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From: "Ozkan Sezer (sezeroz AT gmail DOT com) [via djgpp AT delorie DOT com]" <djgpp AT delorie DOT com>
Date: Thu, 16 Feb 2023 02:55:30 +0300
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Subject: dxe: page fault when derefencing an exported pointer variable
To: djgpp AT delorie DOT com
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Reply-To: djgpp AT delorie DOT com

dxe: page fault when derefencing an exported pointer variable

The project in question is libmikmod along with its mikmod player:
https://github.com/sezero/mikmod

The libmikmod library exports many functions and variables, only
one of those variables is a pointer:
https://github.com/sezero/mikmod/blob/master/libmikmod/playercode/mdriver.c#L51

The 'normal' vars don't seem to have a problem, but dereferencing
that particular pointer results in a page fault:
https://github.com/sezero/mikmod/blob/master/mikmod/src/display.c#L338-L339

At time of dereferencing the pointer is not actually NULL, because
if I write an accessor returning that pointer and export and use it
then things work. (Yes, the library and its api are a mess, I know)

Using dxe3gen from CVS -- can give instructions to reproduce / test
if requested.

Anyone has an insight, please?