On Fri, Jun 14, 2019 at 06:46:00PM +0200, Anisse Astier wrote:
> Otherwise this will create userspace build issues for any program
> (strace, qemu) that includes both <sys/prctl.h> (with musl libc) and
> <linux/ptrace.h> (which then includes <asm/ptrace.h>), like this:
>
> error: redefinition of 'struct prctl_mm_map'
> struct prctl_mm_map {
>
> See
> https://github.com/foundriesio/meta-lmp/commit/6d4a106e191b5d79c41b9ac78fd321316d3013c0
> for a public example of people working around this issue.
>
> Copying the defines is a bit imperfect here, but better than creating a
> whole other header for just two defines that would never change, as part
> of the kernel ABI.
>
> Fixes: 43d4da2c45b2 ("arm64/sve: ptrace and ELF coredump support")
> Cc: [email protected]
> Signed-off-by: Anisse Astier <[email protected]>
> ---
> Changes since v1:
> - made a bit more explicit that we copied defined symbols, in commit
> and code.
> - Use Fixes: tag in commit message
>
> Thanks to Dave Martin and Will Deacon for the review.
>
> ---
> arch/arm64/include/uapi/asm/ptrace.h | 8 +++-----
> 1 file changed, 3 insertions(+), 5 deletions(-)
>
> diff --git a/arch/arm64/include/uapi/asm/ptrace.h
> b/arch/arm64/include/uapi/asm/ptrace.h
> index d78623acb649..438759e7e8a7 100644
> --- a/arch/arm64/include/uapi/asm/ptrace.h
> +++ b/arch/arm64/include/uapi/asm/ptrace.h
> @@ -65,8 +65,6 @@
>
> #ifndef __ASSEMBLY__
>
> -#include <linux/prctl.h>
> -
> /*
> * User structures for general purpose, floating point and debug registers.
> */
> @@ -113,10 +111,10 @@ struct user_sve_header {
>
> /*
> * Common SVE_PT_* flags:
> - * These must be kept in sync with prctl interface in <linux/ptrace.h>
> + * These must be kept in sync with prctl interface in <linux/prctl.h>
> */
> -#define SVE_PT_VL_INHERIT (PR_SVE_VL_INHERIT >> 16)
> -#define SVE_PT_VL_ONEXEC (PR_SVE_SET_VL_ONEXEC >> 16)
> +#define SVE_PT_VL_INHERIT ((1 << 17) /* PR_SVE_VL_INHERIT */ >>
> 16)
> +#define SVE_PT_VL_ONEXEC ((1 << 18) /* PR_SVE_SET_VL_ONEXEC */
> >> 16)
FWIW,
Acked-by: Dave Martin <[email protected]>
Ideally we would create a common <uapi/asm/prctl.h> that arm64 could
specialise as appropriate, but since x86 already has a similar header
shadowing this, it may be more trouble than it's worth to generalise it.
Cheers
---Dave
