Error when trying to create a new fd

[PhenixH]

Hi,
First i want to thank for your amazing work !
I am using simuvex with angr (through Tracer/Driller). I had an issue in a specific testcase.
In this test case, I had the warning "Accessing non-existing file with fd %d. Creating a new file" from posix plugin.
And after that the process crashed because it's trying to access "cache_key" key on a string expression (solver issue).
Thanks to a debugger i found that is was trying to solve "wr" self.open("tmp_%d" % fd, "wr", preferred_fd=fd) . The solver is called here.

I "solved" temporarily my issue by using simuvex.storage.file.Flags.O_CREAT flag (integer -> no need of solving) instead of "wr".

I don't if it's the best thing to do and that is why i am asking for your help.

[rhelmot]

Hey, sorry for not following up on this. Your fix was totally right, and we pushed something along those lines. Can you verity that your issue is resolved?

[PhenixH]

Hi,
Thank you for your answer.
I tested this fix but it's not working yet, the issue is that the Flag RDWR does not allow the creation of a file due to this part of the code :
if mode == Flags.O_RDONLY or (mode & Flags.O_RDWR): try: with open(name, "r") as fp: content = fp.read() except IOError: # if the file doesn't exist return error return -1
It will return -1 and in this case is not the behaviour that I was expecting and it will generate an error instead of creating the file, because it's a read only part.

Moreover, the situation when concrete_fs is set to True, it will generate an Error and stop the process but i think is due to the fact that the error handler is still in progress in read method.