public inbox for cygwin-developers@cygwin.com
 help / color / mirror / Atom feed
* I discovered the problems why the program I'm trying to port crashed
@ 2023-02-19 16:56 w6b7rk5yu4mt25v3
  0 siblings, 0 replies; only message in thread
From: w6b7rk5yu4mt25v3 @ 2023-02-19 16:56 UTC (permalink / raw)
  To: cygwin, cygwin-developers

Quoted from https://cygwin.com/pipermail/cygwin-cvs/2020q3/014516.html:

"The file mapping will be only a single page, 4K, and since 64 bit systems don't support the AT_ROUND_TO_PAGE flag, the remainder of the 64K slot will result in a SEGV when accessed."

"The justification is that there's very likely no application actually utilizing the map beyond EOF, and we know that all bytes beyond EOF are set to 0 anyway."

Unfortunately, the application I'm trying to port do exactly that. If you set JIT_PAGE_SIZE to 64k (same as PAGE_SIZE) to satisfy mprotect then it will expect the whole 64k to be accessible. On other systems, no problems. On Cygwin, crashed with segmentation fault. I was right. Not the application's bug, but Cygwin's quirk (I called it as a quirk but not a bug, because it's a limitation of the platform).

Goodbye. It's better to use WSL directly than messing with Cygwin nowadays.

Sent with Proton Mail secure email.

^ permalink raw reply	[flat|nested] only message in thread

only message in thread, other threads:[~2023-02-20 10:34 UTC | newest]

Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-02-19 16:56 I discovered the problems why the program I'm trying to port crashed w6b7rk5yu4mt25v3

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).