Pull arch/tile bug fixes from Chris Metcalf:
"This includes Paul Gortmaker's change to fix the <asm/system.h>
disintegration issues on tile, a fix to unbreak the tilepro ethernet
driver, and a backlog of bugfix-only changes from internal Tilera
development over the last few months.
They have all been to LKML and on linux-next for the last few days.
The EDAC change to MAINTAINERS is an oddity but discussion on the
linux-edac list suggested I ask you to pull that change through my
tree since they don't have a tree to pull edac changes from at the
moment."
* 'stable' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile: (39 commits)
drivers/net/ethernet/tile: fix netdev_alloc_skb() bombing
MAINTAINERS: update EDAC information
tilepro ethernet driver: fix a few minor issues
tile-srom.c driver: minor code cleanup
edac: say "TILEGx" not "TILEPro" for the tilegx edac driver
arch/tile: avoid accidentally unmasking NMI-type interrupt accidentally
arch/tile: remove bogus performance optimization
arch/tile: return SIGBUS for addresses that are unaligned AND invalid
arch/tile: fix finv_buffer_remote() for tilegx
arch/tile: use atomic exchange in arch_write_unlock()
arch/tile: stop mentioning the "kvm" subdirectory
arch/tile: export the page_home() function.
arch/tile: fix pointer cast in cacheflush.c
arch/tile: fix single-stepping over swint1 instructions on tilegx
arch/tile: implement panic_smp_self_stop()
arch/tile: add "nop" after "nap" to help GX idle power draw
arch/tile: use proper memparse() for "maxmem" options
arch/tile: fix up locking in pgtable.c slightly
arch/tile: don't leak kernel memory when we unload modules
arch/tile: fix bug in delay_backoff()
...
The return path as we reload registers and core state requires that r30
hold a boolean indicating whether we are returning from an NMI, but in a
couple of cases we weren't setting this properly, with the result that we
could accidentally unmask the NMI interrupt(s), which could cause confusion.
Now we set r30 in every place where we jump into the interrupt return path.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
We were re-homing the initial task's kernel stack on the boot cpu,
but in fact it's better to let it stay globally homed, since that
task isn't bound to the boot cpu anyway. This is more of a general
cleanup than an actual performance optimization, but it removes
code, which is a good thing. :-)
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Previously we were returning SIGSEGV in this case. It seems cleaner
to return SIGBUS since the hardware figures out alignment traps
before TLB violations, so SIGBUS is the "more correct" signal.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
There were some correctness issues with this code that are now fixed
with this change. The change is likely less performant than it could
be, but it should no longer be vulnerable to any races with memory
operations on the memory network while invalidating a range of memory.
This code is run infrequently so performance isn't critical, but
correctness definitely is.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
This idiom is used elsewhere when we do an unlock by writing a zero,
but I missed it here. Using an atomic operation avoids waiting
on the write buffer for the unlocking write to be sent to the home cache.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
It causes "make clean" to fail, for example. Once we have KVM support
complete, we'll reinstate the subdir reference.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Pragmatically it couldn't be wrong to cast pointers to long to compare
them (since all kernel addresses are in the top half of VA space),
but it's more correct to cast to unsigned long.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
If we are single-stepping and make a syscall, we call ptrace_notify()
explicitly on the return path back to user space, since we are returning
to a pc value set artificially to the next instruction, and otherwise
we won't register that we stepped over the syscall instruction (swint1).
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
This allows the later-panicking tiles to wait in a lower power state
until they get interrupted with an smp_send_stop().
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
We should be holding the init_mm.page_table_lock in shatter_huge_page()
since we are modifying the kernel page tables. Then, only if we are
walking the other root page tables to update them, do we want to take
the pgd_lock.
Add a comment about taking the pgd_lock that we always do it with
interrupts disabled and therefore are not at risk from the tlbflush
IPI deadlock as is seen on x86.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
We were carefully computing a value to use for the number of loops
to spin for, and then ignoring it.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Previously we only handled kernels up to a single huge page in size.
Now we create additional PTEs appropriately.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
If we took a page fault while we had interrupts disabled, we
shouldn't enable them in the page fault handler.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
We make sure not to try to set the home for an MMIO PTE (on tilegx)
or a PTE that isn't referencing memory managed by Linux.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Doing so raises the possibility of self-deadlock if we are waiting
for a backtrace for an oprofile or perf interrupt while we are
in the middle of migrating our own stack page.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Not associated with any code changes, so I'm just lumping these
comment changes into a commit by themselves.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
We now respond to MEM_ERROR traps (e.g. an atomic instruction to
non-cacheable memory) with a SIGBUS.
We also no longer generate a console crash message if a user
process die due to a SIGTRAP.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
In certain circumstances we need to do a bunch of jump-and-link
instructions to fill the hardware return-address stack with nonzero values.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Fix a long-standing bug in the stack backtracer where we would print
garbage to the console instead of kernel function names, if the kernel
wasn't built with symbol support (e.g. mboot).
Make sure to tag every line of userspace backtrace output if we actually
have the mmap_sem, since that way if there's no tag, we know that it's
because we couldn't trylock the semaphore.
Stop doing a TLB flush and examining page tables during backtrace.
Instead, just trust that __copy_from_user_inatomic() will properly fault
and return a failure, which it should do in all cases.
Fix a latent bug where the backtracer would directly examine a signal
context in user space, rather than copying it safely to kernel memory
first. This meant that a race with another thread could potentially
have caused a kernel panic.
Guard against unaligned sp when trying to restart backtrace at an
interrupt or signal handler point in the kernel backtracer.
Report kernel symbolic information for the call instruction rather
than for the following instruction. We still report the actual numeric
address corresponding to the instruction after the call, for the sake
of consistency with the normal expectations for stack backtracers.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Linus Torvalds
Chris Metcalf