Re: [PATCH v2 2/2] tools/include: Include stdint.h for SIZE_MAX in overflow.h

[SJ Park <sj@kernel.org>]

On Mon, 29 Jun 2026 10:21:24 +0800 Yichong Chen <chenyichong@uniontech.com> wrote:

> tools/include/linux/overflow.h uses SIZE_MAX in its size helper
> functions.
> 
> Include stdint.h so tools users that include overflow.h without another
> SIZE_MAX provider can build.

On the latest mm-new reverting this patch (for test), I was able to build
tools/virtio.

    git checkout akpm.korg.mm/mm-new
    [...]
    HEAD is now at f5ea2fbe68e0c mm/swap, PM: hibernate: atomically replace hibernation pin
    $ git revert 9d462d8b9b705548451325ee4376dfd549e14aa2 -s --no-edit
    [detached HEAD f2202247e38d9] Revert "tools/include: include stdint.h for SIZE_MAX in overflow.h"
     Date: Wed Jul 1 06:33:03 2026 -0700
     1 file changed, 1 deletion(-)
    $ make -C tools/virtio/ clean
    make: Entering directory '/home/lkhack/worktree.linux/tools/virtio'
    rm -f *.o vringh_test virtio_test vhost_net_test vhost_test/*.o \
                  vhost_test/.*.cmd vhost_test/Module.symvers \
                  vhost_test/modules.order *.d
    make: Leaving directory '/home/lkhack/worktree.linux/tools/virtio'
    $ make -C tools/virtio/ test
    make: Entering directory '/home/lkhack/worktree.linux/tools/virtio'
    cc -g -O2 -Werror -Wno-maybe-uninitialized -Wall -I. -I../include/ -I ../../usr/include/ -Wno-pointer-sign -fno-strict-overflow -fno-strict-aliasing -fno-common -MMD -U_FORTIFY_SOURCE -include ../../include/linux/kconfig.h -mfunction-return=thunk -fcf-protection=none -mindirect-branch-register -pthread   -c -o virtio_test.o virtio_test.c
    cc -g -O2 -Werror -Wno-maybe-uninitialized -Wall -I. -I../include/ -I ../../usr/include/ -Wno-pointer-sign -fno-strict-overflow -fno-strict-aliasing -fno-common -MMD -U_FORTIFY_SOURCE -include ../../include/linux/kconfig.h -mfunction-return=thunk -fcf-protection=none -mindirect-branch-register -pthread   -c -o virtio_ring.o ../../drivers/virtio/virtio_ring.c
    cc -pthread  virtio_test.o virtio_ring.o   -o virtio_test
    cc -g -O2 -Werror -Wno-maybe-uninitialized -Wall -I. -I../include/ -I ../../usr/include/ -Wno-pointer-sign -fno-strict-overflow -fno-strict-aliasing -fno-common -MMD -U_FORTIFY_SOURCE -include ../../include/linux/kconfig.h -mfunction-return=thunk -fcf-protection=none -mindirect-branch-register -pthread   -c -o vringh_test.o vringh_test.c
    cc -g -O2 -Werror -Wno-maybe-uninitialized -Wall -I. -I../include/ -I ../../usr/include/ -Wno-pointer-sign -fno-strict-overflow -fno-strict-aliasing -fno-common -MMD -U_FORTIFY_SOURCE -include ../../include/linux/kconfig.h -mfunction-return=thunk -fcf-protection=none -mindirect-branch-register -pthread   -c -o vringh.o ../../drivers/vhost/vringh.c
    cc -pthread  vringh_test.o vringh.o virtio_ring.o   -o vringh_test
    cc -g -O2 -Werror -Wno-maybe-uninitialized -Wall -I. -I../include/ -I ../../usr/include/ -Wno-pointer-sign -fno-strict-overflow -fno-strict-aliasing -fno-common -MMD -U_FORTIFY_SOURCE -include ../../include/linux/kconfig.h -mfunction-return=thunk -fcf-protection=none -mindirect-branch-register -pthread   -c -o vhost_net_test.o vhost_net_test.c
    cc -pthread  vhost_net_test.o virtio_ring.o   -o vhost_net_test
    make: Leaving directory '/home/lkhack/worktree.linux/tools/virtio'


Am I missing something?

> 
> Signed-off-by: Yichong Chen <chenyichong@uniontech.com>
> ---
>  tools/include/linux/overflow.h | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/tools/include/linux/overflow.h b/tools/include/linux/overflow.h
> index 3427d7880326..98963688143f 100644
> --- a/tools/include/linux/overflow.h
> +++ b/tools/include/linux/overflow.h
> @@ -1,4 +1,5 @@
>  /* SPDX-License-Identifier: GPL-2.0 OR MIT */
> +#include <stdint.h>
>  #ifndef __LINUX_OVERFLOW_H
>  #define __LINUX_OVERFLOW_H

Shouldn't the include placed after #define __LINUX_OVERFLOW_H ?


Thanks,
SJ

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