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  1. 07 7月, 2017 18 次提交
  3. 03 7月, 2017 4 次提交
  5. 02 7月, 2017 1 次提交
    • L
      Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · e18aca02
      由 Linus Torvalds 提交于 
      Pull x86 fixes from Thomas Gleixner:
 "Fixlets for x86:

   - Prevent kexec crash when KASLR is enabled, which was caused by an
     address calculation bug

   - Restore the freeing of PUDs on memory hot remove

   - Correct a negated pointer check in the intel uncore performance
     monitoring driver

   - Plug a memory leak in an error exit path in the RDT code"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/intel_rdt: Fix memory leak on mount failure
  x86/boot/KASLR: Fix kexec crash due to 'virt_addr' calculation bug
  x86/boot/KASLR: Add checking for the offset of kernel virtual address randomization
  perf/x86/intel/uncore: Fix wrong box pointer check
  x86/mm/hotplug: Fix BUG_ON() after hot-remove by not freeing PUD
      e18aca02
  7. 01 7月, 2017 11 次提交
  9. 30 6月, 2017 6 次提交
    • B
      x86/boot/KASLR: Fix kexec crash due to 'virt_addr' calculation bug · 8eabf42a
      由 Baoquan He 提交于 
      Kernel text KASLR is separated into physical address and virtual
address randomization. And for virtual address randomization, we
only randomiza to get an offset between 16M and KERNEL_IMAGE_SIZE.
So the initial value of 'virt_addr' should be LOAD_PHYSICAL_ADDR,
but not the original kernel loading address 'output'.

The bug will cause kernel boot failure if kernel is loaded at a different
position than the address, 16M, which is decided at compiled time.
Kexec/kdump is such practical case.

To fix it, just assign LOAD_PHYSICAL_ADDR to virt_addr as initial
value.
Tested-by: NDave Young <dyoung@redhat.com>
Signed-off-by: NBaoquan He <bhe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 8391c73c ("x86/KASLR: Randomize virtual address separately")
Link: http://lkml.kernel.org/r/1498567146-11990-3-git-send-email-bhe@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      8eabf42a
    • B
      x86/boot/KASLR: Add checking for the offset of kernel virtual address randomization · b892cb87
      由 Baoquan He 提交于 
      For kernel text KASLR, the virtual address is confined to area of 1G,
[0xffffffff80000000, 0xffffffffc0000000). For the implemenataion of
virtual address randomization, we only randomize to get an offset
between 16M and 1G, then add this offset to the starting address,
0xffffffff80000000. Here 16M is the offset which is decided at linking
stage. So the amount of the local variable 'virt_addr' which respresents
the offset plus the kernel output size can not exceed KERNEL_IMAGE_SIZE.

Add a debug check for the offset. If out of bounds, print error
message and hang there.
Suggested-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NBaoquan He <bhe@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/1498567146-11990-2-git-send-email-bhe@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      b892cb87
    • S
      tracing/kprobes: Allow to create probe with a module name starting with a digit · 9e52b325
      由 Sabrina Dubroca 提交于 
      Always try to parse an address, since kstrtoul() will safely fail when
given a symbol as input. If that fails (which will be the case for a
symbol), try to parse a symbol instead.

This allows creating a probe such as:

    p:probe/vlan_gro_receive 8021q:vlan_gro_receive+0

Which is necessary for this command to work:

    perf probe -m 8021q -a vlan_gro_receive

Link: http://lkml.kernel.org/r/fd72d666f45b114e2c5b9cf7e27b91de1ec966f1.1498122881.git.sd@queasysnail.net

Cc: stable@vger.kernel.org
Fixes: 413d37d1 ("tracing: Add kprobe-based event tracer")
Acked-by: NMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: NSabrina Dubroca <sd@queasysnail.net>
Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
      9e52b325
    • J
      MIPS: Avoid accidental raw backtrace · 85423636
      由 James Hogan 提交于 
      Since commit 81a76d71 ("MIPS: Avoid using unwind_stack() with
usermode") show_backtrace() invokes the raw backtracer when
cp0_status & ST0_KSU indicates user mode to fix issues on EVA kernels
where user and kernel address spaces overlap.

However this is used by show_stack() which creates its own pt_regs on
the stack and leaves cp0_status uninitialised in most of the code paths.
This results in the non deterministic use of the raw back tracer
depending on the previous stack content.

show_stack() deals exclusively with kernel mode stacks anyway, so
explicitly initialise regs.cp0_status to KSU_KERNEL (i.e. 0) to ensure
we get a useful backtrace.

Fixes: 81a76d71 ("MIPS: Avoid using unwind_stack() with usermode")
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 3.15+
Patchwork: https://patchwork.linux-mips.org/patch/16656/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
      85423636
    • P
      MIPS: Perform post-DMA cache flushes on systems with MAARs · cad482c1
      由 Paul Burton 提交于 
      Recent CPUs from Imagination Technologies such as the I6400 or P6600 are
able to speculatively fetch data from memory into caches. This means
that if used in a system with non-coherent DMA they require that caches
be invalidated after a device performs DMA, and before the CPU reads the
DMA'd data, in order to ensure that stale values weren't speculatively
prefetched.

Such CPUs also introduced Memory Accessibility Attribute Registers
(MAARs) in order to control the regions in which they are allowed to
speculate. Thus we can use the presence of MAARs as a good indication
that the CPU requires the above cache maintenance. Use the presence of
MAARs to determine the result of cpu_needs_post_dma_flush() in the
default case, in order to handle these recent CPUs correctly.

Note that the return type of cpu_needs_post_dma_flush() is changed to
bool, such that it's clearer what's happening when cpu_has_maar is cast
to bool for the return value. If this patch were backported to a
pre-v4.7 kernel then MIPS_CPU_MAAR was 1ull<<34, so when cast to an int
we would incorrectly return 0. It so happens that MIPS_CPU_MAAR is
currently 1ull<<30, so when truncated to an int gives a non-zero value
anyway, but even so the implicit conversion from long long int to bool
makes it clearer to understand what will happen than the implicit
conversion from long long int to int would. The bool return type also
fits this usage better semantically, so seems like an all-round win.

Thanks to Ed for spotting the issue for pre-v4.7 kernels & suggesting
the return type change.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Reviewed-by: NBryan O'Donoghue <pure.logic@nexus-software.ie>
Tested-by: NBryan O'Donoghue <pure.logic@nexus-software.ie>
Cc: Ed Blake <ed.blake@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16363/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
      cad482c1
    • P
      MIPS: Fix IRQ tracing & lockdep when rescheduling · d8550860
      由 Paul Burton 提交于 
      When the scheduler sets TIF_NEED_RESCHED & we call into the scheduler
from arch/mips/kernel/entry.S we disable interrupts. This is true
regardless of whether we reach work_resched from syscall_exit_work,
resume_userspace or by looping after calling schedule(). Although we
disable interrupts in these paths we don't call trace_hardirqs_off()
before calling into C code which may acquire locks, and we therefore
leave lockdep with an inconsistent view of whether interrupts are
disabled or not when CONFIG_PROVE_LOCKING & CONFIG_DEBUG_LOCKDEP are
both enabled.

Without tracing this interrupt state lockdep will print warnings such
as the following once a task returns from a syscall via
syscall_exit_partial with TIF_NEED_RESCHED set:

[   49.927678] ------------[ cut here ]------------
[   49.934445] WARNING: CPU: 0 PID: 1 at kernel/locking/lockdep.c:3687 check_flags.part.41+0x1dc/0x1e8
[   49.946031] DEBUG_LOCKS_WARN_ON(current->hardirqs_enabled)
[   49.946355] CPU: 0 PID: 1 Comm: init Not tainted 4.10.0-00439-gc9fd5d362289-dirty #197
[   49.963505] Stack : 0000000000000000 ffffffff81bb5d6a 0000000000000006 ffffffff801ce9c4
[   49.974431]         0000000000000000 0000000000000000 0000000000000000 000000000000004a
[   49.985300]         ffffffff80b7e487 ffffffff80a24498 a8000000ff160000 ffffffff80ede8b8
[   49.996194]         0000000000000001 0000000000000000 0000000000000000 0000000077c8030c
[   50.007063]         000000007fd8a510 ffffffff801cd45c 0000000000000000 a8000000ff127c88
[   50.017945]         0000000000000000 ffffffff801cf928 0000000000000001 ffffffff80a24498
[   50.028827]         0000000000000000 0000000000000001 0000000000000000 0000000000000000
[   50.039688]         0000000000000000 a8000000ff127bd0 0000000000000000 ffffffff805509bc
[   50.050575]         00000000140084e0 0000000000000000 0000000000000000 0000000000040a00
[   50.061448]         0000000000000000 ffffffff8010e1b0 0000000000000000 ffffffff805509bc
[   50.072327]         ...
[   50.076087] Call Trace:
[   50.079869] [<ffffffff8010e1b0>] show_stack+0x80/0xa8
[   50.086577] [<ffffffff805509bc>] dump_stack+0x10c/0x190
[   50.093498] [<ffffffff8015dde0>] __warn+0xf0/0x108
[   50.099889] [<ffffffff8015de34>] warn_slowpath_fmt+0x3c/0x48
[   50.107241] [<ffffffff801c15b4>] check_flags.part.41+0x1dc/0x1e8
[   50.114961] [<ffffffff801c239c>] lock_is_held_type+0x8c/0xb0
[   50.122291] [<ffffffff809461b8>] __schedule+0x8c0/0x10f8
[   50.129221] [<ffffffff80946a60>] schedule+0x30/0x98
[   50.135659] [<ffffffff80106278>] work_resched+0x8/0x34
[   50.142397] ---[ end trace 0cb4f6ef5b99fe21 ]---
[   50.148405] possible reason: unannotated irqs-off.
[   50.154600] irq event stamp: 400463
[   50.159566] hardirqs last  enabled at (400463): [<ffffffff8094edc8>] _raw_spin_unlock_irqrestore+0x40/0xa8
[   50.171981] hardirqs last disabled at (400462): [<ffffffff8094eb98>] _raw_spin_lock_irqsave+0x30/0xb0
[   50.183897] softirqs last  enabled at (400450): [<ffffffff8016580c>] __do_softirq+0x4ac/0x6a8
[   50.195015] softirqs last disabled at (400425): [<ffffffff80165e78>] irq_exit+0x110/0x128

Fix this by using the TRACE_IRQS_OFF macro to call trace_hardirqs_off()
when CONFIG_TRACE_IRQFLAGS is enabled. This is done before invoking
schedule() following the work_resched label because:

 1) Interrupts are disabled regardless of the path we take to reach
    work_resched() & schedule().

 2) Performing the tracing here avoids the need to do it in paths which
    disable interrupts but don't call out to C code before hitting a
    path which uses the RESTORE_SOME macro that will call
    trace_hardirqs_on() or trace_hardirqs_off() as appropriate.

We call trace_hardirqs_on() using the TRACE_IRQS_ON macro before calling
syscall_trace_leave() for similar reasons, ensuring that lockdep has a
consistent view of state after we re-enable interrupts.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Cc: linux-mips@linux-mips.org
Cc: stable <stable@vger.kernel.org>
Patchwork: https://patchwork.linux-mips.org/patch/15385/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
      d8550860