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* [gcc r13-1936] analyzer: support for creat, dup, dup2 and dup3 [PR106298]
@ 2022-08-02 16:54 Immad Mir
0 siblings, 0 replies; only message in thread
From: Immad Mir @ 2022-08-02 16:54 UTC (permalink / raw)
To: gcc-cvs
https://gcc.gnu.org/g:6a11f2d974a912aaaedb0ce32cdfde10193003cd
commit r13-1936-g6a11f2d974a912aaaedb0ce32cdfde10193003cd
Author: Immad Mir <mirimmad@outlook.com>
Date: Tue Aug 2 22:22:07 2022 +0530
analyzer: support for creat, dup, dup2 and dup3 [PR106298]
This patch extends the state machine in sm-fd.cc to support
creat, dup, dup2 and dup3 functions.
Lightly tested on x86_64 Linux.
gcc/analyzer/ChangeLog:
PR analyzer/106298
* sm-fd.cc (fd_state_machine::on_open): Add
creat, dup, dup2 and dup3 functions.
(enum dup): New.
(fd_state_machine::valid_to_unchecked_state): New.
(fd_state_machine::on_creat): New.
(fd_state_machine::on_dup): New.
gcc/testsuite/ChangeLog:
PR analyzer/106298
* gcc.dg/analyzer/fd-1.c: Add tests for 'creat'.
* gcc.dg/analyzer/fd-2.c: Likewise.
* gcc.dg/analyzer/fd-4.c: Likewise.
* gcc.dg/analyzer/fd-dup-1.c: New tests.
Signed-off-by: Immad Mir <mirimmad@outlook.com>
Diff:
---
gcc/analyzer/sm-fd.cc | 129 +++++++++++++++++-
gcc/testsuite/gcc.dg/analyzer/fd-1.c | 21 +++
gcc/testsuite/gcc.dg/analyzer/fd-2.c | 15 +++
gcc/testsuite/gcc.dg/analyzer/fd-4.c | 31 ++++-
gcc/testsuite/gcc.dg/analyzer/fd-dup-1.c | 223 +++++++++++++++++++++++++++++++
5 files changed, 415 insertions(+), 4 deletions(-)
diff --git a/gcc/analyzer/sm-fd.cc b/gcc/analyzer/sm-fd.cc
index ed923ade100..8bb76d72b05 100644
--- a/gcc/analyzer/sm-fd.cc
+++ b/gcc/analyzer/sm-fd.cc
@@ -69,6 +69,14 @@ enum access_directions
DIRS_WRITE
};
+/* An enum for distinguishing between dup, dup2 and dup3. */
+enum dup
+{
+ DUP_1,
+ DUP_2,
+ DUP_3
+};
+
class fd_state_machine : public state_machine
{
public:
@@ -114,7 +122,9 @@ public:
bool is_readonly_fd_p (state_t s) const;
bool is_writeonly_fd_p (state_t s) const;
enum access_mode get_access_mode_from_flag (int flag) const;
-
+ /* Function for one-to-one correspondence between valid
+ and unchecked states. */
+ state_t valid_to_unchecked_state (state_t state) const;
/* State for a constant file descriptor (>= 0) */
state_t m_constant_fd;
@@ -147,6 +157,8 @@ public:
private:
void on_open (sm_context *sm_ctxt, const supernode *node, const gimple *stmt,
const gcall *call) const;
+ void on_creat (sm_context *sm_ctxt, const supernode *node, const gimple *stmt,
+ const gcall *call) const;
void on_close (sm_context *sm_ctxt, const supernode *node, const gimple *stmt,
const gcall *call) const;
void on_read (sm_context *sm_ctxt, const supernode *node, const gimple *stmt,
@@ -170,6 +182,9 @@ private:
const gimple *stmt, const gcall *call,
const tree callee_fndecl, const char *attr_name,
access_directions fd_attr_access_dir) const;
+ void check_for_dup (sm_context *sm_ctxt, const supernode *node,
+ const gimple *stmt, const gcall *call, const tree callee_fndecl,
+ enum dup kind) const;
};
/* Base diagnostic class relative to fd_state_machine. */
@@ -723,6 +738,20 @@ fd_state_machine::is_constant_fd_p (state_t state) const
return (state == m_constant_fd);
}
+fd_state_machine::state_t
+fd_state_machine::valid_to_unchecked_state (state_t state) const
+{
+ if (state == m_valid_read_write)
+ return m_unchecked_read_write;
+ else if (state == m_valid_write_only)
+ return m_unchecked_write_only;
+ else if (state == m_valid_read_only)
+ return m_unchecked_read_only;
+ else
+ gcc_unreachable ();
+ return NULL;
+}
+
bool
fd_state_machine::on_stmt (sm_context *sm_ctxt, const supernode *node,
const gimple *stmt) const
@@ -736,6 +765,11 @@ fd_state_machine::on_stmt (sm_context *sm_ctxt, const supernode *node,
return true;
} // "open"
+ if (is_named_call_p (callee_fndecl, "creat", call, 2))
+ {
+ on_creat (sm_ctxt, node, stmt, call);
+ } // "creat"
+
if (is_named_call_p (callee_fndecl, "close", call, 1))
{
on_close (sm_ctxt, node, stmt, call);
@@ -754,6 +788,23 @@ fd_state_machine::on_stmt (sm_context *sm_ctxt, const supernode *node,
return true;
} // "read"
+ if (is_named_call_p (callee_fndecl, "dup", call, 1))
+ {
+ check_for_dup (sm_ctxt, node, stmt, call, callee_fndecl, DUP_1);
+ return true;
+ }
+
+ if (is_named_call_p (callee_fndecl, "dup2", call, 2))
+ {
+ check_for_dup (sm_ctxt, node, stmt, call, callee_fndecl, DUP_2);
+ return true;
+ }
+
+ if (is_named_call_p (callee_fndecl, "dup3", call, 3))
+ {
+ check_for_dup (sm_ctxt, node, stmt, call, callee_fndecl, DUP_3);
+ return true;
+ }
{
// Handle __attribute__((fd_arg))
@@ -899,6 +950,78 @@ fd_state_machine::on_open (sm_context *sm_ctxt, const supernode *node,
}
}
+void
+fd_state_machine::on_creat (sm_context *sm_ctxt, const supernode *node,
+ const gimple *stmt, const gcall *call) const
+{
+ tree lhs = gimple_call_lhs (call);
+ if (lhs)
+ sm_ctxt->on_transition (node, stmt, lhs, m_start, m_unchecked_write_only);
+ else
+ sm_ctxt->warn (node, stmt, NULL_TREE, new fd_leak (*this, NULL_TREE));
+}
+
+void
+fd_state_machine::check_for_dup (sm_context *sm_ctxt, const supernode *node,
+ const gimple *stmt, const gcall *call,
+ const tree callee_fndecl, enum dup kind) const
+{
+ tree lhs = gimple_call_lhs (call);
+ tree arg_1 = gimple_call_arg (call, 0);
+ 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)))
+ {
+ check_for_open_fd (sm_ctxt, node, stmt, call, callee_fndecl,
+ DIRS_READ_WRITE);
+ if (kind == DUP_1)
+ return;
+ }
+ switch (kind)
+ {
+ case DUP_1:
+ if (lhs)
+ {
+ if (is_constant_fd_p (state_arg_1))
+ sm_ctxt->set_next_state (stmt, lhs, m_unchecked_read_write);
+ else
+ sm_ctxt->set_next_state (stmt, lhs,
+ valid_to_unchecked_state (state_arg_1));
+ }
+ break;
+
+ case DUP_2:
+ case DUP_3:
+ tree arg_2 = gimple_call_arg (call, 1);
+ state_t state_arg_2 = sm_ctxt->get_state (stmt, arg_2);
+ tree diag_arg_2 = sm_ctxt->get_diagnostic_tree (arg_2);
+ 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)))
+ {
+ sm_ctxt->warn (
+ node, stmt, arg_2,
+ new fd_use_without_check (*this, diag_arg_2, callee_fndecl));
+ return;
+ }
+ /* dup2 returns value of its second argument on success.But, the
+ access mode of the returned file descriptor depends on the duplicated
+ file descriptor i.e the first argument. */
+ if (lhs)
+ {
+ if (is_constant_fd_p (state_arg_1))
+ sm_ctxt->set_next_state (stmt, lhs, m_unchecked_read_write);
+ else
+ sm_ctxt->set_next_state (stmt, lhs,
+ valid_to_unchecked_state (state_arg_1));
+ }
+
+ break;
+ }
+}
+
void
fd_state_machine::on_close (sm_context *sm_ctxt, const supernode *node,
const gimple *stmt, const gcall *call) const
@@ -964,6 +1087,8 @@ fd_state_machine::check_for_open_fd (
}
switch (callee_fndecl_dir)
{
+ case DIRS_READ_WRITE:
+ break;
case DIRS_READ:
if (is_writeonly_fd_p (state))
{
@@ -984,8 +1109,6 @@ fd_state_machine::check_for_open_fd (
*this, diag_arg, DIRS_READ, callee_fndecl));
}
break;
- default:
- gcc_unreachable ();
}
}
}
diff --git a/gcc/testsuite/gcc.dg/analyzer/fd-1.c b/gcc/testsuite/gcc.dg/analyzer/fd-1.c
index 8a72e63833c..5b85a3316e8 100644
--- a/gcc/testsuite/gcc.dg/analyzer/fd-1.c
+++ b/gcc/testsuite/gcc.dg/analyzer/fd-1.c
@@ -3,6 +3,13 @@ int open(const char *, int mode);
#define O_WRONLY 1
#define O_RDWR 2
+typedef enum {
+ S_IRWXU
+ // etc
+} mode_t;
+
+int creat (const char *, mode_t mode);
+
void
test_1 (const char *path)
{
@@ -37,3 +44,17 @@ void test_4 (const char *path)
/* { dg-message "\\(1\\) leaks here" "" { target *-*-* } .-1 } */
}
+void
+test_5 (const char *path, mode_t mode)
+{
+ creat (path, mode); /* { dg-warning "leak of file descriptor \\\[CWE-775\\\]" } */
+}
+
+void
+test_6 (const char *path, mode_t mode)
+{
+ int fd = creat (path, mode);
+ return; /* { dg-warning "leak of file descriptor 'fd' \\\[CWE-775\\\]" } */
+}
+
+
diff --git a/gcc/testsuite/gcc.dg/analyzer/fd-2.c b/gcc/testsuite/gcc.dg/analyzer/fd-2.c
index d794b460a2e..10c9ecdb09d 100644
--- a/gcc/testsuite/gcc.dg/analyzer/fd-2.c
+++ b/gcc/testsuite/gcc.dg/analyzer/fd-2.c
@@ -5,6 +5,13 @@ void close(int fd);
#define O_RDWR 2
#define STDIN 0
+typedef enum {
+ S_IRWXU
+ // etc
+} mode_t;
+
+int creat (const char *, mode_t mode);
+
void
test_1 (const char *path)
{
@@ -46,4 +53,12 @@ test_4 ()
int fd = -1;
close(fd);
close(fd);
+}
+
+void
+test_5 (const char *path, mode_t mode)
+{
+ int fd = creat (path, mode);
+ close(fd);
+ close(fd); /* { dg-warning "double 'close' of file descriptor 'fd' \\\[CWE-1341\\\]" "warning" } */
}
\ No newline at end of file
diff --git a/gcc/testsuite/gcc.dg/analyzer/fd-4.c b/gcc/testsuite/gcc.dg/analyzer/fd-4.c
index ecd787caff7..6b8fca5408f 100644
--- a/gcc/testsuite/gcc.dg/analyzer/fd-4.c
+++ b/gcc/testsuite/gcc.dg/analyzer/fd-4.c
@@ -9,6 +9,12 @@ int read (int fd, void *buf, int nbytes);
#define O_WRONLY 1
#define O_RDWR 2
+typedef enum {
+ S_IRWXU
+ // etc
+} mode_t;
+
+int creat (const char *, mode_t mode);
void
test_1 (const char *path, void *buf)
@@ -69,4 +75,27 @@ test_5 (const char *path)
int fd = open (path, O_RDWR);
close(fd);
printf("%d", fd); /* { dg-bogus "'printf' on a closed file descriptor 'fd'" } */
-}
\ No newline at end of file
+}
+
+
+void
+test_6 (const char *path, mode_t mode, void *buf)
+{
+ int fd = creat (path, mode);
+ if (fd != -1)
+ {
+ read (fd, buf, 1); /* { dg-warning "'read' on write-only file descriptor 'fd'" } */
+ close(fd);
+ }
+}
+
+void
+test_7 (const char *path, mode_t mode, void *buf)
+{
+ int fd = creat (path, mode);
+ if (fd != -1)
+ {
+ write (fd, buf, 1);
+ close(fd);
+ }
+}
diff --git a/gcc/testsuite/gcc.dg/analyzer/fd-dup-1.c b/gcc/testsuite/gcc.dg/analyzer/fd-dup-1.c
new file mode 100644
index 00000000000..eba2570568f
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/analyzer/fd-dup-1.c
@@ -0,0 +1,223 @@
+int open(const char *, int mode);
+void close(int fd);
+int dup (int old_fd);
+int dup2 (int old_fd, int new_fd);
+int dup3 (int old_fd, int new_fd, int flags);
+int write (int fd, void *buf, int nbytes);
+int read (int fd, void *buf, int nbytes);
+#define O_RDONLY 0
+#define O_WRONLY 1
+#define O_RDWR 2
+
+void test_1 (const char *path)
+{
+ int old_fd = open (path, O_RDWR);
+ int new_fd = dup (old_fd); /* { dg-warning "'dup' on possibly invalid file descriptor 'old_fd'" } */
+ close(old_fd);
+ close(new_fd);
+}
+
+void test_2 (const char *path)
+{
+ int old_fd = open (path, O_RDWR);
+ if (old_fd != -1)
+ {
+ int new_fd = dup (old_fd);
+ close(old_fd);
+ return; /* { dg-warning "leak of file descriptor 'new_fd' \\\[CWE-775\\\]" } */
+ }
+}
+
+void test_3 (const char *path, void *buf)
+{
+ int old_fd = open (path, O_RDWR);
+ if (old_fd != -1)
+ {
+ int new_fd = dup (old_fd);
+ write (new_fd, buf, 1); /* { dg-warning "'write' on possibly invalid file descriptor 'new_fd'" } */
+ close (new_fd);
+ close(old_fd);
+ }
+}
+
+
+void test_5 (const char *path, void *buf)
+{
+ int old_fd = open (path, O_RDWR);
+ if (old_fd != -1)
+ {
+ int new_fd = dup (old_fd);
+ if (new_fd != -1)
+ {
+ write (new_fd, buf, 1);
+ close (new_fd);
+
+ }
+ close(old_fd);
+ }
+}
+
+
+void test_7 (const char *path)
+{
+ int old_fd = open (path, O_RDWR);
+ dup2 (old_fd, 4); /* { dg-warning "'dup2' on possibly invalid file descriptor 'old_fd'" } */
+ close(old_fd);
+}
+
+void test_8 (const char *path)
+{
+ int old_fd = open (path, O_RDWR);
+ int new_fd = open (path, O_RDWR);
+ if (old_fd != -1)
+ {
+ dup2 (old_fd, new_fd); /* { dg-warning "'dup2' on possibly invalid file descriptor 'new_fd'" } */
+ close (old_fd);
+ }
+ close (new_fd);
+}
+
+void test_9 (const char *path, void *buf)
+{
+ int old_fd = open (path, O_RDWR);
+
+ if (old_fd != -1)
+ {
+ int new_fd = open (path, O_RDWR);
+ if (new_fd != -1)
+ {
+ int lhs = dup2 (old_fd, new_fd);
+ write (lhs, buf, 1); /* { dg-warning "'write' on possibly invalid file descriptor 'lhs'" } */
+ close(new_fd);
+ close(lhs);
+ }
+ close(old_fd);
+ }
+}
+
+void test_10 (const char *path, int flags)
+{
+ int old_fd = open (path, O_RDWR);
+ int new_fd = open (path, O_RDWR);
+ if (old_fd != -1)
+ {
+ dup3 (old_fd, new_fd, flags); /* { dg-warning "'dup3' on possibly invalid file descriptor 'new_fd'" } */
+ close(old_fd);
+
+ }
+ close(new_fd);
+}
+
+void test_11 (const char *path, int flags)
+{
+ int old_fd = open (path, O_RDWR);
+ int new_fd = open (path, O_RDWR);
+ if (new_fd != -1)
+ {
+ dup3 (old_fd, new_fd, flags); /* { dg-warning "'dup3' on possibly invalid file descriptor 'old_fd'" } */
+ close(new_fd);
+
+ }
+ close(old_fd);
+}
+
+void test_12 (const char *path, void *buf)
+{
+ int old_fd = open (path, O_RDONLY);
+ if (old_fd != -1)
+ {
+ int new_fd = dup (old_fd);
+ if (new_fd != -1)
+ {
+ write (new_fd, buf, 1); /* { dg-warning "'write' on read-only file descriptor 'new_fd'" } */
+ close(new_fd);
+ }
+ close(old_fd);
+ }
+}
+
+void test_13 (const char *path, void *buf)
+{
+ int old_fd = open (path, O_WRONLY);
+ if (old_fd != -1)
+ {
+ int new_fd = dup (old_fd);
+ if (new_fd != -1)
+ {
+ read (new_fd, buf, 1); /* { dg-warning "'read' on write-only file descriptor 'new_fd'" } */
+ close(new_fd);
+ }
+ close(old_fd);
+ }
+}
+
+void test_14 (const char *path, void *buf)
+{
+ int old_fd = open (path, O_RDWR);
+ if (old_fd != -1)
+ {
+ int new_fd = dup (old_fd);
+ if (new_fd != -1)
+ {
+ write (new_fd, buf, 1);
+ read (new_fd, buf, 1);
+ close(new_fd);
+ }
+ close(old_fd);
+ }
+}
+
+void test_15 (void *buf)
+{
+ int fd = dup(0);
+ read (fd, buf, 1); /* { dg-warning "'read' on possibly invalid file descriptor 'fd'" } */
+ close(fd);
+}
+
+void test_16 (void *buf)
+{
+ int fd = dup(1);
+ if (fd != -1)
+ {
+ write (fd, buf, 1);
+ close (fd);
+ }
+}
+
+void test_17 (const char *path)
+{
+ int fd = open (path, O_RDWR);
+ close(fd);
+ dup (fd); /* { dg-warning "'dup' on closed file descriptor 'fd'" } */
+ dup2 (fd, 4); /* { dg-warning "'dup2' on closed file descriptor 'fd'" } */
+}
+
+void
+test_18 (const char *path, void *buf)
+{
+ int fd = open (path, O_RDWR);
+ if (fd != -1)
+ {
+ int fd2 = dup2 (fd, 3);
+ read (fd2, buf, 1); /* { dg-warning "'read' on possibly invalid file descriptor 'fd2'" } */
+ close(fd);
+ close(fd2);
+ }
+}
+
+void
+test_19 (const char *path, void *buf)
+{
+ int fd = open (path, O_WRONLY);
+ if (fd != -1)
+ {
+ int fd2 = dup2 (fd, 4);
+ if (fd2 != -1)
+ {
+ read (fd2, buf, 1); /* { dg-warning "'read' on write-only file descriptor 'fd2'" } */
+ close(fd2);
+ }
+ close (fd);
+ }
+
+}
\ No newline at end of file
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