9:33 a.m.
This caused me to waste about 3 hours looking for a non-existent "data
corrupter" bug, which turned out to be the result of not checking the
return value of xread ...
Rich.
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9:39 a.m.
On Thu, Sep 17, 2009 at 03:33:24PM +0100, Richard W.M. Jones wrote:
This caused me to waste about 3 hours looking for a non-existent "data
corrupter" bug, which turned out to be the result of not checking the
return value of xread ...
You might want to add
__attribute__((__warn_unused_result__))
to the header file decl of xread/xwrite so that the compiler will
warn if any other code areas forget to check the return error code
Daniel
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9:50 a.m.
New subject: [PATCH v2] Daemon: fix handling of errors from xread and xwrite.
On Thu, Sep 17, 2009 at 03:39:45PM +0100, Daniel P. Berrange wrote:
On Thu, Sep 17, 2009 at 03:33:24PM +0100, Richard W.M. Jones wrote:
>
> This caused me to waste about 3 hours looking for a non-existent "data
> corrupter" bug, which turned out to be the result of not checking the
> return value of xread ...
You might want to add
__attribute__((__warn_unused_result__))
to the header file decl of xread/xwrite so that the compiler will
warn if any other code areas forget to check the return error code
Good idea. Updated patch attached.
Rich.
--
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10:01 a.m.
New subject: [PATCH v2] Daemon: fix handling of errors from xread and xwrite.
Richard W.M. Jones wrote:
..
Subject: [PATCH 1/3] Daemon: fix handling of errors from xread and
xwrite.
If xread or xwrite returns -1, that indicates an error and we
should exit. Note that xread/xwrite has already printed the
error message.
...
- (void) xwrite (sock, buf, xdr_getpos (&xdr));
+ if (xwrite (sock, buf, xdr_getpos (&xdr)) == -1)
+ exit (1);
That all looks fine.
Barely worth mentioning, but when the API makes it equivalent,
I find it slightly more appealing to test " < 0 " rather
than " == -1 ", partly because it covers the entire
range of negative return values, and partly because
it's a little easier to read and shorter.
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3 comments
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participants (3)
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Daniel P. Berrange -
Jim Meyering -
Richard W.M. Jones