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* [Buildroot] [PATCH 1/1] linux: fix pahole discovery when BR2_LINUX_KERNEL_NEEDS_HOST_PAHOLE
@ 2026-09-18 12:33 Florian Larysch
  2026-10-03 16:31 ` Thomas Petazzoni via buildroot
  2026-10-10  9:23 ` Thomas Perale via buildroot
  0 siblings, 2 replies; 3+ messages in thread
From: Florian Larysch @ 2026-09-18 12:33 UTC (permalink / raw)
  To: buildroot; +Cc: Florian Larysch

Around Linux 5.11, upstream started introducing checks that execute
"pahole --version" for feature discovery (e.g. [1]).

However, when building with BR2_LINUX_KERNEL_NEEDS_HOST_PAHOLE Buildroot
only lists host-pahole in LINUX_DEPENDENCIES, so it isn't available for
the configure step when using BR2_PER_PACKAGE_DIRECTORIES. This results
in the host pahole being used (resulting in host-dependent behavior), or
no pahole being detected at all when the build host doesn't have it
(which will then disable Kconfig options that require it).

Fix this by adding host-pahole to LINUX_KCONFIG_DEPENDENCIES.

A similar issue occurs when running "make linux-menuconfig" and friends
because PATH deliberately gets stripped when pkg-kconfig.mk builds
x_CONFIGURATOR_MAKE_ENV. Explicitly pass the pahole path to fix this.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=5f9ae91f7c0dbbc4195e2a6c8eedcaeb5b9e4cbb

Signed-off-by: Florian Larysch <fl@n621.de>
---
 linux/linux.mk | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/linux/linux.mk b/linux/linux.mk
index 3599a10b50..cd80904113 100644
--- a/linux/linux.mk
+++ b/linux/linux.mk
@@ -125,6 +125,7 @@ endif
 
 ifeq ($(BR2_LINUX_KERNEL_NEEDS_HOST_PAHOLE),y)
 LINUX_DEPENDENCIES += host-pahole
+LINUX_KCONFIG_DEPENDENCIES += host-pahole
 else
 define LINUX_FIXUP_CONFIG_PAHOLE_CHECK
 	$(Q)if grep -q "^CONFIG_DEBUG_INFO_BTF=y" $(KCONFIG_DOT_CONFIG); then \
@@ -387,6 +388,9 @@ LINUX_KCONFIG_EDITORS = menuconfig xconfig gconfig nconfig
 # therefore host-ccache would be ready, we use HOSTCC_NOCCACHE for
 # consistency with other kconfig packages.
 LINUX_KCONFIG_OPTS = $(LINUX_MAKE_FLAGS) HOSTCC="$(HOSTCC_NOCCACHE)"
+ifeq ($(BR2_LINUX_KERNEL_NEEDS_HOST_PAHOLE),y)
+LINUX_KCONFIG_OPTS += PAHOLE="$(HOST_DIR)/bin/pahole"
+endif
 
 # If no package has yet set it, set it from the Kconfig option
 LINUX_NEEDS_MODULES ?= $(BR2_LINUX_NEEDS_MODULES)
-- 
2.55.0

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^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [Buildroot] [PATCH 1/1] linux: fix pahole discovery when BR2_LINUX_KERNEL_NEEDS_HOST_PAHOLE
  2026-09-18 12:33 [Buildroot] [PATCH 1/1] linux: fix pahole discovery when BR2_LINUX_KERNEL_NEEDS_HOST_PAHOLE Florian Larysch
@ 2026-10-03 16:31 ` Thomas Petazzoni via buildroot
  2026-10-10  9:23 ` Thomas Perale via buildroot
  1 sibling, 0 replies; 3+ messages in thread
From: Thomas Petazzoni via buildroot @ 2026-10-03 16:31 UTC (permalink / raw)
  To: Florian Larysch; +Cc: buildroot

On Fri, Sep 18, 2026 at 02:33:37PM +0200, Florian Larysch wrote:
> Around Linux 5.11, upstream started introducing checks that execute
> "pahole --version" for feature discovery (e.g. [1]).
> 
> However, when building with BR2_LINUX_KERNEL_NEEDS_HOST_PAHOLE Buildroot
> only lists host-pahole in LINUX_DEPENDENCIES, so it isn't available for
> the configure step when using BR2_PER_PACKAGE_DIRECTORIES. This results
> in the host pahole being used (resulting in host-dependent behavior), or
> no pahole being detected at all when the build host doesn't have it
> (which will then disable Kconfig options that require it).
> 
> Fix this by adding host-pahole to LINUX_KCONFIG_DEPENDENCIES.
> 
> A similar issue occurs when running "make linux-menuconfig" and friends
> because PATH deliberately gets stripped when pkg-kconfig.mk builds
> x_CONFIGURATOR_MAKE_ENV. Explicitly pass the pahole path to fix this.
> 
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=5f9ae91f7c0dbbc4195e2a6c8eedcaeb5b9e4cbb
> 
> Signed-off-by: Florian Larysch <fl@n621.de>

Applied to master, thanks!

Best regards,

Thomas Petazzoni
-- 
Thomas Petazzoni, co-owner and CEO, Bootlin
Embedded Linux and Kernel engineering and training
https://bootlin.com
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buildroot mailing list
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^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [Buildroot] [PATCH 1/1] linux: fix pahole discovery when BR2_LINUX_KERNEL_NEEDS_HOST_PAHOLE
  2026-09-18 12:33 [Buildroot] [PATCH 1/1] linux: fix pahole discovery when BR2_LINUX_KERNEL_NEEDS_HOST_PAHOLE Florian Larysch
  2026-10-03 16:31 ` Thomas Petazzoni via buildroot
@ 2026-10-10  9:23 ` Thomas Perale via buildroot
  1 sibling, 0 replies; 3+ messages in thread
From: Thomas Perale via buildroot @ 2026-10-10  9:23 UTC (permalink / raw)
  To: Florian Larysch; +Cc: Thomas Perale, buildroot

In reply of:
> Around Linux 5.11, upstream started introducing checks that execute
> "pahole --version" for feature discovery (e.g. [1]).
> 
> However, when building with BR2_LINUX_KERNEL_NEEDS_HOST_PAHOLE Buildroot
> only lists host-pahole in LINUX_DEPENDENCIES, so it isn't available for
> the configure step when using BR2_PER_PACKAGE_DIRECTORIES. This results
> in the host pahole being used (resulting in host-dependent behavior), or
> no pahole being detected at all when the build host doesn't have it
> (which will then disable Kconfig options that require it).
> 
> Fix this by adding host-pahole to LINUX_KCONFIG_DEPENDENCIES.
> 
> A similar issue occurs when running "make linux-menuconfig" and friends
> because PATH deliberately gets stripped when pkg-kconfig.mk builds
> x_CONFIGURATOR_MAKE_ENV. Explicitly pass the pahole path to fix this.
> 
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=5f9ae91f7c0dbbc4195e2a6c8eedcaeb5b9e4cbb
> 
> Signed-off-by: Florian Larysch <fl@n621.de>

Applied to 2025.02.x & 2026.08.x. Thanks

> ---
>  linux/linux.mk | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/linux/linux.mk b/linux/linux.mk
> index 3599a10b50..cd80904113 100644
> --- a/linux/linux.mk
> +++ b/linux/linux.mk
> @@ -125,6 +125,7 @@ endif
>  
>  ifeq ($(BR2_LINUX_KERNEL_NEEDS_HOST_PAHOLE),y)
>  LINUX_DEPENDENCIES += host-pahole
> +LINUX_KCONFIG_DEPENDENCIES += host-pahole
>  else
>  define LINUX_FIXUP_CONFIG_PAHOLE_CHECK
>  	$(Q)if grep -q "^CONFIG_DEBUG_INFO_BTF=y" $(KCONFIG_DOT_CONFIG); then \
> @@ -387,6 +388,9 @@ LINUX_KCONFIG_EDITORS = menuconfig xconfig gconfig nconfig
>  # therefore host-ccache would be ready, we use HOSTCC_NOCCACHE for
>  # consistency with other kconfig packages.
>  LINUX_KCONFIG_OPTS = $(LINUX_MAKE_FLAGS) HOSTCC="$(HOSTCC_NOCCACHE)"
> +ifeq ($(BR2_LINUX_KERNEL_NEEDS_HOST_PAHOLE),y)
> +LINUX_KCONFIG_OPTS += PAHOLE="$(HOST_DIR)/bin/pahole"
> +endif
>  
>  # If no package has yet set it, set it from the Kconfig option
>  LINUX_NEEDS_MODULES ?= $(BR2_LINUX_NEEDS_MODULES)
> -- 
> 2.55.0
> 
> _______________________________________________
> buildroot mailing list
> buildroot@buildroot.org
> https://lists.buildroot.org/mailman/listinfo/buildroot
_______________________________________________
buildroot mailing list
buildroot@buildroot.org
https://lists.buildroot.org/mailman/listinfo/buildroot

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2026-10-10  9:23 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2026-09-18 12:33 [Buildroot] [PATCH 1/1] linux: fix pahole discovery when BR2_LINUX_KERNEL_NEEDS_HOST_PAHOLE Florian Larysch
2026-10-03 16:31 ` Thomas Petazzoni via buildroot
2026-10-10  9:23 ` Thomas Perale via buildroot

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