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[Valgrind-users] [Brian Nelson] Bug#221413: valgrind: consistent segfaults with a
particular program
From: <ar...@de...> - 2003-11-18 18:56:06
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Hi all. I got this report from a valgrind user. He found this bug in later versions of valgrind (>> 20031012). Is this information enough to solve the problem or may I ask the user for further information? Regards. |
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From: Dimitri Papadopoulos-O. <pap...@sh...> - 2003-11-19 07:48:08
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Hi,
> I got this report from a valgrind user. He found this bug in later versions
> of valgrind (>> 20031012). Is this information enough to solve the problem
> or may I ask the user for further information?
Just a few remarks:
> $ valgrind ./kmagui
> [...]
> ==3546== at 0x49ECDBB8: (within /usr/lib/libGL.so.1.0.4496)
> [...]
This is the latest NVidia driver. It has been reported that NVidia
drivers require __GL_FORCE_GENERIC_CPU be set for lack of MMX, SSE, or
3DNOW! support in Valgrind (see FAQ). I don't know if that's still the
case with curent version of Valgrind. Try setting this variable.
Maybe it would be worth trying on a machine without NVidia drivers, just
to test whether this is related to NVidia drivers.
> ==3546== Syscall param modify_ldt(ptr)(func=1 or 0x11) contains
uninitialised or unaddressable byte(s)
I don't understand this error message. I'd like to suggest rewriting it
using plain English, so that casual users can understand what's
happenning. I suspect many power users on this mailing list do
understand this message, but other programers just don't understand what
this means (that's the case at my place):
modify_ldt(ptr)(func=1 or 0x11)
> ==3546== Conditional jump or move depends on uninitialised value(s)
Again, some programers just wonder what this error message means. I
guess that it has to do with code looking like
if ( variable ) {
[...]
where "variable" isn't initialised. Again maybe this error message could
be rewritten using simple words, if at all possible.
Finally it's a pity there's no searchable archive for this mailing list.
--
Dimitri
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From: Nicholas N. <nj...@ca...> - 2003-11-19 12:37:48
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On Wed, 19 Nov 2003, Dimitri Papadopoulos-Orfanos wrote:
> > ==3546== Syscall param modify_ldt(ptr)(func=1 or 0x11) contains
> uninitialised or unaddressable byte(s)
>
> I don't understand this error message. I'd like to suggest rewriting it
> using plain English, so that casual users can understand what's
> happenning. I suspect many power users on this mailing list do
> understand this message, but other programers just don't understand what
> this means (that's the case at my place):
> modify_ldt(ptr)(func=1 or 0x11)
>
>
> > ==3546== Conditional jump or move depends on uninitialised value(s)
>
> Again, some programers just wonder what this error message means. I
> guess that it has to do with code looking like
> if ( variable ) {
> [...]
> where "variable" isn't initialised. Again maybe this error message could
> be rewritten using simple words, if at all possible.
Can you suggest alternatives that are easier to understand?
N
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From: Dimitri Papadopoulos-O. <pap...@sh...> - 2003-11-19 13:06:58
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Nicholas Nethercote wrote:
> On Wed, 19 Nov 2003, Dimitri Papadopoulos-Orfanos wrote:
>
>
>> > ==3546== Syscall param modify_ldt(ptr)(func=1 or 0x11) contains
>>uninitialised or unaddressable byte(s)
>>
>>I don't understand this error message. I'd like to suggest rewriting it
>>using plain English, so that casual users can understand what's
>>happenning. I suspect many power users on this mailing list do
>>understand this message, but other programers just don't understand what
>>this means (that's the case at my place):
>> modify_ldt(ptr)(func=1 or 0x11)
>>
>>
>> > ==3546== Conditional jump or move depends on uninitialised value(s)
>>
>>Again, some programers just wonder what this error message means. I
>>guess that it has to do with code looking like
>> if ( variable ) {
>> [...]
>>where "variable" isn't initialised. Again maybe this error message could
>>be rewritten using simple words, if at all possible.
>
>
> Can you suggest alternatives that are easier to understand?
Not in the first case. When I say I can't understand the message, I mean it.
In the second case, I think the important part of the message is not
that there's a "conditional jump or move" but an "uninitialised value".
What about
Attempt to read an uninitialised variable
or something like that? I'm not really sure this covers the same error,
but that's the idea.
--
Dimitri
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From: Maarten B. <maa...@mi...> - 2003-11-19 15:17:10
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Hello
On Wed, 2003-11-19 at 08:08, Dimitri Papadopoulos-Orfanos wrote:
> Nicholas Nethercote wrote:
> > On Wed, 19 Nov 2003, Dimitri Papadopoulos-Orfanos wrote:
...
> >> > ==3546== Conditional jump or move depends on uninitialised value(s)
> >>
> >>Again, some programers just wonder what this error message means. I
> >>guess that it has to do with code looking like
> >> if ( variable ) {
> >> [...]
> >>where "variable" isn't initialised. Again maybe this error message could
> >>be rewritten using simple words, if at all possible.
> >
> >
> > Can you suggest alternatives that are easier to understand?
>
> Not in the first case. When I say I can't understand the message, I mean it.
>
> In the second case, I think the important part of the message is not
> that there's a "conditional jump or move" but an "uninitialised value".
> What about
> Attempt to read an uninitialised variable
> or something like that? I'm not really sure this covers the same error,
> but that's the idea.
The order of the message is a little confusing (until you get used
to it ;-/) How about reordering and bringing the "uninitialised"
to the front:
==3546== Uninitialised value(s) used in conditional jump or move.
Anyway, keep up the good work, it is a great tool!
Cheers,
Maarten.
--
Maarten Ballintijn <maa...@mi...>
Massachusetts Institute of Technology
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From: Dimitri Papadopoulos-O. <pap...@sh...> - 2003-11-20 08:25:57
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Hi, >>In the second case, I think the important part of the message is not >>that there's a "conditional jump or move" but an "uninitialised value". >>What about >> Attempt to read an uninitialised variable >>or something like that? I'm not really sure this covers the same error, >>but that's the idea. > > > The order of the message is a little confusing (until you get used > to it ;-/) How about reordering and bringing the "uninitialised" > to the front: > > ==3546== Uninitialised value(s) used in conditional jump or move. Ah, that would be much better! -- Dimitri |