Pull smp hotplug cleanups from Thomas Gleixner:
"This series is merily a cleanup of code copied around in arch/* and
not changing any of the real cpu hotplug horrors yet. I wish I'd had
something more substantial for 3.5, but I underestimated the lurking
horror..."
Fix up trivial conflicts in arch/{arm,sparc,x86}/Kconfig and
arch/sparc/include/asm/thread_info_32.h
* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (79 commits)
um: Remove leftover declaration of alloc_task_struct_node()
task_allocator: Use config switches instead of magic defines
sparc: Use common threadinfo allocator
score: Use common threadinfo allocator
sh-use-common-threadinfo-allocator
mn10300: Use common threadinfo allocator
powerpc: Use common threadinfo allocator
mips: Use common threadinfo allocator
hexagon: Use common threadinfo allocator
m32r: Use common threadinfo allocator
frv: Use common threadinfo allocator
cris: Use common threadinfo allocator
x86: Use common threadinfo allocator
c6x: Use common threadinfo allocator
fork: Provide kmemcache based thread_info allocator
tile: Use common threadinfo allocator
fork: Provide weak arch_release_[task_struct|thread_info] functions
fork: Move thread info gfp flags to header
fork: Remove the weak insanity
sh: Remove cpu_idle_wait()
...
This passes siginfo and mcontext to tilegx32 signal handlers that
don't have SA_SIGINFO set just as we have been doing for tilegx64.
Cc: stable@vger.kernel.org
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
First, we were at risk of handling thread-info flags, in particular
do_signal(), when returning from kernel space. This could happen
after a failed kernel_execve(), or when forking a kernel thread.
The fix is to test in do_work_pending() for user_mode() and return
immediately if so; we already had this test for one of the flags,
so I just hoisted it to the top of the function.
Second, if a ptraced process updated the callee-saved registers
in the ptregs struct and then processed another thread-info flag, we
would overwrite the modifications with the original callee-saved
registers. To fix this, we add a register to note if we've already
saved the registers once, and skip doing it on additional passes
through the loop. To avoid a performance hit from the couple of
extra instructions involved, I modified the GET_THREAD_INFO() macro
to be guaranteed to be one instruction, then bundled it with adjacent
instructions, yielding an overall net savings.
Reported-By: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
This continues the theme started with vm_brk() and vm_munmap():
vm_mmap() does the same thing as do_mmap(), but additionally does the
required VM locking.
This uninlines (and rewrites it to be clearer) do_mmap(), which sadly
duplicates it in mm/mmap.c and mm/nommu.c. But that way we don't have
to export our internal do_mmap_pgoff() function.
Some day we hopefully don't have to export do_mmap() either, if all
modular users can become the simpler vm_mmap() instead. We're actually
very close to that already, with the notable exception of the (broken)
use in i810, and a couple of stragglers in binfmt_elf.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Until we push the unaligned access support for tilegx, it's silly
to have arch/tile/kernel/proc.c generate a warning about an unused
variable. Extend the #ifdef to cover all the code and data for now.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
The scheduler depends on receiving the CPU_STARTING notification, without
which we end up into a lot of trouble. So add the missing call to
notify_cpu_starting() in the bringup code.
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
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>
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>
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>
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>
With lockstat we can end up trying to get a backtrace before
"high_memory" is initialized, so don't worry about range testing
if it is zero.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Commit bd119c6923
"Disintegrate asm/system.h for Tile"
created the asm/switch_to.h file, but did not add an include
of it to all its users.
Also, commit b4816afa39
"Move the asm-generic/system.h xchg() implementation to asm-generic/cmpxchg.h"
introduced the concept of asm/cmpxchg.h but the tile arch
never got one. Fork the cmpxchg content out of the asm/atomic.h
file to create one.
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
