with this program; if not, write to the Free Software
30 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
31 02111-1307, USA.
32
33 The GNU General Public License is contained in the file COPYING.
34 */
35
36 #include "pub_core_aspacemgr.h" // VG_(am_find_nsegment)
37 #include "pub_core_signals.h" // VG_(extend_stack)
38 #include "pub_core_libcprint.h" // VG_(umsg)
39 #include "pub_core_tooliface.h" // VG_TRACK
40 #include "pub_core_machine.h" // VG_STACK_REDZONE_SZB
41 #include "priv_sigframe.h" // self
42
43
44 /* For tracking memory events, indicate the entire frame has been
45 allocated. Except, don't mess with the area which
46 overlaps the previous frame's redzone. */
track_frame_memory(Addr addr,SizeT size,ThreadId tid)47 static void track_frame_memory ( Addr addr, SizeT size, ThreadId tid )
48 {
49 VG_TRACK( new_mem_stack_signal, addr - VG_STACK_REDZONE_SZB, size, tid );
50 }
51
52 #if defined(VGO_linux) || defined(VGO_solaris)
53
54 /* Extend the stack segment downwards if needed so as to ensure the
55 new signal frames are mapped to something. Return a Bool
56 indicating whether or not the operation was successful. */
ML_(sf_maybe_extend_stack)57 Bool ML_(sf_maybe_extend_stack) ( const ThreadState *tst, Addr addr,
58 SizeT size, UInt flags )
59 {
60 ThreadId tid = tst->tid;
61 const NSegment *stackseg = NULL;
62
63 if (flags & VKI_SA_ONSTACK) {
64 /* If the sigframe is allocated on an alternate stack, then we cannot
65 extend that stack. Nothing to do here. */
66 stackseg = VG_(am_find_nsegment)(addr);
67 } else if (VG_(am_addr_is_in_extensible_client_stack)(addr)) {
68 if (VG_(extend_stack)(tid, addr)) {
69 stackseg = VG_(am_find_nsegment)(addr);
70 if (0 && stackseg)
71 VG_(printf)("frame=%#lx seg=%#lx-%#lx\n",
72 addr, stackseg->start, stackseg->end);
73 }
74 } else if ((stackseg = VG_(am_find_nsegment)(addr)) &&
75 VG_(am_is_valid_for_client)(addr, 1,
76 VKI_PROT_READ | VKI_PROT_WRITE)) {
77 /* We come here for explicitly defined pthread-stacks which can be
78 located in any client segment. */
79 } else {
80 /* Something unexpected */
81 stackseg = NULL;
82 }
83
84 if (stackseg == NULL || !stackseg->hasR || !stackseg->hasW) {
85 VG_(umsg)("Can't extend stack to %#lx during signal delivery for "
86 "thread %u:\n", addr, tid);
87 if (stackseg == NULL)
88 VG_(umsg)(" no stack segment\n");
89 else
90 VG_(umsg)(" too small or bad protection modes\n");
91
92 /* set SIGSEGV to default handler */
93 VG_(set_default_handler)(VKI_SIGSEGV);
94 VG_(synth_fault_mapping)(tid, addr);
95
96 /* The whole process should be about to die, since the default
97 action of SIGSEGV to kill the whole process. */
98 return False;
99 }
100
101 /* Tell the tool about the new memory */
102 track_frame_memory(addr, size, tid);
103
104 return True;
105 }
106
107 #elif defined(VGO_darwin)
108
109 /* Extend the stack segment downwards if needed so as to ensure the
110 new signal frames are mapped to something. Return a Bool
111 indicating whether or not the operation was successful. */
ML_(sf_maybe_extend_stack)112 Bool ML_(sf_maybe_extend_stack) ( const ThreadState *tst, Addr addr,
113 SizeT size, UInt flags )
114 {
115 /* Tell the tool about the new memory */
116 track_frame_memory(addr, size, tst->tid);
117 return True;
118 }
119
120 #else
121 #error unknown OS
122 #endif
123
124 /*--------------------------------------------------------------------*/
125 /*--- end ---*/
126 /*--------------------------------------------------------------------*/
127