> -----Original Message-----
> From: Christopher Clark [mailto:christopher.w.cl...@gmail.com]
> Sent: 01 December 2018 01:33
> To: xen-devel@lists.xenproject.org
> Cc: Stefano Stabellini <sstabell...@kernel.org>; Julien Grall
> <julien.gr...@arm.com>; Andrew Cooper <andrew.coop...@citrix.com>; George
> Dunlap <george.dun...@citrix.com>; Ian Jackson <ian.jack...@citrix.com>;
> Jan Beulich <jbeul...@suse.com>; Konrad Rzeszutek Wilk
> <konrad.w...@oracle.com>; Paul Durrant <paul.durr...@citrix.com>; Tim
> (Xen.org) <t...@xen.org>; Wei Liu <wei.l...@citrix.com>; Roger Pau Monne
> <roger....@citrix.com>; Rich Persaud <pers...@gmail.com>; Ross Philipson
> <ross.philip...@gmail.com>; Eric Chanudet <eric.chanu...@gmail.com>; James
> McKenzie <vore...@madingley.org>; Jason Andryuk <jandr...@gmail.com>;
> Daniel Smith <dpsm...@apertussolutions.com>
> Subject: [PATCH 07/25] xen (ARM, x86): add errno-returning functions for
> copy
>
> Applied to both x86 and ARM headers.
>
> Signed-off-by: Christopher Clark <christopher.cla...@baesystems.com>
> ---
> xen/include/asm-arm/guest_access.h | 25 +++++++++++++++++++++++++
> xen/include/asm-x86/guest_access.h | 29 +++++++++++++++++++++++++++++
> xen/include/xen/guest_access.h | 3 +++
> 3 files changed, 57 insertions(+)
>
> diff --git a/xen/include/asm-arm/guest_access.h b/xen/include/asm-
> arm/guest_access.h
> index 224d2a0..7b6f89c 100644
> --- a/xen/include/asm-arm/guest_access.h
> +++ b/xen/include/asm-arm/guest_access.h
> @@ -24,6 +24,11 @@ int access_guest_memory_by_ipa(struct domain *d,
> paddr_t ipa, void *buf,
> #define __raw_copy_from_guest raw_copy_from_guest
> #define __raw_clear_guest raw_clear_guest
>
> +#define raw_copy_from_guest_errno(dst, src, len) \
> + (raw_copy_from_guest((dst), (src), (len)) ? -EFAULT : 0)
> +#define raw_copy_to_guest_errno(dst, src, len) \
> + (raw_copy_to_guest((dst), (src), (len)) ? -EFAULT : 0)
> +
> /* Remainder copied from x86 -- could be common? */
>
> /* Is the guest handle a NULL reference? */
> @@ -113,6 +118,26 @@ int access_guest_memory_by_ipa(struct domain *d,
> paddr_t ipa, void *buf,
> raw_copy_from_guest(_d, _s, sizeof(*_d)); \
> })
>
> +/* errno returning copy functions */
> +#define copy_from_guest_offset_errno(ptr, hnd, off, nr) ({ \
> + const typeof(*(ptr)) *_s = (hnd).p; \
> + typeof(*(ptr)) *_d = (ptr); \
> + raw_copy_from_guest_errno(_d, _s + (off), sizeof(*_d) *
> (nr)); \
> + })
> +
> +#define copy_field_to_guest_errno(hnd, ptr, field) ({ \
> + const typeof(&(ptr)->field) _s = &(ptr)->field; \
> + void *_d = &(hnd).p->field; \
> + ((void)(&(hnd).p->field == &(ptr)->field)); \
> + raw_copy_to_guest_errno(_d, _s, sizeof(*_s)); \
> + })
> +
> +#define copy_field_from_guest_errno(ptr, hnd, field) ({ \
> + const typeof(&(ptr)->field) _s = &(hnd).p->field; \
> + typeof(&(ptr)->field) _d = &(ptr)->field; \
> + raw_copy_from_guest_errno(_d, _s, sizeof(*_d)); \
> + })
> +
> /*
> * Pre-validate a guest handle.
> * Allows use of faster __copy_* functions.
> diff --git a/xen/include/asm-x86/guest_access.h b/xen/include/asm-
> x86/guest_access.h
> index ca700c9..9391cd3 100644
> --- a/xen/include/asm-x86/guest_access.h
> +++ b/xen/include/asm-x86/guest_access.h
> @@ -38,6 +38,15 @@
> clear_user_hvm((dst), (len)) : \
> clear_user((dst), (len)))
>
> +#define raw_copy_from_guest_errno(dst, src, len) \
> + (is_hvm_vcpu(current) ? \
> + copy_from_user_hvm((dst), (src), (len)) : \
> + (copy_from_user((dst), (src), (len)) ? -EFAULT : 0))
AFAICT copy_from_user_hvm() doesn't return -ve errno (it has comment "/* fake a
copy_to_user() return code */" on the return line) so I think your bracketing
is wrong here...
> +#define raw_copy_to_guest_errno(dst, src, len) \
> + (is_hvm_vcpu(current) ? \
> + copy_to_user_hvm((dst), (src), (len)) : \
> + (copy_to_user((dst), (src), (len)) ? -EFAULT : 0))
> +
...and similarly here.
> /* Is the guest handle a NULL reference? */
> #define guest_handle_is_null(hnd) ((hnd).p == NULL)
>
> @@ -121,6 +130,26 @@
> raw_copy_from_guest(_d, _s, sizeof(*_d)); \
> })
>
> +/* errno returning copy functions */
> +#define copy_from_guest_offset_errno(ptr, hnd, off, nr) ({ \
> + const typeof(*(ptr)) *_s = (hnd).p; \
> + typeof(*(ptr)) *_d = (ptr); \
> + raw_copy_from_guest_errno(_d, _s + (off), sizeof(*_d) *
> (nr)); \
> + })
> +
> +#define copy_field_to_guest_errno(hnd, ptr, field) ({ \
> + const typeof(&(ptr)->field) _s = &(ptr)->field; \
> + void *_d = &(hnd).p->field; \
> + ((void)(&(hnd).p->field == &(ptr)->field)); \
> + raw_copy_to_guest_errno(_d, _s, sizeof(*_s)); \
> + })
> +
> +#define copy_field_from_guest_errno(ptr, hnd, field) ({ \
> + const typeof(&(ptr)->field) _s = &(hnd).p->field; \
> + typeof(&(ptr)->field) _d = &(ptr)->field; \
> + raw_copy_from_guest_errno(_d, _s, sizeof(*_d)); \
> + })
> +
> /*
> * Pre-validate a guest handle.
> * Allows use of faster __copy_* functions.
> diff --git a/xen/include/xen/guest_access.h
> b/xen/include/xen/guest_access.h
> index 09989df..3494c5f 100644
> --- a/xen/include/xen/guest_access.h
> +++ b/xen/include/xen/guest_access.h
> @@ -26,6 +26,9 @@
> #define __copy_from_guest(ptr, hnd, nr) \
> __copy_from_guest_offset(ptr, hnd, 0, nr)
>
> +#define copy_from_guest_errno(ptr, hnd, nr) \
> + copy_from_guest_offset_errno(ptr, hnd, 0, nr)
> +
> #define __clear_guest(hnd, nr) \
> __clear_guest_offset(hnd, 0, nr)
>
Given that the only errno possible seems to be EFAULT, I do have to question
why you need these changes?
Paul
> --
> 2.1.4
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