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Re: Cannot exec() program outside of /bin if PATH is unset


Corinna Vinschen wrote:
On Oct 17 11:10, Corinna Vinschen wrote:
On Oct 16 23:51, Christian Franke wrote:
Corinna Vinschen wrote:
...
I implemented this in the latest snapshot.  It calls SetDllDirectory
on Cygwin's /bin, and dlopen addiotnally tries to load the DLL with
LoadLibraryEx(LOAD_WITH_ALTERED_SEARCH_PATH) if all else failed.
For some reason, the SetDllDirectory() call has no effect for exec():

Testcase:

$ unset PATH

$ uname -srvm
-bash: uname: No such file or directory

$ /bin/uname -srvm
CYGWIN_NT-6.1-WOW64 1.7.33s(0.277/5/3) 20141014 19:44:03 i686

$ /usr/sbin/alternatives
/usr/sbin/alternatives: error while loading shared libraries: ?: cannot open
shared object file: No such file or directory
Weird.  The same sequence of commands works fine for me on W8,
W8.1 and W10 64 bit, under i686 as well as x86_64 Cygwin.

[...]

but it doesn't on Vista and W7, wow.

The question now is, is it because the path given to SetDllDirectory
is not propagated to child processes on older systems, or is it
because the directory is only used in calls to LoadLibrary{Ex} on
older systems.

Stay tuned, I have to investigate this.
Ok, so prior to W8, the SetDllDirectory path is not propagated to child
processes :-|

I created a patch and a new snapshot on https://cygwin.com/snapshots/
which calls SetDllDirectory during initialization of every process.
Please give it a try.

Now works.

cygwin_patches_for_postfix_count++; postfix_patches_for_cygwin_count--; :-)

Thanks,
Christian


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