ca7a466f48
TTY has no way of keeping track of multiple readers for a tty minor
device. Instead, it stores a read request for the last reader only.
Consequently, the first ("overwritten") reader gets stuck on a read
request that's never going to be finished. Also, the overwriting
causes a grant mismatch in VFS when TTY returns a reply for the
second reader.
This patch is a work around for the actual problem (i.e., keeping track
of multiple readers). It checks whether there is a read operation in
progress and returns an error if it is --preventing that reader from
getting overwritten and stuck. It fixes a bug triggered by executing
'top | more' and pressing the space bar for a while (easily reproducable
in a VM, not on hardware).
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| .. | ||
| keymaps | ||
| console.c | ||
| keyboard.c | ||
| Makefile | ||
| pty.c | ||
| rs232.c | ||
| tty.c | ||
| tty.h | ||