rasctl(2): Avoid arithmetic overflow.

Reported-by: syzbot+40b6085d020ae47a6997@syzkaller.appspotmail.com
https://syzkaller.appspot.com/bug?id=8fb9b5dee9b056e4f8ad3b937dc5be1296608c5f

rasctl(2): Avoid overflow in address range arithmetic.

Remove various contortions to suppress warnings. Rely on
-Wno-type-limits instead.

Reported-by: syzbot+8b0f1ced3fce82031535@syzkaller.appspotmail.com
https://syzkaller.appspot.com/bug?id=e9055200701cffd653d5b13491d85c34e07f06a3

Remove charade dancing around now-dead RCU patent.

xc_barrier - convenience function to xc_broadcast() a nop.

Make the intent more clear and also avoid a bunch of (xcfunc_t)nullop
casts that gcc 8 -Wcast-function-type is not happy about.

branches: 1.38.18;
Make the execution flow canonical instead of jumping back and forth, and
complete the userland check.

Ensure the restartable atomic sequence is in userland, for real.

branches: 1.36.6;
Push/Pop pragma magic to avoid gcc warning aber a less-than NULL comparision

branches: 1.35.2; 1.35.4;
Remove COMPAT_SA / KERN_SA. Welcome to 6.99.3!
Approved by core@.

branches: 1.34.28; 1.34.32;
Merge wrstuden-revivesa into HEAD.

branches: 1.33.4;
Fix error in previous.

ras_purgeall: avoid taking p_auxlock.

Use kmem_alloc/free.

branches: 1.30.2;
Remove clause 3 and 4 from TNF licenses

Add MI code to support in-kernel preemption. Preemption is deferred by
one of the following:

- Holding kernel_lock (indicating that the code is not MT safe).
- Bracketing critical sections with kpreempt_disable/kpreempt_enable.
- Holding the interrupt priority level above IPL_NONE.

Statistics on kernel preemption are reported via event counters, and
where preemption is deferred for some reason, it's also reported via
lockstat. The LWP priority at which preemption is triggered is tuneable
via sysctl.

branches: 1.28.2;
- Rename crit_enter/crit_exit to kpreempt_disable/kpreempt_enable.
DragonflyBSD uses the crit names for something quite different.
- Add a kpreempt_disabled function for diagnostic assertions.
- Add inline versions of kpreempt_enable/kpreempt_disable for primitives.
- Make some more changes for preemption safety to the x86 pmap.

branches: 1.27.6; 1.27.8;
Actually copy the ras list onto the child process during fork() - hi ad.
Might fix the 'ras' part of kern/37650.
For some reason the itimers aren't inherited either.

Start detangling lock.h from intr.h. This is likely to cause short term
breakage, but the mess of dependencies has been regularly breaking the
build recently anyhow.

Merge vmlocking2 to head.

Convert all the system call entry points from:
int foo(struct lwp *l, void *v, register_t *retval)
to:
int foo(struct lwp *l, const struct foo_args *uap, register_t *retval)
Fixup compat code to not write into 'uap' and (in some cases) to actually
pass a correctly formatted 'uap' structure with the right name to the
next routine.
A few 'compat' routines that just call standard ones have been deleted.
All the 'compat' code compiles (along with the kernels required to test
build it).
98% done by automated scripts.

branches: 1.23.2; 1.23.4; 1.23.8;
ras_sync: deal with spurious wakeup and add comments.

Fix debug builds.

Make ras_lookup() lockless.

branches: 1.20.2; 1.20.6;
Changes to make ktrace LKM friendly and reduce ifdef KTRACE. Proposed
on tech-kern.

branches: 1.19.6; 1.19.10;
Return EEXIST if attempting to install a RAS that is already installed.

branches: 1.18.2;
Pass an ipl argument to pool_init/POOL_INIT to be used when initializing
the pool's lock.

branches: 1.17.2;
Kill caddr_t; there will be some MI fallout, but it will be fixed shortly.

branches: 1.16.2;
Merge newlock2 to head.

remove some __unused from function parameters.

- sprinkle __unused on function decls.
- fix a couple of unused bugs
- no more -Wno-unused for i386

Add specificdata support to procs and lwps, each providing their own
wrappers around the speicificdata subroutines. Also:
- Call the new lwpinit() function from main() after calling procinit().
- Move some pool initialization out of kern_proc.c and into files that
are directly related to the pools in question (kern_lwp.c and kern_ras.c).
- Convert uipc_sem.c to proc_{get,set}specific(), and eliminate the p_ksems
member from struct proc.

branches: 1.12.20; 1.12.22;
Make it compile on archs without __HAVE_RAS.

Make a couple of functions static.

branches: 1.10.4; 1.10.10;
nuke trailing whitespace

branches: 1.9.4; 1.9.6;
ras_fork: don't do PR_WAITOK holding a spinlock.

ras_install: don't do pool_get(PR_WAITOK) while we're holding a spinlock.

branches: 1.7.2;
Convert pool_get()'s from nowait to waitok. We're allowed to block,
and this is more acceptable since the code assumes success.

gmcgarry ok

Remove p_nras from struct proc - use LIST_EMPTY(&p->p_raslist) instead.
Remove p_raslock and rename p_lwplock p_lock (one lock is enough).
Simplify window test when adding a ras and correct test on VM_MAXUSER_ADDRESS.
Avoid unpredictable branch in i386 locore.S
(pad fields left in struct proc to avoid kernel bump)

branches: 1.5.2;
Declare ras_pool in <sys/ras.h> instead of an extern declaration in
the file where it's needed.

Merge the nathanw_sa branch.

Fix signed/unsigned comparison warnings.

Fix debug printf format.

branches: 1.1.2; 1.1.4; 1.1.6;
MI kernel support for user-level Restartable Atomic Sequences (RAS).

rasctl(2): Avoid overflow in address range arithmetic.

Remove various contortions to suppress warnings. Rely on
-Wno-type-limits instead.

Reported-by: syzbot+8b0f1ced3fce82031535@syzkaller.appspotmail.com
https://syzkaller.appspot.com/bug?id=e9055200701cffd653d5b13491d85c34e07f06a3

Remove charade dancing around now-dead RCU patent.

xc_barrier - convenience function to xc_broadcast() a nop.

Make the intent more clear and also avoid a bunch of (xcfunc_t)nullop
casts that gcc 8 -Wcast-function-type is not happy about.

branches: 1.38.18;
Make the execution flow canonical instead of jumping back and forth, and
complete the userland check.

Ensure the restartable atomic sequence is in userland, for real.

branches: 1.36.6;
Push/Pop pragma magic to avoid gcc warning aber a less-than NULL comparision

branches: 1.35.2; 1.35.4;
Remove COMPAT_SA / KERN_SA. Welcome to 6.99.3!
Approved by core@.

branches: 1.34.28; 1.34.32;
Merge wrstuden-revivesa into HEAD.

branches: 1.33.4;
Fix error in previous.

ras_purgeall: avoid taking p_auxlock.

Use kmem_alloc/free.

branches: 1.30.2;
Remove clause 3 and 4 from TNF licenses

Add MI code to support in-kernel preemption. Preemption is deferred by
one of the following:

- Holding kernel_lock (indicating that the code is not MT safe).
- Bracketing critical sections with kpreempt_disable/kpreempt_enable.
- Holding the interrupt priority level above IPL_NONE.

Statistics on kernel preemption are reported via event counters, and
where preemption is deferred for some reason, it's also reported via
lockstat. The LWP priority at which preemption is triggered is tuneable
via sysctl.

branches: 1.28.2;
- Rename crit_enter/crit_exit to kpreempt_disable/kpreempt_enable.
DragonflyBSD uses the crit names for something quite different.
- Add a kpreempt_disabled function for diagnostic assertions.
- Add inline versions of kpreempt_enable/kpreempt_disable for primitives.
- Make some more changes for preemption safety to the x86 pmap.

branches: 1.27.6; 1.27.8;
Actually copy the ras list onto the child process during fork() - hi ad.
Might fix the 'ras' part of kern/37650.
For some reason the itimers aren't inherited either.

Start detangling lock.h from intr.h. This is likely to cause short term
breakage, but the mess of dependencies has been regularly breaking the
build recently anyhow.

Merge vmlocking2 to head.

Convert all the system call entry points from:
int foo(struct lwp *l, void *v, register_t *retval)
to:
int foo(struct lwp *l, const struct foo_args *uap, register_t *retval)
Fixup compat code to not write into 'uap' and (in some cases) to actually
pass a correctly formatted 'uap' structure with the right name to the
next routine.
A few 'compat' routines that just call standard ones have been deleted.
All the 'compat' code compiles (along with the kernels required to test
build it).
98% done by automated scripts.

branches: 1.23.2; 1.23.4; 1.23.8;
ras_sync: deal with spurious wakeup and add comments.

Fix debug builds.

Make ras_lookup() lockless.

branches: 1.20.2; 1.20.6;
Changes to make ktrace LKM friendly and reduce ifdef KTRACE. Proposed
on tech-kern.

branches: 1.19.6; 1.19.10;
Return EEXIST if attempting to install a RAS that is already installed.

branches: 1.18.2;
Pass an ipl argument to pool_init/POOL_INIT to be used when initializing
the pool's lock.

branches: 1.17.2;
Kill caddr_t; there will be some MI fallout, but it will be fixed shortly.

branches: 1.16.2;
Merge newlock2 to head.

remove some __unused from function parameters.

- sprinkle __unused on function decls.
- fix a couple of unused bugs
- no more -Wno-unused for i386

Add specificdata support to procs and lwps, each providing their own
wrappers around the speicificdata subroutines. Also:
- Call the new lwpinit() function from main() after calling procinit().
- Move some pool initialization out of kern_proc.c and into files that
are directly related to the pools in question (kern_lwp.c and kern_ras.c).
- Convert uipc_sem.c to proc_{get,set}specific(), and eliminate the p_ksems
member from struct proc.

branches: 1.12.20; 1.12.22;
Make it compile on archs without __HAVE_RAS.

Make a couple of functions static.

branches: 1.10.4; 1.10.10;
nuke trailing whitespace

branches: 1.9.4; 1.9.6;
ras_fork: don't do PR_WAITOK holding a spinlock.

ras_install: don't do pool_get(PR_WAITOK) while we're holding a spinlock.

branches: 1.7.2;
Convert pool_get()'s from nowait to waitok. We're allowed to block,
and this is more acceptable since the code assumes success.

gmcgarry ok

Remove p_nras from struct proc - use LIST_EMPTY(&p->p_raslist) instead.
Remove p_raslock and rename p_lwplock p_lock (one lock is enough).
Simplify window test when adding a ras and correct test on VM_MAXUSER_ADDRESS.
Avoid unpredictable branch in i386 locore.S
(pad fields left in struct proc to avoid kernel bump)

branches: 1.5.2;
Declare ras_pool in <sys/ras.h> instead of an extern declaration in
the file where it's needed.

Merge the nathanw_sa branch.

Fix signed/unsigned comparison warnings.

Fix debug printf format.

branches: 1.1.2; 1.1.4; 1.1.6;
MI kernel support for user-level Restartable Atomic Sequences (RAS).

Remove charade dancing around now-dead RCU patent.

xc_barrier - convenience function to xc_broadcast() a nop.

Make the intent more clear and also avoid a bunch of (xcfunc_t)nullop
casts that gcc 8 -Wcast-function-type is not happy about.

Make the execution flow canonical instead of jumping back and forth, and
complete the userland check.

Ensure the restartable atomic sequence is in userland, for real.

branches: 1.36.6;
Push/Pop pragma magic to avoid gcc warning aber a less-than NULL comparision

branches: 1.35.2; 1.35.4;
Remove COMPAT_SA / KERN_SA. Welcome to 6.99.3!
Approved by core@.

branches: 1.34.28; 1.34.32;
Merge wrstuden-revivesa into HEAD.

branches: 1.33.4;
Fix error in previous.

ras_purgeall: avoid taking p_auxlock.

Use kmem_alloc/free.

branches: 1.30.2;
Remove clause 3 and 4 from TNF licenses

Add MI code to support in-kernel preemption. Preemption is deferred by
one of the following:

- Holding kernel_lock (indicating that the code is not MT safe).
- Bracketing critical sections with kpreempt_disable/kpreempt_enable.
- Holding the interrupt priority level above IPL_NONE.

Statistics on kernel preemption are reported via event counters, and
where preemption is deferred for some reason, it's also reported via
lockstat. The LWP priority at which preemption is triggered is tuneable
via sysctl.

branches: 1.28.2;
- Rename crit_enter/crit_exit to kpreempt_disable/kpreempt_enable.
DragonflyBSD uses the crit names for something quite different.
- Add a kpreempt_disabled function for diagnostic assertions.
- Add inline versions of kpreempt_enable/kpreempt_disable for primitives.
- Make some more changes for preemption safety to the x86 pmap.

branches: 1.27.6; 1.27.8;
Actually copy the ras list onto the child process during fork() - hi ad.
Might fix the 'ras' part of kern/37650.
For some reason the itimers aren't inherited either.

Start detangling lock.h from intr.h. This is likely to cause short term
breakage, but the mess of dependencies has been regularly breaking the
build recently anyhow.

Merge vmlocking2 to head.

Convert all the system call entry points from:
int foo(struct lwp *l, void *v, register_t *retval)
to:
int foo(struct lwp *l, const struct foo_args *uap, register_t *retval)
Fixup compat code to not write into 'uap' and (in some cases) to actually
pass a correctly formatted 'uap' structure with the right name to the
next routine.
A few 'compat' routines that just call standard ones have been deleted.
All the 'compat' code compiles (along with the kernels required to test
build it).
98% done by automated scripts.

branches: 1.23.2; 1.23.4; 1.23.8;
ras_sync: deal with spurious wakeup and add comments.

Fix debug builds.

Make ras_lookup() lockless.

branches: 1.20.2; 1.20.6;
Changes to make ktrace LKM friendly and reduce ifdef KTRACE. Proposed
on tech-kern.

branches: 1.19.6; 1.19.10;
Return EEXIST if attempting to install a RAS that is already installed.

branches: 1.18.2;
Pass an ipl argument to pool_init/POOL_INIT to be used when initializing
the pool's lock.

branches: 1.17.2;
Kill caddr_t; there will be some MI fallout, but it will be fixed shortly.

branches: 1.16.2;
Merge newlock2 to head.

remove some __unused from function parameters.

- sprinkle __unused on function decls.
- fix a couple of unused bugs
- no more -Wno-unused for i386

Add specificdata support to procs and lwps, each providing their own
wrappers around the speicificdata subroutines. Also:
- Call the new lwpinit() function from main() after calling procinit().
- Move some pool initialization out of kern_proc.c and into files that
are directly related to the pools in question (kern_lwp.c and kern_ras.c).
- Convert uipc_sem.c to proc_{get,set}specific(), and eliminate the p_ksems
member from struct proc.

branches: 1.12.20; 1.12.22;
Make it compile on archs without __HAVE_RAS.

Make a couple of functions static.

branches: 1.10.4; 1.10.10;
nuke trailing whitespace

branches: 1.9.4; 1.9.6;
ras_fork: don't do PR_WAITOK holding a spinlock.

ras_install: don't do pool_get(PR_WAITOK) while we're holding a spinlock.

branches: 1.7.2;
Convert pool_get()'s from nowait to waitok. We're allowed to block,
and this is more acceptable since the code assumes success.

gmcgarry ok

Remove p_nras from struct proc - use LIST_EMPTY(&p->p_raslist) instead.
Remove p_raslock and rename p_lwplock p_lock (one lock is enough).
Simplify window test when adding a ras and correct test on VM_MAXUSER_ADDRESS.
Avoid unpredictable branch in i386 locore.S
(pad fields left in struct proc to avoid kernel bump)

branches: 1.5.2;
Declare ras_pool in <sys/ras.h> instead of an extern declaration in
the file where it's needed.

Merge the nathanw_sa branch.

Fix signed/unsigned comparison warnings.

Fix debug printf format.

branches: 1.1.2; 1.1.4; 1.1.6;
MI kernel support for user-level Restartable Atomic Sequences (RAS).

xc_barrier - convenience function to xc_broadcast() a nop.

Make the intent more clear and also avoid a bunch of (xcfunc_t)nullop
casts that gcc 8 -Wcast-function-type is not happy about.

Make the execution flow canonical instead of jumping back and forth, and
complete the userland check.

Ensure the restartable atomic sequence is in userland, for real.

branches: 1.36.6;
Push/Pop pragma magic to avoid gcc warning aber a less-than NULL comparision

branches: 1.35.2; 1.35.4;
Remove COMPAT_SA / KERN_SA. Welcome to 6.99.3!
Approved by core@.

branches: 1.34.28; 1.34.32;
Merge wrstuden-revivesa into HEAD.

branches: 1.33.4;
Fix error in previous.

ras_purgeall: avoid taking p_auxlock.

Use kmem_alloc/free.

branches: 1.30.2;
Remove clause 3 and 4 from TNF licenses

Add MI code to support in-kernel preemption. Preemption is deferred by
one of the following:

- Holding kernel_lock (indicating that the code is not MT safe).
- Bracketing critical sections with kpreempt_disable/kpreempt_enable.
- Holding the interrupt priority level above IPL_NONE.

Statistics on kernel preemption are reported via event counters, and
where preemption is deferred for some reason, it's also reported via
lockstat. The LWP priority at which preemption is triggered is tuneable
via sysctl.

branches: 1.28.2;
- Rename crit_enter/crit_exit to kpreempt_disable/kpreempt_enable.
DragonflyBSD uses the crit names for something quite different.
- Add a kpreempt_disabled function for diagnostic assertions.
- Add inline versions of kpreempt_enable/kpreempt_disable for primitives.
- Make some more changes for preemption safety to the x86 pmap.

branches: 1.27.6; 1.27.8;
Actually copy the ras list onto the child process during fork() - hi ad.
Might fix the 'ras' part of kern/37650.
For some reason the itimers aren't inherited either.

Start detangling lock.h from intr.h. This is likely to cause short term
breakage, but the mess of dependencies has been regularly breaking the
build recently anyhow.

Merge vmlocking2 to head.

Convert all the system call entry points from:
int foo(struct lwp *l, void *v, register_t *retval)
to:
int foo(struct lwp *l, const struct foo_args *uap, register_t *retval)
Fixup compat code to not write into 'uap' and (in some cases) to actually
pass a correctly formatted 'uap' structure with the right name to the
next routine.
A few 'compat' routines that just call standard ones have been deleted.
All the 'compat' code compiles (along with the kernels required to test
build it).
98% done by automated scripts.

branches: 1.23.2; 1.23.4; 1.23.8;
ras_sync: deal with spurious wakeup and add comments.

Fix debug builds.

Make ras_lookup() lockless.

branches: 1.20.2; 1.20.6;
Changes to make ktrace LKM friendly and reduce ifdef KTRACE. Proposed
on tech-kern.

branches: 1.19.6; 1.19.10;
Return EEXIST if attempting to install a RAS that is already installed.

branches: 1.18.2;
Pass an ipl argument to pool_init/POOL_INIT to be used when initializing
the pool's lock.

branches: 1.17.2;
Kill caddr_t; there will be some MI fallout, but it will be fixed shortly.

branches: 1.16.2;
Merge newlock2 to head.

remove some __unused from function parameters.

- sprinkle __unused on function decls.
- fix a couple of unused bugs
- no more -Wno-unused for i386

Add specificdata support to procs and lwps, each providing their own
wrappers around the speicificdata subroutines. Also:
- Call the new lwpinit() function from main() after calling procinit().
- Move some pool initialization out of kern_proc.c and into files that
are directly related to the pools in question (kern_lwp.c and kern_ras.c).
- Convert uipc_sem.c to proc_{get,set}specific(), and eliminate the p_ksems
member from struct proc.

branches: 1.12.20; 1.12.22;
Make it compile on archs without __HAVE_RAS.

Make a couple of functions static.

branches: 1.10.4; 1.10.10;
nuke trailing whitespace

branches: 1.9.4; 1.9.6;
ras_fork: don't do PR_WAITOK holding a spinlock.

ras_install: don't do pool_get(PR_WAITOK) while we're holding a spinlock.

branches: 1.7.2;
Convert pool_get()'s from nowait to waitok. We're allowed to block,
and this is more acceptable since the code assumes success.

gmcgarry ok

Remove p_nras from struct proc - use LIST_EMPTY(&p->p_raslist) instead.
Remove p_raslock and rename p_lwplock p_lock (one lock is enough).
Simplify window test when adding a ras and correct test on VM_MAXUSER_ADDRESS.
Avoid unpredictable branch in i386 locore.S
(pad fields left in struct proc to avoid kernel bump)

branches: 1.5.2;
Declare ras_pool in <sys/ras.h> instead of an extern declaration in
the file where it's needed.

Merge the nathanw_sa branch.

Fix signed/unsigned comparison warnings.

Fix debug printf format.

branches: 1.1.2; 1.1.4; 1.1.6;
MI kernel support for user-level Restartable Atomic Sequences (RAS).

Make the execution flow canonical instead of jumping back and forth, and
complete the userland check.

Ensure the restartable atomic sequence is in userland, for real.

branches: 1.36.6;
Push/Pop pragma magic to avoid gcc warning aber a less-than NULL comparision

branches: 1.35.2; 1.35.4;
Remove COMPAT_SA / KERN_SA. Welcome to 6.99.3!
Approved by core@.

branches: 1.34.28; 1.34.32;
Merge wrstuden-revivesa into HEAD.

branches: 1.33.4;
Fix error in previous.

ras_purgeall: avoid taking p_auxlock.

Use kmem_alloc/free.

branches: 1.30.2;
Remove clause 3 and 4 from TNF licenses

Add MI code to support in-kernel preemption. Preemption is deferred by
one of the following:

- Holding kernel_lock (indicating that the code is not MT safe).
- Bracketing critical sections with kpreempt_disable/kpreempt_enable.
- Holding the interrupt priority level above IPL_NONE.

Statistics on kernel preemption are reported via event counters, and
where preemption is deferred for some reason, it's also reported via
lockstat. The LWP priority at which preemption is triggered is tuneable
via sysctl.

branches: 1.28.2;
- Rename crit_enter/crit_exit to kpreempt_disable/kpreempt_enable.
DragonflyBSD uses the crit names for something quite different.
- Add a kpreempt_disabled function for diagnostic assertions.
- Add inline versions of kpreempt_enable/kpreempt_disable for primitives.
- Make some more changes for preemption safety to the x86 pmap.

branches: 1.27.6; 1.27.8;
Actually copy the ras list onto the child process during fork() - hi ad.
Might fix the 'ras' part of kern/37650.
For some reason the itimers aren't inherited either.

Start detangling lock.h from intr.h. This is likely to cause short term
breakage, but the mess of dependencies has been regularly breaking the
build recently anyhow.

Merge vmlocking2 to head.

Convert all the system call entry points from:
int foo(struct lwp *l, void *v, register_t *retval)
to:
int foo(struct lwp *l, const struct foo_args *uap, register_t *retval)
Fixup compat code to not write into 'uap' and (in some cases) to actually
pass a correctly formatted 'uap' structure with the right name to the
next routine.
A few 'compat' routines that just call standard ones have been deleted.
All the 'compat' code compiles (along with the kernels required to test
build it).
98% done by automated scripts.

branches: 1.23.2; 1.23.4; 1.23.8;
ras_sync: deal with spurious wakeup and add comments.

Fix debug builds.

Make ras_lookup() lockless.

branches: 1.20.2; 1.20.6;
Changes to make ktrace LKM friendly and reduce ifdef KTRACE. Proposed
on tech-kern.

branches: 1.19.6; 1.19.10;
Return EEXIST if attempting to install a RAS that is already installed.

branches: 1.18.2;
Pass an ipl argument to pool_init/POOL_INIT to be used when initializing
the pool's lock.

branches: 1.17.2;
Kill caddr_t; there will be some MI fallout, but it will be fixed shortly.

branches: 1.16.2;
Merge newlock2 to head.

remove some __unused from function parameters.

- sprinkle __unused on function decls.
- fix a couple of unused bugs
- no more -Wno-unused for i386

Add specificdata support to procs and lwps, each providing their own
wrappers around the speicificdata subroutines. Also:
- Call the new lwpinit() function from main() after calling procinit().
- Move some pool initialization out of kern_proc.c and into files that
are directly related to the pools in question (kern_lwp.c and kern_ras.c).
- Convert uipc_sem.c to proc_{get,set}specific(), and eliminate the p_ksems
member from struct proc.

branches: 1.12.20; 1.12.22;
Make it compile on archs without __HAVE_RAS.

Make a couple of functions static.

branches: 1.10.4; 1.10.10;
nuke trailing whitespace

branches: 1.9.4; 1.9.6;
ras_fork: don't do PR_WAITOK holding a spinlock.

ras_install: don't do pool_get(PR_WAITOK) while we're holding a spinlock.

branches: 1.7.2;
Convert pool_get()'s from nowait to waitok. We're allowed to block,
and this is more acceptable since the code assumes success.

gmcgarry ok

Remove p_nras from struct proc - use LIST_EMPTY(&p->p_raslist) instead.
Remove p_raslock and rename p_lwplock p_lock (one lock is enough).
Simplify window test when adding a ras and correct test on VM_MAXUSER_ADDRESS.
Avoid unpredictable branch in i386 locore.S
(pad fields left in struct proc to avoid kernel bump)

branches: 1.5.2;
Declare ras_pool in <sys/ras.h> instead of an extern declaration in
the file where it's needed.

Merge the nathanw_sa branch.

Fix signed/unsigned comparison warnings.

Fix debug printf format.

branches: 1.1.2; 1.1.4; 1.1.6;
MI kernel support for user-level Restartable Atomic Sequences (RAS).