Re: [PATCH reworded] x86/kbuild: enable modversions for symbols exported from asm

Peter Wu
2016-11-21T15:06:58Z

On Mon, Nov 21, 2016 at 03:52:20PM +0100, Adam Borowski wrote:
> Commit 4efca4ed ("kbuild: modversions for EXPORT_SYMBOL() for asm") adds
> modversion support for symbols exported from asm files. Architectures
> must include C-style declarations for those symbols in asm/asm-prototypes.h
> in order for them to be versioned.
>
> Add these declarations for x86, and an architecture-independent file that
> can be used for common symbols.
>
> User impact: kernels may fail to load modules at all when
> CONFIG_MODVERSIONS=y.
>
> Signed-off-by: Adam Borowski <kilobyte@angband.pl>
> Tested-by: Kalle Valo <kvalo@codeaurora.org>
> Acked-by: Nicholas Piggin <npiggin@gmail.com>
> Tested-by: Peter Wu <oeter@lekensteyn.nl>

Typo: oeter@.. -> peter@..

> ---
> arch/x86/include/asm/asm-prototypes.h | 12 ++++++++++++
> include/asm-generic/asm-prototypes.h | 7 +++++++
> 2 files changed, 19 insertions(+)
> create mode 100644 arch/x86/include/asm/asm-prototypes.h
> create mode 100644 include/asm-generic/asm-prototypes.h
>
> diff --git a/arch/x86/include/asm/asm-prototypes.h b/arch/x86/include/asm/asm-prototypes.h
> new file mode 100644
> index 0000000..ae87224
> --- /dev/null
> +++ b/arch/x86/include/asm/asm-prototypes.h
> @@ -0,0 +1,12 @@
> +#include <asm/ftrace.h>
> +#include <asm/uaccess.h>
> +#include <asm/string.h>
> +#include <asm/page.h>
> +#include <asm/checksum.h>
> +
> +#include <asm-generic/asm-prototypes.h>
> +
> +#include <asm/page.h>
> +#include <asm/pgtable.h>
> +#include <asm/special_insns.h>
> +#include <asm/preempt.h>
> diff --git a/include/asm-generic/asm-prototypes.h b/include/asm-generic/asm-prototypes.h
> new file mode 100644
> index 0000000..df13637
> --- /dev/null
> +++ b/include/asm-generic/asm-prototypes.h
> @@ -0,0 +1,7 @@
> +#include <linux/bitops.h>
> +extern void *__memset(void *, int, __kernel_size_t);
> +extern void *__memcpy(void *, const void *, __kernel_size_t);
> +extern void *__memmove(void *, const void *, __kernel_size_t);
> +extern void *memset(void *, int, __kernel_size_t);
> +extern void *memcpy(void *, const void *, __kernel_size_t);
> +extern void *memmove(void *, const void *, __kernel_size_t);
> --
> 2.10.2
>
> Now with a better description, provided by Nick Piggin (thanks!), and a
> remark about user impact.
>
> This version doesn't split the patch between x86 vs generic parts, would you
> guys prefer that?

From an observer POV: based on the git log include/asm-generic/
arch/x86/include/asm/, a split up seems quite common.

By the way, to make the description and discussion closer, you might
want to structure your mail like this:

[patch description]
---
[discussion]
---
[actual patch]

When applying the patch, the text after the first "---" is automatically
dropped.

Thanks!

Kind regards,
Peter