analyzer: fix ICE casued by dup2 in sm-fd.cc[PR106551]

This patch fixes the ICE caused by valid_to_unchecked_state,
at analyzer/sm-fd.cc by handling the m_start state in
check_for_dup.

Tested lightly on x86_64.

gcc/analyzer/ChangeLog:
	PR analyzer/106551
	* sm-fd.cc (check_for_dup): handle the m_start
	state when transitioning the state of LHS
	of dup, dup2 and dup3 call.

gcc/testsuite/ChangeLog:
	* gcc.dg/analyzer/fd-dup-1.c: New testcases.
	* gcc.dg/analyzer/fd-uninit-1.c: Remove bogus
	warning.
Signed-off-by: Immad Mir <mirimmad@outlook.com>
This commit is contained in:
Immad Mir 2022-08-11 21:45:54 +05:30
parent 04ce2400b3
commit 837142257c
3 changed files with 32 additions and 7 deletions

View File

@ -971,7 +971,8 @@ fd_state_machine::check_for_dup (sm_context *sm_ctxt, const supernode *node,
state_t state_arg_1 = sm_ctxt->get_state (stmt, arg_1);
if (state_arg_1 == m_stop)
return;
if (!(is_constant_fd_p (state_arg_1) || is_valid_fd_p (state_arg_1)))
if (!(is_constant_fd_p (state_arg_1) || is_valid_fd_p (state_arg_1)
|| state_arg_1 == m_start))
{
check_for_open_fd (sm_ctxt, node, stmt, call, callee_fndecl,
DIRS_READ_WRITE);
@ -983,7 +984,7 @@ fd_state_machine::check_for_dup (sm_context *sm_ctxt, const supernode *node,
case DUP_1:
if (lhs)
{
if (is_constant_fd_p (state_arg_1))
if (is_constant_fd_p (state_arg_1) || state_arg_1 == m_start)
sm_ctxt->set_next_state (stmt, lhs, m_unchecked_read_write);
else
sm_ctxt->set_next_state (stmt, lhs,
@ -999,7 +1000,8 @@ fd_state_machine::check_for_dup (sm_context *sm_ctxt, const supernode *node,
if (state_arg_2 == m_stop)
return;
/* Check if -1 was passed as second argument to dup2. */
if (!(is_constant_fd_p (state_arg_2) || is_valid_fd_p (state_arg_2)))
if (!(is_constant_fd_p (state_arg_2) || is_valid_fd_p (state_arg_2)
|| state_arg_2 == m_start))
{
sm_ctxt->warn (
node, stmt, arg_2,
@ -1011,7 +1013,7 @@ fd_state_machine::check_for_dup (sm_context *sm_ctxt, const supernode *node,
file descriptor i.e the first argument. */
if (lhs)
{
if (is_constant_fd_p (state_arg_1))
if (is_constant_fd_p (state_arg_1) || state_arg_1 == m_start)
sm_ctxt->set_next_state (stmt, lhs, m_unchecked_read_write);
else
sm_ctxt->set_next_state (stmt, lhs,

View File

@ -221,3 +221,28 @@ test_19 (const char *path, void *buf)
}
}
extern int m;
void
test_20 ()
{
int fd = dup (m);
close (fd);
}
void
test_21 ()
{
int fd = dup2 (m, 1);
close (fd);
}
void
test_22 (int flags)
{
int fd = dup3 (m, 1, flags);
close (fd);
}

View File

@ -9,8 +9,6 @@ test_1 ()
{
int m;
return dup (m); /* { dg-warning "use of uninitialized value 'm'" "uninit" } */
/* { dg-bogus "'dup' on possibly invalid file descriptor 'm'" "invalid fd false +ve" { xfail *-*-* } .-1 } */
/* XFAIL: probably covered by fix for PR analyzer/106551. */
}
int