linux/arch, branch v3.0.43

PARISC: Redefine ATOMIC_INIT and ATOMIC64_INIT to drop the casts

2012-09-14T17:00:51Z

commit bba3d8c3b3c0f2123be5bc687d1cddc13437c923 upstream. The following build error occured during a parisc build with swap-over-NFS patches applied. net/core/sock.c:274:36: error: initializer element is not constant net/core/sock.c:274:36: error: (near initialization for 'memalloc_socks') net/core/sock.c:274:36: error: initializer element is not constant Dave Anglin says: > Here is the line in sock.i: > > struct static_key memalloc_socks = ((struct static_key) { .enabled = > ((atomic_t) { (0) }) }); The above line contains two compound literals. It also uses a designated initializer to initialize the field enabled. A compound literal is not a constant expression. The location of the above statement isn't fully clear, but if a compound literal occurs outside the body of a function, the initializer list must consist of constant expressions. Reported-by: Fengguang Wu Signed-off-by: Mel Gorman Signed-off-by: James Bottomley Signed-off-by: Greg Kroah-Hartman

powerpc: Restore correct DSCR in context switch

2012-09-14T17:00:49Z

commit 714332858bfd40dcf8f741498336d93875c23aa7 upstream. During a context switch we always restore the per thread DSCR value. If we aren't doing explicit DSCR management (ie thread.dscr_inherit == 0) and the default DSCR changed while the process has been sleeping we end up with the wrong value. Check thread.dscr_inherit and select the default DSCR or per thread DSCR as required. This was found with the following test case, when running with more threads than CPUs (ie forcing context switching): http://ozlabs.org/~anton/junkcode/dscr_default_test.c With the four patches applied I can run a combination of all test cases successfully at the same time: http://ozlabs.org/~anton/junkcode/dscr_default_test.c http://ozlabs.org/~anton/junkcode/dscr_explicit_test.c http://ozlabs.org/~anton/junkcode/dscr_inherit_test.c Signed-off-by: Anton Blanchard Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Greg Kroah-Hartman

powerpc: Fix DSCR inheritance in copy_thread()

2012-09-14T17:00:49Z

commit 1021cb268b3025573c4811f1dee4a11260c4507b upstream. If the default DSCR is non zero we set thread.dscr_inherit in copy_thread() meaning the new thread and all its children will ignore future updates to the default DSCR. This is not intended and is a change in behaviour that a number of our users have hit. We just need to inherit thread.dscr and thread.dscr_inherit from the parent which ends up being much simpler. This was found with the following test case: http://ozlabs.org/~anton/junkcode/dscr_default_test.c Signed-off-by: Anton Blanchard Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Greg Kroah-Hartman

mm: hugetlbfs: correctly populate shared pmd

2012-09-14T17:00:38Z

commit eb48c071464757414538c68a6033c8f8c15196f8 upstream. Each page mapped in a process's address space must be correctly accounted for in _mapcount. Normally the rules for this are straightforward but hugetlbfs page table sharing is different. The page table pages at the PMD level are reference counted while the mapcount remains the same. If this accounting is wrong, it causes bugs like this one reported by Larry Woodman: kernel BUG at mm/filemap.c:135! invalid opcode: 0000 [#1] SMP CPU 22 Modules linked in: bridge stp llc sunrpc binfmt_misc dcdbas microcode pcspkr acpi_pad acpi] Pid: 18001, comm: mpitest Tainted: G W 3.3.0+ #4 Dell Inc. PowerEdge R620/07NDJ2 RIP: 0010:[] [] __delete_from_page_cache+0x15d/0x170 Process mpitest (pid: 18001, threadinfo ffff880428972000, task ffff880428b5cc20) Call Trace: delete_from_page_cache+0x40/0x80 truncate_hugepages+0x115/0x1f0 hugetlbfs_evict_inode+0x18/0x30 evict+0x9f/0x1b0 iput_final+0xe3/0x1e0 iput+0x3e/0x50 d_kill+0xf8/0x110 dput+0xe2/0x1b0 __fput+0x162/0x240 During fork(), copy_hugetlb_page_range() detects if huge_pte_alloc() shared page tables with the check dst_pte == src_pte. The logic is if the PMD page is the same, they must be shared. This assumes that the sharing is between the parent and child. However, if the sharing is with a different process entirely then this check fails as in this diagram: parent | ------------>pmd src_pte----------> data page ^ other--------->pmd--------------------| ^ child-----------| dst_pte For this situation to occur, it must be possible for Parent and Other to have faulted and failed to share page tables with each other. This is possible due to the following style of race. PROC A PROC B copy_hugetlb_page_range copy_hugetlb_page_range src_pte == huge_pte_offset src_pte == huge_pte_offset !src_pte so no sharing !src_pte so no sharing (time passes) hugetlb_fault hugetlb_fault huge_pte_alloc huge_pte_alloc huge_pmd_share huge_pmd_share LOCK(i_mmap_mutex) find nothing, no sharing UNLOCK(i_mmap_mutex) LOCK(i_mmap_mutex) find nothing, no sharing UNLOCK(i_mmap_mutex) pmd_alloc pmd_alloc LOCK(instantiation_mutex) fault UNLOCK(instantiation_mutex) LOCK(instantiation_mutex) fault UNLOCK(instantiation_mutex) These two processes are not poing to the same data page but are not sharing page tables because the opportunity was missed. When either process later forks, the src_pte == dst pte is potentially insufficient. As the check falls through, the wrong PTE information is copied in (harmless but wrong) and the mapcount is bumped for a page mapped by a shared page table leading to the BUG_ON. This patch addresses the issue by moving pmd_alloc into huge_pmd_share which guarantees that the shared pud is populated in the same critical section as pmd. This also means that huge_pte_offset test in huge_pmd_share is serialized correctly now which in turn means that the success of the sharing will be higher as the racing tasks see the pud and pmd populated together. Race identified and changelog written mostly by Mel Gorman. {akpm@linux-foundation.org: attempt to make the huge_pmd_share() comment comprehensible, clean up coding style] Reported-by: Larry Woodman Tested-by: Larry Woodman Reviewed-by: Mel Gorman Signed-off-by: Michal Hocko Reviewed-by: Rik van Riel Cc: David Gibson Cc: Ken Chen Cc: Cong Wang Cc: Hillf Danton Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

alpha: Don't export SOCK_NONBLOCK to user space.

2012-09-14T17:00:37Z

commit a2fa3ccd7b43665fe14cb562761a6c3d26a1d13f upstream. Currently we export SOCK_NONBLOCK to user space but that conflicts with the definition from glibc leading to compilation errors in user programs (e.g. see Debian bug #658460). The generic socket.h restricts the definition of SOCK_NONBLOCK to the kernel, as does the MIPS specific socket.h, so let's do the same on Alpha. Signed-off-by: Michael Cree Acked-by: Matt Turner Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

ARM: imx: select CPU_FREQ_TABLE when needed

2012-09-14T17:00:37Z

commit f637c4c9405e21f44cf0045eaf77eddd3a79ca5a upstream. The i.MX cpufreq implementation uses the CPU_FREQ_TABLE helpers, so it needs to select that code to be built. This problem has apparently existed since the i.MX cpufreq code was first merged in v2.6.37. Building IMX without CPU_FREQ_TABLE results in: arch/arm/plat-mxc/built-in.o: In function `mxc_cpufreq_exit': arch/arm/plat-mxc/cpufreq.c:173: undefined reference to `cpufreq_frequency_table_put_attr' arch/arm/plat-mxc/built-in.o: In function `mxc_set_target': arch/arm/plat-mxc/cpufreq.c:84: undefined reference to `cpufreq_frequency_table_target' arch/arm/plat-mxc/built-in.o: In function `mxc_verify_speed': arch/arm/plat-mxc/cpufreq.c:65: undefined reference to `cpufreq_frequency_table_verify' arch/arm/plat-mxc/built-in.o: In function `mxc_cpufreq_init': arch/arm/plat-mxc/cpufreq.c:154: undefined reference to `cpufreq_frequency_table_cpuinfo' arch/arm/plat-mxc/cpufreq.c:162: undefined reference to `cpufreq_frequency_table_get_attr' Signed-off-by: Arnd Bergmann Acked-by: Shawn Guo Cc: Sascha Hauer Cc: Yong Shen Signed-off-by: Greg Kroah-Hartman

ARM: S3C24XX: Fix s3c2410_dma_enqueue parameters

2012-09-14T17:00:37Z

commit b01858c7806e7e6f6121da2e51c9222fc4d21dc6 upstream. Commit d670ac019f60 (ARM: SAMSUNG: DMA Cleanup as per sparse) changed the prototype of the s3c2410_dma_* functions to use the enum dma_ch instead of an generic unsigned int. In the s3c24xx dma.c s3c2410_dma_enqueue seems to have been forgotten, the other functions there were changed correctly. Signed-off-by: Heiko Stuebner Signed-off-by: Kukjin Kim Signed-off-by: Greg Kroah-Hartman

ARM: 7489/1: errata: fix workaround for erratum #720789 on UP systems

2012-09-14T17:00:36Z

commit 730a8128cd8978467eb1cf546b11014acb57d433 upstream. Commit 5a783cbc4836 ("ARM: 7478/1: errata: extend workaround for erratum #720789") added workarounds for erratum #720789 to the range TLB invalidation functions with the observation that the erratum only affects SMP platforms. However, when running an SMP_ON_UP kernel on a uniprocessor platform we must take care to preserve the ASID as the workaround is not required. This patch ensures that we don't set the ASID to 0 when flushing the TLB on such a system, preserving the original behaviour with the workaround disabled. Signed-off-by: Will Deacon Signed-off-by: Russell King Signed-off-by: Greg Kroah-Hartman

ARM: 7488/1: mm: use 5 bits for swapfile type encoding

2012-09-14T17:00:36Z

commit f5f2025ef3e2cdb593707cbf87378761f17befbe upstream. Page migration encodes the pfn in the offset field of a swp_entry_t. For LPAE, we support physical addresses of up to 36 bits (due to sparsemem limitations with the size of page flags), requiring 24 bits to represent a pfn. A further 3 bits are used to encode a swp_entry into a pte, leaving 5 bits for the type field. Furthermore, the core code defines MAX_SWAPFILES_SHIFT as 5, so the additional type bit does not get used. This patch reduces the width of the type field to 5 bits, allowing us to create up to 31 swapfiles of 64GB each. Reviewed-by: Catalin Marinas Signed-off-by: Will Deacon Signed-off-by: Russell King Signed-off-by: Greg Kroah-Hartman

ARM: 7487/1: mm: avoid setting nG bit for user mappings that aren't present

2012-09-14T17:00:36Z

commit 47f1204329237a0f8655f5a9f14a38ac81946ca1 upstream. Swap entries are encoding in ptes such that !pte_present(pte) and pte_file(pte). The remaining bits of the descriptor are used to identify the swapfile and offset within it to the swap entry. When writing such a pte for a user virtual address, set_pte_at unconditionally sets the nG bit, which (in the case of LPAE) will corrupt the swapfile offset and lead to a BUG: [ 140.494067] swap_free: Unused swap offset entry 000763b4 [ 140.509989] BUG: Bad page map in process rs:main Q:Reg pte:0ec76800 pmd:8f92e003 This patch fixes the problem by only setting the nG bit for user mappings that are actually present. Reviewed-by: Catalin Marinas Signed-off-by: Will Deacon Signed-off-by: Russell King Signed-off-by: Greg Kroah-Hartman