Re: [Crash-utility] [PATCH 1/1] xendump: Use off_t not long for 32bit code
On 06/11/14 14:05, Daniel Kiper wrote:
On Wed, Jun 11, 2014 at 01:28:27PM -0400, Don Slutz wrote:
> This enables crash to handle xen dumps that are larger then 4G
> in size in 32bit mode.
>
> Signed-off-by: Don Slutz <dslutz(a)verizon.com>
> ---
> This is the same as was sent as an attachment. Just a clean top post.
>
> x86.c | 10 ++++-----
> x86_64.c | 10 ++++-----
> xendump.c | 74 +++++++++++++++++++++++++++++++++------------------------------
> xendump.h | 6 +++---
> 4 files changed, 52 insertions(+), 48 deletions(-)
>
> diff --git a/x86.c b/x86.c
> index 833a11b..608bb88 100644
> --- a/x86.c
> +++ b/x86.c
> @@ -4897,7 +4897,7 @@ x86_xendump_p2m_create(struct xendump_data *xd)
> "MEMBER_OFFSET(vcpu_guest_context, ctrlreg): %ld\n",
> ctrlreg_offset);
>
> - offset = (off_t)xd->xc_core.header.xch_ctxt_offset +
> + offset = xd->xc_core.header.xch_ctxt_offset +
> (off_t)ctrlreg_offset;
Good job. However, as I can see this fix requires explicit type
conversions in many places. I am almost sure that next time when
somebody improve the code then he/she will forget about this needed
type conversions. So maybe it is worth creating new struct which
will have xch_ctxt_offset as off_t instead of unsigned long and
do this conversion once somewhere.
I think you are getting this backwards. Most of the changes (like the one above) is
removing the explicit type conversions. I did not need to change the line above
(cast an off_t to an off_t) but did because I think it is just better to drop the cast of
the
same type. The important lines include:
if (STREQ(name, ".xen_shared_info"))
xd->xc_core.shared_info_offset = (off_t)shdr.sh_offset;
if (STREQ(name, ".xen_pfn")) {
- xd->xc_core.header.xch_index_offset = shdr.sh_offset;
+ xd->xc_core.header.xch_index_offset =
+ (off_t)shdr.sh_offset;
xd->flags |= (XC_CORE_NO_P2M|XC_CORE_PFN_CREATE);
}
if (STREQ(name, ".xen_p2m")) {
- xd->xc_core.header.xch_index_offset = shdr.sh_offset;
+ xd->xc_core.header.xch_index_offset =
+ (off_t)shdr.sh_offset;
xd->flags |= XC_CORE_P2M_CREATE;
}
if (STREQ(name, ".xen_pages"))
- xd->xc_core.header.xch_pages_offset =
- (unsigned long)shdr.sh_offset;
+ xd->xc_core.header.xch_pages_offset =
+ (off_t)shdr.sh_offset;
-Don Slutz
Daniel