Xen devel - Sep 2010 - [patch] Bugfix for tools/blktap/lib/xs_api.c (convert_dev_name_to_num)

I rewrote function convert_dev_name_to_num from
tools/blktap/lib/xs_api.c

Difference:

All code in loops has been converted from ..perverted for+while code to
pure for. sizeof for char[]="..." will works faster, than
strlen(string), strange *pte++ have been removed, *p++ changed to p+1 in
function calls.

Second change more disputable: I change code:

ret = (majors[i/2]*256) + atoi(p);

to 

ret = (majors[i/2]*256) + isdigit(p[1]) ? atoi(p) : 0;

I believe it will clear out undefined behavior to atoi when it called
with non-convertible value (like letter or \x0).

I have not access to commits to hg, so diff in attachment for freshest
xen-unstable.hg.

I think this patch can be apply to xen 3.4 too, where I found this bug
early.

---
wBR, George.


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George Shuklin writes ("[Xen-devel] [patch] Bugfix for
tools/blktap/lib/xs_api.c
(convert_dev_name_to_num)"):
> I rewrote function convert_dev_name_to_num from
> tools/blktap/lib/xs_api.c
Thanks but I''m afraid I don''t think your patch is either a
good idea
or suitable.

Ian.

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Well, I do not insist, but could you explain reason of using
construction like *p++; or using atoi to arbitrary string?

В Птн, 24/09/2010 в 16:30 +0100, Ian Jackson пишет:
> George Shuklin writes ("[Xen-devel] [patch] Bugfix for
tools/blktap/lib/xs_api.c (convert_dev_name_to_num)"):
> > I rewrote function convert_dev_name_to_num from
> > tools/blktap/lib/xs_api.c
> 
> Thanks but I''m afraid I don''t think your patch is either
a good idea
> or suitable.
> 
> Ian.


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