Re: clang/objtool failures on linux-next

["Arnd Bergmann" <arnd@arndb.de>]

On Fri, Mar 6, 2026, at 19:29, Josh Poimboeuf wrote:
> On Fri, Mar 06, 2026 at 09:31:02AM -0800, Josh Poimboeuf wrote:
>> On Fri, Mar 06, 2026 at 01:41:59PM +0100, Arnd Bergmann wrote:
>> 
>> Thanks, I'll post a fix for the 1st one right now (haven't looked at the
>> stack overflow yet).
>
> Both fixes posted now:
>
> https://lore.kernel.org/240e6a172cc73292499334a3724d02ccb3247fc7.1772818491.git.jpoimboe@kernel.org
> https://lore.kernel.org/8b97f62d083457f3b0a29a424275f7957dd3372f.1772821683.git.jpoimboe@kernel.org

Thanks a lot, that was quick!

I've applied both to my randconfig tree now and verified that
both issues are addressed in the full build. There is still
the question of the 0xAE77DEF6_defconfig causing an incredibly
long compile time (minutes!) for the one file when using clang.

I've added Nathan to Cc in case he is motivated to try to
reproduce this.

FWIW, this is the current set of objtool warnings that I get that
don't cause the build to fail:

drivers/gpu/drm/amd/amdgpu/amdgpu_cs.o: warning: objtool: amdgpu_cs_parser_bos+0x723: unreachable instruction
drivers/gpu/drm/msm/msm.o: warning: objtool: msm_gem_vm_close+0x1cf: unreachable instruction
drivers/gpu/drm/panthor/panthor.o: warning: objtool: panthor_ioctl_vm_bind+0x32b: __stack_chk_fail() missing __noreturn in .c/.h or NORETURN() in noreturns.h
drivers/gpu/drm/panthor/panthor.o: warning: objtool: panthor_ioctl_vm_bind_async+0x285: unreachable instruction
drivers/gpu/drm/panthor/panthor_drv.o: warning: objtool: panthor_ioctl_vm_bind+0x2df: unreachable instruction
drivers/gpu/drm/xe/xe_bo.o: warning: objtool: xe_bo_create_pin_map_at_novm+0x11d: unreachable instruction
drivers/iio/imu/bmi160/bmi160_core.o: warning: objtool: bmi160_setup_irq() falls through to next function __cfi_bmi160_core_runtime_resume()
kernel/bpf/core.o: warning: objtool: ___bpf_prog_run+0x217: sibling call from callable instruction with modified stack frame
sound/soc/codecs/wcd9335.o: warning: objtool: wcd9335_slimbus_irq() falls through to next function __cfi_wcd9335_set_channel_map()
vmlinux.o: warning: objtool: ___bpf_prog_run+0x1d4: sibling call from callable instruction with modified stack frame
vmlinux.o: warning: objtool: hdmi_power_on_full.isra.0+0xd6: hdmi_pll_compute() missing __noreturn in .c/.h or NORETURN() in noreturns.h

If you want to investigate those, I can send you the configs and/or
object files for these as well.

       Arnd