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2012-11-05x86: Remove the ancient and deprecated disable_hlt() and enable_hlt() facilityLen Brown
commit f6365201d8a21fb347260f89d6e9b3e718d63c70 upstream. The X86_32-only disable_hlt/enable_hlt mechanism was used by the 32-bit floppy driver. Its effect was to replace the use of the HLT instruction inside default_idle() with cpu_relax() - essentially it turned off the use of HLT. This workaround was commented in the code as: "disable hlt during certain critical i/o operations" "This halt magic was a workaround for ancient floppy DMA wreckage. It should be safe to remove." H. Peter Anvin additionally adds: "To the best of my knowledge, no-hlt only existed because of flaky power distributions on 386/486 systems which were sold to run DOS. Since DOS did no power management of any kind, including HLT, the power draw was fairly uniform; when exposed to the much hhigher noise levels you got when Linux used HLT caused some of these systems to fail. They were by far in the minority even back then." Alan Cox further says: "Also for the Cyrix 5510 which tended to go castors up if a HLT occurred during a DMA cycle and on a few other boxes HLT during DMA tended to go astray. Do we care ? I doubt it. The 5510 was pretty obscure, the 5520 fixed it, the 5530 is probably the oldest still in any kind of use." So, let's finally drop this. Signed-off-by: Len Brown <len.brown@intel.com> Signed-off-by: Josh Boyer <jwboyer@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: "H. Peter Anvin" <hpa@zytor.com> Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Stephen Hemminger <shemminger@vyatta.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-3rhk9bzf0x9rljkv488tloib@git.kernel.org [ If anyone cares then alternative instruction patching could be used to replace HLT with a one-byte NOP instruction. Much simpler. ] Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-31x86, mm: Undo incorrect revert in arch/x86/mm/init.cYinghai Lu
commit f82f64dd9f485e13f29f369772d4a0e868e5633a upstream. Commit 844ab6f9 x86, mm: Find_early_table_space based on ranges that are actually being mapped added back some lines back wrongly that has been removed in commit 7b16bbf97 Revert "x86/mm: Fix the size calculation of mapping tables" remove them again. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/CAE9FiQW_vuaYQbmagVnxT2DGsYc=9tNeAbdBq53sYkitPOwxSQ@mail.gmail.com Acked-by: Jacob Shin <jacob.shin@amd.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-31x86, mm: Find_early_table_space based on ranges that are actually being mappedJacob Shin
commit 844ab6f993b1d32eb40512503d35ff6ad0c57030 upstream. Current logic finds enough space for direct mapping page tables from 0 to end. Instead, we only need to find enough space to cover mr[0].start to mr[nr_range].end -- the range that is actually being mapped by init_memory_mapping() This is needed after 1bbbbe779aabe1f0768c2bf8f8c0a5583679b54a, to address the panic reported here: https://lkml.org/lkml/2012/10/20/160 https://lkml.org/lkml/2012/10/21/157 Signed-off-by: Jacob Shin <jacob.shin@amd.com> Link: http://lkml.kernel.org/r/20121024195311.GB11779@jshin-Toonie Tested-by: Tom Rini <trini@ti.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-31ARM: at91/i2c: change id to let i2c-gpio workBo Shen
commit 7840487cd6298f9f931103b558290d8d98d41c49 upstream. The i2c core driver will turn the platform device ID to busnum When using platfrom device ID as -1, it means dynamically assigned the busnum. When writing code, we need to make sure the busnum, and call i2c_register_board_info(int busnum, ...) to register device if using -1, we do not know the value of busnum In order to solve this issue, set the platform device ID as a fix number Here using 0 to match the busnum used in i2c_regsiter_board_info() Signed-off-by: Bo Shen <voice.shen@atmel.com> Acked-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> Acked-by: Ludovic Desroches <ludovic.desroches@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-31ARM: 7559/1: smp: switch away from the idmap before updating init_mm.mm_countWill Deacon
commit 5f40b909728ad784eb43aa309d3c4e9bdf050781 upstream. When booting a secondary CPU, the primary CPU hands two sets of page tables via the secondary_data struct: (1) swapper_pg_dir: a normal, cacheable, shared (if SMP) mapping of the kernel image (i.e. the tables used by init_mm). (2) idmap_pgd: an uncached mapping of the .idmap.text ELF section. The idmap is generally used when enabling and disabling the MMU, which includes early CPU boot. In this case, the secondary CPU switches to swapper as soon as it enters C code: struct mm_struct *mm = &init_mm; unsigned int cpu = smp_processor_id(); /* * All kernel threads share the same mm context; grab a * reference and switch to it. */ atomic_inc(&mm->mm_count); current->active_mm = mm; cpumask_set_cpu(cpu, mm_cpumask(mm)); cpu_switch_mm(mm->pgd, mm); This causes a problem on ARMv7, where the identity mapping is treated as strongly-ordered leading to architecturally UNPREDICTABLE behaviour of exclusive accesses, such as those used by atomic_inc. This patch re-orders the secondary_start_kernel function so that we switch to swapper before performing any exclusive accesses. Reported-by: Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org> Cc: David McKay <david.mckay@st.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-28sparc64: Be less verbose during vmemmap population.David S. Miller
[ Upstream commit 2856cc2e4d0852c3ddaae9dcb19cb9396512eb08 ] On a 2-node machine with 256GB of ram we get 512 lines of console output, which is just too much. This mimicks Yinghai Lu's x86 commit c2b91e2eec9678dbda274e906cc32ea8f711da3b (x86_64/mm: check and print vmemmap allocation continuous) except that we aren't ever going to get contiguous block pointers in between calls so just print when the virtual address or node changes. This decreases the output by an order of 16. Also demote this to KERN_DEBUG. Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-28sparc64: do not clobber personality flags in sys_sparc64_personality()Jiri Kosina
[ Upstream commit a27032eee8cb6e16516f13c8a9752e9d5d4cc430 ] There are multiple errors in how sys_sparc64_personality() handles personality flags stored in top three bytes. - directly comparing current->personality against PER_LINUX32 doesn't work in cases when any of the personality flags stored in the top three bytes are used. - directly forcefully setting personality to PER_LINUX32 or PER_LINUX discards any flags stored in the top three bytes Fix the first one by properly using personality() macro to compare only PER_MASK bytes. Fix the second one by setting only the bits that should be set, instead of overwriting the whole value. Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-28sparc64: Fix bit twiddling in sparc_pmu_enable_event().David S. Miller
[ Upstream commit e793d8c6740f8fe704fa216e95685f4d92c4c4b9 ] There was a serious disconnect in the logic happening in sparc_pmu_disable_event() vs. sparc_pmu_enable_event(). Event disable is implemented by programming a NOP event into the PCR. However, event enable was not reversing this operation. Instead, it was setting the User/Priv/Hypervisor trace enable bits. That's not sparc_pmu_enable_event()'s job, that's what sparc_pmu_enable() and sparc_pmu_disable() do . The intent of sparc_pmu_enable_event() is clear, since it first clear out the event type encoding field. So fix this by OR'ing in the event encoding rather than the trace enable bits. Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-28sparc64: Like x86 we should check current->mm during perf backtrace generation.David S. Miller
[ Upstream commit 08280e6c4c2e8049ac61d9e8e3536ec1df629c0d ] If the MM is not active, only report the top-level PC. Do not try to access the address space. Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-28sparc64: fix ptrace interaction with force_successful_syscall_return()Al Viro
[ Upstream commit 55c2770e413e96871147b9406a9c41fe9bc5209c ] we want syscall_trace_leave() called on exit from any syscall; skipping its call in case we'd done force_successful_syscall_return() is broken... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-28xen/x86: don't corrupt %eip when returning from a signal handlerDavid Vrabel
commit a349e23d1cf746f8bdc603dcc61fae9ee4a695f6 upstream. In 32 bit guests, if a userspace process has %eax == -ERESTARTSYS (-512) or -ERESTARTNOINTR (-513) when it is interrupted by an event /and/ the process has a pending signal then %eip (and %eax) are corrupted when returning to the main process after handling the signal. The application may then crash with SIGSEGV or a SIGILL or it may have subtly incorrect behaviour (depending on what instruction it returned to). The occurs because handle_signal() is incorrectly thinking that there is a system call that needs to restarted so it adjusts %eip and %eax to re-execute the system call instruction (even though user space had not done a system call). If %eax == -514 (-ERESTARTNOHAND (-514) or -ERESTART_RESTARTBLOCK (-516) then handle_signal() only corrupted %eax (by setting it to -EINTR). This may cause the application to crash or have incorrect behaviour. handle_signal() assumes that regs->orig_ax >= 0 means a system call so any kernel entry point that is not for a system call must push a negative value for orig_ax. For example, for physical interrupts on bare metal the inverse of the vector is pushed and page_fault() sets regs->orig_ax to -1, overwriting the hardware provided error code. xen_hypervisor_callback() was incorrectly pushing 0 for orig_ax instead of -1. Classic Xen kernels pushed %eax which works as %eax cannot be both non-negative and -RESTARTSYS (etc.), but using -1 is consistent with other non-system call entry points and avoids some of the tests in handle_signal(). There were similar bugs in xen_failsafe_callback() of both 32 and 64-bit guests. If the fault was corrected and the normal return path was used then 0 was incorrectly pushed as the value for orig_ax. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Acked-by: Jan Beulich <JBeulich@suse.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-28x86: Exclude E820_RESERVED regions and memory holes above 4 GB from direct ↵Jacob Shin
mapping. commit 1bbbbe779aabe1f0768c2bf8f8c0a5583679b54a upstream. On systems with very large memory (1 TB in our case), BIOS may report a reserved region or a hole in the E820 map, even above the 4 GB range. Exclude these from the direct mapping. [ hpa: this should be done not just for > 4 GB but for everything above the legacy region (1 MB), at the very least. That, however, turns out to require significant restructuring. That work is well underway, but is not suitable for rc/stable. ] Signed-off-by: Jacob Shin <jacob.shin@amd.com> Link: http://lkml.kernel.org/r/1319145326-13902-1-git-send-email-jacob.shin@amd.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-28oprofile, x86: Fix wrapping bug in op_x86_get_ctrl()Dan Carpenter
commit 44009105081b51417f311f4c3be0061870b6b8ed upstream. The "event" variable is a u16 so the shift will always wrap to zero making the line a no-op. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Robert Richter <robert.richter@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-28arch/tile: avoid generating .eh_frame information in modulesChris Metcalf
commit 627072b06c362bbe7dc256f618aaa63351f0cfe6 upstream. The tile tool chain uses the .eh_frame information for backtracing. The vmlinux build drops any .eh_frame sections at link time, but when present in kernel modules, it causes a module load failure due to the presence of unsupported pc-relative relocations. When compiling to use compiler feedback support, the compiler by default omits .eh_frame information, so we don't see this problem. But when not using feedback, we need to explicitly suppress the .eh_frame. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-21x86, random: Verify RDRAND functionality and allow it to be disabledH. Peter Anvin
commit 49d859d78c5aeb998b6936fcb5f288f78d713489 upstream. If the CPU declares that RDRAND is available, go through a guranteed reseed sequence, and make sure that it is actually working (producing data.) If it does not, disable the CPU feature flag. Allow RDRAND to be disabled on the command line (as opposed to at compile time) for a user who has special requirements with regards to random numbers. Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-21x86, random: Architectural inlines to get random integers with RDRANDH. Peter Anvin
commit 628c6246d47b85f5357298601df2444d7f4dd3fd upstream. Architectural inlines to get random ints and longs using the RDRAND instruction. Intel has introduced a new RDRAND instruction, a Digital Random Number Generator (DRNG), which is functionally an high bandwidth entropy source, cryptographic whitener, and integrity monitor all built into hardware. This enables RDRAND to be used directly, bypassing the kernel random number pool. For technical documentation, see: http://software.intel.com/en-us/articles/download-the-latest-bull-mountain-software-implementation-guide/ In this patch, this is *only* used for the nonblocking random number pool. RDRAND is a nonblocking source, similar to our /dev/urandom, and is therefore not a direct replacement for /dev/random. The architectural hooks presented in the previous patch only feed the kernel internal users, which only use the nonblocking pool, and so this is not a problem. Since this instruction is available in userspace, there is no reason to have a /dev/hw_rng device driver for the purpose of feeding rngd. This is especially so since RDRAND is a nonblocking source, and needs additional whitening and reduction (see the above technical documentation for details) in order to be of "pure entropy source" quality. The CONFIG_EXPERT compile-time option can be used to disable this use of RDRAND. Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Originally-by: Fenghua Yu <fenghua.yu@intel.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-21xen/bootup: allow read_tscp call for Xen PV guests.Konrad Rzeszutek Wilk
commit cd0608e71e9757f4dae35bcfb4e88f4d1a03a8ab upstream. The hypervisor will trap it. However without this patch, we would crash as the .read_tscp is set to NULL. This patch fixes it and sets it to the native_read_tscp call. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-21xen/bootup: allow {read|write}_cr8 pvops call.Konrad Rzeszutek Wilk
commit 1a7bbda5b1ab0e02622761305a32dc38735b90b2 upstream. We actually do not do anything about it. Just return a default value of zero and if the kernel tries to write anything but 0 we BUG_ON. This fixes the case when an user tries to suspend the machine and it blows up in save_processor_state b/c 'read_cr8' is set to NULL and we get: kernel BUG at /home/konrad/ssd/linux/arch/x86/include/asm/paravirt.h:100! invalid opcode: 0000 [#1] SMP Pid: 2687, comm: init.late Tainted: G O 3.6.0upstream-00002-gac264ac-dirty #4 Bochs Bochs RIP: e030:[<ffffffff814d5f42>] [<ffffffff814d5f42>] save_processor_state+0x212/0x270 .. snip.. Call Trace: [<ffffffff810733bf>] do_suspend_lowlevel+0xf/0xac [<ffffffff8107330c>] ? x86_acpi_suspend_lowlevel+0x10c/0x150 [<ffffffff81342ee2>] acpi_suspend_enter+0x57/0xd5 Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-21ARM: 7541/1: Add ARM ERRATA 775420 workaroundSimon Horman
commit 7253b85cc62d6ff84143d96fe6cd54f73736f4d7 upstream. arm: Add ARM ERRATA 775420 workaround Workaround for the 775420 Cortex-A9 (r2p2, r2p6,r2p8,r2p10,r3p0) erratum. In case a date cache maintenance operation aborts with MMU exception, it might cause the processor to deadlock. This workaround puts DSB before executing ISB if an abort may occur on cache maintenance. Based on work by Kouei Abe and feedback from Catalin Marinas. Signed-off-by: Kouei Abe <kouei.abe.cp@rms.renesas.com> [ horms@verge.net.au: Changed to implementation suggested by catalin.marinas@arm.com ] Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Simon Horman <horms@verge.net.au> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-21mips,kgdb: fix recursive page fault with CONFIG_KPROBESJason Wessel
commit f0a996eeeda214f4293e234df33b29bec003b536 upstream. This fault was detected using the kgdb test suite on boot and it crashes recursively due to the fact that CONFIG_KPROBES on mips adds an extra die notifier in the page fault handler. The crash signature looks like this: kgdbts:RUN bad memory access test KGDB: re-enter exception: ALL breakpoints killed Call Trace: [<807b7548>] dump_stack+0x20/0x54 [<807b7548>] dump_stack+0x20/0x54 The fix for now is to have kgdb return immediately if the fault type is DIE_PAGE_FAULT and allow the kprobe code to decide what is supposed to happen. Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-21ARM: vfp: fix saving d16-d31 vfp registers on v6+ kernelsRussell King
commit 846a136881b8f73c1f74250bf6acfaa309cab1f2 upstream. Michael Olbrich reported that his test program fails when built with -O2 -mcpu=cortex-a8 -mfpu=neon, and a kernel which supports v6 and v7 CPUs: volatile int x = 2; volatile int64_t y = 2; int main() { volatile int a = 0; volatile int64_t b = 0; while (1) { a = (a + x) % (1 << 30); b = (b + y) % (1 << 30); assert(a == b); } } and two instances are run. When built for just v7 CPUs, this program works fine. It uses the "vadd.i64 d19, d18, d16" VFP instruction. It appears that we do not save the high-16 double VFP registers across context switches when the kernel is built for v6 CPUs. Fix that. Tested-By: Michael Olbrich <m.olbrich@pengutronix.de> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-13mm: thp: fix pmd_present for split_huge_page and PROT_NONE with THPAndrea Arcangeli
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 <aarcange@redhat.com> Acked-by: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-13mn10300: only add -mmem-funcs to KBUILD_CFLAGS if gcc supports itGeert Uytterhoeven
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 <tony@bakeyournoodle.com> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: David Howells <dhowells@redhat.com> Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-07x86/alternatives: Fix p6 nops on non-modular kernelsAvi Kivity
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 <tracek@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com> Cc: Michael Tokarev <mjt@tls.msk.ru> Cc: Borislav Petkov <borislav.petkov@amd.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: qemu-devel@nongnu.org Cc: Anthony Liguori <anthony@codemonkey.ws> Cc: H. Peter Anvin <hpa@linux.intel.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Alan Cox <alan@linux.intel.com> Link: http://lkml.kernel.org/r/5034AE84.90708@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Ben Jencks <ben@bjencks.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-02ARM: 7467/1: mutex: use generic xchg-based implementation for ARMv6+Will Deacon
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 <arnd@arndb.de> Acked-by: Nicolas Pitre <nico@linaro.org> Reported-by: Shan Kang <kangshan0910@gmail.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-02MCE: Fix vm86 handling for 32bit mce handlerAndi Kleen
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 <ak@linux.intel.com> Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Thomas Renninger <trenn@suse.de> Reviewed-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-02x86: Fix boot on Twinhead H12YAlan Cox
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 <alan@linux.intel.com> Tested-and-bugfixed-by: Arne Fitzenreiter <arne@fitzenreiter.de> 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 <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-02ARM: 7532/1: decompressor: reset SCTLR.TRE for VMSA ARMv7 coresMatthew Leach
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 <nico@fluxnic.net> Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Matthew Leach <matthew.leach@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-02ARM: fix bad applied patch for arch/arm/Kconfig of stable 3.0.y tree.Tetsuyuki Kobayashi
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 <koba@kmckk.co.jp> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-02xen/boot: Disable NUMA for PV guests.Konrad Rzeszutek Wilk
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: [<ffffffff81d220e6>] __alloc_bootmem_node+0x43/0x96 Pid: 0, comm: swapper Not tainted 3.3.6 #1 AMD Dinar/Dinar RIP: e030:[<ffffffff81d220e6>] [<ffffffff81d220e6>] __alloc_bootmem_node+0x43/0x96 .. snip.. [<ffffffff81d23024>] sparse_early_usemaps_alloc_node+0x64/0x178 [<ffffffff81d23348>] sparse_init+0xe4/0x25a [<ffffffff81d16840>] paging_init+0x13/0x22 [<ffffffff81d07fbb>] setup_arch+0x9c6/0xa9b [<ffffffff81683954>] ? printk+0x3c/0x3e [<ffffffff81d01a38>] start_kernel+0xe5/0x468 [<ffffffff81d012cf>] x86_64_start_reservations+0xba/0xc1 [<ffffffff81007153>] ? xen_setup_runstate_info+0x2c/0x36 [<ffffffff81d050ee>] xen_start_kernel+0x565/0x56c " so we just disable NUMA scanning by setting numa_off=1. Reported-and-Tested-by: Andre Przywara <andre.przywara@amd.com> Acked-by: Andre Przywara <andre.przywara@amd.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-02Redefine ATOMIC_INIT and ATOMIC64_INIT to drop the castsMel Gorman
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 <mgorman@suse.de> Signed-off-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Michael Cree <mcree@orcon.net.nz> Acked-by: Matt Turner <mattst88@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-14PARISC: Redefine ATOMIC_INIT and ATOMIC64_INIT to drop the castsMel Gorman
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 <fengguang.wu@intel.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: James Bottomley <JBottomley@Parallels.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-14powerpc: Restore correct DSCR in context switchAnton Blanchard
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 <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-14powerpc: Fix DSCR inheritance in copy_thread()Anton Blanchard
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 <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-14mm: hugetlbfs: correctly populate shared pmdMichal Hocko
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:[<ffffffff8112cfed>] [<ffffffff8112cfed>] __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 <lwoodman@redhat.com> Tested-by: Larry Woodman <lwoodman@redhat.com> Reviewed-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Michal Hocko <mhocko@suse.cz> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: Ken Chen <kenchen@google.com> Cc: Cong Wang <xiyou.wangcong@gmail.com> Cc: Hillf Danton <dhillf@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-14alpha: Don't export SOCK_NONBLOCK to user space.Michael Cree
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 <mcree@orcon.net.nz> Acked-by: Matt Turner <mattst88@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-14ARM: imx: select CPU_FREQ_TABLE when neededArnd Bergmann
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 <arnd@arndb.de> Acked-by: Shawn Guo <shawn.guo@linaro.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Yong Shen <yong.shen@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-14ARM: S3C24XX: Fix s3c2410_dma_enqueue parametersHeiko Stuebner
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 <heiko@sntech.de> Signed-off-by: Kukjin Kim <kgene.kim@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-14ARM: 7489/1: errata: fix workaround for erratum #720789 on UP systemsWill Deacon
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 <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-14ARM: 7488/1: mm: use 5 bits for swapfile type encodingWill Deacon
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 <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-14ARM: 7487/1: mm: avoid setting nG bit for user mappings that aren't presentWill Deacon
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 <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-26xen: mark local pages as FOREIGN in the m2p_overrideStefano Stabellini
commit b9e0d95c041ca2d7ad297ee37c2e9cfab67a188f upstream. When the frontend and the backend reside on the same domain, even if we add pages to the m2p_override, these pages will never be returned by mfn_to_pfn because the check "get_phys_to_machine(pfn) != mfn" will always fail, so the pfn of the frontend will be returned instead (resulting in a deadlock because the frontend pages are already locked). INFO: task qemu-system-i38:1085 blocked for more than 120 seconds. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. qemu-system-i38 D ffff8800cfc137c0 0 1085 1 0x00000000 ffff8800c47ed898 0000000000000282 ffff8800be4596b0 00000000000137c0 ffff8800c47edfd8 ffff8800c47ec010 00000000000137c0 00000000000137c0 ffff8800c47edfd8 00000000000137c0 ffffffff82213020 ffff8800be4596b0 Call Trace: [<ffffffff81101ee0>] ? __lock_page+0x70/0x70 [<ffffffff81a0fdd9>] schedule+0x29/0x70 [<ffffffff81a0fe80>] io_schedule+0x60/0x80 [<ffffffff81101eee>] sleep_on_page+0xe/0x20 [<ffffffff81a0e1ca>] __wait_on_bit_lock+0x5a/0xc0 [<ffffffff81101ed7>] __lock_page+0x67/0x70 [<ffffffff8106f750>] ? autoremove_wake_function+0x40/0x40 [<ffffffff811867e6>] ? bio_add_page+0x36/0x40 [<ffffffff8110b692>] set_page_dirty_lock+0x52/0x60 [<ffffffff81186021>] bio_set_pages_dirty+0x51/0x70 [<ffffffff8118c6b4>] do_blockdev_direct_IO+0xb24/0xeb0 [<ffffffff811e71a0>] ? ext3_get_blocks_handle+0xe00/0xe00 [<ffffffff8118ca95>] __blockdev_direct_IO+0x55/0x60 [<ffffffff811e71a0>] ? ext3_get_blocks_handle+0xe00/0xe00 [<ffffffff811e91c8>] ext3_direct_IO+0xf8/0x390 [<ffffffff811e71a0>] ? ext3_get_blocks_handle+0xe00/0xe00 [<ffffffff81004b60>] ? xen_mc_flush+0xb0/0x1b0 [<ffffffff81104027>] generic_file_aio_read+0x737/0x780 [<ffffffff813bedeb>] ? gnttab_map_refs+0x15b/0x1e0 [<ffffffff811038f0>] ? find_get_pages+0x150/0x150 [<ffffffff8119736c>] aio_rw_vect_retry+0x7c/0x1d0 [<ffffffff811972f0>] ? lookup_ioctx+0x90/0x90 [<ffffffff81198856>] aio_run_iocb+0x66/0x1a0 [<ffffffff811998b8>] do_io_submit+0x708/0xb90 [<ffffffff81199d50>] sys_io_submit+0x10/0x20 [<ffffffff81a18d69>] system_call_fastpath+0x16/0x1b The explanation is in the comment within the code: We need to do this because the pages shared by the frontend (xen-blkfront) can be already locked (lock_page, called by do_read_cache_page); when the userspace backend tries to use them with direct_IO, mfn_to_pfn returns the pfn of the frontend, so do_blockdev_direct_IO is going to try to lock the same pages again resulting in a deadlock. A simplified call graph looks like this: pygrub QEMU ----------------------------------------------- do_read_cache_page io_submit | | lock_page ext3_direct_IO | bio_add_page | lock_page Internally the xen-blkback uses m2p_add_override to swizzle (temporarily) a 'struct page' to have a different MFN (so that it can point to another guest). It also can easily find out whether another pfn corresponding to the mfn exists in the m2p, and can set the FOREIGN bit in the p2m, making sure that mfn_to_pfn returns the pfn of the backend. This allows the backend to perform direct_IO on these pages, but as a side effect prevents the frontend from using get_user_pages_fast on them while they are being shared with the backend. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-26s390/compat: fix mmap compat system callsHeiko Carstens
commit e85871218513c54f7dfdb6009043cb638f2fecbe upstream. The native 31 bit and the compat behaviour for the mmap system calls differ: In native 31 bit mode the passed in address for the mmap system call will be unmodified passed to sys_mmap_pgoff(). In compat mode however the passed in address will be modified with compat_ptr() which masks out the most significant bit. The result is that in native 31 bit mode each mmap request (with MAP_FIXED) will fail where the most significat bit is set, while in compat mode it may succeed. This odd behaviour was introduced with d3815898 "[S390] mmap: add missing compat_ptr conversion to both mmap compat syscalls". To restore a consistent behaviour accross native and compat mode this patch functionally reverts the above mentioned commit. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-15ARM: mxs: Remove MMAP_MIN_ADDR setting from mxs_defconfigMarek Vasut
commit 3bed491c8d28329e34f8a31e3fe64d03f3a350f1 upstream. The CONFIG_DEFAULT_MMAP_MIN_ADDR was set to 65536 in mxs_defconfig, this caused severe breakage of userland applications since the upper limit for ARM is 32768. By default CONFIG_DEFAULT_MMAP_MIN_ADDR is set to 4096 and can also be changed via /proc/sys/vm/mmap_min_addr if needed. Quoting Russell King [1]: "4096 is also fine for ARM too. There's not much point in having defconfigs change it - that would just be pure noise in the config files." the CONFIG_DEFAULT_MMAP_MIN_ADDR can be removed from the defconfig altogether. This problem was introduced by commit cde7c41 (ARM: configs: add defconfig for mach-mxs). [1] http://marc.info/?l=linux-arm-kernel&m=134401593807820&w=2 Signed-off-by: Marek Vasut <marex@denx.de> Cc: Russell King <linux@arm.linux.org.uk> Cc: Wolfgang Denk <wd@denx.de> Signed-off-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-15x86, microcode: Sanitize per-cpu microcode reloading interfaceBorislav Petkov
commit c9fc3f778a6a215ace14ee556067c73982b6d40f upstream. Microcode reloading in a per-core manner is a very bad idea for both major x86 vendors. And the thing is, we have such interface with which we can end up with different microcode versions applied on different cores of an otherwise homogeneous wrt (family,model,stepping) system. So turn off the possibility of doing that per core and allow it only system-wide. This is a minimal fix which we'd like to see in stable too thus the more-or-less arbitrary decision to allow system-wide reloading only on the BSP: $ echo 1 > /sys/devices/system/cpu/cpu0/microcode/reload ... and disable the interface on the other cores: $ echo 1 > /sys/devices/system/cpu/cpu23/microcode/reload -bash: echo: write error: Invalid argument Also, allowing the reload only from one CPU (the BSP in that case) doesn't allow the reload procedure to degenerate into an O(n^2) deal when triggering reloads from all /sys/devices/system/cpu/cpuX/microcode/reload sysfs nodes simultaneously. A more generic fix will follow. Signed-off-by: Borislav Petkov <borislav.petkov@amd.com> Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1340280437-7718-2-git-send-email-bp@amd64.org Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-15x86, microcode: microcode_core.c simple_strtoul cleanupShuah Khan
commit e826abd523913f63eb03b59746ffb16153c53dc4 upstream. Change reload_for_cpu() in kernel/microcode_core.c to call kstrtoul() instead of calling obsoleted simple_strtoul(). Signed-off-by: Shuah Khan <shuahkhan@gmail.com> Reviewed-by: Borislav Petkov <bp@alien8.de> Link: http://lkml.kernel.org/r/1336324264.2897.9.camel@lorien2 Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-15random: remove rand_initialize_irq()Theodore Ts'o
commit c5857ccf293968348e5eb4ebedc68074de3dcda6 upstream. With the new interrupt sampling system, we are no longer using the timer_rand_state structure in the irq descriptor, so we can stop initializing it now. [ Merged in fixes from Sedat to find some last missing references to rand_initialize_irq() ] Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Sedat Dilek <sedat.dilek@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-15x86, nops: Missing break resulting in incorrect selection on IntelAlan Cox
commit d6250a3f12edb3a86db9598ffeca3de8b4a219e9 upstream. The Intel case falls through into the generic case which then changes the values. For cases like the P6 it doesn't do the right thing so this seems to be a screwup. Signed-off-by: Alan Cox <alan@linux.intel.com> Link: http://lkml.kernel.org/n/tip-lww2uirad4skzjlmrm0vru8o@git.kernel.org Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-15ARM: 7479/1: mm: avoid NULL dereference when flushing gate_vma with VIVT cachesWill Deacon
commit b74253f78400f9a4b42da84bb1de7540b88ce7c4 upstream. The vivt_flush_cache_{range,page} functions check that the mm_struct of the VMA being flushed has been active on the current CPU before performing the cache maintenance. The gate_vma has a NULL mm_struct pointer and, as such, will cause a kernel fault if we try to flush it with the above operations. This happens during ELF core dumps, which include the gate_vma as it may be useful for debugging purposes. This patch adds checks to the VIVT cache flushing functions so that VMAs with a NULL mm_struct are flushed unconditionally (the vectors page may be dirty if we use it to store the current TLS pointer). Reported-by: Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org> Tested-by: Uros Bizjak <ubizjak@gmail.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-15ARM: 7478/1: errata: extend workaround for erratum #720789Will Deacon
commit 5a783cbc48367cfc7b65afc75430953dfe60098f upstream. Commit cdf357f1 ("ARM: 6299/1: errata: TLBIASIDIS and TLBIMVAIS operations can broadcast a faulty ASID") replaced by-ASID TLB flushing operations with all-ASID variants to workaround A9 erratum #720789. This patch extends the workaround to include the tlb_range operations, which were overlooked by the original patch. Tested-by: Steve Capper <steve.capper@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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