On the x86, saving FPU state has the side effect of resetting this
state. In some cases (fork, getcontext), this would cause the state
to be lost. This patch restores the FPU state right after saving it,
except when different state is loaded immediately after.
Previously, user processes could cause a kernel panic upon FPU state
restore, by passing bogus FPU state to the kernel (through e.g.
sigreturn). With this patch, the process is now sent a SIGFPE signal
instead.
There is important information about booting non-ack images in
docs/UPDATING. ack/aout-format images can't be built any more, and
booting clang/ELF-format ones is a little different. Updating to the
new boot monitor is recommended.
Changes in this commit:
. drop boot monitor -> allowing dropping ack support
. facility to copy ELF boot files to /boot so that old boot monitor
can still boot fairly easily, see UPDATING
. no more ack-format libraries -> single-case libraries
. some cleanup of OBJECT_FMT, COMPILER_TYPE, etc cases
. drop several ack toolchain commands, but not all support
commands (e.g. aal is gone but acksize is not yet).
. a few libc files moved to netbsd libc dir
. new /bin/date as minix date used code in libc/
. test compile fix
. harmonize includes
. /usr/lib is no longer special: without ack, /usr/lib plays no
kind of special bootstrapping role any more and bootstrapping
is done exclusively through packages, so releases depend even
less on the state of the machine making them now.
. rename nbsd_lib* to lib*
. reduce mtree
. we cannot use the boot monitor to print the system diag buffer
. for serial, we do nothing, just reset, everything is already printed
. for not-serial, we print the current diag buffer using direct video
memory access from the kernel
- this patch fixes a deadlock which may occur if we get a
spurious interrupt while calibrating clocks during the boot
time. Since we never handle interrupts while in the kernel
(BKL locked) the interrupt code locks the lock. This is a
different situation, a corner case, boot time only. We do not
return to userspace but to the kernel, so the BKL is not
unlocked. So we need irq handler which leaves the BKL
unlocked. The clock handler does it already, this patch adds
a dummy spurious irq handler for the same reason. It is better
to handle the situation this way to keep the normal runtime
code simple.
- this is a temporary change which makes images compiled for SMP
boot in SMP mode by default.
- this change is needed until we can configure the multiboot
images from the boot loader again.
- when kernel copies from userspace, it must be sure that the TLB
entries are not stale and thus the referenced memory is correct
- everytime we change a process' address space we set p_stale_tlb
bits for all CPUs.
- Whenever a cpu finds its bit set when it wants to access the
process' memory, it refreshes the TLB
- it is more conservative than it needs to be but it has low
overhead than checking precisely
- two CPUs can issue IPI to each other now without any hazzard
- we must be able to handle synchronous scheduling IPIs from
other CPUs when we are waiting for attention from another one.
Otherwise we might livelock.
- necessary barriers to prevent reordering
Remove .ident sections, and force separations of .text and
.data sections into separate program headers, for the benefit
of the check done by MINIX boot monitor in multiboot mode.
. only use for single-page invalidations initially
. shows tiny but statistically significant performance
improvement; will be more helpful in certain VM debug
modes
. fold 2 exception-in-kernel cases (pagefault and rest)
into 1
. for exceptions that occur in kernel, don't just print
kernel stacktrace (typically that is just the exception
handler) but also the stacktrace of when the exception
happened
. remove a few asserts in the kernel and 64bi library
that are not compatible with the timing code
. change the TIME_BLOCKS code a little to work in-kernel
Before safecopies, the IO_ENDPT and DL_ENDPT message fields were needed
to know which actual process to copy data from/to, as that process may
not always be the caller. Now that we have full safecopy support, these
fields have become useless for that purpose: the owner of the grant is
*always* the caller. Allowing the caller to supply another endpoint is
in fact dangerous, because the callee may then end up using a grant
from a third party. One could call this a variant of the confused
deputy problem.
From now on, safecopy calls should always use the caller's endpoint as
grant owner. This fully obsoletes the DL_ENDPT field in the
inet/ethernet protocol. IO_ENDPT has other uses besides identifying the
grant owner though. This patch renames IO_ENDPT to USER_ENDPT, not only
because that is a more fitting name (it should never be used for I/O
after all), but also in order to intentionally break any old system
source code outside the base system. If this patch breaks your code,
fixing it is fairly simple:
- DL_ENDPT should be replaced with m_source;
- IO_ENDPT should be replaced with m_source when used for safecopies;
- IO_ENDPT should be replaced with USER_ENDPT for any other use, e.g.
when setting REP_ENDPT, matching requests in CANCEL calls, getting
DEV_SELECT flags, and retrieving of the real user process's endpoint
in DEV_OPEN.
The changes in this patch are binary backward compatible.
