linux/arch, branch v3.12.14

ARM64: unwind: Fix PC calculation

2014-03-05T16:13:54Z

commit e306dfd06fcb44d21c80acb8e5a88d55f3d1cf63 upstream. The frame PC value in the unwind code used to just take the saved LR value and use that. That's incorrect as a stack trace, since it shows the return path stack, not the call path stack. In particular, it shows faulty information in case the bl is done as the very last instruction of one label, since the return point will be in the next label. That can easily be seen with tail calls to panic(), which is marked __noreturn and thus doesn't have anything useful after it. Easiest here is to just correct the unwind code and do a -4, to get the actual call site for the backtrace instead of the return site. Signed-off-by: Olof Johansson Signed-off-by: Catalin Marinas Signed-off-by: Jiri Slaby

xtensa: introduce spill_registers_kernel macro

2014-03-05T16:13:53Z

commit e2fd1374c705abe4661df3fb6fadb3879c7c1846 upstream. Most in-kernel users want registers spilled on the kernel stack and don't require PS.EXCM to be set. That means that they don't need fixup routine and could reuse regular window overflow mechanism for that, which makes spill routine very simple. Suggested-by: Chris Zankel Signed-off-by: Max Filippov Signed-off-by: Jiri Slaby

xtensa: save current register frame in fast_syscall_spill_registers_fixup

2014-03-05T16:13:52Z

commit 3251f1e27a5a17f0efd436cfd1e7b9896cfab0a0 upstream. We need it saved because it contains a3 where we track which register windows we still need to spill, and fixup handler may call C exception handlers. Also fix comments. Signed-off-by: Max Filippov Signed-off-by: Jiri Slaby

perf/x86: Fix event scheduling

2014-03-05T16:13:46Z

commit 26e61e8939b1fe8729572dabe9a9e97d930dd4f6 upstream. Vince "Super Tester" Weaver reported a new round of syscall fuzzing (Trinity) failures, with perf WARN_ON()s triggering. He also provided traces of the failures. This is I think the relevant bit: > pec_1076_warn-2804 [000] d... 147.926153: x86_pmu_disable: x86_pmu_disable > pec_1076_warn-2804 [000] d... 147.926153: x86_pmu_state: Events: { > pec_1076_warn-2804 [000] d... 147.926156: x86_pmu_state: 0: state: .R config: ffffffffffffffff ( (null)) > pec_1076_warn-2804 [000] d... 147.926158: x86_pmu_state: 33: state: AR config: 0 (ffff88011ac99800) > pec_1076_warn-2804 [000] d... 147.926159: x86_pmu_state: } > pec_1076_warn-2804 [000] d... 147.926160: x86_pmu_state: n_events: 1, n_added: 0, n_txn: 1 > pec_1076_warn-2804 [000] d... 147.926161: x86_pmu_state: Assignment: { > pec_1076_warn-2804 [000] d... 147.926162: x86_pmu_state: 0->33 tag: 1 config: 0 (ffff88011ac99800) > pec_1076_warn-2804 [000] d... 147.926163: x86_pmu_state: } > pec_1076_warn-2804 [000] d... 147.926166: collect_events: Adding event: 1 (ffff880119ec8800) So we add the insn:p event (fd[23]). At this point we should have: n_events = 2, n_added = 1, n_txn = 1 > pec_1076_warn-2804 [000] d... 147.926170: collect_events: Adding event: 0 (ffff8800c9e01800) > pec_1076_warn-2804 [000] d... 147.926172: collect_events: Adding event: 4 (ffff8800cbab2c00) We try and add the {BP,cycles,br_insn} group (fd[3], fd[4], fd[15]). These events are 0:cycles and 4:br_insn, the BP event isn't x86_pmu so that's not visible. group_sched_in() pmu->start_txn() /* nop - BP pmu */ event_sched_in() event->pmu->add() So here we should end up with: 0: n_events = 3, n_added = 2, n_txn = 2 4: n_events = 4, n_added = 3, n_txn = 3 But seeing the below state on x86_pmu_enable(), the must have failed, because the 0 and 4 events aren't there anymore. Looking at group_sched_in(), since the BP is the leader, its event_sched_in() must have succeeded, for otherwise we would not have seen the sibling adds. But since neither 0 or 4 are in the below state; their event_sched_in() must have failed; but I don't see why, the complete state: 0,0,1:p,4 fits perfectly fine on a core2. However, since we try and schedule 4 it means the 0 event must have succeeded! Therefore the 4 event must have failed, its failure will have put group_sched_in() into the fail path, which will call: event_sched_out() event->pmu->del() on 0 and the BP event. Now x86_pmu_del() will reduce n_events; but it will not reduce n_added; giving what we see below: n_event = 2, n_added = 2, n_txn = 2 > pec_1076_warn-2804 [000] d... 147.926177: x86_pmu_enable: x86_pmu_enable > pec_1076_warn-2804 [000] d... 147.926177: x86_pmu_state: Events: { > pec_1076_warn-2804 [000] d... 147.926179: x86_pmu_state: 0: state: .R config: ffffffffffffffff ( (null)) > pec_1076_warn-2804 [000] d... 147.926181: x86_pmu_state: 33: state: AR config: 0 (ffff88011ac99800) > pec_1076_warn-2804 [000] d... 147.926182: x86_pmu_state: } > pec_1076_warn-2804 [000] d... 147.926184: x86_pmu_state: n_events: 2, n_added: 2, n_txn: 2 > pec_1076_warn-2804 [000] d... 147.926184: x86_pmu_state: Assignment: { > pec_1076_warn-2804 [000] d... 147.926186: x86_pmu_state: 0->33 tag: 1 config: 0 (ffff88011ac99800) > pec_1076_warn-2804 [000] d... 147.926188: x86_pmu_state: 1->0 tag: 1 config: 1 (ffff880119ec8800) > pec_1076_warn-2804 [000] d... 147.926188: x86_pmu_state: } > pec_1076_warn-2804 [000] d... 147.926190: x86_pmu_enable: S0: hwc->idx: 33, hwc->last_cpu: 0, hwc->last_tag: 1 hwc->state: 0 So the problem is that x86_pmu_del(), when called from a group_sched_in() that fails (for whatever reason), and without x86_pmu TXN support (because the leader is !x86_pmu), will corrupt the n_added state. Reported-and-Tested-by: Vince Weaver Signed-off-by: Peter Zijlstra Cc: Paul Mackerras Cc: Steven Rostedt Cc: Stephane Eranian Cc: Dave Jones Link: http://lkml.kernel.org/r/20140221150312.GF3104@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar Signed-off-by: Jiri Slaby

x86: dma-mapping: fix GFP_ATOMIC macro usage

2014-03-05T16:13:45Z

commit c091c71ad2218fc50a07b3d1dab85783f3b77efd upstream. GFP_ATOMIC is not a single gfp flag, but a macro which expands to the other flags, where meaningful is the LACK of __GFP_WAIT flag. To check if caller wants to perform an atomic allocation, the code must test for a lack of the __GFP_WAIT flag. This patch fixes the issue introduced in v3.5-rc1. Signed-off-by: Marek Szyprowski Signed-off-by: Jiri Slaby

powerpc/crashdump : Fix page frame number check in copy_oldmem_page

2014-03-05T16:13:45Z

commit f5295bd8ea8a65dc5eac608b151386314cb978f1 upstream. In copy_oldmem_page, the current check using max_pfn and min_low_pfn to decide if the page is backed or not, is not valid when the memory layout is not continuous. This happens when running as a QEMU/KVM guest, where RTAS is mapped higher in the memory. In that case max_pfn points to the end of RTAS, and a hole between the end of the kdump kernel and RTAS is not backed by PTEs. As a consequence, the kdump kernel is crashing in copy_oldmem_page when accessing in a direct way the pages in that hole. This fix relies on the memblock's service memblock_is_region_memory to check if the read page is part or not of the directly accessible memory. Signed-off-by: Laurent Dufour Tested-by: Mahesh Salgaonkar Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Jiri Slaby

powerpc/le: Ensure that the 'stop-self' RTAS token is handled correctly

2014-03-05T16:13:45Z

commit 41dd03a94c7d408d2ef32530545097f7d1befe5c upstream. Currently we're storing a host endian RTAS token in rtas_stop_self_args.token. We then pass that directly to rtas. This is fine on big endian however on little endian the token is not what we expect. This will typically result in hitting: panic("Alas, I survived.\n"); To fix this we always use the stop-self token in host order and always convert it to be32 before passing this to rtas. Signed-off-by: Tony Breeds Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Jiri Slaby

powerpc: Increase stack redzone for 64-bit userspace to 512 bytes

2014-03-05T16:13:45Z

commit 573ebfa6601fa58b439e7f15828762839ccd306a upstream. The new ELFv2 little-endian ABI increases the stack redzone -- the area below the stack pointer that can be used for storing data -- from 288 bytes to 512 bytes. This means that we need to allow more space on the user stack when delivering a signal to a 64-bit process. To make the code a bit clearer, we define new USER_REDZONE_SIZE and KERNEL_REDZONE_SIZE symbols in ptrace.h. For now, we leave the kernel redzone size at 288 bytes, since increasing it to 512 bytes would increase the size of interrupt stack frames correspondingly. Gcc currently only makes use of 288 bytes of redzone even when compiling for the new little-endian ABI, and the kernel cannot currently be compiled with the new ABI anyway. In the future, hopefully gcc will provide an option to control the amount of redzone used, and then we could reduce it even more. This also changes the code in arch_compat_alloc_user_space() to preserve the expanded redzone. It is not clear why this function would ever be used on a 64-bit process, though. Signed-off-by: Paul Mackerras Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Jiri Slaby

kvm: x86: fix emulator buffer overflow (CVE-2014-0049)

2014-03-05T16:13:43Z

commit a08d3b3b99efd509133946056531cdf8f3a0c09b upstream. The problem occurs when the guest performs a pusha with the stack address pointing to an mmio address (or an invalid guest physical address) to start with, but then extending into an ordinary guest physical address. When doing repeated emulated pushes emulator_read_write sets mmio_needed to 1 on the first one. On a later push when the stack points to regular memory, mmio_nr_fragments is set to 0, but mmio_is_needed is not set to 0. As a result, KVM exits to userspace, and then returns to complete_emulated_mmio. In complete_emulated_mmio vcpu->mmio_cur_fragment is incremented. The termination condition of vcpu->mmio_cur_fragment == vcpu->mmio_nr_fragments is never achieved. The code bounces back and fourth to userspace incrementing mmio_cur_fragment past it's buffer. If the guest does nothing else it eventually leads to a a crash on a memcpy from invalid memory address. However if a guest code can cause the vm to be destroyed in another vcpu with excellent timing, then kvm_clear_async_pf_completion_queue can be used by the guest to control the data that's pointed to by the call to cancel_work_item, which can be used to gain execution. Fixes: f78146b0f9230765c6315b2e14f56112513389ad Signed-off-by: Andrew Honig Signed-off-by: Paolo Bonzini Signed-off-by: Jiri Slaby

avr32: Makefile: add '-Dlinux' flag for gcc-4.4.7 use

2014-03-05T16:13:41Z

commit 8d80390cfc9434d5aa4fb9e5f9768a66b30cb8a6 upstream. For avr32 cross compiler, do not define '__linux__' internally, so it will cause issue with allmodconfig. The related error: CC [M] fs/coda/psdev.o In file included from include/linux/coda.h:64, from fs/coda/psdev.c:45: include/uapi/linux/coda.h:221: error: expected specifier-qualifier-list before 'u_quad_t' The related toolchain version (which only download, not re-compile): [root@gchen linux-next]# /upstream/toolchain/download/avr32-gnu-toolchain-linux_x86/bin/avr32-gcc -v Using built-in specs. Target: avr32 Configured with: /data2/home/toolsbuild/jenkins-knuth/workspace/avr32-gnu-toolchain/src/gcc/configure --target=avr32 --host=i686-pc-linux-gnu --build=x86_64-pc-linux-gnu --prefix=/home/toolsbuild/jenkins-knuth/workspace/avr32-gnu-toolchain/avr32-gnu-toolchain-linux_x86 --enable-languages=c,c++ --disable-nls --disable-libssp --disable-libstdcxx-pch --with-dwarf2 --enable-version-specific-runtime-libs --disable-shared --enable-doc --with-mpfr-lib=/home/toolsbuild/jenkins-knuth/workspace/avr32-gnu-toolchain/avr32-gnu-toolchain-linux_x86/lib --with-mpfr-include=/home/toolsbuild/jenkins-knuth/workspace/avr32-gnu-toolchain/avr32-gnu-toolchain-linux_x86/include --with-gmp=/home/toolsbuild/jenkins-knuth/workspace/avr32-gnu-toolchain/avr32-gnu-toolchain-linux_x86 --with-mpc=/home/toolsbuild/jenkins-knuth/workspace/avr32-gnu-toolchain/avr32-gnu-toolchain-linux_x86 --enable-__cxa_atexit --disable-shared --with-newlib --with-pkgversion=AVR_32_bit_GNU_Toolchain_3.4.2_435 --with-bugurl=http://www .atmel.com/avr Thread model: single gcc version 4.4.7 (AVR_32_bit_GNU_Toolchain_3.4.2_435) Signed-off-by: Chen Gang Acked-by: Hans-Christian Egtvedt Signed-off-by: Jiri Slaby

linux/arch, branch v3.12.14

ARM64: unwind: Fix PC calculation

xtensa: introduce spill_registers_kernel macro

xtensa: save current register frame in fast_syscall_spill_registers_fixup

perf/x86: Fix event scheduling

x86: dma-mapping: fix GFP_ATOMIC macro usage

powerpc/crashdump : Fix page frame number check in copy_oldmem_page

powerpc/le: Ensure that the 'stop-self' RTAS token is handled correctly

powerpc: Increase stack redzone for 64-bit userspace to 512 bytes

kvm: x86: fix emulator buffer overflow (CVE-2014-0049)

avr32: Makefile: add '-D__linux__' flag for gcc-4.4.7 use

avr32: Makefile: add '-Dlinux' flag for gcc-4.4.7 use