snowball/igloo-kernel.git/arch/tile/include/asm, branch security

arch/tile: fix up some issues in calling do_work_pending()

2012-05-16T20:01:16+00:00

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 Signed-off-by: Chris Metcalf

arch/tile: fix a couple of functions that should be __init

2012-04-25T16:45:26+00:00

They were marked __devinit by mistake, causing some warnings at link time. Signed-off-by: Chris Metcalf

arch/tile: use atomic exchange in arch_write_unlock()

2012-04-02T16:13:49+00:00

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

arch/tile: work around a hardware issue with the return-address stack

2012-04-02T16:12:48+00:00

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

arch/tile: various bugs in stack backtracer

2012-04-02T16:12:45+00:00

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

arch/tile: use 0 for IRQ_RESCHEDULE instead of 1

2012-04-02T16:00:16+00:00

This avoids assigning IRQ 0 to PCI devices, because we've seen that doesn't always work well. Signed-off-by: Chris Metcalf

arch/tile: fix gcc 4.6 warnings in

2012-04-02T16:00:15+00:00

Fix some signedness and variable usage warnings in change_bit() and test_and_change_bit(). Signed-off-by: Chris Metcalf

arch/tile: revert comment for atomic64_add_unless().

2012-04-02T16:00:15+00:00

It still returns whether @v was not @u, not the old value, unlike __atomic_add_unless(). Signed-off-by: Chris Metcalf Acked-by: Arun Sharma

tile: fix multiple build failures from system.h dismantle

2012-04-02T15:57:37+00:00

Commit bd119c69239322caafdb64517a806037d0d0c70a "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 b4816afa3986704d1404fc48e931da5135820472 "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 Signed-off-by: Paul Gortmaker Signed-off-by: Chris Metcalf

Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile

2012-03-29T21:49:45+00:00

Pull arch/tile (really asm-generic) update from Chris Metcalf: "These are a couple of asm-generic changes that apply to tile." * git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile: compat: use sys_sendfile64() implementation for sendfile syscall [PATCH v3] ipc: provide generic compat versions of IPC syscalls