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  1. 14 7月, 2016 2 次提交
    • P
      x86/mm: Audit and remove any unnecessary uses of module.h · 4b599fed
      由 Paul Gortmaker 提交于 
      Historically a lot of these existed because we did not have
a distinction between what was modular code and what was providing
support to modules via EXPORT_SYMBOL and friends.  That changed
when we forked out support for the latter into the export.h file.

This means we should be able to reduce the usage of module.h
in code that is obj-y Makefile or bool Kconfig.  The advantage
in doing so is that module.h itself sources about 15 other headers;
adding significantly to what we feed cpp, and it can obscure what
headers we are effectively using.

Since module.h was the source for init.h (for __init) and for
export.h (for EXPORT_SYMBOL) we consider each obj-y/bool instance
for the presence of either and replace accordingly where needed.

Note that some bool/obj-y instances remain since module.h is
the header for some exception table entry stuff, and for things
like __init_or_module (code that is tossed when MODULES=n).
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.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/20160714001901.31603-3-paul.gortmaker@windriver.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      4b599fed
    • P
      x86: Don't use module.h just for AUTHOR / LICENSE tags · 84e629b6
      由 Paul Gortmaker 提交于 
      The Kconfig controlling compilation of these files are:

 arch/x86/Kconfig.debug:config DEBUG_RODATA_TEST
 arch/x86/Kconfig.debug: bool "Testcase for the marking rodata read-only"

 arch/x86/Kconfig.debug:config X86_PTDUMP_CORE
 arch/x86/Kconfig.debug: def_bool n

...meaning that it currently is not being built as a module by anyone.

Lets remove the couple traces of modular infrastructure use, so that
when reading the driver there is no doubt it is builtin-only.

We delete the MODULE_LICENSE tag etc. since all that information
is already contained at the top of the file in the comments.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: NArjan van de Ven <arjan@linux.intel.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/20160714001901.31603-2-paul.gortmaker@windriver.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      84e629b6
  3. 13 7月, 2016 2 次提交
  5. 10 7月, 2016 2 次提交
  7. 09 7月, 2016 1 次提交
  9. 08 7月, 2016 3 次提交
  11. 06 7月, 2016 1 次提交
  13. 03 7月, 2016 2 次提交
    • J
      perf/x86: Fix 32-bit perf user callgraph collection · fc188225
      由 Josh Poimboeuf 提交于 
      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: NJosh 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: 75925e1a ("perf/x86: Optimize stack walk user accesses")
Link: http://lkml.kernel.org/r/1a547f5077ec30f75f9b57074837c3c80df86e5e.1467432113.git.jpoimboe@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      fc188225
    • S
      perf/x86/intel: Update event constraints when HT is off · 9010ae4a
      由 Stephane Eranian 提交于 
      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: NStephane 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.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      9010ae4a
  15. 02 7月, 2016 1 次提交
  17. 01 7月, 2016 3 次提交
    • A
      x86/platform/intel-mid: Add pinctrl for Intel Merrifield · 0519e8b4
      由 Andy Shevchenko 提交于 
      Intel Merrifield uses a special address space reserved for Family-Level
Interface Shim (FLIS) that allows consumers to mux and configure pins.

Create a platform device for it.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.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/1467226894-107109-1-git-send-email-andriy.shevchenko@linux.intel.com
[ Fixed typo. ]
Signed-off-by: NIngo Molnar <mingo@kernel.org>
      0519e8b4
    • B
      x86/amd_nb: Fix boot crash on non-AMD systems · 1ead852d
      由 Borislav Petkov 提交于 
      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: NTony Battersby <tonyb@cybernetics.com>
Signed-off-by: NBorislav 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.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      1ead852d
    • R
      x86/power/64: Fix kernel text mapping corruption during image restoration · 65c0554b
      由 Rafael J. Wysocki 提交于 
      Logan Gunthorpe reports that hibernation stopped working reliably for
him after commit ab76f7b4 (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 ab76f7b4 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: ab76f7b4 (x86/mm: Set NX on gap between __ex_table and rodata)
Link: http://marc.info/?l=linux-pm&m=146372852823760&w=2Reported-by: NLogan Gunthorpe <logang@deltatee.com>
Reported-and-tested-by: NBorislav Petkov <bp@suse.de>
Tested-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
      65c0554b
  19. 27 6月, 2016 6 次提交
    • Q
      KVM: nVMX: VMX instructions: fix segment checks when L1 is in long mode. · ff30ef40
      由 Quentin Casasnovas 提交于 
      I couldn't get Xen to boot a L2 HVM when it was nested under KVM - it was
getting a GP(0) on a rather unspecial vmread from Xen:

     (XEN) ----[ Xen-4.7.0-rc  x86_64  debug=n  Not tainted ]----
     (XEN) CPU:    1
     (XEN) RIP:    e008:[<ffff82d0801e629e>] vmx_get_segment_register+0x14e/0x450
     (XEN) RFLAGS: 0000000000010202   CONTEXT: hypervisor (d1v0)
     (XEN) rax: ffff82d0801e6288   rbx: ffff83003ffbfb7c   rcx: fffffffffffab928
     (XEN) rdx: 0000000000000000   rsi: 0000000000000000   rdi: ffff83000bdd0000
     (XEN) rbp: ffff83000bdd0000   rsp: ffff83003ffbfab0   r8:  ffff830038813910
     (XEN) r9:  ffff83003faf3958   r10: 0000000a3b9f7640   r11: ffff83003f82d418
     (XEN) r12: 0000000000000000   r13: ffff83003ffbffff   r14: 0000000000004802
     (XEN) r15: 0000000000000008   cr0: 0000000080050033   cr4: 00000000001526e0
     (XEN) cr3: 000000003fc79000   cr2: 0000000000000000
     (XEN) ds: 0000   es: 0000   fs: 0000   gs: 0000   ss: 0000   cs: e008
     (XEN) Xen code around <ffff82d0801e629e> (vmx_get_segment_register+0x14e/0x450):
     (XEN)  00 00 41 be 02 48 00 00 <44> 0f 78 74 24 08 0f 86 38 56 00 00 b8 08 68 00
     (XEN) Xen stack trace from rsp=ffff83003ffbfab0:

     ...

     (XEN) Xen call trace:
     (XEN)    [<ffff82d0801e629e>] vmx_get_segment_register+0x14e/0x450
     (XEN)    [<ffff82d0801f3695>] get_page_from_gfn_p2m+0x165/0x300
     (XEN)    [<ffff82d0801bfe32>] hvmemul_get_seg_reg+0x52/0x60
     (XEN)    [<ffff82d0801bfe93>] hvm_emulate_prepare+0x53/0x70
     (XEN)    [<ffff82d0801ccacb>] handle_mmio+0x2b/0xd0
     (XEN)    [<ffff82d0801be591>] emulate.c#_hvm_emulate_one+0x111/0x2c0
     (XEN)    [<ffff82d0801cd6a4>] handle_hvm_io_completion+0x274/0x2a0
     (XEN)    [<ffff82d0801f334a>] __get_gfn_type_access+0xfa/0x270
     (XEN)    [<ffff82d08012f3bb>] timer.c#add_entry+0x4b/0xb0
     (XEN)    [<ffff82d08012f80c>] timer.c#remove_entry+0x7c/0x90
     (XEN)    [<ffff82d0801c8433>] hvm_do_resume+0x23/0x140
     (XEN)    [<ffff82d0801e4fe7>] vmx_do_resume+0xa7/0x140
     (XEN)    [<ffff82d080164aeb>] context_switch+0x13b/0xe40
     (XEN)    [<ffff82d080128e6e>] schedule.c#schedule+0x22e/0x570
     (XEN)    [<ffff82d08012c0cc>] softirq.c#__do_softirq+0x5c/0x90
     (XEN)    [<ffff82d0801602c5>] domain.c#idle_loop+0x25/0x50
     (XEN)
     (XEN)
     (XEN) ****************************************
     (XEN) Panic on CPU 1:
     (XEN) GENERAL PROTECTION FAULT
     (XEN) [error_code=0000]
     (XEN) ****************************************

Tracing my host KVM showed it was the one injecting the GP(0) when
emulating the VMREAD and checking the destination segment permissions in
get_vmx_mem_address():

     3)               |    vmx_handle_exit() {
     3)               |      handle_vmread() {
     3)               |        nested_vmx_check_permission() {
     3)               |          vmx_get_segment() {
     3)   0.074 us    |            vmx_read_guest_seg_base();
     3)   0.065 us    |            vmx_read_guest_seg_selector();
     3)   0.066 us    |            vmx_read_guest_seg_ar();
     3)   1.636 us    |          }
     3)   0.058 us    |          vmx_get_rflags();
     3)   0.062 us    |          vmx_read_guest_seg_ar();
     3)   3.469 us    |        }
     3)               |        vmx_get_cs_db_l_bits() {
     3)   0.058 us    |          vmx_read_guest_seg_ar();
     3)   0.662 us    |        }
     3)               |        get_vmx_mem_address() {
     3)   0.068 us    |          vmx_cache_reg();
     3)               |          vmx_get_segment() {
     3)   0.074 us    |            vmx_read_guest_seg_base();
     3)   0.068 us    |            vmx_read_guest_seg_selector();
     3)   0.071 us    |            vmx_read_guest_seg_ar();
     3)   1.756 us    |          }
     3)               |          kvm_queue_exception_e() {
     3)   0.066 us    |            kvm_multiple_exception();
     3)   0.684 us    |          }
     3)   4.085 us    |        }
     3)   9.833 us    |      }
     3) + 10.366 us   |    }

Cross-checking the KVM/VMX VMREAD emulation code with the Intel Software
Developper Manual Volume 3C - "VMREAD - Read Field from Virtual-Machine
Control Structure", I found that we're enforcing that the destination
operand is NOT located in a read-only data segment or any code segment when
the L1 is in long mode - BUT that check should only happen when it is in
protected mode.

Shuffling the code a bit to make our emulation follow the specification
allows me to boot a Xen dom0 in a nested KVM and start HVM L2 guests
without problems.

Fixes: f9eb4af6 ("KVM: nVMX: VMX instructions: add checks for #GP/#SS exceptions")
Signed-off-by: NQuentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Eugene Korenevsky <ekorenevsky@gmail.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      ff30ef40
    • M
      KVM: LAPIC: cap __delay at lapic_timer_advance_ns · b606f189
      由 Marcelo Tosatti 提交于 
      The host timer which emulates the guest LAPIC TSC deadline
timer has its expiration diminished by lapic_timer_advance_ns
nanoseconds. Therefore if, at wait_lapic_expire, a difference
larger than lapic_timer_advance_ns is encountered, delay at most
lapic_timer_advance_ns.

This fixes a problem where the guest can cause the host
to delay for large amounts of time.
Reported-by: NAlan Jenkins <alan.christopher.jenkins@gmail.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      b606f189
    • M
      KVM: x86: move nsec_to_cycles from x86.c to x86.h · 8d93c874
      由 Marcelo Tosatti 提交于 
      Move the inline function nsec_to_cycles from x86.c to x86.h, as
the next patch uses it from lapic.c.
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      8d93c874
    • M
      pvclock: Get rid of __pvclock_read_cycles in function pvclock_read_flags · ed911b43
      由 Minfei Huang 提交于 
      There is a generic function __pvclock_read_cycles to be used to get both
flags and cycles. For function pvclock_read_flags, it's useless to get
cycles value. To make this function be more effective, get this variable
flags directly in function.
Signed-off-by: NMinfei Huang <mnghuan@gmail.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      ed911b43
    • M
      pvclock: Cleanup to remove function pvclock_get_nsec_offset · f7550d07
      由 Minfei Huang 提交于 
      Function __pvclock_read_cycles is short enough, so there is no need to
have another function pvclock_get_nsec_offset to calculate tsc delta.
It's better to combine it into function __pvclock_read_cycles.

Remove useless variables in function __pvclock_read_cycles.
Signed-off-by: NMinfei Huang <mnghuan@gmail.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      f7550d07
    • M
      pvclock: Add CPU barriers to get correct version value · 749d088b
      由 Minfei Huang 提交于 
      Protocol for the "version" fields is: hypervisor raises it (making it
uneven) before it starts updating the fields and raises it again (making
it even) when it is done.  Thus the guest can make sure the time values
it got are consistent by checking the version before and after reading
them.

Add CPU barries after getting version value just like what function
vread_pvclock does, because all of callees in this function is inline.

Fixes: 502dfeff
Cc: stable@vger.kernel.org
Signed-off-by: NMinfei Huang <mnghuan@gmail.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      749d088b
  21. 25 6月, 2016 4 次提交
    • M
      x86/efi: get rid of superfluous __GFP_REPEAT · f58f230a
      由 Michal Hocko 提交于 
      __GFP_REPEAT has a rather weak semantic but since it has been introduced
around 2.6.12 it has been ignored for low order allocations.

efi_alloc_page_tables uses __GFP_REPEAT but it allocates an order-0
page.  This means that this flag has never been actually useful here
because it has always been used only for PAGE_ALLOC_COSTLY requests.

Link: http://lkml.kernel.org/r/1464599699-30131-4-git-send-email-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NMatt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      f58f230a
    • M
      x86: get rid of superfluous __GFP_REPEAT · a3a9a59d
      由 Michal Hocko 提交于 
      __GFP_REPEAT has a rather weak semantic but since it has been introduced
around 2.6.12 it has been ignored for low order allocations.

PGALLOC_GFP uses __GFP_REPEAT but none of the allocation which uses this
flag is for more than order-0.  This means that this flag has never been
actually useful here because it has always been used only for
PAGE_ALLOC_COSTLY requests.

Link: http://lkml.kernel.org/r/1464599699-30131-3-git-send-email-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      a3a9a59d
    • M
      tree wide: get rid of __GFP_REPEAT for order-0 allocations part I · 32d6bd90
      由 Michal Hocko 提交于 
      This is the third version of the patchset previously sent [1].  I have
basically only rebased it on top of 4.7-rc1 tree and dropped "dm: get
rid of superfluous gfp flags" which went through dm tree.  I am sending
it now because it is tree wide and chances for conflicts are reduced
considerably when we want to target rc2.  I plan to send the next step
and rename the flag and move to a better semantic later during this
release cycle so we will have a new semantic ready for 4.8 merge window
hopefully.

Motivation:

While working on something unrelated I've checked the current usage of
__GFP_REPEAT in the tree.  It seems that a majority of the usage is and
always has been bogus because __GFP_REPEAT has always been about costly
high order allocations while we are using it for order-0 or very small
orders very often.  It seems that a big pile of them is just a
copy&paste when a code has been adopted from one arch to another.

I think it makes some sense to get rid of them because they are just
making the semantic more unclear.  Please note that GFP_REPEAT is
documented as

* __GFP_REPEAT: Try hard to allocate the memory, but the allocation attempt

* _might_ fail.  This depends upon the particular VM implementation.
  while !costly requests have basically nofail semantic.  So one could
  reasonably expect that order-0 request with __GFP_REPEAT will not loop
  for ever.  This is not implemented right now though.

I would like to move on with __GFP_REPEAT and define a better semantic
for it.

  $ git grep __GFP_REPEAT origin/master | wc -l
  111
  $ git grep __GFP_REPEAT | wc -l
  36

So we are down to the third after this patch series.  The remaining
places really seem to be relying on __GFP_REPEAT due to large allocation
requests.  This still needs some double checking which I will do later
after all the simple ones are sorted out.

I am touching a lot of arch specific code here and I hope I got it right
but as a matter of fact I even didn't compile test for some archs as I
do not have cross compiler for them.  Patches should be quite trivial to
review for stupid compile mistakes though.  The tricky parts are usually
hidden by macro definitions and thats where I would appreciate help from
arch maintainers.

[1] http://lkml.kernel.org/r/1461849846-27209-1-git-send-email-mhocko@kernel.org

This patch (of 19):

__GFP_REPEAT has a rather weak semantic but since it has been introduced
around 2.6.12 it has been ignored for low order allocations.  Yet we
have the full kernel tree with its usage for apparently order-0
allocations.  This is really confusing because __GFP_REPEAT is
explicitly documented to allow allocation failures which is a weaker
semantic than the current order-0 has (basically nofail).

Let's simply drop __GFP_REPEAT from those places.  This would allow to
identify place which really need allocator to retry harder and formulate
a more specific semantic for what the flag is supposed to do actually.

Link: http://lkml.kernel.org/r/1464599699-30131-2-git-send-email-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen Liqin <liqin.linux@gmail.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com> [for tile]
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: John Crispin <blogic@openwrt.org>
Cc: Lennox Wu <lennox.wu@gmail.com>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      32d6bd90
    • L
      x86: fix up a few misc stack pointer vs thread_info confusions · aca9c293
      由 Linus Torvalds 提交于 
      As the actual pointer value is the same for the thread stack allocation
and the thread_info, code that confused the two worked fine, but will
break when the thread info is moved away from the stack allocation.  It
also looks very confusing.

For example, the kprobe code wanted to know the current top of stack.
To do that, it used this:

	(unsigned long)current_thread_info() + THREAD_SIZE

which did indeed give the correct value.  But it's not only a fairly
nonsensical expression, it's also rather complex, especially since we
actually have this:

	static inline unsigned long current_top_of_stack(void)

which not only gives us the value we are interested in, but happens to
be how "current_thread_info()" is currently defined as:

	(struct thread_info *)(current_top_of_stack() - THREAD_SIZE);

so using current_thread_info() to figure out the top of the stack really
is a very round-about thing to do.

The other cases are just simpler confusion about task_thread_info() vs
task_stack_page(), which currently return the same pointer - but if you
want the stack page, you really should be using the latter one.

And there was one entirely unused assignment of the current stack to a
thread_info pointer.

All cleaned up to make more sense today, and make it easier to move the
thread_info away from the stack in the future.

No semantic changes.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      aca9c293
  23. 24 6月, 2016 1 次提交
  25. 23 6月, 2016 2 次提交
  27. 18 6月, 2016 1 次提交
    • W
      isa: Allow ISA-style drivers on modern systems · 3a495511
      由 William Breathitt Gray 提交于 
      Several modern devices, such as PC/104 cards, are expected to run on
modern systems via an ISA bus interface. Since ISA is a legacy interface
for most modern architectures, ISA support should remain disabled in
general. Support for ISA-style drivers should be enabled on a per driver
basis.

To allow ISA-style drivers on modern systems, this patch introduces the
ISA_BUS_API and ISA_BUS Kconfig options. The ISA bus driver will now
build conditionally on the ISA_BUS_API Kconfig option, which defaults to
the legacy ISA Kconfig option. The ISA_BUS Kconfig option allows the
ISA_BUS_API Kconfig option to be selected on architectures which do not
enable ISA (e.g. X86_64).

The ISA_BUS Kconfig option is currently only implemented for X86
architectures. Other architectures may have their own ISA_BUS Kconfig
options added as required.
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NWilliam Breathitt Gray <vilhelm.gray@gmail.com>
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      3a495511
  29. 16 6月, 2016 3 次提交
  31. 15 6月, 2016 2 次提交
  33. 14 6月, 2016 3 次提交
  35. 10 6月, 2016 1 次提交
    • R
      x86/ioapic: Fix incorrect pointers in ioapic_setup_resources() · 9d98bcec
      由 Rui Wang 提交于 
      On a 4-socket Brickland system, hot-removing one ioapic is fine.
Hot-removing the 2nd one causes panic in mp_unregister_ioapic()
while calling release_resource().

It is because the iomem_res pointer has already been released
when removing the first ioapic.

To explain the use of &res[num] here: res is assigned to ioapic_resources,
and later in ioapic_insert_resources() we do:

	struct resource *r = ioapic_resources;

        for_each_ioapic(i) {
                insert_resource(&iomem_resource, r);
                r++;
        }

Here 'r' is treated as an arry of 'struct resource', and the r++ ensures
that each element of the array is inserted separately. Thus we should call
release_resouce() on each element at &res[num].

Fix it by assigning the correct pointers to ioapics[i].iomem_res in
ioapic_setup_resources().
Signed-off-by: NRui Wang <rui.y.wang@intel.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: tony.luck@intel.com
Cc: linux-pci@vger.kernel.org
Cc: rjw@rjwysocki.net
Cc: linux-acpi@vger.kernel.org
Cc: bhelgaas@google.com
Link: http://lkml.kernel.org/r/1465369193-4816-3-git-send-email-rui.y.wang@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      9d98bcec