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2012-10-30arch/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: Ben Hutchings <ben@decadent.org.uk>
2012-10-30ARM: 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. Cc: David McKay <david.mckay@st.com> Reported-by: Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-10-30xen/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: Ben Hutchings <ben@decadent.org.uk>
2012-10-30s390: fix linker script for 31 bit buildsHeiko Carstens
commit c985cb37f1b39c2c8035af741a2a0b79f1fbaca7 upstream. Because of a change in the s390 arch backend of binutils (commit 23ecd77 "Pick the default arch depending on the target size" in binutils repo) 31 bit builds will fail since the linker would now try to create 64 bit binary output. Fix this by setting OUTPUT_ARCH to s390:31-bit instead of s390. Thanks to Andreas Krebbel for figuring out the issue. Fixes this build error: LD init/built-in.o s390x-4.7.2-ld: s390:31-bit architecture of input file `arch/s390/kernel/head.o' is incompatible with s390:64-bit output Cc: Andreas Krebbel <Andreas.Krebbel@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-10-30oprofile, 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: Ben Hutchings <ben@decadent.org.uk>
2012-10-30xen/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: Ben Hutchings <ben@decadent.org.uk>
2012-10-30xen/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: Ben Hutchings <ben@decadent.org.uk>
2012-10-30mips,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. Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: David S. Miller <davem@davemloft.net> Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-10-30ARM: 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: Ben Hutchings <ben@decadent.org.uk>
2012-10-30sparc64: 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: Ben Hutchings <ben@decadent.org.uk>
2012-10-30sparc64: 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: Ben Hutchings <ben@decadent.org.uk>
2012-10-30sparc64: 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: Ben Hutchings <ben@decadent.org.uk>
2012-10-30sparc64: 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: Ben Hutchings <ben@decadent.org.uk>
2012-10-30sparc64: 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: Ben Hutchings <ben@decadent.org.uk>
2012-10-17efi: initialize efi.runtime_version to make ↵Seiji Aguchi
query_variable_info/update_capsule workable commit d6cf86d8f23253225fe2a763d627ecf7dfee9dae upstream. A value of efi.runtime_version is checked before calling update_capsule()/query_variable_info() as follows. But it isn't initialized anywhere. <snip> static efi_status_t virt_efi_query_variable_info(u32 attr, u64 *storage_space, u64 *remaining_space, u64 *max_variable_size) { if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION) return EFI_UNSUPPORTED; <snip> This patch initializes a value of efi.runtime_version at boot time. Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com> Acked-by: Matthew Garrett <mjg@redhat.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-10-17mm: 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: Ben Hutchings <ben@decadent.org.uk>
2012-10-17ARM: OMAP: counter: add locking to read_persistent_clockColin Cross
commit 9d7d6e363b06934221b81a859d509844c97380df upstream. read_persistent_clock uses a global variable, use a spinlock to ensure non-atomic updates to the variable don't overlap and cause time to move backwards. Signed-off-by: Colin Cross <ccross@android.com> Signed-off-by: R Sricharan <r.sricharan@ti.com> Signed-off-by: Tony Lindgren <tony@atomide.com> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-10-17mn10300: 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: Ben Hutchings <ben@decadent.org.uk>
2012-10-17kbuild: Fix gcc -x syntaxJean Delvare
commit b1e0d8b70fa31821ebca3965f2ef8619d7c5e316 upstream. The correct syntax for gcc -x is "gcc -x assembler", not "gcc -xassembler". Even though the latter happens to work, the former is what is documented in the manual page and thus what gcc wrappers such as icecream do expect. This isn't a cosmetic change. The missing space prevents icecream from recognizing compilation tasks it can't handle, leading to silent kernel miscompilations. Besides me, credits go to Michael Matz and Dirk Mueller for investigating the miscompilation issue and tracking it down to this incorrect -x parameter syntax. Signed-off-by: Jean Delvare <jdelvare@suse.de> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Bernhard Walle <bernhard@bwalle.de> Cc: Michal Marek <mmarek@suse.cz> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Michal Marek <mmarek@suse.cz> [bwh: Backported to 3.2: drop unneeded change to arch/x86/Makefile] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-10-17powerpc/eeh: Lock module while handling EEH eventGavin Shan
commit feadf7c0a1a7c08c74bebb4a13b755f8c40e3bbc upstream. The EEH core is talking with the PCI device driver to determine the action (purely reset, or PCI device removal). During the period, the driver might be unloaded and in turn causes kernel crash as follows: EEH: Detected PCI bus error on PHB#4-PE#10000 EEH: This PCI device has failed 3 times in the last hour lpfc 0004:01:00.0: 0:2710 PCI channel disable preparing for reset Unable to handle kernel paging request for data at address 0x00000490 Faulting instruction address: 0xd00000000e682c90 cpu 0x1: Vector: 300 (Data Access) at [c000000fc75ffa20] pc: d00000000e682c90: .lpfc_io_error_detected+0x30/0x240 [lpfc] lr: d00000000e682c8c: .lpfc_io_error_detected+0x2c/0x240 [lpfc] sp: c000000fc75ffca0 msr: 8000000000009032 dar: 490 dsisr: 40000000 current = 0xc000000fc79b88b0 paca = 0xc00000000edb0380 softe: 0 irq_happened: 0x00 pid = 3386, comm = eehd enter ? for help [c000000fc75ffca0] c000000fc75ffd30 (unreliable) [c000000fc75ffd30] c00000000004fd3c .eeh_report_error+0x7c/0xf0 [c000000fc75ffdc0] c00000000004ee00 .eeh_pe_dev_traverse+0xa0/0x180 [c000000fc75ffe70] c00000000004ffd8 .eeh_handle_event+0x68/0x300 [c000000fc75fff00] c0000000000503a0 .eeh_event_handler+0x130/0x1a0 [c000000fc75fff90] c000000000020138 .kernel_thread+0x54/0x70 1:mon> The patch increases the reference of the corresponding driver modules while EEH core does the negotiation with PCI device driver so that the corresponding driver modules can't be unloaded during the period and we're safe to refer the callbacks. Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [bwh: Backported to 3.2: - Adjust context - Reporting functions return int (success = 0), not void * (success = NULL) - Assume that the 'dev' arguments are non-null] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-10-10x86/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> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-10-10xen/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: Ben Hutchings <ben@decadent.org.uk>
2012-10-10xen/boot: Disable BIOS SMP MP table search.Konrad Rzeszutek Wilk
commit bd49940a35ec7d488ae63bd625639893b3385b97 upstream. As the initial domain we are able to search/map certain regions of memory to harvest configuration data. For all low-level we use ACPI tables - for interrupts we use exclusively ACPI _PRT (so DSDT) and MADT for INT_SRC_OVR. The SMP MP table is not used at all. As a matter of fact we do not even support machines that only have SMP MP but no ACPI tables. Lets follow how Moorestown does it and just disable searching for BIOS SMP tables. This also fixes an issue on HP Proliant BL680c G5 and DL380 G6: 9f->100 for 1:1 PTE Freeing 9f-100 pfn range: 97 pages freed 1-1 mapping on 9f->100 .. snip.. e820: BIOS-provided physical RAM map: Xen: [mem 0x0000000000000000-0x000000000009efff] usable Xen: [mem 0x000000000009f400-0x00000000000fffff] reserved Xen: [mem 0x0000000000100000-0x00000000cfd1dfff] usable .. snip.. Scan for SMP in [mem 0x00000000-0x000003ff] Scan for SMP in [mem 0x0009fc00-0x0009ffff] Scan for SMP in [mem 0x000f0000-0x000fffff] found SMP MP-table at [mem 0x000f4fa0-0x000f4faf] mapped at [ffff8800000f4fa0] (XEN) mm.c:908:d0 Error getting mfn 100 (pfn 5555555555555555) from L1 entry 0000000000100461 for l1e_owner=0, pg_owner=0 (XEN) mm.c:4995:d0 ptwr_emulate: could not get_page_from_l1e() BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<ffffffff81ac07e2>] xen_set_pte_init+0x66/0x71 . snip.. Pid: 0, comm: swapper Not tainted 3.6.0-rc6upstream-00188-gb6fb969-dirty #2 HP ProLiant BL680c G5 .. snip.. Call Trace: [<ffffffff81ad31c6>] __early_ioremap+0x18a/0x248 [<ffffffff81624731>] ? printk+0x48/0x4a [<ffffffff81ad32ac>] early_ioremap+0x13/0x15 [<ffffffff81acc140>] get_mpc_size+0x2f/0x67 [<ffffffff81acc284>] smp_scan_config+0x10c/0x136 [<ffffffff81acc2e4>] default_find_smp_config+0x36/0x5a [<ffffffff81ac3085>] setup_arch+0x5b3/0xb5b [<ffffffff81624731>] ? printk+0x48/0x4a [<ffffffff81abca7f>] start_kernel+0x90/0x390 [<ffffffff81abc356>] x86_64_start_reservations+0x131/0x136 [<ffffffff81abfa83>] xen_start_kernel+0x65f/0x661 (XEN) Domain 0 crashed: 'noreboot' set - not rebooting. which is that ioremap would end up mapping 0xff using _PAGE_IOMAP (which is what early_ioremap sticks as a flag) - which meant we would get MFN 0xFF (pte ff461, which is OK), and then it would also map 0x100 (b/c ioremap tries to get page aligned request, and it was trying to map 0xf4fa0 + PAGE_SIZE - so it mapped the next page) as _PAGE_IOMAP. Since 0x100 is actually a RAM page, and the _PAGE_IOMAP bypasses the P2M lookup we would happily set the PTE to 1000461. Xen would deny the request since we do not have access to the Machine Frame Number (MFN) of 0x100. The P2M[0x100] is for example 0x80140. Fixes-Oracle-Bugzilla: https://bugzilla.oracle.com/bugzilla/show_bug.cgi?id=13665 Acked-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-10-10ARM: 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: Ben Hutchings <ben@decadent.org.uk>
2012-09-19ARM: 7526/1: traps: send SIGILL if get_user fails on undef handling pathWill Deacon
commit 2b2040af0b64cd93e5d4df2494c4486cf604090d upstream. get_user may fail to load from the provided __user address due to an unhandled fault generated by the access. In the case of the undefined instruction trap, this results in failure to load the faulting instruction, in which case we should send SIGILL to the task rather than continue with potentially uninitialised data. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-09-19ARM: 7513/1: Make sure dtc is built before running itDavid Brown
commit 70b0476a2394de4f4e32e0b67288d80ff71ca963 upstream. 'make dtbs' in a clean tree will try running the dtc before actually building it. Make these rules depend upon the scripts to build it. Signed-off-by: David Brown <davidb@codeaurora.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-09-19ARM: 7496/1: hw_breakpoint: don't rely on dfsr to show watchpoint access typeWill Deacon
commit bf8801145c01ab600f8df66e8c879ac642fa5846 upstream. From ARM debug architecture v7.1 onwards, a watchpoint exception causes the DFAR to be updated with the faulting data address. However, DFSR.WnR takes an UNKNOWN value and therefore cannot be used in general to determine the access type that triggered the watchpoint. This patch forbids watchpoints without an overflow handler from specifying a specific access type (load/store). Those with overflow handlers must be able to handle false positives potentially triggered by a watchpoint of a different access type on the same address. For SIGTRAP-based handlers (i.e. ptrace), this should have no impact. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-09-19ARM: 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: Ben Hutchings <ben@decadent.org.uk>
2012-09-19powerpc: Make sure IPI handlers see data written by IPI sendersPaul Mackerras
commit 9fb1b36ca1234e64a5d1cc573175303395e3354d upstream. We have been observing hangs, both of KVM guest vcpu tasks and more generally, where a process that is woken doesn't properly wake up and continue to run, but instead sticks in TASK_WAKING state. This happens because the update of rq->wake_list in ttwu_queue_remote() is not ordered with the update of ipi_message in smp_muxed_ipi_message_pass(), and the reading of rq->wake_list in scheduler_ipi() is not ordered with the reading of ipi_message in smp_ipi_demux(). Thus it is possible for the IPI receiver not to see the updated rq->wake_list and therefore conclude that there is nothing for it to do. In order to make sure that anything done before smp_send_reschedule() is ordered before anything done in the resulting call to scheduler_ipi(), this adds barriers in smp_muxed_message_pass() and smp_ipi_demux(). The barrier in smp_muxed_message_pass() is a full barrier to ensure that there is a full ordering between the smp_send_reschedule() caller and scheduler_ipi(). In smp_ipi_demux(), we use xchg() rather than xchg_local() because xchg() includes release and acquire barriers. Using xchg() rather than xchg_local() makes sense given that ipi_message is not just accessed locally. This moves the barrier between setting the message and calling the cause_ipi() function into the individual cause_ipi implementations. Most of them -- those that used outb, out_8 or similar -- already had a full barrier because out_8 etc. include a sync before the MMIO store. This adds an explicit barrier in the two remaining cases. These changes made no measurable difference to the speed of IPIs as measured using a simple ping-pong latency test across two CPUs on different cores of a POWER7 machine. The analysis of the reason why processes were not waking up properly is due to Milton Miller. Reported-by: Milton Miller <miltonm@bga.com> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-09-19powerpc/xics: Harden xics hypervisor backendAnton Blanchard
commit 3ce21cdfe93efffa4ffba9cf3ca2576d3d60d6dc upstream. During kdump stress testing I sometimes see the kdump kernel panic with: Interrupt 0x306 (real) is invalid, disabling it. Kernel panic - not syncing: bad return code EOI - rc = -4, value=ff000306 Instead of panicing print the error message, dump the stack the first time it happens and continue on. Add some more information to the debug messages as well. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-09-19powerpc: 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: Ben Hutchings <ben@decadent.org.uk>
2012-09-19powerpc: 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: Ben Hutchings <ben@decadent.org.uk>
2012-09-19powerpc: Keep thread.dscr and thread.dscr_inherit in syncAnton Blanchard
commit 00ca0de02f80924dfff6b4f630e1dff3db005e35 upstream. When we update the DSCR either via emulation of mtspr(DSCR) or via a change to dscr_default in sysfs we don't update thread.dscr. We will eventually update it at context switch time but there is a period where thread.dscr is incorrect. If we fork at this point we will copy the old value of thread.dscr into the child. To avoid this, always keep thread.dscr in sync with reality. This issue was found with the following testcase: 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: Ben Hutchings <ben@decadent.org.uk>
2012-09-19powerpc: Update DSCR on all CPUs when writing sysfs dscr_defaultAnton Blanchard
commit 1b6ca2a6fe56e7697d57348646e07df08f43b1bb upstream. Writing to dscr_default in sysfs doesn't actually change the DSCR - we rely on a context switch on each CPU to do the work. There is no guarantee we will get a context switch in a reasonable amount of time so fire off an IPI to force an immediate change. This issue was found with the following test case: http://ozlabs.org/~anton/junkcode/dscr_explicit_test.c Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-09-19ARM: 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: Ben Hutchings <ben@decadent.org.uk>
2012-09-19xen/setup: Fix one-off error when adding for-balloon PFNs to the P2M.Konrad Rzeszutek Wilk
commit c96aae1f7f393387d160211f60398d58463a7e65 upstream. When we are finished with return PFNs to the hypervisor, then populate it back, and also mark the E820 MMIO and E820 gaps as IDENTITY_FRAMEs, we then call P2M to set areas that can be used for ballooning. We were off by one, and ended up over-writting a P2M entry that most likely was an IDENTITY_FRAME. For example: 1-1 mapping on 40000->40200 1-1 mapping on bc558->bc5ac 1-1 mapping on bc5b4->bc8c5 1-1 mapping on bc8c6->bcb7c 1-1 mapping on bcd00->100000 Released 614 pages of unused memory Set 277889 page(s) to 1-1 mapping Populating 40200-40466 pfn range: 614 pages added => here we set from 40466 up to bc559 P2M tree to be INVALID_P2M_ENTRY. We should have done it up to bc558. The end result is that if anybody is trying to construct a PTE for PFN bc558 they end up with ~PAGE_PRESENT. Reported-by-and-Tested-by: Andre Przywara <andre.przywara@amd.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-09-19ARM: dts: imx51-babbage: fix esdhc cd/wp propertiesShawn Guo
commit a46d2619d7180bda12bad2bf15bbd0731dfc2dcf upstream. The binding doc and dts use properties "fsl,{cd,wp}-internal" while esdhc driver uses "fsl,{cd,wp}-controller". Fix binding doc and dts to get them match driver code. Reported-by: Chris Ball <cjb@laptop.org> Signed-off-by: Shawn Guo <shawn.guo@linaro.org> Acked-by: Chris Ball <cjb@laptop.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-09-19ARM: imx6: spin the cpu until hardware takes it downShawn Guo
commit c944b0b9354ea06ffb0c8a7178949f1185f9f499 upstream. Though commit 602bf40 (ARM: imx6: exit coherency when shutting down a cpu) improves the stability of imx6q cpu hotplug a lot, there are still hangs seen with a more stressful hotplug testing. It's expected that once imx_enable_cpu(cpu, false) is called, the cpu will be taken down by hardware immediately, and the code after that will not get any chance to execute. However, this is not always the case from the testing. The cpu could possibly be alive for a few cycles before hardware actually takes it down. So rather than letting cpu execute some code that could cause a hang in these cycles, let's make the cpu spin there and wait for hardware to take it down. Signed-off-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-09-19ARM: Orion: Set eth packet size csum offload limitArnaud Patard (Rtp)
commit 58569aee5a1a5dcc25c34a0a2ed9a377874e6b05 upstream. The mv643xx ethernet controller limits the packet size for the TX checksum offloading. This patch sets this limits for Kirkwood and Dove which have smaller limits that the default. As a side note, this patch is an updated version of a patch sent some years ago: http://lists.infradead.org/pipermail/linux-arm-kernel/2010-June/017320.html which seems to have been lost. Signed-off-by: Arnaud Patard <arnaud.patard@rtp-net.org> Signed-off-by: Jason Cooper <jason@lakedaemon.net> [bwh: Backported to 3.2: adjust for the extra two parameters of orion_ge0{0,1}_init()] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-09-19ARM: OMAP2+: Fix dmtimer set source clock failureJon Hunter
commit 54f32a35f4d3a653a18a2c8c239f19ae060bd803 upstream. Calling the dmtimer function omap_dm_timer_set_source() fails if following a call to pm_runtime_put() to disable the timer. For example the following sequence would fail to set the parent clock ... omap_dm_timer_stop(gptimer); omap_dm_timer_set_source(gptimer, OMAP_TIMER_SRC_32_KHZ); The following error message would be seen ... omap_dm_timer_set_source: failed to set timer_32k_ck as parent The problem is that, by design, pm_runtime_put() simply decrements the usage count and returns before the timer has actually been disabled. Therefore, setting the parent clock failed because the timer was still active when the trying to set the parent clock. Setting a parent clock will fail if the clock you are setting the parent of has a non-zero usage count. To ensure that this does not fail use pm_runtime_put_sync() when disabling the timer. Note that this will not be seen on OMAP1 devices, because these devices do not use the clock framework for dmtimers. Signed-off-by: Jon Hunter <jon-hunter@ti.com> Acked-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-09-19ARM: 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: Ben Hutchings <ben@decadent.org.uk>
2012-09-19Redefine 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: Ben Hutchings <ben@decadent.org.uk>
2012-09-12mm: 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: Ben Hutchings <ben@decadent.org.uk>
2012-09-12Redefine 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: Ben Hutchings <ben@decadent.org.uk>
2012-09-12alpha: 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: Ben Hutchings <ben@decadent.org.uk>
2012-09-12ARM: 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: Ben Hutchings <ben@decadent.org.uk>
2012-09-12ARM: 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: Ben Hutchings <ben@decadent.org.uk>
2012-09-12ARM: 7483/1: vfp: only advertise VFPv4 in hwcaps if CONFIG_VFPv3 is enabledWill Deacon
commit 3d9fb0038a9b02febb01efc79a4a5d97f1822a90 upstream. VFPv4 support depends on the VFPv3 context save/restore code, so only advertise support in the hwcaps if the kernel can actually handle it. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-08-19s390/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: Ben Hutchings <ben@decadent.org.uk>
2012-08-19s390/compat: fix compat wrappers for process_vm system callsHeiko Carstens
commit 82aabdb6f1eb61e0034ec23901480f5dd23db7c4 upstream. The compat wrappers incorrectly called the non compat versions of the system process_vm system calls. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>