Bug Summary

File:src/gnu/usr.bin/binutils/gdb/ser-pipe.c
Warning:line 86, column 7
This function call is prohibited after a successful vfork

Annotated Source Code

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clang -cc1 -cc1 -triple amd64-unknown-openbsd7.0 -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name ser-pipe.c -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model pic -pic-level 1 -pic-is-pie -mframe-pointer=all -relaxed-aliasing -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -target-feature +retpoline-indirect-calls -target-feature +retpoline-indirect-branches -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/usr/src/gnu/usr.bin/binutils/obj/gdb -resource-dir /usr/local/lib/clang/13.0.0 -D PIE_DEFAULT=1 -I . -I /usr/src/gnu/usr.bin/binutils/gdb -I /usr/src/gnu/usr.bin/binutils/gdb/config -D LOCALEDIR="/usr/share/locale" -D HAVE_CONFIG_H -I /usr/src/gnu/usr.bin/binutils/gdb/../include/opcode -I ../bfd -I /usr/src/gnu/usr.bin/binutils/gdb/../bfd -I /usr/src/gnu/usr.bin/binutils/gdb/../include -I ../intl -I /usr/src/gnu/usr.bin/binutils/gdb/../intl -D MI_OUT=1 -D TUI=1 -internal-isystem /usr/local/lib/clang/13.0.0/include -internal-externc-isystem /usr/include -O2 -fdebug-compilation-dir=/usr/src/gnu/usr.bin/binutils/obj/gdb -ferror-limit 19 -fwrapv -D_RET_PROTECTOR -ret-protector -fgnuc-version=4.2.1 -fcommon -vectorize-loops -vectorize-slp -fno-builtin-malloc -fno-builtin-calloc -fno-builtin-realloc -fno-builtin-valloc -fno-builtin-free -fno-builtin-strdup -fno-builtin-strndup -analyzer-output=html -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /home/ben/Projects/vmm/scan-build/2022-01-12-194120-40624-1 -x c /usr/src/gnu/usr.bin/binutils/gdb/ser-pipe.c
1/* Serial interface for a pipe to a separate program
2 Copyright 1999, 2000, 2001 Free Software Foundation, Inc.
3
4 Contributed by Cygnus Solutions.
5
6 This file is part of GDB.
7
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
12
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 59 Temple Place - Suite 330,
21 Boston, MA 02111-1307, USA. */
22
23#include "defs.h"
24#include "serial.h"
25#include "ser-unix.h"
26
27#include "gdb_vfork.h"
28
29#include <sys/types.h>
30#include <sys/socket.h>
31#include <sys/time.h>
32#include <fcntl.h>
33#include "gdb_string.h"
34
35#include <signal.h>
36
37static int pipe_open (struct serial *scb, const char *name);
38static void pipe_close (struct serial *scb);
39
40extern void _initialize_ser_pipe (void);
41
42struct pipe_state
43 {
44 int pid;
45 };
46
47/* Open up a raw pipe */
48
49static int
50pipe_open (struct serial *scb, const char *name)
51{
52#if !HAVE_SOCKETPAIR1
53 return -1;
54#else
55 struct pipe_state *state;
56 /* This chunk: */
57 /* Copyright (c) 1988, 1993
58 * The Regents of the University of California. All rights reserved.
59 *
60 * This code is derived from software written by Ken Arnold and
61 * published in UNIX Review, Vol. 6, No. 8.
62 */
63 int pdes[2];
64 int pid;
65 if (socketpair (AF_UNIX1, SOCK_STREAM1, 0, pdes) < 0)
1
Assuming the condition is false
→
2
←
Taking false branch
→
66 return -1;
67
68 /* Create the child process to run the command in. Note that the
69 apparent call to vfork() below *might* actually be a call to
70 fork() due to the fact that autoconf will ``#define vfork fork''
71 on certain platforms. */
72 pid = vfork ();
73
74 /* Error. */
75 if (pid == -1)
3
←
Taking false branch
→
76 {
77 close (pdes[0]);
78 close (pdes[1]);
79 return -1;
80 }
81
82 /* Child. */
83 if (pid
3.1
'pid' is equal to 0
 == 0)
4
←
Taking true branch
→
84 {
85 /* re-wire pdes[1] to stdin/stdout */
86 close (pdes[0]);
5
←
This function call is prohibited after a successful vfork
87 if (pdes[1] != STDOUT_FILENO1)
88 {
89 dup2 (pdes[1], STDOUT_FILENO1);
90 close (pdes[1]);
91 }
92 dup2 (STDOUT_FILENO1, STDIN_FILENO0);
93#if 0
94 /* close any stray FD's - FIXME - how? */
95 /* POSIX.2 B.3.2.2 "popen() shall ensure that any streams
96 from previous popen() calls that remain open in the
97 parent process are closed in the new child process. */
98 for (old = pidlist; old; old = old->next)
99 close (fileno (old->fp)(!__isthreaded ? ((old->fp)->_file) : (fileno)(old->
fp))); /* don't allow a flush */
100#endif
101 execl ("/bin/sh", "sh", "-c", name, (char *) 0);
102 _exit (127);
103 }
104
105 /* Parent. */
106 close (pdes[1]);
107 /* :end chunk */
108 state = XMALLOC (struct pipe_state)((struct pipe_state*) xmalloc (sizeof (struct pipe_state)));
109 state->pid = pid;
110 scb->fd = pdes[0];
111 scb->state = state;
112
113 /* If we don't do this, GDB simply exits when the remote side dies. */
114 signal (SIGPIPE13, SIG_IGN(void (*)(int))1);
115 return 0;
116#endif
117}
118
119static void
120pipe_close (struct serial *scb)
121{
122 struct pipe_state *state = scb->state;
123 if (state != NULL((void*)0))
124 {
125 int pid = state->pid;
126 close (scb->fd);
127 scb->fd = -1;
128 xfree (state);
129 scb->state = NULL((void*)0);
130 kill (pid, SIGTERM15);
131 /* Might be useful to check that the child does die. */
132 }
133}
134
135static struct serial_ops pipe_ops;
136
137void
138_initialize_ser_pipe (void)
139{
140 struct serial_ops *ops = XMALLOC (struct serial_ops)((struct serial_ops*) xmalloc (sizeof (struct serial_ops)));
141 memset (ops, 0, sizeof (struct serial_ops));
142 ops->name = "pipe";
143 ops->next = 0;
144 ops->open = pipe_open;
145 ops->close = pipe_close;
146 ops->readchar = ser_unix_readchar;
147 ops->write = ser_unix_write;
148 ops->flush_output = ser_unix_nop_flush_output;
149 ops->flush_input = ser_unix_flush_input;
150 ops->send_break = ser_unix_nop_send_break;
151 ops->go_raw = ser_unix_nop_raw;
152 ops->get_tty_state = ser_unix_nop_get_tty_state;
153 ops->set_tty_state = ser_unix_nop_set_tty_state;
154 ops->print_tty_state = ser_unix_nop_print_tty_state;
155 ops->noflush_set_tty_state = ser_unix_nop_noflush_set_tty_state;
156 ops->setbaudrate = ser_unix_nop_setbaudrate;
157 ops->setstopbits = ser_unix_nop_setstopbits;
158 ops->drain_output = ser_unix_nop_drain_output;
159 ops->async = ser_unix_async;
160 serial_add_interface (ops);
161}