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b46b8f19c9
There are two problems with the existing redzone implementation. Firstly, it's causing misalignment of structures which contain a 64-bit integer, such as netfilter's 'struct ipt_entry' -- causing netfilter modules to fail to load because of the misalignment. (In particular, the first check in net/ipv4/netfilter/ip_tables.c::check_entry_size_and_hooks()) On ppc32 and sparc32, amongst others, __alignof__(uint64_t) == 8. With slab debugging, we use 32-bit redzones. And allocated slab objects aren't sufficiently aligned to hold a structure containing a uint64_t. By _just_ setting ARCH_KMALLOC_MINALIGN to __alignof__(u64) we'd disable redzone checks on those architectures. By using 64-bit redzones we avoid that loss of debugging, and also fix the other problem while we're at it. When investigating this, I noticed that on 64-bit platforms we're using a 32-bit value of RED_ACTIVE/RED_INACTIVE in the 64-bit memory location set aside for the redzone. Which means that the four bytes immediately before or after the allocated object at 0x00,0x00,0x00,0x00 for LE and BE machines, respectively. Which is probably not the most useful choice of poison value. One way to fix both of those at once is just to switch to 64-bit redzones in all cases. Signed-off-by: David Woodhouse <dwmw2@infradead.org> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Christoph Lameter <clameter@engr.sgi.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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| .. | ||
| allocpercpu.c | ||
| backing-dev.c | ||
| bootmem.c | ||
| bounce.c | ||
| fadvise.c | ||
| filemap_xip.c | ||
| filemap.c | ||
| filemap.h | ||
| fremap.c | ||
| highmem.c | ||
| hugetlb.c | ||
| internal.h | ||
| Kconfig | ||
| madvise.c | ||
| Makefile | ||
| memory_hotplug.c | ||
| memory.c | ||
| mempolicy.c | ||
| mempool.c | ||
| migrate.c | ||
| mincore.c | ||
| mlock.c | ||
| mmap.c | ||
| mmzone.c | ||
| mprotect.c | ||
| mremap.c | ||
| msync.c | ||
| nommu.c | ||
| oom_kill.c | ||
| page_alloc.c | ||
| page_io.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.c | ||
| swap_state.c | ||
| swap.c | ||
| swapfile.c | ||
| thrash.c | ||
| tiny-shmem.c | ||
| truncate.c | ||
| util.c | ||
| vmalloc.c | ||
| vmscan.c | ||
| vmstat.c | ||