Created attachment 293235 [details]
reproduce.tar.gz

Attachment (reproduce.tar.gz) content:
 - sample.config: Config file to reproduce the bug.
 - build_out.txt: Output of Kbuild including the error messages.

When MFD_STM32_TIMERS is enabled and HAS_IOMEM is disabled, it results in the
following Kbuild warning:

WARNING: unmet direct dependencies detected for MFD_STM32_TIMERS
  Depends on [n]: HAS_IOMEM [=n] && (ARCH_STM32 && OF [=y] || COMPILE_TEST [=y])
  Selected by [y]:
  - STM32_ADC_CORE [=y] && IIO [=y] && (ARCH_STM32 || COMPILE_TEST [=y]) && OF [=y] && REGULATOR [=y]

Building the kernel fails due to this unmet direct dependency issue as follows:

[...]
  LD      .tmp_vmlinux1
/home/necip/0day/gcc-9.3.0-nolibc/s390-linux/bin/s390-linux-ld: drivers/irqchip/irq-renesas-rza1.o: in function `rza1_irqc_probe':
irq-renesas-rza1.c:(.text+0x2b0): undefined reference to `devm_platform_ioremap_resource'
/home/necip/0day/gcc-9.3.0-nolibc/s390-linux/bin/s390-linux-ld: drivers/phy/marvell/phy-mvebu-a3700-utmi.o: in function `mvebu_a3700_utmi_phy_probe':
phy-mvebu-a3700-utmi.c:(.text+0x3e6): undefined reference to `devm_ioremap_resource'
/home/necip/0day/gcc-9.3.0-nolibc/s390-linux/bin/s390-linux-ld: drivers/phy/ti/phy-omap-control.o: in function `omap_control_phy_probe':
phy-omap-control.c:(.text+0x1d0): undefined reference to `devm_ioremap_resource'
/home/necip/0day/gcc-9.3.0-nolibc/s390-linux/bin/s390-linux-ld: phy-omap-control.c:(.text+0x210): undefined reference to `devm_ioremap_resource'
/home/necip/0day/gcc-9.3.0-nolibc/s390-linux/bin/s390-linux-ld: phy-omap-control.c:(.text+0x282): undefined reference to `devm_ioremap_resource'
/home/necip/0day/gcc-9.3.0-nolibc/s390-linux/bin/s390-linux-ld: drivers/soc/bcm/brcmstb/common.o: in function `brcmstb_soc_device_early_init':
common.c:(.init.text+0x196): undefined reference to `of_iomap'
/home/necip/0day/gcc-9.3.0-nolibc/s390-linux/bin/s390-linux-ld: common.c:(.init.text+0x1c2): undefined reference to `iounmap'
/home/necip/0day/gcc-9.3.0-nolibc/s390-linux/bin/s390-linux-ld: drivers/soc/bcm/brcmstb/biuctrl.o: in function `brcmstb_biuctrl_init':
biuctrl.c:(.init.text+0x42): undefined reference to `of_iomap'
/home/necip/0day/gcc-9.3.0-nolibc/s390-linux/bin/s390-linux-ld: drivers/soc/fsl/dpaa2-console.o: in function `dpaa2_console_close':
dpaa2-console.c:(.text+0x5a): undefined reference to `iounmap'
/home/necip/0day/gcc-9.3.0-nolibc/s390-linux/bin/s390-linux-ld: drivers/soc/fsl/dpaa2-console.o: in function `dpaa2_console_probe':
dpaa2-console.c:(.text+0xe2): undefined reference to `of_address_to_resource'
/home/necip/0day/gcc-9.3.0-nolibc/s390-linux/bin/s390-linux-ld: drivers/soc/fsl/dpaa2-console.o: in function `dpaa2_generic_console_open.isra.0.constprop.0':
dpaa2-console.c:(.text+0x334): undefined reference to `ioremap'
/home/necip/0day/gcc-9.3.0-nolibc/s390-linux/bin/s390-linux-ld: dpaa2-console.c:(.text+0x388): undefined reference to `iounmap'
/home/necip/0day/gcc-9.3.0-nolibc/s390-linux/bin/s390-linux-ld: dpaa2-console.c:(.text+0x39e): undefined reference to `ioremap'
/home/necip/0day/gcc-9.3.0-nolibc/s390-linux/bin/s390-linux-ld: dpaa2-console.c:(.text+0x414): undefined reference to `iounmap'
/home/necip/0day/gcc-9.3.0-nolibc/s390-linux/bin/s390-linux-ld: drivers/char/hw_random/exynos-trng.o: in function `exynos_trng_probe':
exynos-trng.c:(.text+0xfc): undefined reference to `devm_ioremap_resource'
/home/necip/0day/gcc-9.3.0-nolibc/s390-linux/bin/s390-linux-ld: drivers/char/hw_random/meson-rng.o: in function `meson_rng_probe':
meson-rng.c:(.text+0x78): undefined reference to `devm_ioremap_resource'
/home/necip/0day/gcc-9.3.0-nolibc/s390-linux/bin/s390-linux-ld: drivers/char/hw_random/mtk-rng.o: in function `mtk_rng_probe':
mtk-rng.c:(.text+0xbe): undefined reference to `devm_ioremap_resource'
/home/necip/0day/gcc-9.3.0-nolibc/s390-linux/bin/s390-linux-ld: drivers/mfd/stm32-timers.o: in function `stm32_timers_probe':
stm32-timers.c:(.text+0x12c): undefined reference to `devm_ioremap_resource'
/home/necip/0day/gcc-9.3.0-nolibc/s390-linux/bin/s390-linux-ld: stm32-timers.c:(.text+0x16c): undefined reference to `__devm_regmap_init_mmio_clk'
/home/necip/0day/gcc-9.3.0-nolibc/s390-linux/bin/s390-linux-ld: drivers/pcmcia/cistpl.o: in function `set_cis_map':
cistpl.c:(.text+0x20c): undefined reference to `ioremap'
/home/necip/0day/gcc-9.3.0-nolibc/s390-linux/bin/s390-linux-ld: cistpl.c:(.text+0x246): undefined reference to `iounmap'
/home/necip/0day/gcc-9.3.0-nolibc/s390-linux/bin/s390-linux-ld: cistpl.c:(.text+0x2cc): undefined reference to `iounmap'
/home/necip/0day/gcc-9.3.0-nolibc/s390-linux/bin/s390-linux-ld: cistpl.c:(.text+0x2de): undefined reference to `ioremap'
/home/necip/0day/gcc-9.3.0-nolibc/s390-linux/bin/s390-linux-ld: drivers/pcmcia/cistpl.o: in function `release_cis_mem':
(.text+0x13e0): undefined reference to `iounmap'
/home/necip/0day/gcc-9.3.0-nolibc/s390-linux/bin/s390-linux-ld: drivers/clocksource/timer-of.o: in function `timer_of_init':
timer-of.c:(.init.text+0x40): undefined reference to `of_iomap'
/home/necip/0day/gcc-9.3.0-nolibc/s390-linux/bin/s390-linux-ld: timer-of.c:(.init.text+0x96): undefined reference to `iounmap'
/home/necip/0day/gcc-9.3.0-nolibc/s390-linux/bin/s390-linux-ld: drivers/clocksource/timer-of.o: in function `timer_of_cleanup':
timer-of.c:(.init.text+0x274): undefined reference to `iounmap'
/home/necip/0day/gcc-9.3.0-nolibc/s390-linux/bin/s390-linux-ld: drivers/iio/adc/stm32-adc-core.o: in function `stm32_adc_probe':
stm32-adc-core.c:(.text+0x498): undefined reference to `devm_ioremap_resource'
Makefile:1077: recipe for target 'vmlinux' failed
make: *** [vmlinux] Error 1

Steps to reproduce the bug for v5.4.4:
  1. wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
  2. chmod +x ~/bin/make.cross
  3. tar -xvf reproduce.tar.gz # sample.config and build_out.txt
  4. cp sample.config path/to/linux-source-v5.4.4/.config
  5. cd path/to/linux-source-v5.4.4/
  6. ~/bin/make.cross ARCH=TODO_ARCH clean
  7. ~/bin/make.cross ARCH=TODO_ARCH olddefconfig # unmet direct dependency warning
  8. ~/bin/make.cross ARCH=TODO_ARCH # should have a build error

The output for the steps [6-8] can be found in build_out.txt.

The bug is reproducible for v5.10-rc1 as well with the same steps.

Kernel successfully builds when the unmet direct dependencies are resolved
by enabling them in the configuration. Depending on instead of selecting
the symbols, or selecting the dependencies of the selected symbols as well
might fix the bug.

Thanks,
Necip