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* x86/dumpstack/64: Handle faults when printing the "Stack: " part of an OOPSAndy Lutomirski2016-07-151-2/+10
| | | | | | | | | | | | | | | | | | If we overflow the stack into a guard page, we'll recursively fault when trying to dump the contents of the guard page. Use probe_kernel_address() so we can recover if this happens. Signed-off-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/e626d47a55d7b04dcb1b4d33faa95e8505b217c8.1468527351.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/dumpstack: Try harder to get a call trace on stack overflowAndy Lutomirski2016-07-151-1/+9
| | | | | | | | | | | | | | | | | | If we overflow the stack, print_context_stack() will abort. Detect this case and rewind back into the valid part of the stack so that we can trace it. Signed-off-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/ee1690eb2715ccc5dc187fde94effa4ca0ccbbcd.1468527351.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/mm: Remove kernel_unmap_pages_in_pgd() and efi_cleanup_page_tables()Andy Lutomirski2016-07-156-41/+0
| | | | | | | | | | | | | | | | | | | | | | | | | kernel_unmap_pages_in_pgd() is dangerous: if a PGD entry in init_mm.pgd were to be cleared, callers would need to ensure that the pgd entry hadn't been propagated to any other pgd. Its only caller was efi_cleanup_page_tables(), and that, in turn, was unused, so just delete both functions. This leaves a couple of other helpers unused, so delete them, too. Signed-off-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Acked-by: Borislav Petkov <bp@suse.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/77ff20fdde3b75cd393be5559ad8218870520248.1468527351.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/mm/cpa: In populate_pgd(), don't set the PGD entry until it's populatedAndy Lutomirski2016-07-151-3/+6
| | | | | | | | | | | | | | | | | | | | | This avoids pointless races in which another CPU or task might see a partially populated global PGD entry. These races should normally be harmless, but, if another CPU propagates the entry via vmalloc_fault() and then populate_pgd() fails (due to memory allocation failure, for example), this prevents a use-after-free of the PGD entry. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/bf99df27eac6835f687005364bd1fbd89130946c.1468527351.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/mm/hotplug: Don't remove PGD entries in remove_pagetable()Ingo Molnar2016-07-151-27/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | So when memory hotplug removes a piece of physical memory from pagetable mappings, it also frees the underlying PGD entry. This complicates PGD management, so don't do this. We can keep the PGD mapped and the PUD table all clear - it's only a single 4K page per 512 GB of memory hotplugged. Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <Waiman.Long@hp.com> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/064ff6c7275734537f969e876f6cd0baa954d2cc.1468527351.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Merge branch 'x86/asm' into x86/mm, to resolve conflictsIngo Molnar2016-07-1545-278/+590
|\ | | | | | | | | | | | | Conflicts: tools/testing/selftests/x86/Makefile Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * x86/entry: Inline enter_from_user_mode()Paolo Bonzini2016-07-101-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This matches what is already done for prepare_exit_to_usermode(), and saves about 60 clock cycles (4% speedup) with the benchmark in the previous commit message. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Rik van Riel <riel@redhat.com> Reviewed-by: Andy Lutomirski <luto@kernel.org> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kvm@vger.kernel.org Link: http://lkml.kernel.org/r/1466434712-31440-3-git-send-email-pbonzini@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * x86/entry: Avoid interrupt flag save and restorePaolo Bonzini2016-07-101-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Thanks to all the work that was done by Andy Lutomirski and others, enter_from_user_mode() and prepare_exit_to_usermode() are now called only with interrupts disabled. Let's provide them a version of user_enter()/user_exit() that skips saving and restoring the interrupt flag. On an AMD-based machine I tested this patch on, with force-enabled context tracking, the speed-up in system calls was 90 clock cycles or 6%, measured with the following simple benchmark: #include <sys/signal.h> #include <time.h> #include <unistd.h> #include <stdio.h> unsigned long rdtsc() { unsigned long result; asm volatile("rdtsc; shl $32, %%rdx; mov %%eax, %%eax\n" "or %%rdx, %%rax" : "=a" (result) : : "rdx"); return result; } int main() { unsigned long tsc1, tsc2; int pid = getpid(); int i; tsc1 = rdtsc(); for (i = 0; i < 100000000; i++) kill(pid, SIGWINCH); tsc2 = rdtsc(); printf("%ld\n", tsc2 - tsc1); } Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Rik van Riel <riel@redhat.com> Reviewed-by: Andy Lutomirski <luto@kernel.org> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kvm@vger.kernel.org Link: http://lkml.kernel.org/r/1466434712-31440-2-git-send-email-pbonzini@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * Merge branch 'linus' into x86/asm, to pick up fixes before merging new changesIngo Molnar2016-07-09167-563/+1076
| |\ | | | | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * Merge tag 'arm64-fixes' of ↵Linus Torvalds2016-07-086-3/+30
| | |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 fixes from Will Deacon: "A couple of late fixes here, but one that we've been sitting on for a few weeks while the details were worked out. Specifically, we now enforce USER_DS on taking exceptions whilst in the kernel, which avoids leaking kernel data to userspace through things like perf. The other patch is an update to a workaround for a hardware erratum on some Cavium SoCs. Summary: - Enforce USER_DS on exception entry from EL1 - Apply workaround for Cavium errata #27456 on Thunderx-81xx parts" * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: Enable workaround for Cavium erratum 27456 on thunderx-81xx arm64: kernel: Save and restore UAO and addr_limit on exception entry
| | | * arm64: Enable workaround for Cavium erratum 27456 on thunderx-81xxGanapatrao Kulkarni2016-07-072-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Cavium erratum 27456 commit 104a0c02e8b1 ("arm64: Add workaround for Cavium erratum 27456") is applicable for thunderx-81xx pass1.0 SoC as well. Adding code to enable to 81xx. Signed-off-by: Ganapatrao Kulkarni <gkulkarni@cavium.com> Reviewed-by: Andrew Pinski <apinski@cavium.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
| | | * arm64: kernel: Save and restore UAO and addr_limit on exception entryJames Morse2016-07-074-3/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If we take an exception while at EL1, the exception handler inherits the original context's addr_limit and PSTATE.UAO values. To be consistent always reset addr_limit and PSTATE.UAO on (re-)entry to EL1. This prevents accidental re-use of the original context's addr_limit. Based on a similar patch for arm from Russell King. Cc: <stable@vger.kernel.org> # 4.6- Acked-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
| | * | Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds2016-07-081-2/+2
| | |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: "Three fixes: - A boot crash fix with certain configs - a MAINTAINERS entry update - Documentation typo fixes" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/Documentation: Fix various typos in Documentation/x86/ files x86/amd_nb: Fix boot crash on non-AMD systems MAINTAINERS: Update the Calgary IOMMU entry
| | | * | x86/amd_nb: Fix boot crash on non-AMD systemsBorislav Petkov2016-07-011-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix boot crash that triggers if this driver is built into a kernel and run on non-AMD systems. AMD northbridges users call amd_cache_northbridges() and it returns a negative value to signal that we weren't able to cache/detect any northbridges on the system. At least, it should do so as all its callers expect it to do so. But it does return a negative value only when kmalloc() fails. Fix it to return -ENODEV if there are no NBs cached as otherwise, amd_nb users like amd64_edac, for example, which relies on it to know whether it should load or not, gets loaded on systems like Intel Xeons where it shouldn't. Reported-and-tested-by: Tony Battersby <tonyb@cybernetics.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: <stable@vger.kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1466097230-5333-2-git-send-email-bp@alien8.de Link: https://lkml.kernel.org/r/5761BEB0.9000807@cybernetics.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds2016-07-083-7/+37
| | |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "Various fixes: - 32-bit callgraph bug fix - suboptimal event group scheduling bug fix - event constraint fixes for Broadwell/Skylake - RAPL module name collision fix" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/core: Fix pmu::filter_match for SW-led groups x86/perf/intel/rapl: Fix module name collision with powercap intel-rapl perf/x86: Fix 32-bit perf user callgraph collection perf/x86/intel: Update event constraints when HT is off
| | | * | | x86/perf/intel/rapl: Fix module name collision with powercap intel-raplVille Syrjälä2016-07-061-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since commit 4b6e2571bf00 the rapl perf module calls itself intel-rapl. That name was already in use by the rapl powercap driver, which now fails to load if the perf module is loaded. Fix the problem by renaming the perf module to intel-rapl-perf, so that both modules can coexist. Fixes: 4b6e2571bf00 ("x86/perf/intel/rapl: Make the Intel RAPL PMU driver modular") Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Kan Liang <kan.liang@intel.com> Cc: Stephane Eranian <eranian@google.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Jiri Olsa <jolsa@redhat.com> Link: http://lkml.kernel.org/r/1466694409-3620-1-git-send-email-ville.syrjala@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | | * | | perf/x86: Fix 32-bit perf user callgraph collectionJosh Poimboeuf2016-07-031-5/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A basic perf callgraph record operation causes an immediate panic on a 32-bit kernel compiled with CONFIG_CC_STACKPROTECTOR=y: $ perf record -g ls Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: c0404fbd CPU: 0 PID: 998 Comm: ls Not tainted 4.7.0-rc5+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.1-1.fc24 04/01/2014 c0dd5967 ff7afe1c 00000086 f41dbc2c c07445a0 464c457f f41dbca8 f41dbc44 c05646f4 f41dbca8 464c457f f41dbca8 464c457f f41dbc54 c04625be c0ce56fc c0404fbd f41dbc88 c0404fbd b74668f0 f41dc000 00000000 c0000000 00000000 Call Trace: [<c07445a0>] dump_stack+0x58/0x78 [<c05646f4>] panic+0x8e/0x1c6 [<c04625be>] __stack_chk_fail+0x1e/0x30 [<c0404fbd>] ? perf_callchain_user+0x22d/0x230 [<c0404fbd>] perf_callchain_user+0x22d/0x230 [<c055f89f>] get_perf_callchain+0x1ff/0x270 [<c055f988>] perf_callchain+0x78/0x90 [<c055c7eb>] perf_prepare_sample+0x24b/0x370 [<c055c934>] perf_event_output_forward+0x24/0x70 [<c05531c0>] __perf_event_overflow+0xa0/0x210 [<c0550a93>] ? cpu_clock_event_read+0x43/0x50 [<c0553431>] perf_swevent_hrtimer+0x101/0x180 [<c0456235>] ? kmap_atomic_prot+0x35/0x140 [<c056dc69>] ? get_page_from_freelist+0x279/0x950 [<c058fdd8>] ? vma_interval_tree_remove+0x158/0x230 [<c05939f4>] ? wp_page_copy.isra.82+0x2f4/0x630 [<c05a050d>] ? page_add_file_rmap+0x1d/0x50 [<c0565611>] ? unlock_page+0x61/0x80 [<c0566755>] ? filemap_map_pages+0x305/0x320 [<c059769f>] ? handle_mm_fault+0xb7f/0x1560 [<c074cbeb>] ? timerqueue_del+0x1b/0x70 [<c04cfefe>] ? __remove_hrtimer+0x2e/0x60 [<c04d017b>] __hrtimer_run_queues+0xcb/0x2a0 [<c0553330>] ? __perf_event_overflow+0x210/0x210 [<c04d0a2a>] hrtimer_interrupt+0x8a/0x180 [<c043ecc2>] local_apic_timer_interrupt+0x32/0x60 [<c043f643>] smp_apic_timer_interrupt+0x33/0x50 [<c0b0cd38>] apic_timer_interrupt+0x34/0x3c Kernel Offset: disabled ---[ end Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: c0404fbd The panic is caused by the fact that perf_callchain_user() mistakenly assumes it's 64-bit only and ends up corrupting the stack. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: stable@vger.kernel.org # v4.5+ Fixes: 75925e1ad7f5 ("perf/x86: Optimize stack walk user accesses") Link: http://lkml.kernel.org/r/1a547f5077ec30f75f9b57074837c3c80df86e5e.1467432113.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | | * | | perf/x86/intel: Update event constraints when HT is offStephane Eranian2016-07-031-0/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch updates the event constraints for non-PEBS mode for Intel Broadwell and Skylake processors. When HT is off, each CPU gets 8 generic counters. However, not all events can be programmed on any of the 8 counters. This patch adds the constraints for the MEM_* events which can only be measured on the bottom 4 counters. The constraints are also valid when HT is off because, then, there are only 4 generic counters and they are the bottom counters. Signed-off-by: Stephane Eranian <eranian@google.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: kan.liang@intel.com Link: http://lkml.kernel.org/r/1467411742-13245-1-git-send-email-eranian@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | | Merge tag 'acpi-4.7-rc7' of ↵Linus Torvalds2016-07-081-0/+1
| | |\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull ACPI fixes from Rafael Wysocki: "All of these fix recent regressions in ACPICA, in the ACPI PCI IRQ management code and in the ACPI AML debugger. Specifics: - Fix a lock ordering issue in ACPICA introduced by a recent commit that attempted to fix a deadlock in the dynamic table loading code which in turn appeared after changes related to the handling of module-level AML also made in this cycle (Lv Zheng). - Fix a recent regression in the ACPI IRQ management code that may cause PCI drivers to be unable to register an IRQ if that IRQ happens to be shared with a device on the ISA bus, like the parallel port, by reverting one commit entirely and restoring the previous behavior in two other places (Sinan Kaya). - Fix a recent regression in the ACPI AML debugger introduced by the commit that removed incorrect usage of IS_ERR_VALUE() from multiple places (Lv Zheng)" * tag 'acpi-4.7-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: ACPI / debugger: Fix regression introduced by IS_ERR_VALUE() removal ACPICA: Namespace: Fix namespace/interpreter lock ordering ACPI,PCI,IRQ: separate ISA penalty calculation Revert "ACPI, PCI, IRQ: remove redundant code in acpi_irq_penalty_init()" ACPI,PCI,IRQ: factor in PCI possible
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| | | *-. | | | Merge branches 'acpica-fixes', 'acpi-pci-fixes' and 'acpi-debug-fixes'Rafael J. Wysocki2016-07-072011-24637/+70088
| | | |\ \| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * acpica-fixes: ACPICA: Namespace: Fix namespace/interpreter lock ordering * acpi-pci-fixes: ACPI,PCI,IRQ: separate ISA penalty calculation Revert "ACPI, PCI, IRQ: remove redundant code in acpi_irq_penalty_init()" ACPI,PCI,IRQ: factor in PCI possible * acpi-debug-fixes: ACPI / debugger: Fix regression introduced by IS_ERR_VALUE() removal
| | | | * | | | Revert "ACPI, PCI, IRQ: remove redundant code in acpi_irq_penalty_init()"Sinan Kaya2016-07-021-0/+1
| | | | | |_|/ | | | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Trying to make the ISA and PCI init functionality common turned out to be a bad idea, because the ISA path depends on external functionality. Restore the previous behavior and limit the refactoring to PCI interrupts only. Fixes: 1fcb6a813c4f "ACPI,PCI,IRQ: remove redundant code in acpi_irq_penalty_init()" Signed-off-by: Sinan Kaya <okaya@codeaurora.org> Tested-by: Wim Osterholt <wim@djo.tudelft.nl> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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| | *-. \ \ \ \ Merge branches 'pm-cpuidle-fixes' and 'pm-sleep-fixes'Rafael J. Wysocki2016-07-072-43/+109
| | |\ \ \ \ \ \ | | | | |_|/ / / | | | |/| | / / | | | |_|_|/ / | | |/| | | | | | | | | | | | | | | | | | | | | | | | | * pm-cpuidle-fixes: cpuidle: Fix last_residency division * pm-sleep-fixes: x86/power/64: Fix kernel text mapping corruption during image restoration
| | | | * | | x86/power/64: Fix kernel text mapping corruption during image restorationRafael J. Wysocki2016-06-302-43/+109
| | | |/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Logan Gunthorpe reports that hibernation stopped working reliably for him after commit ab76f7b4ab23 (x86/mm: Set NX on gap between __ex_table and rodata). That turns out to be a consequence of a long-standing issue with the 64-bit image restoration code on x86, which is that the temporary page tables set up by it to avoid page tables corruption when the last bits of the image kernel's memory contents are copied into their original page frames re-use the boot kernel's text mapping, but that mapping may very well get corrupted just like any other part of the page tables. Of course, if that happens, the final jump to the image kernel's entry point will go to nowhere. The exact reason why commit ab76f7b4ab23 matters here is that it sometimes causes a PMD of a large page to be split into PTEs that are allocated dynamically and get corrupted during image restoration as described above. To fix that issue note that the code copying the last bits of the image kernel's memory contents to the page frames occupied by them previoulsy doesn't use the kernel text mapping, because it runs from a special page covered by the identity mapping set up for that code from scratch. Hence, the kernel text mapping is only needed before that code starts to run and then it will only be used just for the final jump to the image kernel's entry point. Accordingly, the temporary page tables set up in swsusp_arch_resume() on x86-64 need to contain the kernel text mapping too. That mapping is only going to be used for the final jump to the image kernel, so it only needs to cover the image kernel's entry point, because the first thing the image kernel does after getting control back is to switch over to its own original page tables. Moreover, the virtual address of the image kernel's entry point in that mapping has to be the same as the one mapped by the image kernel's page tables. With that in mind, modify the x86-64's arch_hibernation_header_save() and arch_hibernation_header_restore() routines to pass the physical address of the image kernel's entry point (in addition to its virtual address) to the boot kernel (a small piece of assembly code involved in passing the entry point's virtual address to the image kernel is not necessary any more after that, so drop it). Update RESTORE_MAGIC too to reflect the image header format change. Next, in set_up_temporary_mappings(), use the physical and virtual addresses of the image kernel's entry point passed in the image header to set up a minimum kernel text mapping (using memory pages that won't be overwritten by the image kernel's memory contents) that will map those addresses to each other as appropriate. This makes the concern about the possible corruption of the original boot kernel text mapping go away and if the the minimum kernel text mapping used for the final jump marks the image kernel's entry point memory as executable, the jump to it is guaraneed to succeed. Fixes: ab76f7b4ab23 (x86/mm: Set NX on gap between __ex_table and rodata) Link: http://marc.info/?l=linux-pm&m=146372852823760&w=2 Reported-by: Logan Gunthorpe <logang@deltatee.com> Reported-and-tested-by: Borislav Petkov <bp@suse.de> Tested-by: Kees Cook <keescook@chromium.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| * | | | | x86/asm/entry: Make thunk's restore a local labelBorislav Petkov2016-07-081-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | No need to have it appear in objdump output. No functionality change. Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160708141016.GH3808@pd.tnic Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | x86/signals: Add build-time checks to the siginfo compat codeDave Hansen2016-06-141-0/+93
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There were at least 3 features added to the __SI_FAULT area of the siginfo struct that did not make it to the compat siginfo: 1. The si_addr_lsb used in SIGBUS's sent for machine checks 2. The upper/lower bounds for MPX SIGSEGV faults 3. The protection key for pkey faults There was also some turmoil when I was attempting to add the pkey field because it needs to be a fixed size on 32 and 64-bit and not have any alignment constraints. This patch adds some compile-time checks to the compat code to make it harder to screw this up. Basically, the checks are supposed to trip any time someone changes the siginfo structure. That sounds bad, but it's what we want. If someone changes siginfo, we want them to also be _forced_ to go look at the compat code. The details are in the comments. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave@sr71.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: linux-edac@vger.kernel.org Link: http://lkml.kernel.org/r/20160608172534.C73DAFC3@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | x86/signals: Add missing signal_compat code for x86 featuresDave Hansen2016-06-142-0/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The 32-bit siginfo is a different binary format than the 64-bit one. So, when running 32-bit binaries on 64-bit kernels, we have to convert the kernel's 64-bit version to a 32-bit version that userspace can grok. We've added a few features to siginfo over the past few years and neglected to add them to arch/x86/kernel/signal_compat.c: 1. The si_addr_lsb used in SIGBUS's sent for machine checks 2. The upper/lower bounds for MPX SIGSEGV faults 3. The protection key for pkey faults I caught this with some protection keys unit tests and realized it affected a few more features. This was tested only with my protection keys patch that looks for a proper value in si_pkey. I didn't actually test the machine check or MPX code. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave@sr71.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: linux-edac@vger.kernel.org Link: http://lkml.kernel.org/r/20160608172533.F8F05637@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | x86/vdso/32: Assemble sigreturn.S separatelyAndy Lutomirski2016-06-143-16/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | sigreturn.S was historically included by the various __kernel_vsyscall implementations due to assumptions about all the 32-bit vDSO images having the sigreturn symbols at the same address. Those assumptions were removed in v3.16, and as of v4.4, there is only a single 32-bit vDSO left. Simplify the build process by assembling sigreturn.S into a normal object file. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/d7b6dfde3c7397aa26977320da90448363b5a7e9.1465505753.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | x86/xen: Simplify set_aliased_prot()Andy Lutomirski2016-06-111-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A year ago, via the following commit: aa1acff356bb ("x86/xen: Probe target addresses in set_aliased_prot() before the hypercall") I added an explicit probe to work around a hypercall issue. The code can be simplified by using probe_kernel_read(). No change in functionality. Signed-off-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: David Vrabel <david.vrabel@citrix.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: David Vrabel <dvrabel@cantab.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jan Beulich <jbeulich@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: xen-devel <xen-devel@lists.xen.org> Link: http://lkml.kernel.org/r/0706f1a2538e481194514197298cca6b5e3f2638.1464129798.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | Merge branch 'linus' into x86/asm, to pick up fixesIngo Molnar2016-06-1145-453/+118
| |\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | x86, asm: Use CC_SET()/CC_OUT() and static_cpu_has() in archrandom.hH. Peter Anvin2016-06-082-70/+62
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use CC_SET()/CC_OUT() and static_cpu_has(). This produces code good enough to eliminate ad hoc use of alternatives in <asm/archrandom.h>, greatly simplifying the code. While we are at it, make x86_init_rdrand() compile out completely if we don't need it. Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Link: http://lkml.kernel.org/r/1465414726-197858-11-git-send-email-hpa@linux.intel.com v2: fix a conflict between <linux/random.h> and <asm/archrandom.h> discovered by Ingo Molnar. There are a few places in x86-specific code where we need all of <arch/archrandom.h> even when CONFIG_ARCH_RANDOM is disabled, so <linux/random.h> does not suffice.
| * | | | | | x86, asm, boot: Use CC_SET()/CC_OUT() in arch/x86/boot/boot.hH. Peter Anvin2016-06-081-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove open-coded uses of set instructions to use CC_SET()/CC_OUT() in arch/x86/boot/boot.h. Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Link: http://lkml.kernel.org/r/1465414726-197858-10-git-send-email-hpa@linux.intel.com Reviewed-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Borislav Petkov <bp@suse.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
| * | | | | | x86, asm: Use CC_SET()/CC_OUT() in <asm/rwsem.h>H. Peter Anvin2016-06-081-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove open-coded uses of set instructions to use CC_SET()/CC_OUT() in <asm/rwsem.h>. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Link: http://lkml.kernel.org/r/1465414726-197858-9-git-send-email-hpa@linux.intel.com Reviewed-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Borislav Petkov <bp@suse.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
| * | | | | | x86, asm: Use CC_SET()/CC_OUT() in <asm/percpu.h>H. Peter Anvin2016-06-081-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove open-coded uses of set instructions to use CC_SET()/CC_OUT() in <asm/percpu.h>. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Link: http://lkml.kernel.org/r/1465414726-197858-8-git-send-email-hpa@linux.intel.com Reviewed-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Borislav Petkov <bp@suse.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
| * | | | | | x86, asm: Use CC_SET()/CC_OUT() in <asm/bitops.h>H. Peter Anvin2016-06-081-8/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove open-coded uses of set instructions to use CC_SET()/CC_OUT() in <asm/bitops.h>. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Link: http://lkml.kernel.org/r/1465414726-197858-7-git-send-email-hpa@linux.intel.com Reviewed-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Borislav Petkov <bp@suse.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
| * | | | | | x86, asm: change GEN_*_RMWcc() to use CC_SET()/CC_OUT()H. Peter Anvin2016-06-081-5/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change the GEN_*_RMWcc() macros to use the CC_SET()/CC_OUT() macros defined in <asm/asm.h>, and disable the use of asm goto if __GCC_ASM_FLAG_OUTPUTS__ is enabled. This allows gcc to receive the flags output directly in gcc 6+. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Link: http://lkml.kernel.org/r/1465414726-197858-6-git-send-email-hpa@linux.intel.com Reviewed-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Borislav Petkov <bp@suse.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
| * | | | | | x86, asm: define CC_SET() and CC_OUT() macrosH. Peter Anvin2016-06-081-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The CC_SET() and CC_OUT() macros can be used together to take advantage of the new __GCC_ASM_FLAG_OUTPUTS__ feature in gcc 6+ while remaining backwards compatible. CC_SET() generates a SET instruction on older compilers; CC_OUT() makes sure the output is received in the correct variable. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Link: http://lkml.kernel.org/r/1465414726-197858-5-git-send-email-hpa@linux.intel.com Reviewed-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Borislav Petkov <bp@suse.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
| * | | | | | x86, asm: change the GEN_*_RMWcc() macros to not quote the conditionH. Peter Anvin2016-06-086-18/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change the lexical defintion of the GEN_*_RMWcc() macros to not take the condition code as a quoted string. This will help support changing them to use the new __GCC_ASM_FLAG_OUTPUTS__ feature in a subsequent patch. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Link: http://lkml.kernel.org/r/1465414726-197858-4-git-send-email-hpa@linux.intel.com Reviewed-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Borislav Petkov <bp@suse.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
| * | | | | | x86, asm: use bool for bitops and other assembly outputsH. Peter Anvin2016-06-0812-60/+63
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The gcc people have confirmed that using "bool" when combined with inline assembly always is treated as a byte-sized operand that can be assumed to be 0 or 1, which is exactly what the SET instruction emits. Change the output types and intermediate variables of as many operations as practical to "bool". Signed-off-by: H. Peter Anvin <hpa@zytor.com> Link: http://lkml.kernel.org/r/1465414726-197858-3-git-send-email-hpa@linux.intel.com Reviewed-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Borislav Petkov <bp@suse.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
| * | | | | | x86, bitops: remove use of "sbb" to return CFH. Peter Anvin2016-06-085-34/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use SETC instead of SBB to return the value of CF from assembly. Using SETcc enables uniformity with other flags-returning pieces of assembly code. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Link: http://lkml.kernel.org/r/1465414726-197858-2-git-send-email-hpa@linux.intel.com Reviewed-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Borislav Petkov <bp@suse.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
| * | | | | | x86/hweight: Get rid of the special calling conventionBorislav Petkov2016-06-086-20/+93
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | People complained about ARCH_HWEIGHT_CFLAGS and how it throws a wrench into kcov, lto, etc, experimentations. Add asm versions for __sw_hweight{32,64}() and do explicit saving and restoring of clobbered registers. This gets rid of the special calling convention. We get to call those functions on !X86_FEATURE_POPCNT CPUs. We still need to hardcode POPCNT and register operands as some old gas versions which we support, do not know about POPCNT. Btw, remove redundant REX prefix from 32-bit POPCNT because alternatives can do padding now. Suggested-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1464605787-20603-1-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | | | | x86/mm: Use pte_none() to test for empty PTEDave Hansen2016-07-133-8/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The page table manipulation code seems to have grown a couple of sites that are looking for empty PTEs. Just in case one of these entries got a stray bit set, use pte_none() instead of checking for a zero pte_val(). The use pte_same() makes me a bit nervous. If we were doing a pte_same() check against two cleared entries and one of them had a stray bit set, it might fail the pte_same() check. But, I don't think we ever _do_ pte_same() for cleared entries. It is almost entirely used for checking for races in fault-in paths. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave@sr71.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Cc: dave.hansen@intel.com Cc: linux-mm@kvack.org Cc: mhocko@suse.com Link: http://lkml.kernel.org/r/20160708001915.813703D9@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | | | | x86/mm: Disallow running with 32-bit PTEs to work around erratumDave Hansen2016-07-135-0/+38
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Intel(R) Xeon Phi(TM) Processor x200 Family (codename: Knights Landing) has an erratum where a processor thread setting the Accessed or Dirty bits may not do so atomically against its checks for the Present bit. This may cause a thread (which is about to page fault) to set A and/or D, even though the Present bit had already been atomically cleared. These bits are truly "stray". In the case of the Dirty bit, the thread associated with the stray set was *not* allowed to write to the page. This means that we do not have to launder the bit(s); we can simply ignore them. If the PTE is used for storing a swap index or a NUMA migration index, the A bit could be misinterpreted as part of the swap type. The stray bits being set cause a software-cleared PTE to be interpreted as a swap entry. In some cases (like when the swap index ends up being for a non-existent swapfile), the kernel detects the stray value and WARN()s about it, but there is no guarantee that the kernel can always detect it. When we have 64-bit PTEs (64-bit mode or 32-bit PAE), we were able to move the swap PTE format around to avoid these troublesome bits. But, 32-bit non-PAE is tight on bits. So, disallow it from running on this hardware. I can't imagine anyone wanting to run 32-bit non-highmem kernels on this hardware, but disallowing them from running entirely is surely the safe thing to do. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave@sr71.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Cc: dave.hansen@intel.com Cc: linux-mm@kvack.org Cc: mhocko@suse.com Link: http://lkml.kernel.org/r/20160708001914.D0B50110@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | | | | x86/mm: Ignore A/D bits in pte/pmd/pud_none()Dave Hansen2016-07-132-3/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The erratum we are fixing here can lead to stray setting of the A and D bits. That means that a pte that we cleared might suddenly have A/D set. So, stop considering those bits when determining if a pte is pte_none(). The same goes for the other pmd_none() and pud_none(). pgd_none() can be skipped because it is not affected; we do not use PGD entries for anything other than pagetables on affected configurations. This adds a tiny amount of overhead to all pte_none() checks. I doubt we'll be able to measure it anywhere. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave@sr71.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Cc: dave.hansen@intel.com Cc: linux-mm@kvack.org Cc: mhocko@suse.com Link: http://lkml.kernel.org/r/20160708001912.5216F89C@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | | | | x86/mm: Move swap offset/type up in PTE to work around erratumDave Hansen2016-07-131-6/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This erratum can result in Accessed/Dirty getting set by the hardware when we do not expect them to be (on !Present PTEs). Instead of trying to fix them up after this happens, we just allow the bits to get set and try to ignore them. We do this by shifting the layout of the bits we use for swap offset/type in our 64-bit PTEs. It looks like this: bitnrs: | ... | 11| 10| 9|8|7|6|5| 4| 3|2|1|0| names: | ... |SW3|SW2|SW1|G|L|D|A|CD|WT|U|W|P| before: | OFFSET (9-63) |0|X|X| TYPE(1-5) |0| after: | OFFSET (14-63) | TYPE (9-13) |0|X|X|X| X| X|X|X|0| Note that D was already a don't care (X) even before. We just move TYPE up and turn its old spot (which could be hit by the A bit) into all don't cares. We take 5 bits away from the offset, but that still leaves us with 50 bits which lets us index into a 62-bit swapfile (4 EiB). I think that's probably fine for the moment. We could theoretically reclaim 5 of the bits (1, 2, 3, 4, 7) but it doesn't gain us anything. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave@sr71.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Cc: dave.hansen@intel.com Cc: linux-mm@kvack.org Cc: mhocko@suse.com Link: http://lkml.kernel.org/r/20160708001911.9A3FD2B6@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | | | | x86/vdso: Add mremap hook to vm_special_mappingDmitry Safonov2016-07-081-5/+42
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add possibility for 32-bit user-space applications to move the vDSO mapping. Previously, when a user-space app called mremap() for the vDSO address, in the syscall return path it would land on the previous address of the vDSOpage, resulting in segmentation violation. Now it lands fine and returns to userspace with a remapped vDSO. This will also fix the context.vdso pointer for 64-bit, which does not affect the user of vDSO after mremap() currently, but this may change in the future. As suggested by Andy, return -EINVAL for mremap() that would split the vDSO image: that operation cannot possibly result in a working system so reject it. Renamed and moved the text_mapping structure declaration inside map_vdso(), as it used only there and now it complements the vvar_mapping variable. There is still a problem for remapping the vDSO in glibc applications: the linker relocates addresses for syscalls on the vDSO page, so you need to relink with the new addresses. Without that the next syscall through glibc may fail: Program received signal SIGSEGV, Segmentation fault. #0 0xf7fd9b80 in __kernel_vsyscall () #1 0xf7ec8238 in _exit () from /usr/lib32/libc.so.6 Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: 0x7f454c46@gmail.com Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20160628113539.13606-2-dsafonov@virtuozzo.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | | | | x86/mm/pat, /dev/mem: Remove superfluous error messageJiri Kosina2016-07-081-4/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently it's possible for broken (or malicious) userspace to flood a kernel log indefinitely with messages a-la Program dmidecode tried to access /dev/mem between f0000->100000 because range_is_allowed() is case of CONFIG_STRICT_DEVMEM being turned on dumps this information each and every time devmem_is_allowed() fails. Reportedly userspace that is able to trigger contignuous flow of these messages exists. It would be possible to rate limit this message, but that'd have a questionable value; the administrator wouldn't get information about all the failing accessess, so then the information would be both superfluous and incomplete at the same time :) Returning EPERM (which is what is actually happening) is enough indication for userspace what has happened; no need to log this particular error as some sort of special condition. Signed-off-by: Jiri Kosina <jkosina@suse.cz> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Link: http://lkml.kernel.org/r/alpine.LNX.2.00.1607081137020.24757@cbobk.fhfr.pm Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | | | | Merge tag 'v4.7-rc6' into x86/mm, to merge fixes before applying new changesIngo Molnar2016-07-082129-25577/+71547
|\ \ \ \ \ \ \ | | |_|/ / / / | |/| | | | | | | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linusLinus Torvalds2016-07-031-4/+6
| |\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull MIPS fix from Ralf Baechle: "Only a single fix for 4.7 pending at this point. It fixes an issue that may lead to corruption of the cache mode bits in the page table" * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: MIPS: Fix possible corruption of cache mode by mprotect.
| | * | | | | | MIPS: Fix possible corruption of cache mode by mprotect.Ralf Baechle2016-07-021-4/+6
| | | |_|/ / / | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following testcase may result in a page table entries with a invalid CCA field being generated: static void *bindstack; static int sysrqfd; static void protect_low(int protect) { mprotect(bindstack, BINDSTACK_SIZE, protect); } static void sigbus_handler(int signal, siginfo_t * info, void *context) { void *addr = info->si_addr; write(sysrqfd, "x", 1); printf("sigbus, fault address %p (should not happen, but might)\n", addr); abort(); } static void run_bind_test(void) { unsigned int *p = bindstack; p[0] = 0xf001f001; write(sysrqfd, "x", 1); /* Set trap on access to p[0] */ protect_low(PROT_NONE); write(sysrqfd, "x", 1); /* Clear trap on access to p[0] */ protect_low(PROT_READ | PROT_WRITE | PROT_EXEC); write(sysrqfd, "x", 1); /* Check the contents of p[0] */ if (p[0] != 0xf001f001) { write(sysrqfd, "x", 1); /* Reached, but shouldn't be */ printf("badness, shouldn't happen but does\n"); abort(); } } int main(void) { struct sigaction sa; sysrqfd = open("/proc/sysrq-trigger", O_WRONLY); if (sigprocmask(SIG_BLOCK, NULL, &sa.sa_mask)) { perror("sigprocmask"); return 0; } sa.sa_sigaction = sigbus_handler; sa.sa_flags = SA_SIGINFO | SA_NODEFER | SA_RESTART; if (sigaction(SIGBUS, &sa, NULL)) { perror("sigaction"); return 0; } bindstack = mmap(NULL, BINDSTACK_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); if (bindstack == MAP_FAILED) { perror("mmap bindstack"); return 0; } printf("bindstack: %p\n", bindstack); run_bind_test(); printf("done\n"); return 0; } There are multiple ingredients for this: 1) PAGE_NONE is defined to _CACHE_CACHABLE_NONCOHERENT, which is CCA 3 on all platforms except SB1 where it's CCA 5. 2) _page_cachable_default must have bits set which are not set _CACHE_CACHABLE_NONCOHERENT. 3) Either the defective version of pte_modify for XPA or the standard version must be in used. However pte_modify for the 36 bit address space support is no affected. In that case additional bits in the final CCA mode may generate an invalid value for the CCA field. On the R10000 system where this was tracked down for example a CCA 7 has been observed, which is Uncached Accelerated. Fixed by: 1) Using the proper CCA mode for PAGE_NONE just like for all the other PAGE_* pte/pmd bits. 2) Fix the two affected variants of pte_modify. Further code inspection also shows the same issue to exist in pmd_modify which would affect huge page systems. Issue in pte_modify tracked down by Alastair Bridgewater, PAGE_NONE and pmd_modify issue found by me. The history of this goes back beyond Linus' git history. Chris Dearman's commit 351336929ccf222ae38ff0cb7a8dd5fd5c6236a0 ("[MIPS] Allow setting of the cache attribute at run time.") missed the opportunity to fix this but it was originally introduced in lmo commit d523832cf12007b3242e50bb77d0c9e63e0b6518 ("Missing from last commit.") and 32cc38229ac7538f2346918a09e75413e8861f87 ("New configuration option CONFIG_MIPS_UNCACHED.") Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Reported-by: Alastair Bridgewater <alastair.bridgewater@gmail.com>
| * | | | | | Merge tag 'powerpc-4.7-5' of ↵Linus Torvalds2016-07-037-19/+65
| |\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc fixes from Michael Ellerman: - tm: Always reclaim in start_thread() for exec() class syscalls from Cyril Bur - tm: Avoid SLB faults in treclaim/trecheckpoint when RI=0 from Michael Neuling - eeh: Fix wrong argument passed to eeh_rmv_device() from Gavin Shan - Initialise pci_io_base as early as possible from Darren Stevens * tag 'powerpc-4.7-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc: Initialise pci_io_base as early as possible powerpc/tm: Avoid SLB faults in treclaim/trecheckpoint when RI=0 powerpc/eeh: Fix wrong argument passed to eeh_rmv_device() powerpc/tm: Always reclaim in start_thread() for exec() class syscalls