drm/i915: fix potential dangling else problems in for_each_ macros
We have serious dangling else bugs waiting to happen in our for_each_
style macros with ifs. Consider, for example,
#define for_each_power_domain(domain, mask) \
for ((domain) = 0; (domain) < POWER_DOMAIN_NUM; (domain)++) \
if ((1 << (domain)) & (mask))
If this is used in context:
if (condition)
for_each_power_domain(domain, mask);
else
foo();
foo() will be called for each domain *not* in mask, if condition holds,
and not at all if condition doesn't hold.
Fix this by reversing the conditions in the macros, and adding an else
branch for the "for each" block, so that other if/else blocks can't
interfere. Provide a "for_each_if" helper macro to make it easier to get
this right.
v2: move for_each_if to drmP.h in a separate patch.
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1448392916-2281-2-git-send-email-jani.nikula@intel.com
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 95bb27d..fd88060 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -288,7 +288,7 @@
list_for_each_entry(intel_plane, \
&(dev)->mode_config.plane_list, \
base.head) \
- if ((intel_plane)->pipe == (intel_crtc)->pipe)
+ for_each_if ((intel_plane)->pipe == (intel_crtc)->pipe)
#define for_each_intel_crtc(dev, intel_crtc) \
list_for_each_entry(intel_crtc, &dev->mode_config.crtc_list, base.head)
@@ -305,15 +305,15 @@
#define for_each_encoder_on_crtc(dev, __crtc, intel_encoder) \
list_for_each_entry((intel_encoder), &(dev)->mode_config.encoder_list, base.head) \
- if ((intel_encoder)->base.crtc == (__crtc))
+ for_each_if ((intel_encoder)->base.crtc == (__crtc))
#define for_each_connector_on_encoder(dev, __encoder, intel_connector) \
list_for_each_entry((intel_connector), &(dev)->mode_config.connector_list, base.head) \
- if ((intel_connector)->base.encoder == (__encoder))
+ for_each_if ((intel_connector)->base.encoder == (__encoder))
#define for_each_power_domain(domain, mask) \
for ((domain) = 0; (domain) < POWER_DOMAIN_NUM; (domain)++) \
- if ((1 << (domain)) & (mask))
+ for_each_if ((1 << (domain)) & (mask))
struct drm_i915_private;
struct i915_mm_struct;
@@ -734,7 +734,7 @@
for ((i__) = 0, (domain__) = &(dev_priv__)->uncore.fw_domain[0]; \
(i__) < FW_DOMAIN_ID_COUNT; \
(i__)++, (domain__) = &(dev_priv__)->uncore.fw_domain[i__]) \
- if (((mask__) & (dev_priv__)->uncore.fw_domains) & (1 << (i__)))
+ for_each_if (((mask__) & (dev_priv__)->uncore.fw_domains) & (1 << (i__)))
#define for_each_fw_domain(domain__, dev_priv__, i__) \
for_each_fw_domain_mask(domain__, FORCEWAKE_ALL, dev_priv__, i__)
@@ -1979,7 +1979,7 @@
/* Iterate over initialised rings */
#define for_each_ring(ring__, dev_priv__, i__) \
for ((i__) = 0; (i__) < I915_NUM_RINGS; (i__)++) \
- if (((ring__) = &(dev_priv__)->ring[(i__)]), intel_ring_initialized((ring__)))
+ for_each_if ((((ring__) = &(dev_priv__)->ring[(i__)]), intel_ring_initialized((ring__))))
enum hdmi_force_audio {
HDMI_AUDIO_OFF_DVI = -2, /* no aux data for HDMI-DVI converter */
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 9f02a09..bea7f3ae 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -12281,7 +12281,7 @@
list_for_each_entry((intel_crtc), \
&(dev)->mode_config.crtc_list, \
base.head) \
- if (mask & (1 <<(intel_crtc)->pipe))
+ for_each_if (mask & (1 <<(intel_crtc)->pipe))
static bool
intel_compare_m_n(unsigned int m, unsigned int n,
diff --git a/drivers/gpu/drm/i915/intel_dsi.h b/drivers/gpu/drm/i915/intel_dsi.h
index e6cb252..02551ff 100644
--- a/drivers/gpu/drm/i915/intel_dsi.h
+++ b/drivers/gpu/drm/i915/intel_dsi.h
@@ -117,7 +117,7 @@
#define for_each_dsi_port(__port, __ports_mask) \
for ((__port) = PORT_A; (__port) < I915_MAX_PORTS; (__port)++) \
- if ((__ports_mask) & (1 << (__port)))
+ for_each_if ((__ports_mask) & (1 << (__port)))
static inline struct intel_dsi *enc_to_intel_dsi(struct drm_encoder *encoder)
{
diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c
index d89c1d0..13f1420 100644
--- a/drivers/gpu/drm/i915/intel_runtime_pm.c
+++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
@@ -57,13 +57,13 @@
i < (power_domains)->power_well_count && \
((power_well) = &(power_domains)->power_wells[i]); \
i++) \
- if ((power_well)->domains & (domain_mask))
+ for_each_if ((power_well)->domains & (domain_mask))
#define for_each_power_well_rev(i, power_well, domain_mask, power_domains) \
for (i = (power_domains)->power_well_count - 1; \
i >= 0 && ((power_well) = &(power_domains)->power_wells[i]);\
i--) \
- if ((power_well)->domains & (domain_mask))
+ for_each_if ((power_well)->domains & (domain_mask))
bool intel_display_power_well_is_enabled(struct drm_i915_private *dev_priv,
int power_well_id);