Until now, the ptrace syscall was implemented as a wrapper that called
various functions in procfs depending on which ptrace operation was
requested. Most of these functions were themselves wrappers around
procfs_{read,write}_{,db,fp}regs(), with only some extra error checks,
which weren't necessary in the ptrace case anyway.
This commit moves procfs_rwmem() from procfs_mem.c into sys_process.c
(renaming it to proc_rwmem() in the process), and implements ptrace()
directly in terms of procfs_{read,write}_{,db,fp}regs() instead of
having it fake up a struct uio and then call procfs_do{,db,fp}regs().
It also moves the prototypes for procfs_{read,write}_{,db,fp}regs()
and proc_rwmem() from proc.h to ptrace.h, and marks all procfs files
except procfs_machdep.c as "optional procfs" instead of "standard".
broken and fixing it only creates a duplicate of what is already
in the FreeBSD kernel. Therefore, map the syscall directly to
getpgid().
PR: kern/21402
Submitted by: Christian Weisgerber <naddy@mips.inka.de>
While here, redefine the second entry for setpgid() so that we
don't need a stub. This is achieved by giving the second instance
the type NODEF.
will be private to each CPU.
- Re-style(9) the globaldata structures. There really needs to be a MI
struct pcpu that has a MD struct mdpcpu member at some point.
macro. The commit log clearly states that the index given to the
macro is one higher than previously used to index the array. This
wasn't represented in the code and resulted in kernel page faults.
Reported by: Andrew Atrens <atrens@nortelnetworks.com>
Note ALL MODULES MUST BE RECOMPILED
make the kernel aware that there are smaller units of scheduling than the
process. (but only allow one thread per process at this time).
This is functionally equivalent to teh previousl -current except
that there is a thread associated with each process.
Sorry john! (your next MFC will be a doosie!)
Reviewed by: peter@freebsd.org, dillon@freebsd.org
X-MFC after: ha ha ha ha
it to the MI area. KSE touched cpu_wait() which had the same change
replicated five ways for each platform. Now it can just do it once.
The only MD parts seemed to be dealing with fpu state cleanup and things
like vm86 cleanup on x86. The rest was identical.
XXX: ia64 and powerpc did not have cpu_throw(), so I've put a functional
stub in place.
Reviewed by: jake, tmm, dillon
with the last change to the way the pmap_emulate_reference() works. This
should fix a number of memory corruption problems and also should stop the
mtimes of executables changing all the time.
o Introduce private types for use in linux syscalls for two reasons:
1. establish type independence for ease in porting and,
2. provide a visual queue as to which syscalls have proper
prototypes to further cleanup the i386/alpha split.
Linuxulator types are prefixed by 'l_'. void and char have not
been "virtualized".
o Provide dummy functions for all syscalls and remove dummy functions
or implementations of truely obsolete syscalls.
o Sanitize the shm*, sem* and msg* syscalls.
o Make a first attempt to implement the linux_sysctl syscall. At this
time it only returns one MIB (KERN_VERSION), but most importantly,
it tells us when we need to add additional sysctls :-)
o Bump the kenel version up to 2.4.2 (this is not the same as the
KERN_VERSION MIB, BTW).
o Implement new syscalls, of which most are specific to i386. Our
syscall table is now up to date with Linux 2.4.2. Some highlights:
- Implement the 32-bit uid_t and gid_t bases syscalls.
- Implement a couple of 64-bit file size/offset bases syscalls.
o Fix or improve numerous syscalls and prototypes.
o Reduce style(9) violations while I'm here. Especially indentation
inconsistencies within the same file are addressed. Re-indenting
did not obfuscate actual changes to the extend that it could not
be combined.
NOTE: I spend some time testing these changes and found that if there
were regressions, they were not caused by these changes AFAICT.
It was observed that installing a RH 7.1 runtime environment
did make matters worse. Hangs and/or reboots have been observed
with and without these changes, so when it failed to make life
better in cases it doesn't look like it made it worse.
1. establish type independence for ease in porting and,
2. provide a visual queue as to which syscalls have proper
prototypes to further cleanup the i386/alpha split.
Linuxulator types are prefixed by 'l_'. void and char have not
been "virtualized".
o Provide dummy functions for all unimplemented syscalls, except for
the osf1 syscalls. This can only be done if the osfulator
implements at least all syscalls used by the linuxulator. Remove
dummy functions for syscalls that are now truely unimplemented.
o Set the syscall namespace as follows: Mark a syscall as OSF1 if
the Linux kernel has prefixed the syscall with 'osf_' and has
provided special implementations for it. Otherwise mark the
syscall as LINUX by default. Some of the LINUX syscalls remain
marked as BSD or POSIX.
o Rename syscalls so they match the names used in the Linux kernel.
Also, provide more accurate prototypes. This generally improves
cross-referencing and reduces head-scratching.
o Fix the (g|s)etresuid syscalls. They mapped to (g|s)etresgid.
o Sanitize the the shm*, sem* and msg* syscalls. Their prototypes
were dictated by the way these syscalls were used in the i386
code. That has been fixed. NOTE: linux_semctl now passes it's
'arg' parameter by value and not by reference.
o Fix prototype of linux_utime. It takes a struct timeval, not a
struct utimbuf.
o Fix the linux_sysfs syscall. It's index is not 255, but 254.
o Implement the following syscalls:
linux_sysctl
o Add the following new syscalls:
(g|s)etresgid
linux_pivot_root (dummy)
linux_mincore (dummy)
linux_pciconfig_iobase (dummy)
linux_getdents64
Instead introduce the [M] prefix to existing keywords. e.g.
MSTD is the MP SAFE version of STD. This is prepatory for a
massive Giant lock pushdown. The old MPSAFE keyword made
syscalls.master too messy.
Begin comments MP-Safe procedures with the comment:
/*
* MPSAFE
*/
This comments means that the procedure may be called without
Giant held (The procedure itself may still need to obtain
Giant temporarily to do its thing).
sv_prepsyscall() is now MP SAFE and assumed to be MP SAFE
sv_transtrap() is now MP SAFE and assumed to be MP SAFE
ktrsyscall() and ktrsysret() are now MP SAFE (Giant Pushdown)
trapsignal() is now MP SAFE (Giant Pushdown)
Places which used to do the if (mtx_owned(&Giant)) mtx_unlock(&Giant)
test in syscall[2]() in */*/trap.c now do not. Instead they
explicitly unlock Giant if they previously obtained it, and then
assert that it is no longer held to catch broken system calls.
Rebuild syscall tables.
o Unify <machine/endian.h>'s across all architectures.
o Make bswapXX() functions use a different spelling of u_int16_t and
friends to reduce namespace pollution. The bswapXX() functions
don't actually exist, but we'll probably import these at some
point. Atleast one driver (if_de) depends on bswapXX() for big
endian cases.
o Deprecate byteorder(3) prototypes from <sys/types.h>, these are
now prototyped indirectly in <arpa/inet.h>.
o Deprecate in_addr_t and in_port_t typedefs in <sys/types.h>, these
are now typedef'd in <arpa/inet.h>.
o Change byteorder(3) prototypes to use standards compliant uint32_t
(spelled __uint32_t to reduce namespace pollution).
o Document new preferred headers and standards compliance.
Discussed with: bde
PR: 29946
Reviewed by: bmilekic
timeout callwheel and buffer cache, out of the platform specific areas
and into the machine independant area. i386 and alpha adjusted here.
Other cpus can be fixed piecemeal.
Reviewed by: freebsd-smp, jake
but it's better than the buggy behavior we have now. If we contigmalloc()
buffers in bus_dmamem_alloc(), then we must configfree() them in
bus_dmamem_free(). Trying to free() them is wrong, and will cause
a panic (at least, it does on the alpha.)
I tripped over this when trying to kldunload my busdma-ified if_rl
driver.
to see if it was malloc()ed first" bug. In bus_dmamap_create(), one of
two things can happen: either we need to allocate a special map due to
some manner of bounce buffering requirement, or we can DMA a buffer
in place. On the x86 platform, the "in place" case results in
bus_dmamap_create() returning a dmamap of NULL. The bus_dmamap_destroy()
routine later checks for NULL and won't bother free()ing the map if
it detects this condition.
But on the alpha, we don't use NULL, we use a statically allocated map
called nobounce_dmamap(). Unfortunately, bus_dmamap_destroy() does not
handle the condition where we attempt to destroy such a map: it tries
to free() the dmamap, which causes a panic.
Fix: test that map != &nobounce_dmamap before trying to free() it.
With this fix, my busdma-ified if_sis driver works on the alpha. I'm
a bit alarmed that I'm the first person ever to trip over this bug, since
we have been using busdma on the alpha for a while, and since it sort
of screams out "Hi! I'm a bug! Booga-booga!" when you look at it.
(Somewhere, somebody will say: "But Bill, why don't you just not bother
destroying the maps in this case." Because the API is supposed to be
a) symetrical and b) opaque to the caller. I can't know whether it's safe
to skip the bus_dmamap_destroy() step or not without sticking my fingers
into unsafe places, which is what I wanted to avoid in the first place.)
boot CPU. This was the reason reboots on SMP systems could result in
weird hangs. Unlike the x86, we do not need to switch back to the boot
CPU in order to reboot the machine. See Section 3.4.5 of Part III
(Console Interface Architecture) from the Alpha Architecture Reference
Manual (aka the Brown Book) for more info.
the process of exiting the kernel. The ast() function now loops as long
as the PS_ASTPENDING or PS_NEEDRESCHED flags are set. It returns with
preemption disabled so that any further AST's that arrive via an
interrupt will be delayed until the low-level MD code returns to user
mode.
- Use u_int's to store the tick counts for profiling purposes so that we
do not need sched_lock just to read p_sticks. This also closes a
problem where the call to addupc_task() could screw up the arithmetic
due to non-atomic reads of p_sticks.
- Axe need_proftick(), aston(), astoff(), astpending(), need_resched(),
clear_resched(), and resched_wanted() in favor of direct bit operations
on p_sflag.
- Fix up locking with sched_lock some. In addupc_intr(), use sched_lock
to ensure pr_addr and pr_ticks are updated atomically with setting
PS_OWEUPC. In ast() we clear pr_ticks atomically with clearing
PS_OWEUPC. We also do not grab the lock just to test a flag.
- Simplify the handling of Giant in ast() slightly.
Reviewed by: bde (mostly)
are a really nasty interface that should have been killed long ago
when 'ptrace(PT_[SG]ETREGS' etc came along. The entity that they
operate on (struct user) will not be around much longer since it
is part-per-process and part-per-thread in a post-KSE world.
gdb does not actually use this except for the obscure 'info udot'
command which does a hexdump of as much of the child's 'struct user'
as it can get. It carries its own #defines so it doesn't break
compiles.
dynamic symbol table buckets and chains. The sparc64 toolchain uses 32
bit .hash entries, unlike other 64 bits architectures (alpha), which use
64 bit entries.
Discussed with: dfr, jdp
were indices in a dense array. The cpuids are a sparse set and treat
them as such, setting up containers only for CPUs activated during
mb_init().
- Fix netstat(1) and systat(1) to treat the per-CPU stats area as a sparse
map, in accordance with the above.
This allows us to properly boot with certain CPUs disactivated. However, if
we later decide to re-activate said CPUs, we will barf until we decide to
implement CPU spinon/spinoff callback hooks to allow for said CPUs' per-CPU
containers to get configured on their activation.
Reported by: mjacob
Partially (sys/ diffs) Submitted by: mjacob
simply manipulates the pte which faulted instead of traversing the mapping
list for that page. This makes it possible to complete the trap without
needing locks and incidentally improves the accuracy of some statistics
used by the VM system.
blown over by the Hurricane and had a house dropped on you by the Tornado.
Now it's time to have your parade rained on by... the Typhoon!
This commit adds driver support for 3Com 3cR990 10/100 ethernet
adapters based on the Typhoon I and Typhoon II chipsets. This is actually
a port of the OpenBSD driver with many hacks by me.
No Virginia, there isn't any support for the hardware crypto yet. However
there is support for TCP/IP checksum offload and VLANs.
Special thanks go to Jason Wright, Aaron Campbell and Theo de Raadt for
squeezing enough info out of 3Com to get this written, and for doing
most of the hard work.
Manual page is included. Compiled as a module and included in GENERIC.
sure when things got so bad (JHB says preemption worked just fine for months
before the AlbertVM commit). Even post DillionVM locking commit, Miatas
(DEC Personal Workstations) are very fragile -- not making it thru a world
build. With this patch it does.
Those hacking on SMPng will want to locally back out this commit. The rest
of us will want to run with it until the SMPng guys figure out the problem(s).
Submitted by: peter
on Alpha 4100s.
Basically, if you're halting or you're rebooting, you should
tell all other processors to halt first. Define IPI_HALT- IPI_STOP
is not what we want for this purpose, which will call prom_halt(0)
on receipt.
The processor running the halt or reboot wil send an IPI_HALT to all
other processors, delay a bit, then continue to do what what it was
planning on doing (prom_halt({0|1})).
By default, we will end up with a duplicate set of hints if people have
a properly populated /boot/device.hints. So for now, remove the hints
here until Peter revisits the new hints processing from mid-June that
broke Alpha booting.
'dwatch'. The new commands install hardware watchpoints if supported
by the architecture and if there are enough registers to cover the
desired memory area.
No objection by: audit@, hackers@
MFC after: 2 weeks
Also removed some spl's and added some VM mutexes, but they are not actually
used yet, so this commit does not really make any operational changes
to the system.
vm_page.c relates to vm_page_t manipulation, including high level deactivation,
activation, etc... vm_pageq.c relates to finding free pages and aquiring
exclusive access to a page queue (exclusivity part not yet implemented).
And the world still builds... :-)
(this commit is just the first stage). Also add various GIANT_ macros to
formalize the removal of Giant, making it easy to test in a more piecemeal
fashion. These macros will allow us to test fine-grained locks to a degree
before removing Giant, and also after, and to remove Giant in a piecemeal
fashion via sysctl's on those subsystems which the authors believe can
operate without Giant.
.cvsignore file for [A-Za-z]* to keep these directories around rather
than waste a file on .keepme. This should also make people's built
trees place nice with CVS.
Idea for .cvsignore: peter (although I suggested the regexp)
Pointed out by: Makoto MATSUSHITA-san <matusita@jp.FreeBSD.org>
Llama's costuming by: Fernamdo Llamas
vm_page_t's.
- Add a KTR_TRAP tracepoint to trap() on the alpha that displays the
contents of a0, a1, and a2 to make debugging of nested traps that
panic before displaying any useful output easier.
lock until after grabbing the sched_lock to avoid CURSIG racing with
psignal.
- Don't grab Giant for addupc_task() as it isn't needed.
Reported by: tegge (signal race), bde (addupc_task a while back)
- Use db_printf() instead of printf().
- Clean up decode_syscall() to use regular if-then-else rather than goto's.
- Use the same method of parsing PID's for per-process traces as the x86
code does: that is, if the address passed in is not a valid kernel
address, treat it is a decimal pid.
- If the pid of the current process is specified, fall back to using the
"default" parameters for the trace as curproc's pcb is not valid at this
point.
MFC after: 1 week
cpu_mp_start() is never called, mp_ncpus will have a non-zero value.
This prevents systat from dying with an arithmatic exception caused
by a divide-by-zero error on UP alphas running a GENERIC kernel.
Replace the a.out emulation of 'struct linker_set' with something
a little more flexible. <sys/linker_set.h> now provides macros for
accessing elements and completely hides the implementation.
The linker_set.h macros have been on the back burner in various
forms since 1998 and has ideas and code from Mike Smith (SET_FOREACH()),
John Polstra (ELF clue) and myself (cleaned up API and the conversion
of the rest of the kernel to use it).
The macros declare a strongly typed set. They return elements with the
type that you declare the set with, rather than a generic void *.
For ELF, we use the magic ld symbols (__start_<setname> and
__stop_<setname>). Thanks to Richard Henderson <rth@redhat.com> for the
trick about how to force ld to provide them for kld's.
For a.out, we use the old linker_set struct.
NOTE: the item lists are no longer null terminated. This is why
the code impact is high in certain areas.
The runtime linker has a new method to find the linker set
boundaries depending on which backend format is in use.
linker sets are still module/kld unfriendly and should never be used
for anything that may be modular one day.
Reviewed by: eivind
out nearly every platform but the one I tested on requires the intpin
to swizzle out the correct intline.
tested by: Martijn Pronk <mpkisbkl@xs4all.nl> (lca_pci)
greatly improved traceback code from Ross Harvey. This code
requires the use of more traceback friendly temporary labels
at kernel entry points, hence the changes to exception.s and
asm.h
Reviewed by: jhb, dfr
Obtained from: NetBSD
MFC after: 1 week
the interface conversion to platform.pci_intr_route(). I've left the
platform.pci_intr_route() function pointer in place, as well as
alpha_pci_route_interrupt(), but no platform currently implements it.
To work around the removal of alpha_platform_assign_pciintr(cfg);
from the pci probe code, I've hooked in calls to platform.pci_intr_map()
in pcib_read_config (similar to the x86 APIC_IO ifdef in pci_cfgregread)
for every chipset that has a platform which needs it.
While here, I've removed the interupt mapping/routing code from the
AS2x00 platform because its not required (it has never been present in
-stable).
Tested on: UP1000, Miata(GL), XP1000, AS2100, AS500
- move the sysctl code to kern_intr.c
- do not use INTRCNT_COUNT, but rather eintrcnt - intrcnt to determine
the length of the intrcnt array
- move the declarations of intrnames, eintrnames, intrcnt and eintrcnt
from machine-dependent include files to sys/interrupt.h
- remove the hw.nintr sysctl, it is not needed.
- fix various style bugs
Requested by: bde
Reviewed by: bde (some time ago)
all alphas with devices behind ppb's. I'm working on a better solution now.
Note that all alphas that use per-platform interrupt mapping are broken
again (as they have been for several months)
breakage:
- call PCIB_ROUTE_INTERRUPT() regardless of how valid the intline looks.
Some alphas leave garbage in the intline and leave the intr mapping
to OS platform support routines that map slots/buses to intlines
- Down in the alpha pci code, first try platform.pci_intr_route() and
if it doesn't exist or returns garbage, just read the intline out of
config space.
tested on AS500 (garbage in intline) and UP1000 (PC-like, intline is valid)
Note that a nice little hack like the APIC_IO section of pci_cfgregread()
is not workable. This is because the calling interface for
alpha_pci_route_interrupt() requires us to figure out the bus/slot/etc
from a device_t. At pci_read_device() time, we don't have a device_t
for the bus/slot/func in question.
real uid, saved uid, real gid, and saved gid to ucred, as well as the
pcred->pc_uidinfo, which was associated with the real uid, only rename
it to cr_ruidinfo so as not to conflict with cr_uidinfo, which
corresponds to the effective uid.
o Remove p_cred from struct proc; add p_ucred to struct proc, replacing
original macro that pointed.
p->p_ucred to p->p_cred->pc_ucred.
o Universally update code so that it makes use of ucred instead of pcred,
p->p_ucred instead of p->p_pcred, cr_ruidinfo instead of p_uidinfo,
cr_{r,sv}{u,g}id instead of p_*, etc.
o Remove pcred0 and its initialization from init_main.c; initialize
cr_ruidinfo there.
o Restruction many credential modification chunks to always crdup while
we figure out locking and optimizations; generally speaking, this
means moving to a structure like this:
newcred = crdup(oldcred);
...
p->p_ucred = newcred;
crfree(oldcred);
It's not race-free, but better than nothing. There are also races
in sys_process.c, all inter-process authorization, fork, exec, and
exit.
o Remove sigio->sio_ruid since sigio->sio_ucred now contains the ruid;
remove comments indicating that the old arrangement was a problem.
o Restructure exec1() a little to use newcred/oldcred arrangement, and
use improved uid management primitives.
o Clean up exit1() so as to do less work in credential cleanup due to
pcred removal.
o Clean up fork1() so as to do less work in credential cleanup and
allocation.
o Clean up ktrcanset() to take into account changes, and move to using
suser_xxx() instead of performing a direct uid==0 comparision.
o Improve commenting in various kern_prot.c credential modification
calls to better document current behavior. In a couple of places,
current behavior is a little questionable and we need to check
POSIX.1 to make sure it's "right". More commenting work still
remains to be done.
o Update credential management calls, such as crfree(), to take into
account new ruidinfo reference.
o Modify or add the following uid and gid helper routines:
change_euid()
change_egid()
change_ruid()
change_rgid()
change_svuid()
change_svgid()
In each case, the call now acts on a credential not a process, and as
such no longer requires more complicated process locking/etc. They
now assume the caller will do any necessary allocation of an
exclusive credential reference. Each is commented to document its
reference requirements.
o CANSIGIO() is simplified to require only credentials, not processes
and pcreds.
o Remove lots of (p_pcred==NULL) checks.
o Add an XXX to authorization code in nfs_lock.c, since it's
questionable, and needs to be considered carefully.
o Simplify posix4 authorization code to require only credentials, not
processes and pcreds. Note that this authorization, as well as
CANSIGIO(), needs to be updated to use the p_cansignal() and
p_cansched() centralized authorization routines, as they currently
do not take into account some desirable restrictions that are handled
by the centralized routines, as well as being inconsistent with other
similar authorization instances.
o Update libkvm to take these changes into account.
Obtained from: TrustedBSD Project
Reviewed by: green, bde, jhb, freebsd-arch, freebsd-audit
the chipset. This is already how the multi-hose systems handle resource
allocation and it fixes a bug where dense and bwx memory allocations were
not handled properly.
Reviewed by: gallatin
systems were repo-copied from sys/miscfs to sys/fs.
- Renamed the following file systems and their modules:
fdesc -> fdescfs, portal -> portalfs, union -> unionfs.
- Renamed corresponding kernel options:
FDESC -> FDESCFS, PORTAL -> PORTALFS, UNION -> UNIONFS.
- Install header files for the above file systems.
- Removed bogus -I${.CURDIR}/../../sys CFLAGS from userland
Makefiles.
flags if it is safe to do so, otherwise it will just alter the pmap state
(eg, clear the appropriate PG_FOx bits).
This gets alpha booting in the face of the vm_mtx introduction.
Reviewed by: dfr
- Attach a writable sysctl to bootverbose (debug.bootverbose) so it can be
toggled after boot.
- Move the printf of the version string to a SI_SUB_COPYRIGHT SYSINIT just
afer the display of the copyright message instead of doing it by hand in
three MD places.
registers better. Hold sched_lock not only for checking the flag but
also while performing the actual operation to ensure the process doesn't
get swapped out by another CPU while we the operation is being performed.
. FD_CLRERR clears the error counter, thus re-enables kernel error
printf()s,
. FD_GSTAT obtains the last FDC operation state, if any,
. FDOPT_NOERRLOG (temporarily) turns off kernel printf() floppy
error logging,
. FDOPT_NOERROR makes the kernel ignore an FDC error, thus can
enable the transfer of an erroneous sector to the user application
All options are being cleared on (last) close.
Prime consumer of the last features will be fdread(1), to be committed
shortly.
(FD_CLRERR should be wired into fdcontrol(8), but then fdcontrol(8)
needs a major rewrite anyway.)
If for some reason DEVFS is undesired, the "NODEVFS" option is
needed now.
Pending any significant issues, DEVFS will be made mandatory in
-current on july 1st so that we can start reaping the full
benefits of having it.
other "system" header files.
Also help the deprecation of lockmgr.h by making it a sub-include of
sys/lock.h and removing sys/lockmgr.h form kernel .c files.
Sort sys/*.h includes where possible in affected files.
OK'ed by: bde (with reservations)
been made machine independent and various other adjustments have been made
to support Alpha SMP.
- It splits the per-process portions of hardclock() and statclock() off
into hardclock_process() and statclock_process() respectively. hardclock()
and statclock() call the *_process() functions for the current process so
that UP systems will run as before. For SMP systems, it is simply necessary
to ensure that all other processors execute the *_process() functions when the
main clock functions are triggered on one CPU by an interrupt. For the alpha
4100, clock interrupts are delievered in a staggered broadcast fashion, so
we simply call hardclock/statclock on the boot CPU and call the *_process()
functions on the secondaries. For x86, we call statclock and hardclock as
usual and then call forward_hardclock/statclock in the MD code to send an IPI
to cause the AP's to execute forwared_hardclock/statclock which then call the
*_process() functions.
- forward_signal() and forward_roundrobin() have been reworked to be MI and to
involve less hackery. Now the cpu doing the forward sets any flags, etc. and
sends a very simple IPI_AST to the other cpu(s). AST IPIs now just basically
return so that they can execute ast() and don't bother with setting the
astpending or needresched flags themselves. This also removes the loop in
forward_signal() as sched_lock closes the race condition that the loop worked
around.
- need_resched(), resched_wanted() and clear_resched() have been changed to take
a process to act on rather than assuming curproc so that they can be used to
implement forward_roundrobin() as described above.
- Various other SMP variables have been moved to a MI subr_smp.c and a new
header sys/smp.h declares MI SMP variables and API's. The IPI API's from
machine/ipl.h have moved to machine/smp.h which is included by sys/smp.h.
- The globaldata_register() and globaldata_find() functions as well as the
SLIST of globaldata structures has become MI and moved into subr_smp.c.
Also, the globaldata list is only available if SMP support is compiled in.
Reviewed by: jake, peter
Looked over by: eivind
It might be more correct to make stathz as close as possible to 128,
but that would involve adding complexity to the clock intr path, which
I don't want to do.
saves 32 registers) to do on every context switch. This is only required
for SMP, so only do it there.
We should also look at moving the critical enter/exit out to the callers
structure. This field keeps track of how many levels deep we are nested
into the kernel. The nesting level is bumped at the start of a trap,
interrupt, syscall, or exception and is decremented on return. This is
used to detect the case when the kernel is returning back to a kernel
context in exception_return(). If we are returning to the kernel we need
to update the globaldata pointer register saved in the stack frame in case
we have switched CPU's between taking the initial interrupt that saved the
frame and returning. If we don't do this fixup it is possible for a CPU to
use the wrong per-cpu data. On UP systems this is not a problem, so the
code is conditional on SMP.
A count was used instead of simply checking the process status register in
the frame during exception_return() since there are critical sections at
the very start and end of a trap, exception, or interrupt from userland in
which we could trash the t7 register being used in userland. The counter
is incremented after adn before these critical sections respectively so
that we will not overwrite the saved t7 register if we are interrupted
during one of these critical sections.
This is will be required to prevent lowering the ipl when a critical_enter()
is present in the interrupt path when handling a machine check.
reviewed by: jhb
and AS4100s into single user mode. This work was done jointly by jhb and
myself, and builds on dfr's earlier work.
smp_init_secondary() / smp_start_secondary()
- use the uniq val to pass the globalp (me)
- fancy footwork to take any pending machine checks (me)
- doing things the FreeBSD way and getting the per-cpu idleproc created
correctly, and synchronizing the startup of secondaries (jhb)
mp_start()
- better recognition of available cpus (jhb)
smp_rendezvous()
- if smp hasn't started, only run the rendezvous function on the current
cpu. Sleuthing and (prior) incorrect fix by me, correct fix by jhb
smp_handle_ipi()
- more verbose handling of console messages (jhb)
- grab sched lock around setting PS_ASTPENDING (jhb)
forward_*clock()
- commented out. Joint decision by dfr, jhb and myself
General synchronization improvements (more mb()s, etc) (jhb)
Printf cleanups (joint)
Whitespace cleanups (jhb)
- don't do the stack overflow sanity check on MP systems -- p->p_addr
will be malloc'ed memory (not K0SEG) and the check will fail.
- don't ignore clock interrupts on secondaries. Alphas apparently
roundrobin clock interrupts to all cpus, so we're going to take clock
interrupts on all CPUS and not forward them.
- use the unique value to save the per-cpu globalp struct like the
comment says
- don't lower the ipl to ALPHA_PSL_IPL_HIGH: we may have a pending machine
check to take and we're not prepared for that yet, as we haven't setup
our interrupt entry points. (this may only happen on sable/lynx)
- indicate the fact that the working version of smp_init_secondary() doesn't
return (this is tied up in other changes and hasn't yet been committed).
panic_cpu shared variable. I used a simple atomic operation here instead
of a spin lock as it seemed to be excessive overhead. Also, this can avoid
recursive panics if, for example, witness is broken.
"inside" of locked regions. That is, an acquire atomic operation will
always enforce a memory barrier after the atomic operation and a release
operation will always enforce a memory barrier before the atomic
operation.
- Explicitly use 'mb' instead of 'wmb' in release atomic operations. The
'wmb' memory barrier is not strong enough to guarantee coherence with
other processors. This is effectively a nop since alpha_wmb() actually
performs a 'mb' and not a 'wmb', but I wanted the code to be more
correct since at some point in the future alpha_wmb()'s implementation
may switch to being a real 'wmb'.
we should call ast(). This allows us to branch to a separate Lkernelret
label so we can fixup the saved t7 register in the trapframe. Otherwise
we can run into a problem on SMP systems where a process is interrupted by
a trap or interrupt on one CPU, migrates to another CPU, and then returns
with the t7 in the stack clobbering the CPU's t7. As a result, two CPU's
would both point to the same per-CPU data and things would go downhill from
there.
Sleuthing help by: gallatin
- Add a new ddb command: 'show pcpu' similar to the i386 command added
recently. By default it displays the current CPU's info, but an optional
argument can specify the logical ID of a specific CPU to examine.
