Nick Piggin 124d3b7041 fix writev regression: pan hanging unkillable and un-straceable ... Frederik Himpe reported an unkillable and un-straceable pan process. Zero length iovecs can go into an infinite loop in writev, because the iovec iterator does not always advance over them. The sequence required to trigger this is not trivial. I think it requires that a zero-length iovec be followed by a non-zero-length iovec which causes a pagefault in the atomic usercopy. This causes the writev code to drop back into single-segment copy mode, which then tries to copy the 0 bytes of the zero-length iovec; a zero length copy looks like a failure though, so it loops. Put a test into iov_iter_advance to catch zero-length iovecs. We could just put the test in the fallback path, but I feel it is more robust to skip over zero-length iovecs throughout the code (iovec iterator may be used in filesystems too, so it should be robust). Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2008-02-03 07:55:39 +11:00
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allocpercpu.c
backing-dev.c
bootmem.c
bounce.c
fadvise.c
filemap_xip.c
filemap.c	fix writev regression: pan hanging unkillable and un-straceable	2008-02-03 07:55:39 +11:00
fremap.c
highmem.c
hugetlb.c
internal.h
Kconfig	sh: Bump number of quicklists for SH-5.	2008-01-28 13:18:55 +09:00
madvise.c
Makefile
memory_hotplug.c
memory.c	x86: print which shared library/executable faulted in segfault etc. messages v3	2008-01-30 13:33:18 +01:00
mempolicy.c
mempool.c
migrate.c
mincore.c
mlock.c
mmap.c	x86: randomize brk	2008-01-30 13:30:40 +01:00
mmzone.c
mprotect.c
mremap.c
msync.c
nommu.c
oom_kill.c	sched: sched_rt_entity	2008-01-25 21:08:27 +01:00
page_alloc.c
page_io.c
page_isolation.c
page-writeback.c
pdflush.c
prio_tree.c
quicklist.c
readahead.c
rmap.c
shmem_acl.c
shmem.c
slab.c
slob.c
slub.c
sparse-vmemmap.c
sparse.c
swap_state.c
swap.c
swapfile.c
thrash.c
tiny-shmem.c
truncate.c
util.c
vmalloc.c
vmscan.c
vmstat.c