Add AutoRemoteSyscalls::syscall_ptr to avoid sign extension for syscalls that return pointer results
diff --git a/src/AutoRemoteSyscalls.cc b/src/AutoRemoteSyscalls.cc
index 9789e28..010564a 100644
--- a/src/AutoRemoteSyscalls.cc
+++ b/src/AutoRemoteSyscalls.cc
@@ -121,7 +121,7 @@
ASSERT(t, t->ptrace_event() == 0);
}
-long AutoRemoteSyscalls::syscall_helper(SyscallWaiting wait, int syscallno,
+void AutoRemoteSyscalls::syscall_helper(SyscallWaiting wait, int syscallno,
Registers& callregs) {
callregs.set_syscallno(syscallno);
t->set_regs(callregs);
@@ -140,12 +140,11 @@
pending_syscallno = syscallno;
t->cont_syscall_nonblocking();
if (WAIT == wait) {
- return wait_syscall(syscallno);
+ wait_syscall(syscallno);
}
- return 0;
}
-long AutoRemoteSyscalls::wait_syscall(int syscallno) {
+void AutoRemoteSyscalls::wait_syscall(int syscallno) {
ASSERT(t, pending_syscallno == syscallno || syscallno < 0);
// Wait for syscall-exit trap.
@@ -155,8 +154,6 @@
ASSERT(t, t->regs().original_syscallno() == syscallno || syscallno < 0)
<< "Should be entering " << t->syscall_name(syscallno)
<< ", but instead at " << t->syscall_name(t->regs().original_syscallno());
-
- return t->regs().syscall_result_signed();
}
SupportedArch AutoRemoteSyscalls::arch() const { return t->arch(); }
@@ -407,7 +404,8 @@
FATAL() << "Failed to create parent socket";
}
// Complete child's connect() syscall
- int child_syscall_result = wait_syscall();
+ wait_syscall();
+ int child_syscall_result = t->regs().syscall_result_signed();
if (child_syscall_result) {
FATAL() << "Failed to connect() in tracee; err="
<< errno_name(-child_syscall_result);
@@ -418,7 +416,8 @@
close(listen_sock);
unlink(path);
child_sendmsg(*this, remote_buf, sc_args, sc_args_end, child_sock, fd);
- child_syscall_result = wait_syscall();
+ wait_syscall();
+ child_syscall_result = t->regs().syscall_result_signed();
if (0 >= child_syscall_result) {
FATAL() << "Failed to sendmsg() in tracee; err="
<< errno_name(-child_syscall_result);
@@ -446,12 +445,13 @@
size_t length, int prot,
int flags, int child_fd,
uint64_t offset_pages) {
+ // The first syscall argument is called "arg 1", so
+ // our syscall-arg-index template parameter starts
+ // with "1".
if (has_mmap2_syscall(arch())) {
- syscall(syscall_number_for_mmap2(arch()), addr, length, prot, flags,
- child_fd, (off_t)offset_pages);
- } else {
- syscall(syscall_number_for_mmap(arch()), addr, length, prot, flags,
- child_fd, offset_pages * page_size());
+ return syscall_ptr(syscall_number_for_mmap2(arch()), addr, length, prot,
+ flags, child_fd, (off_t)offset_pages);
}
- return t->regs().syscall_result();
+ return syscall_ptr(syscall_number_for_mmap(arch()), addr, length, prot, flags,
+ child_fd, offset_pages * page_size());
}
