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  1. 01 12月, 2018 34 次提交
  3. 30 11月, 2018 6 次提交
    • S
      tracing/fgraph: Fix set_graph_function from showing interrupts · 5cf99a0f
      由 Steven Rostedt (VMware) 提交于 
      The tracefs file set_graph_function is used to only function graph functions
that are listed in that file (or all functions if the file is empty). The
way this is implemented is that the function graph tracer looks at every
function, and if the current depth is zero and the function matches
something in the file then it will trace that function. When other functions
are called, the depth will be greater than zero (because the original
function will be at depth zero), and all functions will be traced where the
depth is greater than zero.

The issue is that when a function is first entered, and the handler that
checks this logic is called, the depth is set to zero. If an interrupt comes
in and a function in the interrupt handler is traced, its depth will be
greater than zero and it will automatically be traced, even if the original
function was not. But because the logic only looks at depth it may trace
interrupts when it should not be.

The recent design change of the function graph tracer to fix other bugs
caused the depth to be zero while the function graph callback handler is
being called for a longer time, widening the race of this happening. This
bug was actually there for a longer time, but because the race window was so
small it seldom happened. The Fixes tag below is for the commit that widen
the race window, because that commit belongs to a series that will also help
fix the original bug.

Cc: stable@kernel.org
Fixes: 39eb456d ("function_graph: Use new curr_ret_depth to manage depth instead of curr_ret_stack")
Reported-by: NJoe Lawrence <joe.lawrence@redhat.com>
Tested-by: NJoe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
      5cf99a0f
    • Z
      tracepoint: Use __idx instead of idx in DO_TRACE macro to make it unique · 0c7a52e4
      由 Zenghui Yu 提交于 
      After enabling KVM event tracing, almost all of trace_kvm_exit()'s
printk shows

	"kvm_exit: IRQ: ..."

even if the actual exception_type is NOT IRQ.  More specifically,
trace_kvm_exit() is defined in virt/kvm/arm/trace.h by TRACE_EVENT.

This slight problem may have existed after commit e6753f23
("tracepoint: Make rcuidle tracepoint callers use SRCU"). There are
two variables in trace_kvm_exit() and __DO_TRACE() which have the
same name, *idx*. Thus the actual value of *idx* will be overwritten
when tracing. Fix it by adding a simple prefix.

Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Wang Haibin <wanghaibin.wang@huawei.com>
Cc: linux-trace-devel@vger.kernel.org
Cc: stable@vger.kernel.org
Fixes: e6753f23 ("tracepoint: Make rcuidle tracepoint callers use SRCU")
Reviewed-by: NJoel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: NZenghui Yu <yuzenghui@huawei.com>
Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
      0c7a52e4
    • D
      afs: Use d_instantiate() rather than d_add() and don't d_drop() · 73116df7
      由 David Howells 提交于 
      Use d_instantiate() rather than d_add() and don't d_drop() in
afs_vnode_new_inode().  The dentry shouldn't be removed as it's not
changing its name.
Reported-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      73116df7
    • D
      afs: Fix missing net error handling · 4584ae96
      由 David Howells 提交于 
      kAFS can be given certain network errors (EADDRNOTAVAIL, EHOSTDOWN and
ERFKILL) that it doesn't handle in its server/address rotation algorithms.
They cause the probing and rotation to abort immediately rather than
rotating.

Fix this by:

 (1) Abstracting out the error prioritisation from the VL and FS rotation
     algorithms into a common function and expand usage into the server
     probing code.

     When multiple errors are available, this code selects the one we'd
     prefer to return.

 (2) Add handling for EADDRNOTAVAIL, EHOSTDOWN and ERFKILL.

Fixes: 0fafdc9f ("afs: Fix file locking")
Fixes: 0338747d8454 ("afs: Probe multiple fileservers simultaneously")
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      4584ae96
    • D
      afs: Fix validation/callback interaction · ae3b7361
      由 David Howells 提交于 
      When afs_validate() is called to validate a vnode (inode), there are two
unhandled cases in the fastpath at the top of the function:

 (1) If the vnode is promised (AFS_VNODE_CB_PROMISED is set), the break
     counters match and the data has expired, then there's an implicit case
     in which the vnode needs revalidating.

     This has no consequences since the default "valid = false" set at the
     top of the function happens to do the right thing.

 (2) If the vnode is not promised and it hasn't been deleted
     (AFS_VNODE_DELETED is not set) then there's a default case we're not
     handling in which the vnode is invalid.  If the vnode is invalid, we
     need to bring cb_s_break and cb_v_break up to date before we refetch
     the status.

     As a consequence, once the server loses track of the client
     (ie. sufficient time has passed since we last sent it an operation),
     it will send us a CB.InitCallBackState* operation when we next try to
     talk to it.  This calls afs_init_callback_state() which increments
     afs_server::cb_s_break, but this then doesn't propagate to the
     afs_vnode record.

     The result being that every afs_validate() call thereafter sends a
     status fetch operation to the server.

Clarify and fix this by:

 (A) Setting valid in all the branches rather than initialising it at the
     top so that the compiler catches where we've missed.

 (B) Restructuring the logic in the 'promised' branch so that we set valid
     to false if the callback is due to expire (or has expired) and so that
     the final case is that the vnode is still valid.

 (C) Adding an else-statement that ups cb_s_break and cb_v_break if the
     promised and deleted cases don't match.

Fixes: c435ee34 ("afs: Overhaul the callback handling")
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      ae3b7361
    • L
      Merge tag 'acpi-4.20-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm · 94f371cb
      由 Linus Torvalds 提交于 
      Pull ACPI fix from Rafael Wysocki:
 "Fix a recent regression in ACPICA releted to the Generic Serial Bus
  protocol handling and causing it to read or write too little or too
  much data in some cases, so incorrect data may be written to hardware
  as a result (Hans de Goede)"

* tag 'acpi-4.20-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPICA: Fix handling of buffer-size in acpi_ex_write_data_to_field()
      94f371cb