Lucas De Marchi [off-list ref] writes:

Hi!

CC'ing Rusty and mailing lists

Thanks.

Rusty and ohers: it looks like both CONFIG_CRC32 and
CONFIG_CRYPTO_CRC32 can be compiled as module, and they generate
modules with the same name, crc32.  Could that be fixed?

Gah.  Looks like it's been that way since at least 2014, too.

I think we could rename it to crypto_crc32, but I don't think it's the
only one.  Marco, I think depmod should probably FAIL if two modules
have the same name, which would at least find such problems.

(BTW is there a nice way to figure out if a config var is a tristate?  These
are only problematic if both CONFIG_ are tristate.)

Here's a hacky attempt to look for problems:

rusty@rusty-Lemur:~/devel/kernel/linux (master)$ KCONFIGS=`find * -name 'Kconfig*'`; for m in `find [b-z]* -name 'Makefile*'`; do sed -n 's,obj-\$(CONFIG.*+= \([a-z0-9_-]\+\.o\)$,'$m' \1,p' <$m | sort -u; done | sort -k 2 | uniq -D -f 1 | while read m obj; do fgrep -w $obj $m /dev/null; done | while read LINE; do conf=`echo $LINE | sed 's/.*\$(CONFIG_\([A-Z0-9_]*\).*/\1/'`; if grep -C2 "^config $conf\$" $KCONFIGS | fgrep -q tristate; then echo $LINE; fi; done

Here are the results (mildly filtered by me):

drivers/gpu/drm/i2c/Makefile:obj-$(CONFIG_DRM_I2C_ADV7511) += adv7511.o
drivers/media/i2c/Makefile:obj-$(CONFIG_VIDEO_ADV7511) += adv7511.o

drivers/media/platform/coda/Makefile:obj-$(CONFIG_VIDEO_CODA) += coda.o
fs/coda/Makefile:obj-$(CONFIG_CODA_FS) += coda.o

drivers/gpu/drm/omapdrm/displays/Makefile:obj-$(CONFIG_DISPLAY_CONNECTOR_ANALOG_TV) += connector-analog-tv.o
drivers/video/fbdev/omap2/omapfb/displays/Makefile:obj-$(CONFIG_FB_OMAP2_CONNECTOR_ANALOG_TV) += connector-analog-tv.o

drivers/gpu/drm/omapdrm/displays/Makefile:obj-$(CONFIG_DISPLAY_CONNECTOR_DVI) += connector-dvi.o
drivers/video/fbdev/omap2/omapfb/displays/Makefile:obj-$(CONFIG_FB_OMAP2_CONNECTOR_DVI) += connector-dvi.o

drivers/gpu/drm/omapdrm/displays/Makefile:obj-$(CONFIG_DISPLAY_CONNECTOR_HDMI) += connector-hdmi.o
drivers/video/fbdev/omap2/omapfb/displays/Makefile:obj-$(CONFIG_FB_OMAP2_CONNECTOR_HDMI) += connector-hdmi.o

crypto/Makefile:obj-$(CONFIG_CRYPTO_CRC32) += crc32.o
lib/Makefile:obj-$(CONFIG_CRC32) += crc32.o

drivers/gpu/drm/omapdrm/displays/Makefile:obj-$(CONFIG_DISPLAY_ENCODER_OPA362) += encoder-opa362.o
drivers/video/fbdev/omap2/omapfb/displays/Makefile:obj-$(CONFIG_FB_OMAP2_ENCODER_OPA362) += encoder-opa362.o

drivers/gpu/drm/omapdrm/displays/Makefile:obj-$(CONFIG_DISPLAY_ENCODER_TFP410) += encoder-tfp410.o
drivers/video/fbdev/omap2/omapfb/displays/Makefile:obj-$(CONFIG_FB_OMAP2_ENCODER_TFP410) += encoder-tfp410.o

drivers/gpu/drm/omapdrm/displays/Makefile:obj-$(CONFIG_DISPLAY_ENCODER_TPD12S015) += encoder-tpd12s015.o
drivers/video/fbdev/omap2/omapfb/displays/Makefile:obj-$(CONFIG_FB_OMAP2_ENCODER_TPD12S015) += encoder-tpd12s015.o

drivers/gpu/drm/omapdrm/displays/Makefile:obj-$(CONFIG_DISPLAY_PANEL_DPI) += panel-dpi.o
drivers/video/fbdev/omap2/omapfb/displays/Makefile:obj-$(CONFIG_FB_OMAP2_PANEL_DPI) += panel-dpi.o

drivers/gpu/drm/omapdrm/displays/Makefile:obj-$(CONFIG_DISPLAY_PANEL_DSI_CM) += panel-dsi-cm.o
drivers/video/fbdev/omap2/omapfb/displays/Makefile:obj-$(CONFIG_FB_OMAP2_PANEL_DSI_CM) += panel-dsi-cm.o

drivers/gpu/drm/omapdrm/displays/Makefile:obj-$(CONFIG_DISPLAY_PANEL_LGPHILIPS_LB035Q02) += panel-lgphilips-lb035q02.o
drivers/video/fbdev/omap2/omapfb/displays/Makefile:obj-$(CONFIG_FB_OMAP2_PANEL_LGPHILIPS_LB035Q02) += panel-lgphilips-lb035q02.o

drivers/gpu/drm/omapdrm/displays/Makefile:obj-$(CONFIG_DISPLAY_PANEL_NEC_NL8048HL11) += panel-nec-nl8048hl11.o
drivers/video/fbdev/omap2/omapfb/displays/Makefile:obj-$(CONFIG_FB_OMAP2_PANEL_NEC_NL8048HL11) += panel-nec-nl8048hl11.o

drivers/gpu/drm/omapdrm/displays/Makefile:obj-$(CONFIG_DISPLAY_PANEL_SHARP_LS037V7DW01) += panel-sharp-ls037v7dw01.o
drivers/video/fbdev/omap2/omapfb/displays/Makefile:obj-$(CONFIG_FB_OMAP2_PANEL_SHARP_LS037V7DW01) += panel-sharp-ls037v7dw01.o

drivers/gpu/drm/omapdrm/displays/Makefile:obj-$(CONFIG_DISPLAY_PANEL_SONY_ACX565AKM) += panel-sony-acx565akm.o
drivers/video/fbdev/omap2/omapfb/displays/Makefile:obj-$(CONFIG_FB_OMAP2_PANEL_SONY_ACX565AKM) += panel-sony-acx565akm.o

drivers/gpu/drm/omapdrm/displays/Makefile:obj-$(CONFIG_DISPLAY_PANEL_TPO_TD028TTEC1) += panel-tpo-td028ttec1.o
drivers/video/fbdev/omap2/omapfb/displays/Makefile:obj-$(CONFIG_FB_OMAP2_PANEL_TPO_TD028TTEC1) += panel-tpo-td028ttec1.o

drivers/gpu/drm/omapdrm/displays/Makefile:obj-$(CONFIG_DISPLAY_PANEL_TPO_TD043MTEA1) += panel-tpo-td043mtea1.o
drivers/video/fbdev/omap2/omapfb/displays/Makefile:obj-$(CONFIG_FB_OMAP2_PANEL_TPO_TD043MTEA1) += panel-tpo-td043mtea1.o

drivers/mtd/onenand/Makefile:obj-$(CONFIG_MTD_ONENAND_SAMSUNG) += samsung.o
drivers/tty/serial/Makefile:obj-$(CONFIG_SERIAL_SAMSUNG) += samsung.o

sound/soc/codecs/Makefile:obj-$(CONFIG_SND_SOC_AC97_CODEC) += snd-soc-ac97.o
sound/soc/samsung/Makefile:obj-$(CONFIG_SND_SAMSUNG_AC97) += snd-soc-ac97.o

drivers/hwmon/Makefile:obj-$(CONFIG_SENSORS_VEXPRESS) += vexpress.o
drivers/regulator/Makefile:obj-$(CONFIG_REGULATOR_VEXPRESS) += vexpress.o

Can maintainers please tell me which of these are harmless?

Thanks!
Rusty.