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From: Ashutosh Dixit <ashutosh.dixit@intel.com>
To: intel-gfx@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org, Rodrigo Vivi <rodrigo.vivi@intel.com>
Subject: [Intel-gfx] [PATCH] drm/i915/hwmon: Silence UBSAN uninitialized bool variable warning
Date: Wed, 10 May 2023 11:36:06 -0700	[thread overview]
Message-ID: <20230510183606.2480777-1-ashutosh.dixit@intel.com> (raw)

Loading i915 on UBSAN enabled kernels (CONFIG_UBSAN/CONFIG_UBSAN_BOOL)
causes the following warning:

  UBSAN: invalid-load in drivers/gpu/drm/i915/gt/uc/intel_uc.c:558:2
  load of value 255 is not a valid value for type '_Bool'
  Call Trace:
   dump_stack_lvl+0x57/0x7d
   ubsan_epilogue+0x5/0x40
   __ubsan_handle_load_invalid_value.cold+0x43/0x48
   __uc_init_hw+0x76a/0x903 [i915]
   ...
   i915_driver_probe+0xfb1/0x1eb0 [i915]
   i915_pci_probe+0xbe/0x2d0 [i915]

The warning happens because during probe i915_hwmon is still not available
which results in the output boolean variable *old remaining
uninitialized. Silence the warning by initializing the variable to an
arbitrary value.

Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
---
 drivers/gpu/drm/i915/i915_hwmon.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_hwmon.c b/drivers/gpu/drm/i915/i915_hwmon.c
index a3bdd9f68a458..685663861bc0b 100644
--- a/drivers/gpu/drm/i915/i915_hwmon.c
+++ b/drivers/gpu/drm/i915/i915_hwmon.c
@@ -502,8 +502,11 @@ void i915_hwmon_power_max_disable(struct drm_i915_private *i915, bool *old)
 	struct i915_hwmon *hwmon = i915->hwmon;
 	u32 r;
 
-	if (!hwmon || !i915_mmio_reg_valid(hwmon->rg.pkg_rapl_limit))
+	if (!hwmon || !i915_mmio_reg_valid(hwmon->rg.pkg_rapl_limit)) {
+		/* Fix uninitialized bool variable warning */
+		*old = false;
 		return;
+	}
 
 	mutex_lock(&hwmon->hwmon_lock);
 
-- 
2.38.0


             reply	other threads:[~2023-05-10 18:36 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-05-10 18:36 Ashutosh Dixit [this message]
2023-05-11  0:20 ` [Intel-gfx] ✓ Fi.CI.BAT: success for drm/i915/hwmon: Silence UBSAN uninitialized bool variable warning Patchwork
2023-05-11  3:56 ` [Intel-gfx] ✗ Fi.CI.IGT: failure " Patchwork
2023-05-11 17:43 ` [Intel-gfx] [PATCH] " Dixit, Ashutosh
2023-05-12  9:33   ` Andi Shyti
2023-05-12 20:40     ` Dixit, Ashutosh
2023-05-12  9:41 ` Andrzej Hajda

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