* [PATCH] um: Use asm-generic/timex.h over the host architecture one
@ 2026-08-19 7:24 Thomas Weißschuh
2026-08-21 8:22 ` David Gow
2026-08-30 15:52 ` SJ Park
0 siblings, 2 replies; 3+ messages in thread
From: Thomas Weißschuh @ 2026-08-19 7:24 UTC (permalink / raw)
To: Richard Weinberger, Anton Ivanov, Johannes Berg,
Christophe Leroy (CS GROUP), Thomas Gleixner
Cc: linux-um, linux-kernel, Thomas Weißschuh
The removal of the architecture-specific asm/timex.h was meant to fall
back to asm-generic/timex.h. However on UML, the host architecture
headers are earlier on the include path and therefore asm/timex.h from
the host architecture is used.
On x86 that header in turn requires the generation of cpufeaturemasks.h,
which is not set up for UML and the build fails.
In file included from ../arch/x86/include/asm/tsc.h:9,
from ../arch/x86/include/asm/timex.h:6,
from ../include/linux/timex.h:67,
from ../include/linux/time32.h:13,
from ../include/linux/time.h:60,
from ../include/linux/jiffies.h:10,
from ../include/linux/ktime.h:25,
from ../include/linux/timer.h:6,
from ../include/linux/uprobes.h:18,
from ../include/linux/mm_types.h:16,
from ../include/linux/mmzone.h:22,
from ../include/linux/gfp.h:7,
from ../include/linux/slab.h:17,
from ../include/linux/crypto.h:18,
from ../arch/um/kernel/asm-offsets.c:6:
arch/x86/include/asm/tsc.h: In function ‘get_cycles’:
arch/um/include/asm/cpufeature.h:52:39: error: implicit declaration of function ‘DISABLED_MASK_BIT_SET’ [-Wimplicit-function-declaration]
52 | (__builtin_constant_p(bit) && DISABLED_MASK_BIT_SET(bit) ? 0 : _static_cpu_has(bit))
| ^~~~~~~~~~~~~~~~~~~~~
arch/x86/include/asm/tsc.h:79:14: note: in expansion of macro ‘cpu_feature_enabled’
79 | if (!cpu_feature_enabled(X86_FEATURE_TSC))
| ^~~~~~~~~~~~~~~~~~~
arch/um/include/asm/cpufeature.h:115:17: error: implicit declaration of function ‘_static_cpu_has’ [-Wimplicit-function-declaration]
115 | _static_cpu_has(bit) \
| ^~~~~~~~~~~~~~~
arch/um/include/asm/cpufeature.h:52:72: note: in expansion of macro ‘_static_cpu_has’
52 | (__builtin_constant_p(bit) && DISABLED_MASK_BIT_SET(bit) ? 0 : _static_cpu_has(bit))
| ^~~~~~~~~~~~~~~
arch/x86/include/asm/tsc.h:79:14: note: in expansion of macro ‘cpu_feature_enabled’
79 | if (!cpu_feature_enabled(X86_FEATURE_TSC))
| ^~~~~~~~~~~~~~~~~~~
arch/um/include/asm/cpufeature.h:115:17: note: ‘_static_cpu_has’ is a function-like macro and might be used incorrectly
arch/um/include/asm/cpufeature.h:52:72: note: in expansion of macro ‘_static_cpu_has’
52 | (__builtin_constant_p(bit) && DISABLED_MASK_BIT_SET(bit) ? 0 : _static_cpu_has(bit))
| ^~~~~~~~~~~~~~~
arch/x86/include/asm/tsc.h:79:14: note: in expansion of macro ‘cpu_feature_enabled’
79 | if (!cpu_feature_enabled(X86_FEATURE_TSC))
| ^~~~~~~~~~~~~~~~~~~
The x86-specific timex.h also doesn't make sense on UML in general.
Reintroduce the UML-specific asm/timex.h and add a comment to document
its necessity.
Fixes: 3ed403bbc967 ("treewide: Remove CLOCK_TICK_RATE")
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
arch/um/include/asm/timex.h | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/arch/um/include/asm/timex.h b/arch/um/include/asm/timex.h
new file mode 100644
index 000000000000..dfb4f460fb87
--- /dev/null
+++ b/arch/um/include/asm/timex.h
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __UM_TIMEX_H
+#define __UM_TIMEX_H
+
+/* Do not fall back to the host architecture header. */
+#include <asm-generic/timex.h>
+
+#endif
---
base-commit: bd5f485f3f026225b86573e559af0b7254ef4184
change-id: 20260819-uml-timex-fix-fccb27f9ca51
Best regards,
--
Thomas Weißschuh <thomas.weissschuh@linutronix.de>
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] um: Use asm-generic/timex.h over the host architecture one
2026-08-19 7:24 [PATCH] um: Use asm-generic/timex.h over the host architecture one Thomas Weißschuh
@ 2026-08-21 8:22 ` David Gow
2026-08-30 15:52 ` SJ Park
1 sibling, 0 replies; 3+ messages in thread
From: David Gow @ 2026-08-21 8:22 UTC (permalink / raw)
To: Thomas Weißschuh, Richard Weinberger, Anton Ivanov,
Johannes Berg, Christophe Leroy (CS GROUP), Thomas Gleixner
Cc: linux-um, linux-kernel
Le 19/08/2026 à 3:24 PM, Thomas Weißschuh a écrit :
> The removal of the architecture-specific asm/timex.h was meant to fall
> back to asm-generic/timex.h. However on UML, the host architecture
> headers are earlier on the include path and therefore asm/timex.h from
> the host architecture is used.
> On x86 that header in turn requires the generation of cpufeaturemasks.h,
> which is not set up for UML and the build fails.
>
> In file included from ../arch/x86/include/asm/tsc.h:9,
> from ../arch/x86/include/asm/timex.h:6,
> from ../include/linux/timex.h:67,
> from ../include/linux/time32.h:13,
> from ../include/linux/time.h:60,
> from ../include/linux/jiffies.h:10,
> from ../include/linux/ktime.h:25,
> from ../include/linux/timer.h:6,
> from ../include/linux/uprobes.h:18,
> from ../include/linux/mm_types.h:16,
> from ../include/linux/mmzone.h:22,
> from ../include/linux/gfp.h:7,
> from ../include/linux/slab.h:17,
> from ../include/linux/crypto.h:18,
> from ../arch/um/kernel/asm-offsets.c:6:
> arch/x86/include/asm/tsc.h: In function ‘get_cycles’:
> arch/um/include/asm/cpufeature.h:52:39: error: implicit declaration of function ‘DISABLED_MASK_BIT_SET’ [-Wimplicit-function-declaration]
> 52 | (__builtin_constant_p(bit) && DISABLED_MASK_BIT_SET(bit) ? 0 : _static_cpu_has(bit))
> | ^~~~~~~~~~~~~~~~~~~~~
> arch/x86/include/asm/tsc.h:79:14: note: in expansion of macro ‘cpu_feature_enabled’
> 79 | if (!cpu_feature_enabled(X86_FEATURE_TSC))
> | ^~~~~~~~~~~~~~~~~~~
> arch/um/include/asm/cpufeature.h:115:17: error: implicit declaration of function ‘_static_cpu_has’ [-Wimplicit-function-declaration]
> 115 | _static_cpu_has(bit) \
> | ^~~~~~~~~~~~~~~
> arch/um/include/asm/cpufeature.h:52:72: note: in expansion of macro ‘_static_cpu_has’
> 52 | (__builtin_constant_p(bit) && DISABLED_MASK_BIT_SET(bit) ? 0 : _static_cpu_has(bit))
> | ^~~~~~~~~~~~~~~
> arch/x86/include/asm/tsc.h:79:14: note: in expansion of macro ‘cpu_feature_enabled’
> 79 | if (!cpu_feature_enabled(X86_FEATURE_TSC))
> | ^~~~~~~~~~~~~~~~~~~
> arch/um/include/asm/cpufeature.h:115:17: note: ‘_static_cpu_has’ is a function-like macro and might be used incorrectly
> arch/um/include/asm/cpufeature.h:52:72: note: in expansion of macro ‘_static_cpu_has’
> 52 | (__builtin_constant_p(bit) && DISABLED_MASK_BIT_SET(bit) ? 0 : _static_cpu_has(bit))
> | ^~~~~~~~~~~~~~~
> arch/x86/include/asm/tsc.h:79:14: note: in expansion of macro ‘cpu_feature_enabled’
> 79 | if (!cpu_feature_enabled(X86_FEATURE_TSC))
> | ^~~~~~~~~~~~~~~~~~~
>
> The x86-specific timex.h also doesn't make sense on UML in general.
>
> Reintroduce the UML-specific asm/timex.h and add a comment to document
> its necessity.
>
> Fixes: 3ed403bbc967 ("treewide: Remove CLOCK_TICK_RATE")
> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
> ---
Thanks: I just hit this, and came up with the identical fix. Can confirm
it works again across both 32- and 64-bit UML.
Reviewed-by: David Gow <david@davidgow.net>
Cheers,
-- David
> arch/um/include/asm/timex.h | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/arch/um/include/asm/timex.h b/arch/um/include/asm/timex.h
> new file mode 100644
> index 000000000000..dfb4f460fb87
> --- /dev/null
> +++ b/arch/um/include/asm/timex.h
> @@ -0,0 +1,8 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef __UM_TIMEX_H
> +#define __UM_TIMEX_H
> +
> +/* Do not fall back to the host architecture header. */
> +#include <asm-generic/timex.h>
> +
> +#endif
>
> ---
> base-commit: bd5f485f3f026225b86573e559af0b7254ef4184
> change-id: 20260819-uml-timex-fix-fccb27f9ca51
>
> Best regards,
> --
> Thomas Weißschuh <thomas.weissschuh@linutronix.de>
>
>
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] um: Use asm-generic/timex.h over the host architecture one
2026-08-19 7:24 [PATCH] um: Use asm-generic/timex.h over the host architecture one Thomas Weißschuh
2026-08-21 8:22 ` David Gow
@ 2026-08-30 15:52 ` SJ Park
1 sibling, 0 replies; 3+ messages in thread
From: SJ Park @ 2026-08-30 15:52 UTC (permalink / raw)
To: Thomas Weißschuh
Cc: SJ Park, Richard Weinberger, Anton Ivanov, Johannes Berg,
Christophe Leroy (CS GROUP), Thomas Gleixner, linux-um,
linux-kernel
On Wed, 19 Aug 2026 09:24:21 +0200 Thomas Weißschuh <thomas.weissschuh@linutronix.de> wrote:
> The removal of the architecture-specific asm/timex.h was meant to fall
> back to asm-generic/timex.h. However on UML, the host architecture
> headers are earlier on the include path and therefore asm/timex.h from
> the host architecture is used.
> On x86 that header in turn requires the generation of cpufeaturemasks.h,
> which is not set up for UML and the build fails.
>
> In file included from ../arch/x86/include/asm/tsc.h:9,
> from ../arch/x86/include/asm/timex.h:6,
> from ../include/linux/timex.h:67,
> from ../include/linux/time32.h:13,
> from ../include/linux/time.h:60,
> from ../include/linux/jiffies.h:10,
> from ../include/linux/ktime.h:25,
> from ../include/linux/timer.h:6,
> from ../include/linux/uprobes.h:18,
> from ../include/linux/mm_types.h:16,
> from ../include/linux/mmzone.h:22,
> from ../include/linux/gfp.h:7,
> from ../include/linux/slab.h:17,
> from ../include/linux/crypto.h:18,
> from ../arch/um/kernel/asm-offsets.c:6:
> arch/x86/include/asm/tsc.h: In function ‘get_cycles’:
> arch/um/include/asm/cpufeature.h:52:39: error: implicit declaration of function ‘DISABLED_MASK_BIT_SET’ [-Wimplicit-function-declaration]
> 52 | (__builtin_constant_p(bit) && DISABLED_MASK_BIT_SET(bit) ? 0 : _static_cpu_has(bit))
> | ^~~~~~~~~~~~~~~~~~~~~
> arch/x86/include/asm/tsc.h:79:14: note: in expansion of macro ‘cpu_feature_enabled’
> 79 | if (!cpu_feature_enabled(X86_FEATURE_TSC))
> | ^~~~~~~~~~~~~~~~~~~
> arch/um/include/asm/cpufeature.h:115:17: error: implicit declaration of function ‘_static_cpu_has’ [-Wimplicit-function-declaration]
> 115 | _static_cpu_has(bit) \
> | ^~~~~~~~~~~~~~~
> arch/um/include/asm/cpufeature.h:52:72: note: in expansion of macro ‘_static_cpu_has’
> 52 | (__builtin_constant_p(bit) && DISABLED_MASK_BIT_SET(bit) ? 0 : _static_cpu_has(bit))
> | ^~~~~~~~~~~~~~~
> arch/x86/include/asm/tsc.h:79:14: note: in expansion of macro ‘cpu_feature_enabled’
> 79 | if (!cpu_feature_enabled(X86_FEATURE_TSC))
> | ^~~~~~~~~~~~~~~~~~~
> arch/um/include/asm/cpufeature.h:115:17: note: ‘_static_cpu_has’ is a function-like macro and might be used incorrectly
> arch/um/include/asm/cpufeature.h:52:72: note: in expansion of macro ‘_static_cpu_has’
> 52 | (__builtin_constant_p(bit) && DISABLED_MASK_BIT_SET(bit) ? 0 : _static_cpu_has(bit))
> | ^~~~~~~~~~~~~~~
> arch/x86/include/asm/tsc.h:79:14: note: in expansion of macro ‘cpu_feature_enabled’
> 79 | if (!cpu_feature_enabled(X86_FEATURE_TSC))
> | ^~~~~~~~~~~~~~~~~~~
>
> The x86-specific timex.h also doesn't make sense on UML in general.
>
> Reintroduce the UML-specific asm/timex.h and add a comment to document
> its necessity.
I got the same issue, and confirmed this patch fixes it on my setup. Thank you
for sharing this patch.
>
> Fixes: 3ed403bbc967 ("treewide: Remove CLOCK_TICK_RATE")
> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Tested-by: SJ Park <sj@kernel.org>
Thanks,
SJ
[...]
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2026-08-30 15:52 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-08-19 7:24 [PATCH] um: Use asm-generic/timex.h over the host architecture one Thomas Weißschuh
2026-08-21 8:22 ` David Gow
2026-08-30 15:52 ` SJ Park
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox