user/sven/linux.git/arch, branch v3.0.46

mm: thp: fix pmd_present for split_huge_page and PROT_NONE with THP

2012-10-12T20:28:10Z

commit 027ef6c87853b0a9df53175063028edb4950d476 upstream. In many places !pmd_present has been converted to pmd_none. For pmds that's equivalent and pmd_none is quicker so using pmd_none is better. However (unless we delete pmd_present) we should provide an accurate pmd_present too. This will avoid the risk of code thinking the pmd is non present because it's under __split_huge_page_map, see the pmd_mknotpresent there and the comment above it. If the page has been mprotected as PROT_NONE, it would also lead to a pmd_present false negative in the same way as the race with split_huge_page. Because the PSE bit stays on at all times (both during split_huge_page and when the _PAGE_PROTNONE bit get set), we could only check for the PSE bit, but checking the PROTNONE bit too is still good to remember pmd_present must always keep PROT_NONE into account. This explains a not reproducible BUG_ON that was seldom reported on the lists. The same issue is in pmd_large, it would go wrong with both PROT_NONE and if it races with split_huge_page. Signed-off-by: Andrea Arcangeli Acked-by: Rik van Riel Cc: Johannes Weiner Cc: Hugh Dickins Cc: Mel Gorman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

mn10300: only add -mmem-funcs to KBUILD_CFLAGS if gcc supports it

2012-10-12T20:28:02Z

commit 9957423f035c2071f6d1c5d2f095cdafbeb25ad7 upstream. It seems the current (gcc 4.6.3) no longer provides this so make it conditional. As reported by Tony before, the mn10300 architecture cross-compiles with gcc-4.6.3 if -mmem-funcs is not added to KBUILD_CFLAGS. Reported-by: Tony Breeds Signed-off-by: Geert Uytterhoeven Cc: David Howells Cc: Koichi Yasutake Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

x86/alternatives: Fix p6 nops on non-modular kernels

2012-10-07T15:27:27Z

commit cb09cad44f07044d9810f18f6f9a6a6f3771f979 upstream. Probably a leftover from the early days of self-patching, p6nops are marked __initconst_or_module, which causes them to be discarded in a non-modular kernel. If something later triggers patching, it will overwrite kernel code with garbage. Reported-by: Tomas Racek Signed-off-by: Avi Kivity Cc: Michael Tokarev Cc: Borislav Petkov Cc: Marcelo Tosatti Cc: qemu-devel@nongnu.org Cc: Anthony Liguori Cc: H. Peter Anvin Cc: Alan Cox Cc: Alan Cox Link: http://lkml.kernel.org/r/5034AE84.90708@redhat.com Signed-off-by: Ingo Molnar Cc: Ben Jencks Signed-off-by: Greg Kroah-Hartman

ARM: 7467/1: mutex: use generic xchg-based implementation for ARMv6+

2012-10-02T16:47:55Z

commit a76d7bd96d65fa5119adba97e1b58d95f2e78829 upstream. The open-coded mutex implementation for ARMv6+ cores suffers from a severe lack of barriers, so in the uncontended case we don't actually protect any accesses performed during the critical section. Furthermore, the code is largely a duplication of the ARMv6+ atomic_dec code but optimised to remove a branch instruction, as the mutex fastpath was previously inlined. Now that this is executed out-of-line, we can reuse the atomic access code for the locking (in fact, we use the xchg code as this produces shorter critical sections). This patch uses the generic xchg based implementation for mutexes on ARMv6+, which introduces barriers to the lock/unlock operations and also has the benefit of removing a fair amount of inline assembly code. Acked-by: Arnd Bergmann Acked-by: Nicolas Pitre Reported-by: Shan Kang Signed-off-by: Will Deacon Signed-off-by: Russell King Signed-off-by: Greg Kroah-Hartman

MCE: Fix vm86 handling for 32bit mce handler

2012-10-02T16:47:55Z

commit a129a7c84582629741e5fa6f40026efcd7a65bd4 upstream. When running on 32bit the mce handler could misinterpret vm86 mode as ring 0. This can affect whether it does recovery or not; it was possible to panic when recovery was actually possible. Fix this by always forcing vm86 to look like ring 3. [ Backport to 3.0 notes: Things changed there slightly: - move mce_get_rip() up. It fills up m->cs and m->ip values which are evaluated in mce_severity(). Therefore move it up right before the mce_severity call. This seem to be another bug in 3.0? - Place the backport (fix m->cs in V86 case) to where m->cs gets filled which is mce_get_rip() in 3.0 ] Signed-off-by: Andi Kleen Signed-off-by: Tony Luck Signed-off-by: Thomas Renninger Reviewed-by: Tony Luck Signed-off-by: Greg Kroah-Hartman

x86: Fix boot on Twinhead H12Y

2012-10-02T16:47:41Z

commit 80b3e557371205566a71e569fbfcce5b11f92dbe upstream. Despite lots of investigation into why this is needed we don't know or have an elegant cure. The only answer found on this laptop is to mark a problem region as used so that Linux doesn't put anything there. Currently all the users add reserve= command lines and anyone not knowing this needs to find the magic page that documents it. Automate it instead. Signed-off-by: Alan Cox Tested-and-bugfixed-by: Arne Fitzenreiter Resolves-bug: https://bugzilla.kernel.org/show_bug.cgi?id=10231 Link: http://lkml.kernel.org/r/20120515174347.5109.94551.stgit@bluebook Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

ARM: 7532/1: decompressor: reset SCTLR.TRE for VMSA ARMv7 cores

2012-10-02T16:47:27Z

commit e1e5b7e4251c7538ca08c2c5545b0c2fbd8a6635 upstream. This patch zeroes the SCTLR.TRE bit prior to setting the mapping as cacheable for ARMv7 cores in the decompressor, ensuring that the memory region attributes are obtained from the C and B bits, not from the page tables. Cc: Nicolas Pitre Reviewed-by: Will Deacon Signed-off-by: Matthew Leach Signed-off-by: Will Deacon Signed-off-by: Russell King Signed-off-by: Greg Kroah-Hartman

ARM: fix bad applied patch for arch/arm/Kconfig of stable 3.0.y tree.

2012-10-02T16:47:27Z

No upstream commit as this is a merge error in the 3.0 tree. ARM_ERRATA_764369 and PL310_ERRATA_769419 do not appear in config menu in stable 3.0.y tree. This is because backported patch for arm/arm/Kconfig applied wrong place. This patch solves it. Signed-off-by: Tetsuyuki Kobayashi Signed-off-by: Greg Kroah-Hartman

xen/boot: Disable NUMA for PV guests.

2012-10-02T16:47:26Z

commit 8d54db795dfb1049d45dc34f0dddbc5347ec5642 upstream. The hypervisor is in charge of allocating the proper "NUMA" memory and dealing with the CPU scheduler to keep them bound to the proper NUMA node. The PV guests (and PVHVM) have no inkling of where they run and do not need to know that right now. In the future we will need to inject NUMA configuration data (if a guest spans two or more NUMA nodes) so that the kernel can make the right choices. But those patches are not yet present. In the meantime, disable the NUMA capability in the PV guest, which also fixes a bootup issue. Andre says: "we see Dom0 crashes due to the kernel detecting the NUMA topology not by ACPI, but directly from the northbridge (CONFIG_AMD_NUMA). This will detect the actual NUMA config of the physical machine, but will crash about the mismatch with Dom0's virtual memory. Variation of the theme: Dom0 sees what it's not supposed to see. This happens with the said config option enabled and on a machine where this scanning is still enabled (K8 and Fam10h, not Bulldozer class) We have this dump then: NUMA: Warning: node ids are out of bound, from=-1 to=-1 distance=10 Scanning NUMA topology in Northbridge 24 Number of physical nodes 4 Node 0 MemBase 0000000000000000 Limit 0000000040000000 Node 1 MemBase 0000000040000000 Limit 0000000138000000 Node 2 MemBase 0000000138000000 Limit 00000001f8000000 Node 3 MemBase 00000001f8000000 Limit 0000000238000000 Initmem setup node 0 0000000000000000-0000000040000000 NODE_DATA [000000003ffd9000 - 000000003fffffff] Initmem setup node 1 0000000040000000-0000000138000000 NODE_DATA [0000000137fd9000 - 0000000137ffffff] Initmem setup node 2 0000000138000000-00000001f8000000 NODE_DATA [00000001f095e000 - 00000001f0984fff] Initmem setup node 3 00000001f8000000-0000000238000000 Cannot find 159744 bytes in node 3 BUG: unable to handle kernel NULL pointer dereference at (null) IP: [] __alloc_bootmem_node+0x43/0x96 Pid: 0, comm: swapper Not tainted 3.3.6 #1 AMD Dinar/Dinar RIP: e030:[] [] __alloc_bootmem_node+0x43/0x96 .. snip.. [] sparse_early_usemaps_alloc_node+0x64/0x178 [] sparse_init+0xe4/0x25a [] paging_init+0x13/0x22 [] setup_arch+0x9c6/0xa9b [] ? printk+0x3c/0x3e [] start_kernel+0xe5/0x468 [] x86_64_start_reservations+0xba/0xc1 [] ? xen_setup_runstate_info+0x2c/0x36 [] xen_start_kernel+0x565/0x56c " so we just disable NUMA scanning by setting numa_off=1. Reported-and-Tested-by: Andre Przywara Acked-by: Andre Przywara Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: Greg Kroah-Hartman

Redefine ATOMIC_INIT and ATOMIC64_INIT to drop the casts

2012-10-02T16:47:25Z

commit 67a806d9499353fabd5b5ff07337f3aa88a1c3ba upstream. The following build error occurred during an alpha build: 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. Signed-off-by: Mel Gorman Signed-off-by: Fengguang Wu Signed-off-by: Michael Cree Acked-by: Matt Turner Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman