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From e57c6e07345a8459d933cb3b09badad9199ccee0 Mon Sep 17 00:00:00 2001
From: Kees Cook <keescook@chromium.org>
Date: Wed, 3 Jun 2020 13:09:38 -0700
Subject: treewide: Remove uninitialized_var() usage
Git-commit: 3f649ab728cda8038259d8f14492fe400fbab911
Patch-mainline: v5.9-rc1
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322

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>
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/bridge/sil-sii8620.c            | 2 +-
 drivers/gpu/drm/drm_edid.c                      | 2 +-
 drivers/gpu/drm/exynos/exynos_drm_dsi.c         | 6 +++---
 drivers/gpu/drm/i915/display/intel_fbc.c        | 2 +-
 drivers/gpu/drm/i915/gt/intel_lrc.c             | 2 +-
 drivers/gpu/drm/i915/intel_uncore.c             | 2 +-
 drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c | 4 ++--
 drivers/video/fbdev/matrox/matroxfb_maven.c     | 6 +++---
 drivers/video/fbdev/pm3fb.c                     | 6 +++---
 drivers/video/fbdev/riva/riva_hw.c              | 3 +--
 10 files changed, 17 insertions(+), 18 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 412572f88b67..61807e4b1aca 100644
--- a/drivers/gpu/drm/i915/display/intel_fbc.c
+++ b/drivers/gpu/drm/i915/display/intel_fbc.c
@@ -461,7 +461,7 @@ 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 cb07e1d2a353..f6bc6852892d 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/video/fbdev/matrox/matroxfb_maven.c b/drivers/video/fbdev/matrox/matroxfb_maven.c
index eda893b7a2e9..9a98c4a6ba33 100644
--- a/drivers/video/fbdev/matrox/matroxfb_maven.c
+++ b/drivers/video/fbdev/matrox/matroxfb_maven.c
@@ -300,7 +300,7 @@ static int matroxfb_mavenclock(const struct matrox_pll_ctl *ctl,
 		unsigned int* in, unsigned int* feed, unsigned int* post,
 		unsigned int* htotal2) {
 	unsigned int fvco;
-	unsigned int uninitialized_var(p);
+	unsigned int p;
 
 	fvco = matroxfb_PLL_mavenclock(&maven1000_pll, ctl, htotal, vtotal, in, feed, &p, htotal2);
 	if (!fvco)
@@ -732,8 +732,8 @@ static int maven_find_exact_clocks(unsigned int ht, unsigned int vt,
 
 	for (x = 0; x < 8; x++) {
 		unsigned int c;
-		unsigned int uninitialized_var(a), uninitialized_var(b),
-			     uninitialized_var(h2);
+		unsigned int a, b,
+			     h2;
 		unsigned int h = ht + 2 + x;
 
 		if (!matroxfb_mavenclock((m->mode == MATROXFB_OUTPUT_MODE_PAL) ? &maven_PAL : &maven_NTSC, h, vt, &a, &b, &c, &h2)) {
diff --git a/drivers/video/fbdev/pm3fb.c b/drivers/video/fbdev/pm3fb.c
index 7497bd36334c..a8faf46adeb1 100644
--- a/drivers/video/fbdev/pm3fb.c
+++ b/drivers/video/fbdev/pm3fb.c
@@ -821,9 +821,9 @@ static void pm3fb_write_mode(struct fb_info *info)
 
 	wmb();
 	{
-		unsigned char uninitialized_var(m);	/* ClkPreScale */
-		unsigned char uninitialized_var(n);	/* ClkFeedBackScale */
-		unsigned char uninitialized_var(p);	/* ClkPostScale */
+		unsigned char m;	/* ClkPreScale */
+		unsigned char n;	/* ClkFeedBackScale */
+		unsigned char p;	/* ClkPostScale */
 		unsigned long pixclock = PICOS2KHZ(info->var.pixclock);
 
 		(void)pm3fb_calculate_clock(pixclock, &m, &n, &p);
diff --git a/drivers/video/fbdev/riva/riva_hw.c b/drivers/video/fbdev/riva/riva_hw.c
index 08c9ee46978e..4168ac464565 100644
--- a/drivers/video/fbdev/riva/riva_hw.c
+++ b/drivers/video/fbdev/riva/riva_hw.c
@@ -1245,8 +1245,7 @@ int CalcStateExt
 )
 {
     int pixelDepth;
-    int uninitialized_var(VClk),uninitialized_var(m),
-        uninitialized_var(n),	uninitialized_var(p);
+    int VClk, m, n, p;
 
     /*
      * Save mode parameters.
-- 
2.29.2