From: invalid AT erehwon DOT invalid (Graaagh the Mighty) Newsgroups: comp.os.msdos.djgpp Subject: Re: CWSDPMI/DJGPP integration [was Re: Peculiar behavior of program.] Organization: Low Charisma Anonymous Message-ID: <3b3c14b3.264226436@news.primus.ca> References: <3b3c0ae8 DOT 261718669 AT news DOT primus DOT ca> <3b3bcc05 DOT sandmann AT clio DOT rice DOT edu> X-Newsreader: Forte Free Agent 1.11/32.235 Lines: 27 Date: Fri, 29 Jun 2001 05:41:29 GMT NNTP-Posting-Host: 207.176.153.3 X-Complaints-To: news AT primus DOT ca X-Trace: news2.tor.primus.ca 993793434 207.176.153.3 (Fri, 29 Jun 2001 01:43:54 EDT) NNTP-Posting-Date: Fri, 29 Jun 2001 01:43:54 EDT To: djgpp AT delorie DOT com DJ-Gateway: from newsgroup comp.os.msdos.djgpp Reply-To: djgpp AT delorie DOT com On Fri, 29 Jun 2001 0:29:57, "Charles Sandmann" sat on a tribble, which squeaked: >> A serious limitation of debugging capabilities under DPMI was under >> discussion. > >I'll admit I didn't read the entire thread, but I'll guess this is about >previous note on crashes to the CWSDPMI error message with no traceback. >The fix to this is not to hack up CWSDPMI. We could make it more >bullet proof using a DPMI 1.0 extension in CWSDPMI. Mainly, we would >need to strictly clean up the DJGPP code to make the exception code >be broken into read-only sections and read/write. Use DPMI 1.0 functions >to write-protect the executable code and exception jump table. We would >also set some amount of the bottom of the stack (64K?) to be null-page >not mapped also. This would catch stack underruns. It would catch >trashing the executable code that implements the exception handlers and >tracebacks... The DJGPP code that sets some of this stuff up wounld, of course, need to detect DPMI 1.0 feature availability and act accordingly. What about stack overruns? -- Bill Gates: "No computer will ever need more than 640K of RAM." -- 1980 "There's nobody getting rich writing software that I know of." -- 1980 "This antitrust thing will blow over." -- 1998 Combine neo, an underscore, and one thousand sixty-one to make my hotmail addy.