treewide: Remove uninitialized_var() usage

Using uninitialized_var() is dangerous as it papers over real bugs[1]
(or can in the future), and suppresses unrelated compiler warnings
(e.g. "unused variable"). If the compiler thinks it is uninitialized,
either simply initialize the variable or make compiler changes.

In preparation for removing[2] the[3] macro[4], remove all remaining
needless uses with the following script:

git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \
	xargs perl -pi -e \
		's/\buninitialized_var\(([^\)]+)\)/\1/g;
		 s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;'

drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid
pathological white-space.

No outstanding warnings were found building allmodconfig with GCC 9.3.0
for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64,
alpha, and m68k.

[1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/
[2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/
[3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/
[4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/

Reviewed-by: Leon Romanovsky <leonro@mellanox.com> # drivers/infiniband and mlx4/mlx5
Acked-by: Jason Gunthorpe <jgg@mellanox.com> # IB
Acked-by: Kalle Valo <kvalo@codeaurora.org> # wireless drivers
Reviewed-by: Chao Yu <yuchao0@huawei.com> # erofs
Signed-off-by: Kees Cook <keescook@chromium.org>

86 files changed, 136 insertions, 137 deletions

diff --git a/drivers/acpi/acpi_pad.c b/drivers/acpi/acpi_pad.c
index e7dc0133f817..6cc4c92d9ff9 100644
--- a/drivers/acpi/acpi_pad.c
+++ b/drivers/acpi/acpi_pad.c
@@ -88,7 +88,7 @@ static void round_robin_cpu(unsigned int tsk_index)
 	cpumask_var_t tmp;
 	int cpu;
 	unsigned long min_weight = -1;
-	unsigned long uninitialized_var(preferred_cpu);
+	unsigned long preferred_cpu;
 
 	if (!alloc_cpumask_var(&tmp, GFP_KERNEL))
 		return;
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 46336084b1a9..ec233208585b 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -93,7 +93,7 @@ static ssize_t ata_scsi_park_show(struct device *device,
 	struct ata_link *link;
 	struct ata_device *dev;
 	unsigned long now;
-	unsigned int uninitialized_var(msecs);
+	unsigned int msecs;
 	int rc = 0;
 
 	ap = ata_shost_to_port(sdev->host);
diff --git a/drivers/atm/zatm.c b/drivers/atm/zatm.c
index 57f97b95a453..165eebe06e39 100644
--- a/drivers/atm/zatm.c
+++ b/drivers/atm/zatm.c
@@ -940,7 +940,7 @@ static int open_tx_first(struct atm_vcc *vcc)
 	    vcc->qos.txtp.max_pcr >= ATM_OC3_PCR);
 	if (unlimited && zatm_dev->ubr != -1) zatm_vcc->shaper = zatm_dev->ubr;
 	else {
-		int uninitialized_var(pcr);
+		int pcr;
 
 		if (unlimited) vcc->qos.txtp.max_sdu = ATM_MAX_AAL5_PDU;
 		if ((zatm_vcc->shaper = alloc_shaper(vcc->dev,&pcr,
diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index da4a3ebe04ef..c0017cc51ecc 100644
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -3423,7 +3423,7 @@ int drbd_adm_dump_devices(struct sk_buff *skb, struct netlink_callback *cb)
 {
 	struct nlattr *resource_filter;
 	struct drbd_resource *resource;
-	struct drbd_device *uninitialized_var(device);
+	struct drbd_device *device;
 	int minor, err, retcode;
 	struct drbd_genlmsghdr *dh;
 	struct device_info device_info;
@@ -3512,7 +3512,7 @@ int drbd_adm_dump_connections(struct sk_buff *skb, struct netlink_callback *cb)
 {
 	struct nlattr *resource_filter;
 	struct drbd_resource *resource = NULL, *next_resource;
-	struct drbd_connection *uninitialized_var(connection);
+	struct drbd_connection *connection;
 	int err = 0, retcode;
 	struct drbd_genlmsghdr *dh;
 	struct connection_info connection_info;
@@ -3674,7 +3674,7 @@ int drbd_adm_dump_peer_devices(struct sk_buff *skb, struct netlink_callback *cb)
 {
 	struct nlattr *resource_filter;
 	struct drbd_resource *resource;
-	struct drbd_device *uninitialized_var(device);
+	struct drbd_device *device;
 	struct drbd_peer_device *peer_device = NULL;
 	int minor, err, retcode;
 	struct drbd_genlmsghdr *dh;
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 4f61e9209461..d9c0e7d154f9 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -1993,7 +1993,7 @@ static int rbd_object_map_update_finish(struct rbd_obj_request *obj_req,
 	struct rbd_device *rbd_dev = obj_req->img_request->rbd_dev;
 	struct ceph_osd_data *osd_data;
 	u64 objno;
-	u8 state, new_state, uninitialized_var(current_state);
+	u8 state, new_state, current_state;
 	bool has_current_state;
 	void *p;
 
diff --git a/drivers/clk/clk-gate.c b/drivers/clk/clk-gate.c
index 2ca1f2ac38a6..070dc47e95a1 100644
--- a/drivers/clk/clk-gate.c
+++ b/drivers/clk/clk-gate.c
@@ -56,7 +56,7 @@ static void clk_gate_endisable(struct clk_hw *hw, int enable)
 {
 	struct clk_gate *gate = to_clk_gate(hw);
 	int set = gate->flags & CLK_GATE_SET_TO_DISABLE ? 1 : 0;
-	unsigned long uninitialized_var(flags);
+	unsigned long flags;
 	u32 reg;
 
 	set ^= enable;
diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index 54fdc39cd0bc..7dde21b18b04 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -1099,7 +1099,7 @@ static void context_tasklet(unsigned long data)
 static int context_add_buffer(struct context *ctx)
 {
 	struct descriptor_buffer *desc;
-	dma_addr_t uninitialized_var(bus_addr);
+	dma_addr_t bus_addr;
 	int offset;
 
 	/*
@@ -1289,7 +1289,7 @@ static int at_context_queue_packet(struct context *ctx,
 				   struct fw_packet *packet)
 {
 	struct fw_ohci *ohci = ctx->ohci;
-	dma_addr_t d_bus, uninitialized_var(payload_bus);
+	dma_addr_t d_bus, payload_bus;
 	struct driver_data *driver_data;
 	struct descriptor *d, *last;
 	__le32 *header;
@@ -2445,7 +2445,7 @@ static int ohci_set_config_rom(struct fw_card *card,
 {
 	struct fw_ohci *ohci;
 	__be32 *next_config_rom;
-	dma_addr_t uninitialized_var(next_config_rom_bus);
+	dma_addr_t next_config_rom_bus;
 
 	ohci = fw_ohci(card);
 
@@ -2933,10 +2933,10 @@ static struct fw_iso_context *ohci_allocate_iso_context(struct fw_card *card,
 				int type, int channel, size_t header_size)
 {
 	struct fw_ohci *ohci = fw_ohci(card);
-	struct iso_context *uninitialized_var(ctx);
-	descriptor_callback_t uninitialized_var(callback);
-	u64 *uninitialized_var(channels);
-	u32 *uninitialized_var(mask), uninitialized_var(regs);
+	struct iso_context *ctx;
+	descriptor_callback_t callback;
+	u64 *channels;
+	u32 *mask, regs;
 	int index, ret = -EBUSY;
 
 	spin_lock_irq(&ohci->lock);
diff --git a/drivers/gpu/drm/bridge/sil-sii8620.c b/drivers/gpu/drm/bridge/sil-sii8620.c
index 92acd336aa89..6cd8e012de5d 100644
--- a/drivers/gpu/drm/bridge/sil-sii8620.c
+++ b/drivers/gpu/drm/bridge/sil-sii8620.c
@@ -986,7 +986,7 @@ static void sii8620_set_auto_zone(struct sii8620 *ctx)
 
 static void sii8620_stop_video(struct sii8620 *ctx)
 {
-	u8 uninitialized_var(val);
+	u8 val;
 
 	sii8620_write_seq_static(ctx,
 		REG_TPI_INTR_EN, 0,
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index fed653f13c26..b98fa573e706 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -3051,7 +3051,7 @@ static int drm_cvt_modes(struct drm_connector *connector,
 	const u8 empty[3] = { 0, 0, 0 };
 
 	for (i = 0; i < 4; i++) {
-		int uninitialized_var(width), height;
+		int width, height;
 		cvt = &(timing->data.other_data.data.cvt[i]);
 
 		if (!memcmp(cvt->code, empty, 3))
diff --git a/drivers/gpu/drm/exynos/exynos_drm_dsi.c b/drivers/gpu/drm/exynos/exynos_drm_dsi.c
index ee96a95fb6be..7a6f6df5e954 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_dsi.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_dsi.c
@@ -547,9 +547,9 @@ static unsigned long exynos_dsi_pll_find_pms(struct exynos_dsi *dsi,
 	unsigned long best_freq = 0;
 	u32 min_delta = 0xffffffff;
 	u8 p_min, p_max;
-	u8 _p, uninitialized_var(best_p);
-	u16 _m, uninitialized_var(best_m);
-	u8 _s, uninitialized_var(best_s);
+	u8 _p, best_p;
+	u16 _m, best_m;
+	u8 _s, best_s;
 
 	p_min = DIV_ROUND_UP(fin, (12 * MHZ));
 	p_max = fin / (6 * MHZ);
diff --git a/drivers/gpu/drm/i915/display/intel_fbc.c b/drivers/gpu/drm/i915/display/intel_fbc.c
index 1c26673acb2d..c3a83c06c1b5 100644
--- a/drivers/gpu/drm/i915/display/intel_fbc.c
+++ b/drivers/gpu/drm/i915/display/intel_fbc.c
@@ -474,7 +474,7 @@ static int intel_fbc_alloc_cfb(struct drm_i915_private *dev_priv,
 			       unsigned int size, unsigned int fb_cpp)
 {
 	struct intel_fbc *fbc = &dev_priv->fbc;
-	struct drm_mm_node *uninitialized_var(compressed_llb);
+	struct drm_mm_node *compressed_llb;
 	int ret;
 
 	drm_WARN_ON(&dev_priv->drm,
diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index 7c3d8ef4a47c..234bf45c290b 100644
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -1103,7 +1103,7 @@ static struct i915_request *
 __unwind_incomplete_requests(struct intel_engine_cs *engine)
 {
 	struct i915_request *rq, *rn, *active = NULL;
-	struct list_head *uninitialized_var(pl);
+	struct list_head *pl;
 	int prio = I915_PRIORITY_INVALID;
 
 	lockdep_assert_held(&engine->active.lock);
diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
index a61cb8ca4d50..c8fd2bcb17ee 100644
--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -1991,7 +1991,7 @@ int __intel_wait_for_register_fw(struct intel_uncore *uncore,
 				 unsigned int slow_timeout_ms,
 				 u32 *out_value)
 {
-	u32 uninitialized_var(reg_value);
+	u32 reg_value;
 #define done (((reg_value = intel_uncore_read_fw(uncore, reg)) & mask) == value)
 	int ret;
 
diff --git a/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c b/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
index 3feff0c45b3f..542dcf7eddd6 100644
--- a/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
+++ b/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
@@ -517,8 +517,8 @@ dw_mipi_dsi_get_lane_mbps(void *priv_data, const struct drm_display_mode *mode,
 	unsigned long best_freq = 0;
 	unsigned long fvco_min, fvco_max, fin, fout;
 	unsigned int min_prediv, max_prediv;
-	unsigned int _prediv, uninitialized_var(best_prediv);
-	unsigned long _fbdiv, uninitialized_var(best_fbdiv);
+	unsigned int _prediv, best_prediv;
+	unsigned long _fbdiv, best_fbdiv;
 	unsigned long min_delta = ULONG_MAX;
 
 	dsi->format = format;
diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c
index bc698240