Re: [syzbot] [PATCH] Test divide err in drm

From: syzbot
Date: Fri Nov 17 2023 - 22:43:02 EST


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Subject: [PATCH] Test divide err in drm
Author: eadavis@xxxxxx

please test divide err in drm

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 888cf78c29e2

diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
index ac9a406250c5..e3f05539f704 100644
--- a/drivers/gpu/drm/drm_modes.c
+++ b/drivers/gpu/drm/drm_modes.c
@@ -1283,9 +1283,9 @@ EXPORT_SYMBOL(drm_mode_set_name);
* @modes's vrefresh rate in Hz, rounded to the nearest integer. Calculates the
* value first if it is not yet set.
*/
-int drm_mode_vrefresh(const struct drm_display_mode *mode)
+long drm_mode_vrefresh(const struct drm_display_mode *mode)
{
- unsigned int num, den;
+ unsigned long num, den;

if (mode->htotal == 0 || mode->vtotal == 0)
return 0;
@@ -1300,6 +1300,8 @@ int drm_mode_vrefresh(const struct drm_display_mode *mode)
if (mode->vscan > 1)
den *= mode->vscan;

+ printk("mode: %p, ht: %llu, vt: %llu, c: %llu, vsc: %llu, den: %llu, num: %llu, %s",
+ mode, mode->htotal, mode->vtotal, mode->clock, mode->vscan, den, num, __func__);
return DIV_ROUND_CLOSEST_ULL(mul_u32_u32(num, 1000), den);
}
EXPORT_SYMBOL(drm_mode_vrefresh);
diff --git a/include/drm/drm_modes.h b/include/drm/drm_modes.h
index c613f0abe9dc..19e37e92dfaf 100644
--- a/include/drm/drm_modes.h
+++ b/include/drm/drm_modes.h
@@ -422,7 +422,7 @@ struct drm_display_mode {
/**
* DRM_MODE_FMT - printf string for &struct drm_display_mode
*/
-#define DRM_MODE_FMT "\"%s\": %d %d %d %d %d %d %d %d %d %d 0x%x 0x%x"
+#define DRM_MODE_FMT "\"%s\": %llu %d %d %d %d %d %d %d %d %d 0x%x 0x%x"

/**
* DRM_MODE_ARG - printf arguments for &struct drm_display_mode
@@ -526,7 +526,7 @@ static inline int of_get_drm_panel_display_mode(struct device_node *np,
#endif

void drm_mode_set_name(struct drm_display_mode *mode);
-int drm_mode_vrefresh(const struct drm_display_mode *mode);
+long drm_mode_vrefresh(const struct drm_display_mode *mode);
void drm_mode_get_hv_timing(const struct drm_display_mode *mode,
int *hdisplay, int *vdisplay);