--- /dev/null
+/*
+ * Check decoding of return values injected into a syscall that "never fails".
+ *
+ * Copyright (c) 2018 The strace developers.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "tests.h"
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <asm/unistd.h>
+
+#include "raw_syscall.h"
+
+#ifdef __alpha__
+/* alpha has no getpid */
+# define SC_NR __NR_getpgrp
+# define SC_NAME "getpgrp"
+# define getpid getpgrp
+#else
+# define SC_NR __NR_getpid
+# define SC_NAME "getpid"
+#endif
+
+#ifdef raw_syscall_0
+# define INVOKE_SC(err) raw_syscall_0(SC_NR, &err)
+#else
+/* No raw_syscall_0, let's use getpid() and hope for the best. */
+# define INVOKE_SC(err) getpid()
+#endif
+
+/*
+ * This prototype is intentionally different
+ * from the prototype provided by <unistd.h>.
+ */
+extern kernel_ulong_t getpid(void);
+
+int
+main(int ac, char **av)
+{
+ assert(ac == 1 || ac == 2);
+
+ kernel_ulong_t expected =
+ (ac == 1) ? getpid() : strtoull(av[1], NULL, 0);
+ kernel_ulong_t err = 0;
+ kernel_ulong_t rc = INVOKE_SC(err);
+
+ if (err || rc != expected)
+ error_msg_and_fail("expected %#llx, got rval=%#llx err=%#llx",
+ (unsigned long long) expected,
+ (unsigned long long) rc,
+ (unsigned long long) err);
+
+ if (ac == 2) {
+ printf("%s() = %lld (INJECTED)\n",
+ SC_NAME, (unsigned long long) rc);
+
+ puts("+++ exited with 0 +++");
+ }
+
+ return 0;
+}
--- /dev/null
+#!/bin/sh -efu
+
+# Check decoding of return values injected into a syscall that "never fails".
+
+. "${srcdir=.}/scno_tampering.sh"
+
+case "$STRACE_ARCH" in
+alpha)
+ SYSCALL=getpgrp
+ ;;
+*)
+ SYSCALL=getpid
+ ;;
+esac
+
+run_prog
+prog="$args"
+fault_args="-a9 -e trace=${SYSCALL} -e inject=${SYSCALL}:retval="
+
+test_rval()
+{
+ local rval
+ rval="$1"; shift
+
+ run_strace $fault_args$rval $prog $rval > "$EXP"
+ match_diff "$LOG" "$EXP"
+}
+
+test_rval 0
+test_rval 1
+test_rval 2147483647 # 0x7fffffff
+
+case "$SIZEOF_KERNEL_LONG_T" in
+8)
+ test_rval 2147483648 # 0x80000000
+ test_rval 4294963200 # 0xfffff000
+ test_rval 4294967294 # 0xfffffffe
+ test_rval 4294967295 # 0xffffffff
+ test_rval 4294967296 # 0x100000000
+ test_rval 9223372036854775807 # 0x7fffffffffffffff
+ ;;
+esac