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  1. 09 7月, 2020 3 次提交
    • N
      perf annotate: Fix non-null terminated buffer returned by readlink() · b39730a6
      由 Numfor Mbiziwo-Tiapo 提交于 
      Our local MSAN (Memory Sanitizer) build of perf throws a warning that
comes from the "dso__disassemble_filename" function in
"tools/perf/util/annotate.c" when running perf record.

The warning stems from the call to readlink, in which "build_id_path"
was being read into "linkname". Since readlink does not null terminate,
an uninitialized memory access would later occur when "linkname" is
passed into the strstr function. This is simply fixed by
null-terminating "linkname" after the call to readlink.

To reproduce this warning, build perf by running:

  $ make -C tools/perf CLANG=1 CC=clang EXTRA_CFLAGS="-fsanitize=memory -fsanitize-memory-track-origins"

(Additionally, llvm might have to be installed and clang might have to
be specified as the compiler - export CC=/usr/bin/clang)

Then running:

  tools/perf/perf record -o - ls / | tools/perf/perf --no-pager annotate -i - --stdio

Please see the cover letter for why false positive warnings may be
generated.
Signed-off-by: NNumfor Mbiziwo-Tiapo <nums@google.com>
Acked-by: NIan Rogers <irogers@google.com>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Mark Drayton <mbd@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20190729205750.193289-1-nums@google.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      b39730a6
    • S
      perf inject jit: Remove //anon mmap events · c8f6ae1f
      由 Steve MacLean 提交于 
      **perf-<pid>.map and jit-<pid>.dump designs:

When a JIT generates code to be executed, it must allocate memory and
mark it executable using an mmap call.

*** perf-<pid>.map design

The perf-<pid>.map assumes that any sample recorded in an anonymous
memory page is JIT code. It then tries to resolve the symbol name by
looking at the process' perf-<pid>.map.

*** jit-<pid>.dump design

The jit-<pid>.dump mechanism takes a different approach. It requires a
JIT to write a `<path>/jit-<pid>.dump` file. This file must also be
mmapped so that perf inject -jit can find the file. The JIT must also
add JIT_CODE_LOAD records for any functions it generates. The records
are timestamped using a clock which can be correlated to the perf record
clock.

After perf record,  the `perf inject -jit` pass parses the recording
looking for a `<path>/jit-<pid>.dump` file. When it finds the file, it
parses it and for each JIT_CODE_LOAD record:
* creates an elf file `<path>/jitted-<pid>-<code_index>.so
* injects a new mmap record mapping the new elf file into the process.

*** Coexistence design

The kernel and perf support both of these mechanisms. We need to make
sure perf works on an app supporting either or both of these mechanisms.
Both designs rely on mmap records to determine how to resolve an ip
address.

The mmap records of both techniques by definition overlap. When the JIT
compiles a method, it must:

* allocate memory (mmap)
* add execution privilege (mprotect or mmap. either will
generate an mmap event form the kernel to perf)
* compile code into memory
* add a function record to perf-<pid>.map and/or jit-<pid>.dump

Because the jit-<pid>.dump mechanism supports greater capabilities, perf
prefers the symbols from jit-<pid>.dump. It implements this based on
timestamp ordering of events. There is an implicit ASSUMPTION that the
JIT_CODE_LOAD record timestamp will be after the // anon mmap event that
was generated during memory allocation or adding the execution privilege setting.

*** Problems with the ASSUMPTION

The ASSUMPTION made in the Coexistence design section above is violated
in the following scenario.

*** Scenario

While a JIT is jitting code it will eventually need to commit more
pages and change these pages to executable permissions. Typically the
JIT will want these collocated to minimize branch displacements.

The kernel will coalesce these anonymous mapping with identical
permissions before sending an MMAP event for the new pages. The address
range of the new mmap will not be just the most recently mmap pages.
It will include the entire coalesced mmap region.

See mm/mmap.c

unsigned long mmap_region(struct file *file, unsigned long addr,
                unsigned long len, vm_flags_t vm_flags, unsigned long pgoff,
                struct list_head *uf)
{
...
        /*
         * Can we just expand an old mapping?
         */
...
        perf_event_mmap(vma);
...
}

*** Symptoms

The coalesced // anon mmap event will be timestamped after the
JIT_CODE_LOAD records. This means it will be used as the most recent
mapping for that entire address range. For remaining events it will look
at the inferior perf-<pid>.map for symbols.

If both mechanisms are supported, the symbol will appear twice with
different module names. This causes weird behavior in reporting.

If only jit-<pid>.dump is supported, the symbol will no longer be resolved.

** Implemented solution

This patch solves the issue by removing // anon mmap events for any
process which has a valid jit-<pid>.dump file.

It tracks on a per process basis to handle the case where some running
apps support jit-<pid>.dump, but some only support perf-<pid>.map.

It adds new assumptions:
* // anon mmap events are only required for perf-<pid>.map support.
* An app that uses jit-<pid>.dump, no longer needs
perf-<pid>.map support. It assumes that any perf-<pid>.map info is
inferior.

*** Details

Use thread->priv to store whether a jitdump file has been processed

During "perf inject --jit", discard "//anon*" mmap events for any pid which
has sucessfully processed a jitdump file.

** Testing:

// jitdump case

  perf record <app with jitdump>
  perf inject --jit --input perf.data --output perfjit.data

// verify mmap "//anon" events present initially

  perf script --input perf.data --show-mmap-events | grep '//anon'

// verify mmap "//anon" events removed

  perf script --input perfjit.data --show-mmap-events | grep '//anon'

// no jitdump case

  perf record <app without jitdump>
  perf inject --jit --input perf.data --output perfjit.data

// verify mmap "//anon" events present initially

  perf script --input perf.data --show-mmap-events | grep '//anon'

// verify mmap "//anon" events not removed

  perf script --input perfjit.data --show-mmap-events | grep '//anon'

** Repro:

This issue was discovered while testing the initial CoreCLR jitdump
implementation. https://github.com/dotnet/coreclr/pull/26897.

** Alternate solutions considered

These were also briefly considered:

* Change kernel to not coalesce mmap regions.

* Change kernel reporting of coalesced mmap regions to perf. Only
include newly mapped memory.

* Only strip parts of // anon mmap events overlapping existing
jitted-<pid>-<code_index>.so mmap events.
Signed-off-by: NSteve MacLean <Steve.MacLean@Microsoft.com>
Acked-by: NIan Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/1590544271-125795-1-git-send-email-steve.maclean@linux.microsoft.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      c8f6ae1f
    • A
      Merge remote-tracking branch 'torvalds/master' into perf/core · facbf0b9
      由 Arnaldo Carvalho de Melo 提交于 
      To pick up fixes and move perf/core forward, minor conflict as
perf_evlist__add_dummy() lost its 'perf_' prefix as it operates on a
'struct evlist', not on a 'struct perf_evlist', i.e. its tools/perf/
specific, it is not in libperf.
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      facbf0b9
  3. 08 7月, 2020 7 次提交
  5. 07 7月, 2020 4 次提交
    • J
      Revert commit e918e570 ("tpm_tis: Remove the HID IFX0102") · 786a2aa2
      由 Jarkko Sakkinen 提交于 
      Removing IFX0102 from tpm_tis was not a right move because both tpm_tis
and tpm_infineon use the same device ID. Revert the commit and add a
remark about a bug caused by commit 93e1b7d4 ("[PATCH] tpm: add HID
module parameter").

Fixes: e918e570 ("tpm_tis: Remove the HID IFX0102")
Reported-by: NPeter Huewe <peterhuewe@gmx.de>
Reviewed-by: NJerry Snitselaar <jsnitsel@redhat.com>
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
      786a2aa2
    • L
      Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm · bfe91da2
      由 Linus Torvalds 提交于 
      Pull kvm fixes from Paolo Bonzini:
 "Bugfixes and a one-liner patch to silence a sparse warning"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: arm64: Stop clobbering x0 for HVC_SOFT_RESTART
  KVM: arm64: PMU: Fix per-CPU access in preemptible context
  KVM: VMX: Use KVM_POSSIBLE_CR*_GUEST_BITS to initialize guest/host masks
  KVM: x86: Mark CR4.TSD as being possibly owned by the guest
  KVM: x86: Inject #GP if guest attempts to toggle CR4.LA57 in 64-bit mode
  kvm: use more precise cast and do not drop __user
  KVM: x86: bit 8 of non-leaf PDPEs is not reserved
  KVM: X86: Fix async pf caused null-ptr-deref
  KVM: arm64: vgic-v4: Plug race between non-residency and v4.1 doorbell
  KVM: arm64: pvtime: Ensure task delay accounting is enabled
  KVM: arm64: Fix kvm_reset_vcpu() return code being incorrect with SVE
  KVM: arm64: Annotate hyp NMI-related functions as __always_inline
  KVM: s390: reduce number of IO pins to 1
      bfe91da2
    • L
      Merge tag 's390-5.8-4' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux · 5c82ec00
      由 Linus Torvalds 提交于 
      Pull s390 fixes from Heiko Carstens:

 - Initialize jump labels before early command line parsing in order to
   make init_on_alloc and init_on_free options work

 - Fix vfio-ccw build error due to missing include

 - Prevent callchain data collection with hardware sampling, since the
   callchains simply do not exist

 - Prevent multiple registrations of the same zPCI function

 - Update defconfigs

* tag 's390-5.8-4' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  vfio-ccw: Fix a build error due to missing include of linux/slab.h
  s390: update defconfigs
  s390/cpum_sf: prohibit callchain data collection
  s390/setup: init jump labels before command line parsing
  s390/maccess: add no DAT mode to kernel_write
  s390/pci: fix enabling a reserved PCI function
      5c82ec00
    • P
      Merge tag 'kvmarm-fixes-5.8-3' of... · 8038a922
      由 Paolo Bonzini 提交于 
      Merge tag 'kvmarm-fixes-5.8-3' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-master

KVM/arm fixes for 5.8, take #3

- Disable preemption on context-switching PMU EL0 state happening
  on system register trap
- Don't clobber X0 when tearing down KVM via a soft reset (kexec)
      8038a922
  7. 06 7月, 2020 26 次提交