Date: Sat, 26 Oct 1996 22:35:17 +0200 From: Mark Murray <mark@grondar.za> To: Soren Schmidt <sos@freefall.freebsd.org> Cc: CVS-committers@freefall.freebsd.org, cvs-all@freefall.freebsd.org, cvs-sys@freefall.freebsd.org Subject: Re: cvs commit: src/sys/i386/isa syscons.c Message-ID: <199610262035.WAA13468@grumble.grondar.za>
next in thread | raw e-mail | index | archive | help
Soren Schmidt wrote:
> Fixed side effects from calling add_keyboard_randomness() in the console
> getc routine by not calling it. add_keyboard_randomness() currently
> always reenables interrupts on 386's and 486's. This is very bad if the
> console getc routine is called from the debugger and the debugger was
> entered with interrupts disabled.
add_keyboard_randomness() calls add_timer_randomness(), which does this:
disable_intr();
outb(TIMER_MODE, TIMER_SEL0 | TIMER_LATCH);
num ^= inb(TIMER_CNTR0) << 16;
num ^= inb(TIMER_CNTR0) << 24;
enable_intr();
If this was changed to not disable/enable the interrupts, would it cause
any trouble? I don't mind getting funny numbers out of the counter, that
just adds to entropy, but causing the counter device to misbehave would be
a bad thing.
If this was fixed, could this be added back to syscons?
M
--
Mark Murray
46 Harvey Rd, Claremont, Cape Town 7700, South Africa
+27 21 61-3768 GMT+0200
Finger mark@grondar.za for PGP key
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199610262035.WAA13468>