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d614a753 | 1 | /* Copyright (C) 2003-2020 Free Software Foundation, Inc. |
09d65ff3 UD |
2 | This file is part of the GNU C Library. |
3 | Contributed by Ulrich Drepper <drepper@redhat.com> | |
4 | and Richard Henderson <rth@redhat.com>, 2003. | |
5 | ||
6 | The GNU C Library is free software; you can redistribute it and/or | |
7 | modify it under the terms of the GNU Lesser General Public | |
8 | License as published by the Free Software Foundation; either | |
9 | version 2.1 of the License, or (at your option) any later version. | |
10 | ||
11 | The GNU C Library is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | Lesser General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU Lesser General Public | |
59ba27a6 | 17 | License along with the GNU C Library; if not, see |
5a82c748 | 18 | <https://www.gnu.org/licenses/>. */ |
09d65ff3 UD |
19 | |
20 | #include <setjmp.h> | |
7f0dfae0 | 21 | #include <stdio.h> |
09d65ff3 | 22 | #include <stdlib.h> |
d347a4ab | 23 | #include <string.h> |
6e66dc78 | 24 | #include <unistd.h> |
09d65ff3 | 25 | #include "pthreadP.h" |
2098d403 | 26 | #include <libc-diag.h> |
8dea90aa | 27 | #include <jmpbuf-unwind.h> |
09d65ff3 | 28 | |
44e94149 | 29 | #ifdef _STACK_GROWS_DOWN |
675620f7 UD |
30 | # define FRAME_LEFT(frame, other, adj) \ |
31 | ((uintptr_t) frame - adj >= (uintptr_t) other - adj) | |
44e94149 | 32 | #elif _STACK_GROWS_UP |
675620f7 UD |
33 | # define FRAME_LEFT(frame, other, adj) \ |
34 | ((uintptr_t) frame - adj <= (uintptr_t) other - adj) | |
44e94149 UD |
35 | #else |
36 | # error "Define either _STACK_GROWS_DOWN or _STACK_GROWS_UP" | |
37 | #endif | |
38 | ||
09d65ff3 UD |
39 | static _Unwind_Reason_Code |
40 | unwind_stop (int version, _Unwind_Action actions, | |
41 | _Unwind_Exception_Class exc_class, | |
42 | struct _Unwind_Exception *exc_obj, | |
43 | struct _Unwind_Context *context, void *stop_parameter) | |
44 | { | |
45 | struct pthread_unwind_buf *buf = stop_parameter; | |
44e94149 UD |
46 | struct pthread *self = THREAD_SELF; |
47 | struct _pthread_cleanup_buffer *curp = THREAD_GETMEM (self, cleanup); | |
48 | int do_longjump = 0; | |
f76c8499 | 49 | |
675620f7 UD |
50 | /* Adjust all pointers used in comparisons, so that top of thread's |
51 | stack is at the top of address space. Without that, things break | |
52 | if stack is allocated above the main stack. */ | |
53 | uintptr_t adj = (uintptr_t) self->stackblock + self->stackblock_size; | |
09d65ff3 UD |
54 | |
55 | /* Do longjmp if we're at "end of stack", aka "end of unwind data". | |
56 | We assume there are only C frame without unwind data in between | |
57 | here and the jmp_buf target. Otherwise simply note that the CFA | |
58 | of a function is NOT within it's stack frame; it's the SP of the | |
59 | previous frame. */ | |
60 | if ((actions & _UA_END_OF_STACK) | |
675620f7 UD |
61 | || ! _JMPBUF_CFA_UNWINDS_ADJ (buf->cancel_jmp_buf[0].jmp_buf, context, |
62 | adj)) | |
44e94149 UD |
63 | do_longjump = 1; |
64 | ||
a1ffb40e | 65 | if (__glibc_unlikely (curp != NULL)) |
44e94149 UD |
66 | { |
67 | /* Handle the compatibility stuff. Execute all handlers | |
68 | registered with the old method which would be unwound by this | |
69 | step. */ | |
70 | struct _pthread_cleanup_buffer *oldp = buf->priv.data.cleanup; | |
ca7b8af5 | 71 | void *cfa = (void *) (_Unwind_Ptr) _Unwind_GetCFA (context); |
44e94149 | 72 | |
675620f7 | 73 | if (curp != oldp && (do_longjump || FRAME_LEFT (cfa, curp, adj))) |
44e94149 UD |
74 | { |
75 | do | |
76 | { | |
77 | /* Pointer to the next element. */ | |
78 | struct _pthread_cleanup_buffer *nextp = curp->__prev; | |
79 | ||
80 | /* Call the handler. */ | |
81 | curp->__routine (curp->__arg); | |
82 | ||
83 | /* To the next. */ | |
84 | curp = nextp; | |
85 | } | |
675620f7 UD |
86 | while (curp != oldp |
87 | && (do_longjump || FRAME_LEFT (cfa, curp, adj))); | |
44e94149 UD |
88 | |
89 | /* Mark the current element as handled. */ | |
90 | THREAD_SETMEM (self, cleanup, curp); | |
91 | } | |
92 | } | |
93 | ||
2098d403 JM |
94 | DIAG_PUSH_NEEDS_COMMENT; |
95 | #if __GNUC_PREREQ (7, 0) | |
96 | /* This call results in a -Wstringop-overflow warning because struct | |
97 | pthread_unwind_buf is smaller than jmp_buf. setjmp and longjmp | |
98 | do not use anything beyond the common prefix (they never access | |
99 | the saved signal mask), so that is a false positive. */ | |
100 | DIAG_IGNORE_NEEDS_COMMENT (11, "-Wstringop-overflow="); | |
101 | #endif | |
44e94149 | 102 | if (do_longjump) |
f76c8499 | 103 | __libc_unwind_longjmp ((struct __jmp_buf_tag *) buf->cancel_jmp_buf, 1); |
2098d403 | 104 | DIAG_POP_NEEDS_COMMENT; |
09d65ff3 UD |
105 | |
106 | return _URC_NO_REASON; | |
107 | } | |
108 | ||
109 | ||
110 | static void | |
111 | unwind_cleanup (_Unwind_Reason_Code reason, struct _Unwind_Exception *exc) | |
112 | { | |
29b095a1 UD |
113 | /* When we get here a C++ catch block didn't rethrow the object. We |
114 | cannot handle this case and therefore abort. */ | |
7f0dfae0 | 115 | __libc_fatal ("FATAL: exception not rethrown\n"); |
09d65ff3 UD |
116 | } |
117 | ||
09d65ff3 UD |
118 | |
119 | void | |
120 | __cleanup_fct_attribute __attribute ((noreturn)) | |
121 | __pthread_unwind (__pthread_unwind_buf_t *buf) | |
122 | { | |
123 | struct pthread_unwind_buf *ibuf = (struct pthread_unwind_buf *) buf; | |
124 | struct pthread *self = THREAD_SELF; | |
125 | ||
44e94149 UD |
126 | /* This is not a catchable exception, so don't provide any details about |
127 | the exception type. We do need to initialize the field though. */ | |
128 | THREAD_SETMEM (self, exc.exception_class, 0); | |
c515fb51 | 129 | THREAD_SETMEM (self, exc.exception_cleanup, &unwind_cleanup); |
44e94149 UD |
130 | |
131 | _Unwind_ForcedUnwind (&self->exc, unwind_stop, ibuf); | |
09d65ff3 UD |
132 | /* NOTREACHED */ |
133 | ||
134 | /* We better do not get here. */ | |
135 | abort (); | |
136 | } | |
56421b23 | 137 | hidden_def (__pthread_unwind) |
09d65ff3 UD |
138 | |
139 | ||
140 | void | |
141 | __cleanup_fct_attribute __attribute ((noreturn)) | |
142 | __pthread_unwind_next (__pthread_unwind_buf_t *buf) | |
143 | { | |
144 | struct pthread_unwind_buf *ibuf = (struct pthread_unwind_buf *) buf; | |
145 | ||
49b65043 | 146 | __pthread_unwind ((__pthread_unwind_buf_t *) ibuf->priv.data.prev); |
09d65ff3 | 147 | } |
da0c02ee | 148 | hidden_def (__pthread_unwind_next) |