From: "Gustavo A. R. Silva" gustavoars@kernel.org
stable inclusion from stable-v5.10.120 commit 1f0681f3bd5665080bde3c5b9568cc27df765ce0 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5L6BR
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
--------------------------------
commit 336feb502a715909a8136eb6a62a83d7268a353b upstream.
Fix the following -Wstringop-overflow warnings when building with GCC-11:
drivers/gpu/drm/i915/intel_pm.c:3106:9: warning: ‘intel_read_wm_latency’ accessing 16 bytes in a region of size 10 [-Wstringop-overflow=] 3106 | intel_read_wm_latency(dev_priv, dev_priv->wm.pri_latency); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/gpu/drm/i915/intel_pm.c:3106:9: note: referencing argument 2 of type ‘u16 *’ {aka ‘short unsigned int *’} drivers/gpu/drm/i915/intel_pm.c:2861:13: note: in a call to function ‘intel_read_wm_latency’ 2861 | static void intel_read_wm_latency(struct drm_i915_private *dev_priv, | ^~~~~~~~~~~~~~~~~~~~~
by removing the over-specified array size from the argument declarations.
It seems that this code is actually safe because the size of the array depends on the hardware generation, and the function checks for that.
Notice that wm can be an array of 5 elements: drivers/gpu/drm/i915/intel_pm.c:3109: intel_read_wm_latency(dev_priv, dev_priv->wm.pri_latency);
or an array of 8 elements: drivers/gpu/drm/i915/intel_pm.c:3131: intel_read_wm_latency(dev_priv, dev_priv->wm.skl_latency);
and the compiler legitimately complains about that.
This helps with the ongoing efforts to globally enable -Wstringop-overflow.
Link: https://github.com/KSPP/linux/issues/181 Signed-off-by: Gustavo A. R. Silva gustavoars@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Acked-by: Xie XiuQi xiexiuqi@huawei.com --- drivers/gpu/drm/i915/intel_pm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index 472aaea75ef8..2f2dc029668b 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -2846,7 +2846,7 @@ static void ilk_compute_wm_level(const struct drm_i915_private *dev_priv, }
static void intel_read_wm_latency(struct drm_i915_private *dev_priv, - u16 wm[8]) + u16 wm[]) { struct intel_uncore *uncore = &dev_priv->uncore;