Bug #1065

GModelSpectralNodes::update_flux_cache(void) behavior when zero Nodes

Added by Gerard Lucie over 10 years ago. Updated about 10 years ago.

Status:ClosedStart date:01/08/2014
Priority:NormalDue date:
Assigned To:Knödlseder Jürgen% Done:

100%

Category:-
Target version:00-08-00
Duration:

Description

In GModelSpectralNodes when there is zero Nodes:
m_lin_energies.size() and m_values.size() are less then zero,
but m_lin_energies[i+1] and m_values[i+1] in lines 1494 and 1496 are called, leading to a segfault.

I propose adding the following lines before the loop.

   if(m_energies.size()<1){
    GException::not_enough_nodes(G_UPDATE_FLUX_CACHE,m_energies.size() );
    }

Recurrence

No recurrence.

History

#1 Updated by Knödlseder Jürgen over 10 years ago

Did this lead to a problem in your case? The loop is

    for (int i = 0; i < m_energies.size()-1; ++i) {

which should only be entered if the condition i < m_energies.size()-1 is fulfilled. For zero nodes, the right hand side should be -1, hence 0 < -1 is not fulfilled. For one node, the right hand side should be 0, hence 0 < 0 is not fulfilled. The loop is only entered if there are at least 2 nodes, hence there shouldn’t be a problem.

#2 Updated by Gerard Lucie over 10 years ago

It leads to a segfault. m_energies.size() = 0 but the for loop is still entered. The problem is that m_energies.size() -1 = 18446744073709551615, nonsense because m_energies.size() returns a unsigned int (I guess).
What works for me is to write:

for (int i = 0; i < (int)m_energies.size()-1; ++i) {

, that is to cast m_energies.size() into an int.

Then you are right throwing an exception before the for loop is not necessary.

#3 Updated by Knödlseder Jürgen over 10 years ago

Gerard Lucie wrote:

It leads to a segfault. m_energies.size() = 0 but the for loop is still entered. The problem is that m_energies.size() -1 = 18446744073709551615, nonsense because m_energies.size() returns a unsigned int (I guess).
What works for me is to write:
[...]
, that is to cast m_energies.size() into an int.

Then you are right throwing an exception before the for loop is not necessary.

Thanks for this fix. Indeed, I have not considered the possibility that m_energies.size() returns a unsigned int.

I’ll do the following

    // Determine number of nodes
    int nodes = m_energies.size(); // cast to int as size() returns unsigned

    // Loop over all nodes-1
    for (int i = 0; i < nodes-1; ++i) {

and push it the trunk.

Once this is done, does this solve the problem or do you get a crash at another point?

#4 Updated by Gerard Lucie over 10 years ago

It solves the problem. An exception is thrown later on because the node array is empty, as expected.

#5 Updated by Knödlseder Jürgen over 10 years ago

  • Status changed from New to Feedback
  • Assigned To set to Knödlseder Jürgen
  • Target version set to 00-08-00
  • % Done changed from 0 to 100

Okay, great. I pushed the above change in devel.

#6 Updated by Knödlseder Jürgen about 10 years ago

  • Status changed from Feedback to Closed

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