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  1. 16 Feb, 2018 3 commits
  3. 15 Feb, 2018 16 commits
  5. 14 Feb, 2018 2 commits
    • Linus Torvalds's avatar
      Merge tag 'gfs2-4.16.rc1.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2 · 6556677a
      Linus Torvalds authored 
      Pull gfs2 fix from Bob Peterson:
 "Fix regressions in the gfs2 iomap for block_map implementation we
  recently discovered in commit 3974320c"

* tag 'gfs2-4.16.rc1.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
  gfs2: Fixes to "Implement iomap for block_map"
      6556677a
    • Linus Torvalds's avatar
      Merge tag 'powerpc-4.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux · 694a20da
      Linus Torvalds authored 
      Pull powerpc fixes from Michael Ellerman:
 "A larger batch of fixes than we'd like. Roughly 1/3 fixes for new
  code, 1/3 fixes for stable and 1/3 minor things.

  There's four commits fixing bugs when using 16GB huge pages on hash,
  caused by some of the preparatory changes for pkeys.

  Two fixes for bugs in the enhanced IRQ soft masking for local_t, one
  of which broke KVM in some circumstances.

  Four fixes for Power9. The most bizarre being a bug where futexes
  stopped working because a NULL pointer dereference didn't trap during
  early boot (it aliased the kernel mapping). A fix for memory hotplug
  when using the Radix MMU, and a fix for live migration of guests using
  the Radix MMU.

  Two fixes for hotplug on pseries machines. One where we weren't
  correctly updating NUMA info when CPUs are added and removed. And the
  other fixes crashes/hangs seen when doing memory hot remove during
  boot, which is apparently a thing people do.

  Finally a handful of build fixes for obscure configs and other minor
  fixes.

  Thanks to: Alexey Kardashevskiy, Aneesh Kumar K.V, Balbir Singh, Colin
  Ian King, Daniel Henrique Barboza, Florian Weimer, Guenter Roeck,
  Harish, Laurent Vivier, Madhavan Srinivasan, Mauricio Faria de
  Oliveira, Nathan Fontenot, Nicholas Piggin, Sam Bobroff"

* tag 'powerpc-4.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  selftests/powerpc: Fix to use ucontext_t instead of struct ucontext
  powerpc/kdump: Fix powernv build break when KEXEC_CORE=n
  powerpc/pseries: Fix build break for SPLPAR=n and CPU hotplug
  powerpc/mm/hash64: Zero PGD pages on allocation
  powerpc/mm/hash64: Store the slot information at the right offset for hugetlb
  powerpc/mm/hash64: Allocate larger PMD table if hugetlb config is enabled
  powerpc/mm: Fix crashes with 16G huge pages
  powerpc/mm: Flush radix process translations when setting MMU type
  powerpc/vas: Don't set uses_vas for kernel windows
  powerpc/pseries: Enable RAS hotplug events later
  powerpc/mm/radix: Split linear mapping on hot-unplug
  powerpc/64s/radix: Boot-time NULL pointer protection using a guard-PID
  ocxl: fix signed comparison with less than zero
  powerpc/64s: Fix may_hard_irq_enable() for PMI soft masking
  powerpc/64s: Fix MASKABLE_RELON_EXCEPTION_HV_OOL macro
  powerpc/numa: Invalidate numa_cpu_lookup_table on cpu remove
      694a20da
  7. 13 Feb, 2018 19 commits
    • Andreas Gruenbacher's avatar
      gfs2: Fixes to "Implement iomap for block_map" · 49edd5bf
      Andreas Gruenbacher authored 
      It turns out that commit 3974320c "Implement iomap for block_map"
introduced a few bugs that trigger occasional failures with xfstest
generic/476:

In gfs2_iomap_begin, we jump to do_alloc when we determine that we are
beyond the end of the allocated metadata (height > ip->i_height).
There, we can end up calling hole_size with a metapath that doesn't
match the current metadata tree, which doesn't make sense.  After
untangling the code at do_alloc, fix this by checking if the block we
are looking for is within the range of allocated metadata.

In addition, add a BUG() in case gfs2_iomap_begin is accidentally called
for reading stuffed files: this is handled separately.  Make sure we
don't truncate iomap->length for reads beyond the end of the file; in
that case, the entire range counts as a hole.

Finally, revert to taking a bitmap write lock when doing allocations.
It's unclear why that change didn't lead to any failures during testing.
Signed-off-by: default avatarAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: default avatarBob Peterson <rpeterso@redhat.com>
      49edd5bf
    • Linus Torvalds's avatar
      Merge tag 'mips_4.16_2' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/mips · 61f14c01
      Linus Torvalds authored 
      Pull MIPS fix from James Hogan:
 "A single change (and associated DT binding update) to allow the
  address of the MIPS Cluster Power Controller (CPC) to be chosen by DT,
  which allows SMP to work on generic MIPS kernels where the bootloader
  hasn't configured the CPC address (i.e. the new Ranchu platform)"

* tag 'mips_4.16_2' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/mips:
  MIPS: CPC: Map registers using DT in mips_cpc_default_phys_base()
  dt-bindings: Document mti,mips-cpc binding
      61f14c01
    • Tony Luck's avatar
      x86/mm, mm/hwpoison: Don't unconditionally unmap kernel 1:1 pages · fd0e786d
      Tony Luck authored 
      In the following commit:

  ce0fa3e5 ("x86/mm, mm/hwpoison: Clear PRESENT bit for kernel 1:1 mappings of poison pages")

... we added code to memory_failure() to unmap the page from the
kernel 1:1 virtual address space to avoid speculative access to the
page logging additional errors.

But memory_failure() may not always succeed in taking the page offline,
especially if the page belongs to the kernel.  This can happen if
there are too many corrected errors on a page and either mcelog(8)
or drivers/ras/cec.c asks to take a page offline.

Since we remove the 1:1 mapping early in memory_failure(), we can
end up with the page unmapped, but still in use. On the next access
the kernel crashes :-(

There are also various debug paths that call memory_failure() to simulate
occurrence of an error. Since there is no actual error in memory, we
don't need to map out the page for those cases.

Revert most of the previous attempt and keep the solution local to
arch/x86/kernel/cpu/mcheck/mce.c. Unmap the page only when:

	1) there is a real error
	2) memory_failure() succeeds.

All of this only applies to 64-bit systems. 32-bit kernel doesn't map
all of memory into kernel space. It isn't worth adding the code to unmap
the piece that is mapped because nobody would run a 32-bit kernel on a
machine that has recoverable machine checks.
Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave <dave.hansen@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robert (Persistent Memory) <elliott@hpe.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Cc: stable@vger.kernel.org #v4.14
Fixes: ce0fa3e5 ("x86/mm, mm/hwpoison: Clear PRESENT bit for kernel 1:1 mappings of poison pages")
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      fd0e786d
    • Arnd Bergmann's avatar
      x86/error_inject: Make just_return_func() globally visible · 01684e72
      Arnd Bergmann authored 
      With link time optimizations enabled, I get a link failure:

  ./ccLbOEHX.ltrans19.ltrans.o: In function `override_function_with_return':
  <artificial>:(.text+0x7f3): undefined reference to `just_return_func'

Marking the symbol .globl makes it work as expected.
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Acked-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
Acked-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nicolas Pitre <nico@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Fixes: 540adea3 ("error-injection: Separate error-injection from kprobe")
Link: http://lkml.kernel.org/r/20180202145634.200291-3-arnd@arndb.deSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      01684e72
    • mike.travis@hpe.com's avatar
      x86/platform/UV: Fix GAM Range Table entries less than 1GB · c25d99d2
      mike.travis@hpe.com authored 
      The latest UV platforms include the new ApachePass NVDIMMs into the
UV address space.  This has introduced address ranges in the Global
Address Map Table that are less than the previous lowest range, which
was 2GB.  Fix the address calculation so it accommodates address ranges
from bytes to exabytes.
Signed-off-by: default avatarMike Travis <mike.travis@hpe.com>
Reviewed-by: default avatarAndrew Banman <andrew.banman@hpe.com>
Reviewed-by: default avatarDimitri Sivanich <dimitri.sivanich@hpe.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russ Anderson <russ.anderson@hpe.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180205221503.190219903@stormcage.americas.sgi.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      c25d99d2
    • Progyan Bhattacharya's avatar
      x86/build: Add arch/x86/tools/insn_decoder_test to .gitignore · 74eb816b
      Progyan Bhattacharya authored 
      The file was generated by make command and should not be in the source tree.
Signed-off-by: default avatarProgyan Bhattacharya <progyanb@acm.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      74eb816b
    • Masayoshi Mizuma's avatar
      x86/smpboot: Fix uncore_pci_remove() indexing bug when hot-removing a physical CPU · 295cc7eb
      Masayoshi Mizuma authored 
      When a physical CPU is hot-removed, the following warning messages
are shown while the uncore device is removed in uncore_pci_remove():

  WARNING: CPU: 120 PID: 5 at arch/x86/events/intel/uncore.c:988
  uncore_pci_remove+0xf1/0x110
  ...
  CPU: 120 PID: 5 Comm: kworker/u1024:0 Not tainted 4.15.0-rc8 #1
  Workqueue: kacpi_hotplug acpi_hotplug_work_fn
  ...
  Call Trace:
  pci_device_remove+0x36/0xb0
  device_release_driver_internal+0x145/0x210
  pci_stop_bus_device+0x76/0xa0
  pci_stop_root_bus+0x44/0x60
  acpi_pci_root_remove+0x1f/0x80
  acpi_bus_trim+0x54/0x90
  acpi_bus_trim+0x2e/0x90
  acpi_device_hotplug+0x2bc/0x4b0
  acpi_hotplug_work_fn+0x1a/0x30
  process_one_work+0x141/0x340
  worker_thread+0x47/0x3e0
  kthread+0xf5/0x130

When uncore_pci_remove() runs, it tries to get the package ID to
clear the value of uncore_extra_pci_dev[].dev[] by using
topology_phys_to_logical_pkg(). The warning messesages are
shown because topology_phys_to_logical_pkg() returns -1.

  arch/x86/events/intel/uncore.c:
  static void uncore_pci_remove(struct pci_dev *pdev)
  {
  ...
          phys_id = uncore_pcibus_to_physid(pdev->bus);
  ...
                  pkg = topology_phys_to_logical_pkg(phys_id); // returns -1
                  for (i = 0; i < UNCORE_EXTRA_PCI_DEV_MAX; i++) {
                          if (uncore_extra_pci_dev[pkg].dev[i] == pdev) {
                                  uncore_extra_pci_dev[pkg].dev[i] = NULL;
                                  break;
                          }
                  }
                  WARN_ON_ONCE(i >= UNCORE_EXTRA_PCI_DEV_MAX); // <=========== HERE!!

topology_phys_to_logical_pkg() tries to find
cpuinfo_x86->phys_proc_id that matches the phys_pkg argument.

  arch/x86/kernel/smpboot.c:
  int topology_phys_to_logical_pkg(unsigned int phys_pkg)
  {
          int cpu;

          for_each_possible_cpu(cpu) {
                  struct cpuinfo_x86 *c = &cpu_data(cpu);

                  if (c->initialized && c->phys_proc_id == phys_pkg)
                          return c->logical_proc_id;
          }
          return -1;
  }

However, the phys_proc_id was already set to 0 by remove_siblinginfo()
when the CPU was offlined.

So, topology_phys_to_logical_pkg() cannot find the correct
logical_proc_id and always returns -1.

As the result, uncore_pci_remove() calls WARN_ON_ONCE() and the warning
messages are shown.

What is worse is that the bogus 'pkg' index results in two bugs:

 - We dereference uncore_extra_pci_dev[] with a negative index
 - We fail to clean up a stale pointer in uncore_extra_pci_dev[][]

To fix these bugs, remove the clearing of ->phys_proc_id from remove_siblinginfo().

This should not cause any problems, because ->phys_proc_id is not
used after it is hot-removed and it is re-set while hot-adding.
Signed-off-by: default avatarMasayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Acked-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: yasu.isimatu@gmail.com
Cc: <stable@vger.kernel.org>
Fixes: 30bb9811 ("x86/topology: Avoid wasting 128k for package id array")
Link: http://lkml.kernel.org/r/ed738d54-0f01-b38b-b794-c31dc118c207@gmail.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      295cc7eb
    • Harish's avatar
      selftests/powerpc: Fix to use ucontext_t instead of struct ucontext · ecdf06e1
      Harish authored 
      With glibc 2.26 'struct ucontext' is removed to improve POSIX
compliance, which breaks powerpc/alignment_handler selftest. Fix the
test by using ucontext_t. Tested on ppc, works with older glibc
versions as well.

Fixes the following:
  alignment_handler.c: In function ‘sighandler’:
  alignment_handler.c:68:5: error: dereferencing pointer to incomplete type ‘struct ucontext’
    ucp->uc_mcontext.gp_regs[PT_NIP] += 4;
Signed-off-by: default avatarHarish <harish@linux.vnet.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      ecdf06e1
    • Guenter Roeck's avatar
      powerpc/kdump: Fix powernv build break when KEXEC_CORE=n · 91096175
      Guenter Roeck authored 
      If KEXEC_CORE is not enabled, powernv builds fail as follows.

  arch/powerpc/platforms/powernv/smp.c: In function 'pnv_smp_cpu_kill_self':
  arch/powerpc/platforms/powernv/smp.c:236:4: error:
  	implicit declaration of function 'crash_ipi_callback'

Add dummy function calls, similar to kdump_in_progress(), to solve the
problem.

Fixes: 4145f358 ("powernv/kdump: Fix cases where the kdump kernel can get HMI's")
Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
Acked-by: default avatarBalbir Singh <bsingharora@gmail.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      91096175
    • Guenter Roeck's avatar
      powerpc/pseries: Fix build break for SPLPAR=n and CPU hotplug · 82343484
      Guenter Roeck authored 
      Commit e67e02a5 ("powerpc/pseries: Fix cpu hotplug crash with
memoryless nodes") adds an unconditional call to
find_and_online_cpu_nid(), which is only declared if CONFIG_PPC_SPLPAR
is enabled. This results in the following build error if this is not
the case.

  arch/powerpc/platforms/pseries/hotplug-cpu.o: In function `dlpar_online_cpu':
  arch/powerpc/platforms/pseries/hotplug-cpu.c:369:
  			undefined reference to `.find_and_online_cpu_nid'

Follow the guideline provided by similar functions and provide a dummy
function if CONFIG_PPC_SPLPAR is not enabled. This also moves the
external function declaration into an include file where it should be.

Fixes: e67e02a5 ("powerpc/pseries: Fix cpu hotplug crash with memoryless nodes")
Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
[mpe: Change subject to emphasise the build fix]
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      82343484
    • Aneesh Kumar K.V's avatar
      powerpc/mm/hash64: Zero PGD pages on allocation · fc5c2f4a
      Aneesh Kumar K.V authored 
      On powerpc we allocate page table pages from slab caches of different
sizes. Currently we have a constructor that zeroes out the objects when
we allocate them for the first time.

We expect the objects to be zeroed out when we free the the object
back to slab cache. This happens in the unmap path. For hugetlb pages
we call huge_pte_get_and_clear() to do that.

With the current configuration of page table size, both PUD and PGD
level tables are allocated from the same slab cache. At the PUD level,
we use the second half of the table to store the slot information. But
we never clear that when unmapping.

When such a freed object is then allocated for a PGD page, the second
half of the page table page will not be zeroed as expected. This
results in a kernel crash.

Fix it by always clearing PGD pages when they're allocated.
Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
[mpe: Change log wording and formatting, add whitespace]
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      fc5c2f4a
    • Aneesh Kumar K.V's avatar
      powerpc/mm/hash64: Store the slot information at the right offset for hugetlb · ff31e105
      Aneesh Kumar K.V authored 
      The hugetlb pte entries are at the PMD and PUD level, so we can't use
PTRS_PER_PTE to find the second half of the page table. Use the right
offset for PUD/PMD to get to the second half of the table.

Fixes: bf9a95f9 ("powerpc: Free up four 64K PTE bits in 64K backed HPTE pages")
Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: default avatarRam Pai <linuxram@us.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      ff31e105
    • Aneesh Kumar K.V's avatar
      powerpc/mm/hash64: Allocate larger PMD table if hugetlb config is enabled · 4a7aa4fe
      Aneesh Kumar K.V authored 
      We use the second half of the page table to store slot information, so we must
allocate it always if hugetlb is possible.

Fixes: bf9a95f9 ("powerpc: Free up four 64K PTE bits in 64K backed HPTE pages")
Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: default avatarRam Pai <linuxram@us.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      4a7aa4fe
    • Aneesh Kumar K.V's avatar
      powerpc/mm: Fix crashes with 16G huge pages · fae22116
      Aneesh Kumar K.V authored 
      To support memory keys, we moved the hash pte slot information to the
second half of the page table. This was ok with PTE entries at level
4 (PTE page) and level 3 (PMD). We already allocate larger page table
pages at those levels to accomodate extra details. For level 4 we
already have the extra space which was used to track 4k hash page
table entry details and at level 3 the extra space was allocated to
track the THP details.

With hugetlbfs PTE, we used this extra space at the PMD level to store
the slot details. But we also support hugetlbfs PTE at PUD level for
16GB pages and PUD level page didn't allocate extra space. This
resulted in memory corruption.

Fix this by allocating extra space at PUD level when HUGETLB is
enabled.

Fixes: bf9a95f9 ("powerpc: Free up four 64K PTE bits in 64K backed HPTE pages")
Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: default avatarRam Pai <linuxram@us.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      fae22116
    • Alexey Kardashevskiy's avatar
      powerpc/mm: Flush radix process translations when setting MMU type · 62e984dd
      Alexey Kardashevskiy authored 
      Radix guests do normally invalidate process-scoped translations when a
new pid is allocated but migrated guests do not invalidate these so
migrated guests crash sometime, especially easy to reproduce with
migration happening within first 10 seconds after the guest boot start
on the same machine.

This adds the "Invalidate process-scoped translations" flush to fix
radix guests migration.

Fixes: 2ee13be3 ("KVM: PPC: Book3S HV: Update kvmppc_set_arch_compat() for ISA v3.00")
Cc: stable@vger.kernel.org # v4.10+
Signed-off-by: default avatarAlexey Kardashevskiy <aik@ozlabs.ru>
Tested-by: default avatarLaurent Vivier <lvivier@redhat.com>
Tested-by: default avatarDaniel Henrique Barboza <danielhb@linux.vnet.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      62e984dd
    • Nicholas Piggin's avatar
      powerpc/vas: Don't set uses_vas for kernel windows · b00b6289
      Nicholas Piggin authored 
      cp_abort is only required for user windows, because kernel context
must not be preempted between a copy/paste pair.

Without this patch, the init task gets used_vas set when it runs the
nx842_powernv_init initcall, which opens windows for kernel usage.

used_vas is then never cleared anywhere, so it gets propagated into
all other tasks. It's a property of the address space, so it should
really be cleared when a new mm is created (or in dup_mmap if the
mmaps are marked as VM_DONTCOPY). For now we seem to have no such
driver, so leave that for another patch.

Fixes: 6c8e6bb2 ("powerpc/vas: Add support for user receive window")
Cc: stable@vger.kernel.org # v4.15+
Signed-off-by: default avatarNicholas Piggin <npiggin@gmail.com>
Reviewed-by: default avatarSukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      b00b6289
    • Sam Bobroff's avatar
      powerpc/pseries: Enable RAS hotplug events later · c9dccf1d
      Sam Bobroff authored 
      Currently if the kernel receives a memory hot-unplug event early
enough, it may get stuck in an infinite loop in
dissolve_free_huge_pages(). This appears as a stall just after:

  pseries-hotplug-mem: Attempting to hot-remove XX LMB(s) at YYYYYYYY

It appears to be caused by "minimum_order" being uninitialized, due to
init_ras_IRQ() executing before hugetlb_init().

To correct this, extract the part of init_ras_IRQ() that enables
hotplug event processing and place it in the machine_late_initcall
phase, which is guaranteed to be after hugetlb_init() is called.
Signed-off-by: default avatarSam Bobroff <sam.bobroff@au1.ibm.com>
Acked-by: default avatarBalbir Singh <bsingharora@gmail.com>
[mpe: Reorder the functions to make the diff readable]
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      c9dccf1d
    • Jia Zhang's avatar
      x86/mm/kcore: Add vsyscall page to /proc/kcore conditionally · cd026ca2
      Jia Zhang authored 
      The vsyscall page should be visible only if vsyscall=emulate/native when dumping /proc/kcore.
Signed-off-by: default avatarJia Zhang <zhang.jia@linux.alibaba.com>
Reviewed-by: default avatarJiri Olsa <jolsa@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: jolsa@redhat.com
Link: http://lkml.kernel.org/r/1518446694-21124-3-git-send-email-zhang.jia@linux.alibaba.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      cd026ca2
    • Jia Zhang's avatar
      vfs/proc/kcore, x86/mm/kcore: Fix SMAP fault when dumping vsyscall user page · 595dd46e
      Jia Zhang authored 
      Commit:

  df04abfd ("fs/proc/kcore.c: Add bounce buffer for ktext data")

... introduced a bounce buffer to work around CONFIG_HARDENED_USERCOPY=y.
However, accessing the vsyscall user page will cause an SMAP fault.

Replace memcpy() with copy_from_user() to fix this bug works, but adding
a common way to handle this sort of user page may be useful for future.

Currently, only vsyscall page requires KCORE_USER.
Signed-off-by: default avatarJia Zhang <zhang.jia@linux.alibaba.com>
Reviewed-by: default avatarJiri Olsa <jolsa@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: jolsa@redhat.com
Link: http://lkml.kernel.org/r/1518446694-21124-2-git-send-email-zhang.jia@linux.alibaba.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
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