[PATCH 1/3] treewide: Lift switch variables out of switches

Kees Cook
2019-01-23T11:04:17Z

Variables declared in a switch statement before any case statements
cannot be initialized, so move all instances out of the switches.
After this, future always-initialized stack variables will work
and not throw warnings like this:

fs/fcntl.c: In function ‘send_sigio_to_task’:
fs/fcntl.c:738:13: warning: statement will never be executed [-Wswitch-unreachable]
siginfo_t si;
^~

Signed-off-by: Kees Cook <keescook@chromium.org>
---
arch/x86/xen/enlighten_pv.c | 7 ++++---
drivers/char/pcmcia/cm4000_cs.c | 2 +-
drivers/char/ppdev.c | 20 ++++++++-----------
drivers/gpu/drm/drm_edid.c | 4 ++--
drivers/gpu/drm/i915/intel_display.c | 2 +-
drivers/gpu/drm/i915/intel_pm.c | 4 ++--
drivers/net/ethernet/intel/e1000/e1000_main.c | 3 ++-
drivers/tty/n_tty.c | 3 +--
drivers/usb/gadget/udc/net2280.c | 5 ++---
fs/fcntl.c | 3 ++-
mm/shmem.c | 5 +++--
net/core/skbuff.c | 4 ++--
net/ipv6/ip6_gre.c | 4 ++--
net/ipv6/ip6_tunnel.c | 4 ++--
net/openvswitch/flow_netlink.c | 7 +++----
security/tomoyo/common.c | 3 ++-
security/tomoyo/condition.c | 7 ++++---
security/tomoyo/util.c | 4 ++--
18 files changed, 45 insertions(+), 46 deletions(-)

diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index c54a493e139a..a79d4b548a08 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -907,14 +907,15 @@ static u64 xen_read_msr_safe(unsigned int msr, int *err)
static int xen_write_msr_safe(unsigned int msr, unsigned low, unsigned high)
{
int ret;
+#ifdef CONFIG_X86_64
+ unsigned which;
+ u64 base;
+#endif

ret = 0;

switch (msr) {
#ifdef CONFIG_X86_64
- unsigned which;
- u64 base;
-
case MSR_FS_BASE: which = SEGBASE_FS; goto set;
case MSR_KERNEL_GS_BASE: which = SEGBASE_GS_USER; goto set;
case MSR_GS_BASE: which = SEGBASE_GS_KERNEL; goto set;
diff --git a/drivers/char/pcmcia/cm4000_cs.c b/drivers/char/pcmcia/cm4000_cs.c
index 7a4eb86aedac..7211dc0e6f4f 100644
--- a/drivers/char/pcmcia/cm4000_cs.c
+++ b/drivers/char/pcmcia/cm4000_cs.c
@@ -663,6 +663,7 @@ static void monitor_card(struct timer_list *t)
{
struct cm4000_dev *dev = from_timer(dev, t, timer);
unsigned int iobase = dev->p_dev->resource[0]->start;
+ unsigned char flags0;
unsigned short s;
struct ptsreq ptsreq;
int i, atrc;
@@ -731,7 +732,6 @@ static void monitor_card(struct timer_list *t)
}

switch (dev->mstate) {
- unsigned char flags0;
case M_CARDOFF:
DEBUGP(4, dev, "M_CARDOFF\n");
flags0 = inb(REG_FLAGS0(iobase));
diff --git a/drivers/char/ppdev.c b/drivers/char/ppdev.c
index 1ae77b41050a..d77c97e4f996 100644
--- a/drivers/char/ppdev.c
+++ b/drivers/char/ppdev.c
@@ -359,14 +359,19 @@ static int pp_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
struct pp_struct *pp = file->private_data;
struct parport *port;
void __user *argp = (void __user *)arg;
+ struct ieee1284_info *info;
+ unsigned char reg;
+ unsigned char mask;
+ int mode;
+ s32 time32[2];
+ s64 time64[2];
+ struct timespec64 ts;
+ int ret;

/* First handle the cases that don't take arguments. */
switch (cmd) {
case PPCLAIM:
{
- struct ieee1284_info *info;
- int ret;
-
if (pp->flags & PP_CLAIMED) {
dev_dbg(&pp->pdev->dev, "you've already got it!\n");
return -EINVAL;
@@ -517,15 +522,6 @@ static int pp_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg)

port = pp->pdev->port;
switch (cmd) {
- struct ieee1284_info *info;
- unsigned char reg;
- unsigned char mask;
- int mode;
- s32 time32[2];
- s64 time64[2];
- struct timespec64 ts;
- int ret;
-
case PPRSTATUS:
reg = parport_read_status(port);
if (copy_to_user(argp, &reg, sizeof(reg)))
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index b506e3622b08..8f93956c1628 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -3942,12 +3942,12 @@ static void drm_edid_to_eld(struct drm_connector *connector, struct edid *edid)
}

for_each_cea_db(cea, i, start, end) {
+ int sad_count;
+
db = &cea[i];
dbl = cea_db_payload_len(db);

switch (cea_db_tag(db)) {
- int sad_count;
-
case AUDIO_BLOCK:
/* Audio Data Block, contains SADs */
sad_count = min(dbl / 3, 15 - total_sad_count);
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 3da9c0f9e948..aa1c2ebea456 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -11341,6 +11341,7 @@ static bool check_digital_port_conflicts(struct drm_atomic_state *state)
drm_for_each_connector_iter(connector, &conn_iter) {
struct drm_connector_state *connector_state;
struct intel_encoder *encoder;
+ unsigned int port_mask;

connector_state = drm_atomic_get_new_connector_state(state, connector);
if (!connector_state)
@@ -11354,7 +11355,6 @@ static bool check_digital_port_conflicts(struct drm_atomic_state *state)
WARN_ON(!connector_state->crtc);

switch (encoder->type) {
- unsigned int port_mask;
case INTEL_OUTPUT_DDI:
if (WARN_ON(!HAS_DDI(to_i915(dev))))
break;
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index a26b4eddda25..c135fdec96b3 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -478,9 +478,9 @@ static void vlv_get_fifo_size(struct intel_crtc_state *crtc_state)
struct vlv_fifo_state *fifo_state = &crtc_state->wm.vlv.fifo_state;
enum pipe pipe = crtc->pipe;
int sprite0_start, sprite1_start;
+ uint32_t dsparb, dsparb2, dsparb3;

switch (pipe) {
- uint32_t dsparb, dsparb2, dsparb3;
case PIPE_A:
dsparb = I915_READ(DSPARB);
dsparb2 = I915_READ(DSPARB2);
@@ -1944,6 +1944,7 @@ static void vlv_atomic_update_fifo(struct intel_atomic_state *state,
const struct vlv_fifo_state *fifo_state =
&crtc_state->wm.vlv.fifo_state;
int sprite0_start, sprite1_start, fifo_size;
+ uint32_t dsparb, dsparb2, dsparb3;

if (!crtc_state->fifo_changed)
return;
@@ -1969,7 +1970,6 @@ static void vlv_atomic_update_fifo(struct intel_atomic_state *state,
spin_lock(&dev_priv->uncore.lock);

switch (crtc->pipe) {
- uint32_t dsparb, dsparb2, dsparb3;
case PIPE_A:
dsparb = I915_READ_FW(DSPARB);
dsparb2 = I915_READ_FW(DSPARB2);
diff --git a/drivers/net/ethernet/intel/e1000/e1000_main.c b/drivers/net/ethernet/intel/e1000/e1000_main.c
index 8fe9af0e2ab7..041062736845 100644
--- a/drivers/net/ethernet/intel/e1000/e1000_main.c
+++ b/drivers/net/ethernet/intel/e1000/e1000_main.c
@@ -3140,8 +3140,9 @@ static netdev_tx_t e1000_xmit_frame(struct sk_buff *skb,

hdr_len = skb_transport_offset(skb) + tcp_hdrlen(skb);
if (skb->data_len && hdr_len == len) {
+ unsigned int pull_size;
+
switch (hw->mac_type) {
- unsigned int pull_size;
case e1000_82544:
/* Make sure we have room to chop off 4 bytes,
* and that the end alignment will work out to
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index 5dc9686697cf..eafb39157281 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -634,6 +634,7 @@ static size_t __process_echoes(struct tty_struct *tty)
while (MASK(ldata->echo_commit) != MASK(tail)) {
c = echo_buf(ldata, tail);
if (c == ECHO_OP_START) {
+ unsigned int num_chars, num_bs;
unsigned char op;
int no_space_left = 0;

@@ -652,8 +653,6 @@ static size_t __process_echoes(struct tty_struct *tty)
op = echo_buf(ldata, tail + 1);

switch (op) {
- unsigned int num_chars, num_bs;
-
case ECHO_OP_ERASE_TAB:
if (MASK(ldata->echo_commit) == MASK(tail + 2))
goto not_yet_stored;
diff --git a/drivers/usb/gadget/udc/net2280.c b/drivers/usb/gadget/udc/net2280.c
index e7dae5379e04..2b275a574e94 100644
--- a/drivers/usb/gadget/udc/net2280.c
+++ b/drivers/usb/gadget/udc/net2280.c
@@ -2854,16 +2854,15 @@ static void ep_clear_seqnum(struct net2280_ep *ep)
static void handle_stat0_irqs_superspeed(struct net2280 *dev,
struct net2280_ep *ep, struct usb_ctrlrequest r)
{
+ struct net2280_ep *e;
int tmp = 0;
+ u16 status;

#define w_value le16_to_cpu(r.wValue)
#define w_index le16_to_cpu(r.wIndex)
#define w_length le16_to_cpu(r.wLength)

switch (r.bRequest) {
- struct net2280_ep *e;
- u16 status;
-
case USB_REQ_SET_CONFIGURATION:
dev->addressed_state = !w_value;
goto usb3_delegate;
diff --git a/fs/fcntl.c b/fs/fcntl.c
index 083185174c6d..0640b64ecdc2 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -725,6 +725,8 @@ static void send_sigio_to_task(struct task_struct *p,
struct fown_struct *fown,
int fd, int reason, enum pid_type type)
{
+ kernel_siginfo_t si;
+
/*
* F_SETSIG can change ->signum lockless in parallel, make
* sure we read it once and use the same value throughout.
@@ -735,7 +737,6 @@ static void send_sigio_to_task(struct task_struct *p,
return;

switch (signum) {
- kernel_siginfo_t si;
default:
/* Queue a rt signal with the appropriate fd as its
value. We use SI_SIGIO as the source, not
diff --git a/mm/shmem.c b/mm/shmem.c
index 6ece1e2fe76e..0b02624dd8b2 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1721,6 +1721,9 @@ static int shmem_getpage_gfp(struct inode *inode, pgoff_t index,
swap_free(swap);

} else {
+ loff_t i_size;
+ pgoff_t off;
+
if (vma && userfaultfd_missing(vma)) {
*fault_type = handle_userfault(vmf, VM_UFFD_MISSING);
return 0;
@@ -1734,8 +1737,6 @@ static int shmem_getpage_gfp(struct inode *inode, pgoff_t index,
if (shmem_huge == SHMEM_HUGE_FORCE)
goto alloc_huge;
switch (sbinfo->huge) {
- loff_t i_size;
- pgoff_t off;
case SHMEM_HUGE_NEVER:
goto alloc_nohuge;
case SHMEM_HUGE_WITHIN_SIZE:
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 26d848484912..7597b3fc9d21 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -4506,9 +4506,9 @@ static __sum16 *skb_checksum_setup_ip(struct sk_buff *skb,
typeof(IPPROTO_IP) proto,
unsigned int off)
{
- switch (proto) {
- int err;
+ int err;

+ switch (proto) {
case IPPROTO_TCP:
err = skb_maybe_pull_tail(skb, off + sizeof(struct tcphdr),
off + MAX_TCP_HDR_LEN);
diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index b1be67ca6768..9aee1add46c0 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -427,9 +427,11 @@ static int ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
u8 type, u8 code, int offset, __be32 info)
{
struct net *net = dev_net(skb->dev);
+ struct ipv6_tlv_tnl_enc_lim *tel;
const struct ipv6hdr *ipv6h;
struct tnl_ptk_info tpi;
struct ip6_tnl *t;
+ __u32 teli;

if (gre_parse_header(skb, &tpi, NULL, htons(ETH_P_IPV6),
offset) < 0)
@@ -442,8 +444,6 @@ static int ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
return -ENOENT;

switch (type) {
- struct ipv6_tlv_tnl_enc_lim *tel;
- __u32 teli;
case ICMPV6_DEST_UNREACH:
net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
t->parms.name);
diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index 0c6403cf8b52..94ccc7a9037b 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -478,10 +478,12 @@ ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
struct net *net = dev_net(skb->dev);
u8 rel_type = ICMPV6_DEST_UNREACH;
u8 rel_code = ICMPV6_ADDR_UNREACH;
+ struct ipv6_tlv_tnl_enc_lim *tel;
__u32 rel_info = 0;
struct ip6_tnl *t;
int err = -ENOENT;
int rel_msg = 0;
+ __u32 mtu, teli;
u8 tproto;
__u16 len;

@@ -501,8 +503,6 @@ ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
err = 0;

switch (*type) {
- struct ipv6_tlv_tnl_enc_lim *tel;
- __u32 mtu, teli;
case ICMPV6_DEST_UNREACH:
net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
t->parms.name);
diff --git a/net/openvswitch/flow_netlink.c b/net/openvswitch/flow_netlink.c
index 691da853bef5..dee2f9516ae8 100644
--- a/net/openvswitch/flow_netlink.c
+++ b/net/openvswitch/flow_netlink.c
@@ -2652,8 +2652,11 @@ static int validate_set(const struct nlattr *a,
u8 mac_proto, __be16 eth_type, bool masked, bool log)
{
const struct nlattr *ovs_key = nla_data(a);
+ const struct ovs_key_ipv4 *ipv4_key;
+ const struct ovs_key_ipv6 *ipv6_key;
int key_type = nla_type(ovs_key);
size_t key_len;
+ int err;

/* There can be only one key in a action */
if (nla_total_size(nla_len(ovs_key)) != nla_len(a))
@@ -2671,10 +2674,6 @@ static int validate_set(const struct nlattr *a,
return -EINVAL;

switch (key_type) {
- const struct ovs_key_ipv4 *ipv4_key;
- const struct ovs_key_ipv6 *ipv6_key;
- int err;
-
case OVS_KEY_ATTR_PRIORITY:
case OVS_KEY_ATTR_SKB_MARK:
case OVS_KEY_ATTR_CT_MARK:
diff --git a/security/tomoyo/common.c b/security/tomoyo/common.c
index c598aa00d5e3..bedbd0518153 100644
--- a/security/tomoyo/common.c
+++ b/security/tomoyo/common.c
@@ -1583,8 +1583,9 @@ static void tomoyo_read_domain(struct tomoyo_io_buffer *head)
list_for_each_cookie(head->r.domain, &tomoyo_domain_list) {
struct tomoyo_domain_info *domain =
list_entry(head->r.domain, typeof(*domain), list);
+ u8 i;
+
switch (head->r.step) {
- u8 i;
case 0:
if (domain->is_deleted &&
!head->r.print_this_domain_only)
diff --git a/security/tomoyo/condition.c b/security/tomoyo/condition.c
index 8d0e1b9c9c57..c10d903febe5 100644
--- a/security/tomoyo/condition.c
+++ b/security/tomoyo/condition.c
@@ -787,10 +787,11 @@ bool tomoyo_condition(struct tomoyo_request_info *r,
/* Check string expressions. */
if (right == TOMOYO_NAME_UNION) {
const struct tomoyo_name_union *ptr = names_p++;
+ struct tomoyo_path_info *symlink;
+ struct tomoyo_execve *ee;
+ struct file *file;
+
switch (left) {
- struct tomoyo_path_info *symlink;
- struct tomoyo_execve *ee;
- struct file *file;
case TOMOYO_SYMLINK_TARGET:
symlink = obj ? obj->symlink_target : NULL;
if (!symlink ||
diff --git a/security/tomoyo/util.c b/security/tomoyo/util.c
index badffc8271c8..8e2bb36df37b 100644
--- a/security/tomoyo/util.c
+++ b/security/tomoyo/util.c
@@ -668,6 +668,8 @@ static bool tomoyo_file_matches_pattern2(const char *filename,
{
while (filename < filename_end && pattern < pattern_end) {
char c;
+ int i, j;
+
if (*pattern != '\\') {
if (*filename++ != *pattern++)
return false;
@@ -676,8 +678,6 @@ static bool tomoyo_file_matches_pattern2(const char *filename,
c = *filename;
pattern++;
switch (*pattern) {
- int i;
- int j;
case '?':
if (c == '/') {
return false;
--
2.17.1