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>

7 files changed, 10 insertions, 10 deletions

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;