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  1. 21 Jan, 2019 3 commits
    • Tony Jones's avatar
      perf script: Fix crash when processing recorded stat data · 8bf8c6da
      Tony Jones authored 
      While updating perf to work with Python3 and Python2 I noticed that the
stat-cpi script was dumping core.

$ perf  stat -e cycles,instructions record -o /tmp/perf.data /bin/false

 Performance counter stats for '/bin/false':

           802,148      cycles

           604,622      instructions                                                       802,148      cycles
           604,622      instructions

       0.001445842 seconds time elapsed

$ perf script -i /tmp/perf.data -s scripts/python/stat-cpi.py
Segmentation fault (core dumped)
...
...
    rblist=rblist@entry=0xb2a200 <rt_stat>,
    new_entry=new_entry@entry=0x7ffcb755c310) at util/rblist.c:33
    ctx=<optimized out>, type=<optimized out>, create=<optimized out>,
    cpu=<optimized out>, evsel=<optimized out>) at util/stat-shadow.c:118
    ctx=<optimized out>, type=<optimized out>, st=<optimized out>)
    at util/stat-shadow.c:196
    count=count@entry=727442, cpu=cpu@entry=0, st=0xb2a200 <rt_stat>)
    at util/stat-shadow.c:239
    config=config@entry=0xafeb40 <stat_config>,
    counter=counter@entry=0x133c6e0) at util/stat.c:372
...
...

The issue is that since 1fcd0394 perf_stat__update_shadow_stats now calls
update_runtime_stat passing rt_stat rather than calling update_stats but
perf_stat__init_shadow_stats has never been called to initialize rt_stat in
the script path processing recorded stat data.

Since I can't see any reason why perf_stat__init_shadow_stats() is presently
initialized like it is in builtin-script.c::perf_sample__fprint_metric()
[4bd1bef8] I'm proposing it instead be initialized once in __cmd_script

Committer testing:

After applying the patch:

  # perf script -i /tmp/perf.data -s tools/perf/scripts/python/stat-cpi.py
       0.001970: cpu -1, thread -1 -> cpi 1.709079 (1075684/629394)
  #

No segfault.
Signed-off-by: default avatarTony Jones <tonyj@suse.de>
Reviewed-by: default avatarJiri Olsa <jolsa@kernel.org>
Tested-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: default avatarRavi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Fixes: 1fcd0394 ("perf stat: Update per-thread shadow stats")
Link: http://lkml.kernel.org/r/20190120191414.12925-1-tonyj@suse.deSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      8bf8c6da
    • He Kuang's avatar
      perf top: Fix wrong hottest instruction highlighted · da06d568
      He Kuang authored 
      The annotation line percentage is compared and inserted into the rbtree,
but the percent field of 'struct annotation_data' is an array, the
comparison result between them is the address difference.

This patch compares the right slot of percent array according to
opts->percent_type and makes things right.

The problem can be reproduced by pressing 'H' in perf top annotation view.
It should highlight the instruction line which has the highest sampling
percentage.
Signed-off-by: default avatarHe Kuang <hekuang@huawei.com>
Reviewed-by: default avatarJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20190120160523.4391-1-hekuang@huawei.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      da06d568
    • Stephane Eranian's avatar
      perf tools: Handle TOPOLOGY headers with no CPU · 1497e804
      Stephane Eranian authored 
      This patch fixes an issue in cpumap.c when used with the TOPOLOGY
header. In some configurations, some NUMA nodes may have no CPU (empty
cpulist). Yet a cpumap map must be created otherwise perf abort with an
error. This patch handles this case by creating a dummy map.

  Before:

  $ perf record -o - -e cycles noploop 2 | perf script -i -
  0x6e8 [0x6c]: failed to process type: 80

  After:

  $ perf record -o - -e cycles noploop 2 | perf script -i -
  noploop for 2 seconds
Signed-off-by: default avatarStephane Eranian <eranian@google.com>
Acked-by: default avatarJiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1547885559-1657-1-git-send-email-eranian@google.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      1497e804
  3. 18 Jan, 2019 3 commits
    • Arnaldo Carvalho de Melo's avatar
      perf python: Remove -fstack-clash-protection when building with some clang versions · 94ec1eb7
      Arnaldo Carvalho de Melo authored 
      These options are not present in some (all?) clang versions, so when we
build for a distro that has a gcc new enough to have these options and
that the distro python build config settings use them but clang doesn't
support, b00m.

This is the case with fedora rawhide (now gearing towards f30), so check
if clang has the  and remove the missing ones from CFLAGS.

Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Thiago Macieira <thiago.macieira@intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-5q50q9w458yawgxf9ez54jbp@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      94ec1eb7
    • Stephane Eranian's avatar
      perf core: Fix perf_proc_update_handler() bug · 1a51c5da
      Stephane Eranian authored 
      The perf_proc_update_handler() handles /proc/sys/kernel/perf_event_max_sample_rate
syctl variable.  When the PMU IRQ handler timing monitoring is disabled, i.e,
when /proc/sys/kernel/perf_cpu_time_max_percent is equal to 0 or 100,
then no modification to sysctl_perf_event_sample_rate is allowed to prevent
possible hang from wrong values.

The problem is that the test to prevent modification is made after the
sysctl variable is modified in perf_proc_update_handler().

You get an error:

  $ echo 10001 >/proc/sys/kernel/perf_event_max_sample_rate
  echo: write error: invalid argument

But the value is still modified causing all sorts of inconsistencies:

  $ cat /proc/sys/kernel/perf_event_max_sample_rate
  10001

This patch fixes the problem by moving the parsing of the value after
the test.

Committer testing:

  # echo 100 > /proc/sys/kernel/perf_cpu_time_max_percent
  # echo 10001 > /proc/sys/kernel/perf_event_max_sample_rate
  -bash: echo: write error: Invalid argument
  # cat /proc/sys/kernel/perf_event_max_sample_rate
  10001
  #
Signed-off-by: default avatarStephane Eranian <eranian@google.com>
Reviewed-by: default avatarAndi Kleen <ak@linux.intel.com>
Reviewed-by: default avatarJiri Olsa <jolsa@kernel.org>
Tested-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1547169436-6266-1-git-send-email-eranian@google.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      1a51c5da
    • Andi Kleen's avatar
      perf script: Fix crash with printing mixed trace point and other events · 96167167
      Andi Kleen authored 
      'perf script' crashes currently when printing mixed trace points and
other events because the trace format does not handle events without
trace meta data. Add a simple check to avoid that.

  % cat > test.c
  main()
  {
      printf("Hello world\n");
  }
  ^D
  % gcc -g -o test test.c
  % sudo perf probe -x test 'test.c:3'
  % perf record -e '{cpu/cpu-cycles,period=10000/,probe_test:main}:S' ./test
  % perf script
  <segfault>

Committer testing:

Before:

  # perf probe -x /lib64/libc-2.28.so malloc
  Added new event:
    probe_libc:malloc    (on malloc in /usr/lib64/libc-2.28.so)

  You can now use it in all perf tools, such as:

	perf record -e probe_libc:malloc -aR sleep 1

  # perf probe -l
  probe_libc:malloc    (on __libc_malloc@malloc/malloc.c in /usr/lib64/libc-2.28.so)
  # perf record -e '{cpu/cpu-cycles,period=10000/,probe_libc:*}:S' sleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.023 MB perf.data (40 samples) ]
  # perf script
  Segmentation fault (core dumped)
  ^C
  #

After:

  # perf script | head -6
     sleep 2888 94796.944981: 16198 cpu/cpu-cycles,period=10000/: ffffffff925dc04f get_random_u32+0x1f (/lib/modules/5.0.0-rc2+/build/vmlinux)
     sleep 2888 [-01] 94796.944981: probe_libc:malloc:
     sleep 2888 94796.944983:  4713 cpu/cpu-cycles,period=10000/: ffffffff922763af change_protection+0xcf (/lib/modules/5.0.0-rc2+/build/vmlinux)
     sleep 2888 [-01] 94796.944983: probe_libc:malloc:
     sleep 2888 94796.944986:  9934 cpu/cpu-cycles,period=10000/: ffffffff922777e0 move_page_tables+0x0 (/lib/modules/5.0.0-rc2+/build/vmlinux)
     sleep 2888 [-01] 94796.944986: probe_libc:malloc:
  #
Signed-off-by: default avatarAndi Kleen <ak@linux.intel.com>
Tested-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: default avatarJiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/20190117194834.21940-1-andi@firstfloor.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      96167167
  5. 17 Jan, 2019 1 commit
  7. 11 Jan, 2019 1 commit
    • Ingo Molnar's avatar
      Merge tag 'perf-core-for-mingo-5.0-20190110' of... · 4e72ee88
      Ingo Molnar authored 
      Merge tag 'perf-core-for-mingo-5.0-20190110' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent

Pull perf/core fixes and improvements from Arnaldo Carvalho de Melo:

perf trace:

  Ravi Bangoria:

  - Rework PowerPC syscall table generation, now using a .tbl file just like
    x86_64 and S/390, also silencing a tools build warning about headers out of
    sync with the kernel sources.

tools include uapi:

  Arnaldo Carvalho de Melo:

  - Sync linux/if_link.h copy with the kernel sources, silencing a build warning.

perf top:

  Arnaldo Carvalho de Melo:

  - Add 'arch_cpu_idle' to the list of kernel idle symbols, noticed on a Orange
    Pi Zero ARM board, just like with other symbols in other arches.
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      4e72ee88
  9. 10 Jan, 2019 2 commits
    • Ravi Bangoria's avatar
      tools headers powerpc: Remove unistd.h · 15c03092
      Ravi Bangoria authored 
      We use syscall.tbl to generate system call table on powerpc.

The unistd.h copy is no longer required now. Remove it.
Signed-off-by: default avatarRavi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/20190110094936.3132-2-ravi.bangoria@linux.ibm.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      15c03092
    • Ravi Bangoria's avatar
      perf powerpc: Rework syscall table generation · 02061318
      Ravi Bangoria authored 
      Commit aff85039 ("powerpc: add system call table generation
support") changed how systemcall table is generated for powerpc.
Incorporate these changes into perf as well.

Committer testing:

  $ podman run --entrypoint=/bin/sh --privileged -v /home/acme/git:/git --rm -ti docker.io/acmel/linux-perf-tools-build-ubuntu:18.04-x-powerpc64
  perfbuilder@d7a7af166a80:/git/perf$ head -2 /etc/os-release
  NAME="Ubuntu"
  VERSION="18.04.1 LTS (Bionic Beaver)"
  perfbuilder@d7a7af166a80:/git/perf$
  perfbuilder@d7a7af166a80:/git/perf$ make ARCH=powerpc CROSS_COMPILE=powerpc64-linux-gnu- EXTRA_CFLAGS= -C /git/linux/tools/perf O=/tmp/build/perf
  make: Entering directory '/git/linux/tools/perf'
    BUILD:   Doing 'make -j8' parallel build
    HOSTCC   /tmp/build/perf/fixdep.o
    HOSTLD   /tmp/build/perf/fixdep-in.o
    LINK     /tmp/build/perf/fixdep
  Warning: Kernel ABI header at 'tools/include/uapi/linux/mman.h' differs from latest version at 'include/uapi/linux/mman.h'
  diff -u tools/include/uapi/linux/mman.h include/uapi/linux/mman.h
  sh: 1: command: Illegal option -c

  Auto-detecting system features:
  ...                         dwarf: [ on  ]
  ...            dwarf_getlocations: [ on  ]
  ...                         glibc: [ on  ]
  ...                          gtk2: [ OFF ]
  ...                      libaudit: [ OFF ]
  ...                        libbfd: [ OFF ]
  ...                        libelf: [ on  ]
  ...                       libnuma: [ OFF ]
  ...        numa_num_possible_cpus: [ OFF ]
  ...                       libperl: [ OFF ]
  ...                     libpython: [ OFF ]
  ...                      libslang: [ OFF ]
  ...                     libcrypto: [ OFF ]
  ...                     libunwind: [ OFF ]
  ...            libdw-dwarf-unwind: [ on  ]
  ...                          zlib: [ on  ]
  ...                          lzma: [ OFF ]
  ...                     get_cpuid: [ OFF ]
  ...                           bpf: [ on  ]

  Makefile.config:445: No sys/sdt.h found, no SDT events are defined, please install systemtap-sdt-devel or systemtap-sdt-dev
  Makefile.config:491: No libunwind found. Please install libunwind-dev[el] >= 1.1 and/or set LIBUNWIND_DIR
  Makefile.config:583: No libcrypto.h found, disables jitted code injection, please install libssl-devel or libssl-dev
  Makefile.config:598: slang not found, disables TUI support. Please install slang-devel, libslang-dev or libslang2-dev
  Makefile.config:612: GTK2 not found, disables GTK2 support. Please install gtk2-devel or libgtk2.0-dev
  Makefile.config:639: Missing perl devel files. Disabling perl scripting support, please install perl-ExtUtils-Embed/libperl-dev
  Makefile.config:666: No python interpreter was found: disables Python support - please install python-devel/python-dev
  Makefile.config:721: No bfd.h/libbfd found, please install binutils-dev[el]/zlib-static/libiberty-dev to gain symbol demangling
  Makefile.config:750: No liblzma found, disables xz kernel module decompression, please install xz-devel/liblzma-dev
  Makefile.config:763: No numa.h found, disables 'perf bench numa mem' benchmark, please install numactl-devel/libnuma-devel/libnuma-dev
  Makefile.config:814: No libbabeltrace found, disables 'perf data' CTF format support, please install libbabeltrace-dev[el]/libbabeltrace-ctf-dev
  Makefile.config:840: No alternatives command found, you need to set JDIR= to point to the root of your Java directory
    GEN      /tmp/build/perf/common-cmds.h
  <SNIP>
    CC       /tmp/build/perf/util/syscalltbl.o
  <SNIP>
    LD       /tmp/build/perf/libperf-in.o
    AR       /tmp/build/perf/libperf.a
    LINK     /tmp/build/perf/perf
  make: Leaving directory '/git/linux/tools/perf'
  perfbuilder@d7a7af166a80:/git/perf$ head /tmp/build/perf/arch/powerpc/include/generated/asm/syscalls_64.c
  static const char *syscalltbl_powerpc_64[] = {
  	[0] = "restart_syscall",
  	[1] = "exit",
  	[2] = "fork",
  	[3] = "read",
  	[4] = "write",
  	[5] = "open",
  	[6] = "close",
  	[7] = "waitpid",
  	[8] = "creat",
  perfbuilder@d7a7af166a80:/git/perf$ tail /tmp/build/perf/arch/powerpc/include/generated/asm/syscalls_64.c
  	[381] = "pwritev2",
  	[382] = "kexec_file_load",
  	[383] = "statx",
  	[384] = "pkey_alloc",
  	[385] = "pkey_free",
  	[386] = "pkey_mprotect",
  	[387] = "rseq",
  	[388] = "io_pgetevents",
  };
  #define SYSCALLTBL_POWERPC_64_MAX_ID 388
  perfbuilder@d7a7af166a80:/git/perf$ head /tmp/build/perf/arch/powerpc/include/generated/asm/syscalls_32.c
  static const char *syscalltbl_powerpc_32[] = {
  	[0] = "restart_syscall",
  	[1] = "exit",
  	[2] = "fork",
  	[3] = "read",
  	[4] = "write",
  	[5] = "open",
  	[6] = "close",
  	[7] = "waitpid",
  	[8] = "creat",
  perfbuilder@d7a7af166a80:/git/perf$ tail /tmp/build/perf/arch/powerpc/include/generated/asm/syscalls_32.c
  	[381] = "pwritev2",
  	[382] = "kexec_file_load",
  	[383] = "statx",
  	[384] = "pkey_alloc",
  	[385] = "pkey_free",
  	[386] = "pkey_mprotect",
  	[387] = "rseq",
  	[388] = "io_pgetevents",
  };
  #define SYSCALLTBL_POWERPC_32_MAX_ID 388
  perfbuilder@d7a7af166a80:/git/perf$
Signed-off-by: default avatarRavi Bangoria <ravi.bangoria@linux.ibm.com>
Reported-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/20190110094936.3132-1-ravi.bangoria@linux.ibm.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      02061318
  11. 09 Jan, 2019 3 commits
  13. 08 Jan, 2019 17 commits
  15. 07 Jan, 2019 4 commits
    • Masahiro Yamada's avatar
      arch: restore generic-y += shmparam.h for some architectures · 3bd6e94b
      Masahiro Yamada authored 
      For some reasons, I accidentally got rid of "generic-y += shmparam.h"
from some architectures.

Restore them to fix building c6x, h8300, hexagon, m68k, microblaze,
openrisc, and unicore32.

Fixes: d6e4b3e3 ("arch: remove redundant UAPI generic-y defines")
Signed-off-by: default avatarMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      3bd6e94b
    • Linus Torvalds's avatar
      Linux 5.0-rc1 · bfeffd15
      Linus Torvalds authored
      bfeffd15
    • Linus Torvalds's avatar
      Merge tag 'kbuild-v4.21-3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild · 85e1ffbd
      Linus Torvalds authored 
      Pull more Kbuild updates from Masahiro Yamada:

 - improve boolinit.cocci and use_after_iter.cocci semantic patches

 - fix alignment for kallsyms

 - move 'asm goto' compiler test to Kconfig and clean up jump_label
   CONFIG option

 - generate asm-generic wrappers automatically if arch does not
   implement mandatory UAPI headers

 - remove redundant generic-y defines

 - misc cleanups

* tag 'kbuild-v4.21-3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kconfig: rename generated .*conf-cfg to *conf-cfg
  kbuild: remove unnecessary stubs for archheader and archscripts
  kbuild: use assignment instead of define ... endef for filechk_* rules
  arch: remove redundant UAPI generic-y defines
  kbuild: generate asm-generic wrappers if mandatory headers are missing
  arch: remove stale comments "UAPI Header export list"
  riscv: remove redundant kernel-space generic-y
  kbuild: change filechk to surround the given command with { }
  kbuild: remove redundant target cleaning on failure
  kbuild: clean up rule_dtc_dt_yaml
  kbuild: remove UIMAGE_IN and UIMAGE_OUT
  jump_label: move 'asm goto' support test to Kconfig
  kallsyms: lower alignment on ARM
  scripts: coccinelle: boolinit: drop warnings on named constants
  scripts: coccinelle: check for redeclaration
  kconfig: remove unused "file" field of yylval union
  nds32: remove redundant kernel-space generic-y
  nios2: remove unneeded HAS_DMA define
      85e1ffbd
    • Linus Torvalds's avatar
      Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · ac5eed2b
      Linus Torvalds authored 
      Pull perf tooling updates form Ingo Molnar:
 "A final batch of perf tooling changes: mostly fixes and small
  improvements"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (29 commits)
  perf session: Add comment for perf_session__register_idle_thread()
  perf thread-stack: Fix thread stack processing for the idle task
  perf thread-stack: Allocate an array of thread stacks
  perf thread-stack: Factor out thread_stack__init()
  perf thread-stack: Allow for a thread stack array
  perf thread-stack: Avoid direct reference to the thread's stack
  perf thread-stack: Tidy thread_stack__bottom() usage
  perf thread-stack: Simplify some code in thread_stack__process()
  tools gpio: Allow overriding CFLAGS
  tools power turbostat: Override CFLAGS assignments and add LDFLAGS to build command
  tools thermal tmon: Allow overriding CFLAGS assignments
  tools power x86_energy_perf_policy: Override CFLAGS assignments and add LDFLAGS to build command
  perf c2c: Increase the HITM ratio limit for displayed cachelines
  perf c2c: Change the default coalesce setup
  perf trace beauty ioctl: Beautify USBDEVFS_ commands
  perf trace beauty: Export function to get the files for a thread
  perf trace: Wire up ioctl's USBDEBFS_ cmd table generator
  perf beauty ioctl: Add generator for USBDEVFS_ ioctl commands
  tools headers uapi: Grab a copy of usbdevice_fs.h
  perf trace: Store the major number for a file when storing its pathname
  ...
      ac5eed2b
  17. 06 Jan, 2019 6 commits
    • Linus Torvalds's avatar
      Change mincore() to count "mapped" pages rather than "cached" pages · 574823bf
      Linus Torvalds authored 
      The semantics of what "in core" means for the mincore() system call are
somewhat unclear, but Linux has always (since 2.3.52, which is when
mincore() was initially done) treated it as "page is available in page
cache" rather than "page is mapped in the mapping".

The problem with that traditional semantic is that it exposes a lot of
system cache state that it really probably shouldn't, and that users
shouldn't really even care about.

So let's try to avoid that information leak by simply changing the
semantics to be that mincore() counts actual mapped pages, not pages
that might be cheaply mapped if they were faulted (note the "might be"
part of the old semantics: being in the cache doesn't actually guarantee
that you can access them without IO anyway, since things like network
filesystems may have to revalidate the cache before use).

In many ways the old semantics were somewhat insane even aside from the
information leak issue.  From the very beginning (and that beginning is
a long time ago: 2.3.52 was released in March 2000, I think), the code
had a comment saying

  Later we can get more picky about what "in core" means precisely.

and this is that "later".  Admittedly it is much later than is really
comfortable.

NOTE! This is a real semantic change, and it is for example known to
change the output of "fincore", since that program literally does a
mmmap without populating it, and then doing "mincore()" on that mapping
that doesn't actually have any pages in it.

I'm hoping that nobody actually has any workflow that cares, and the
info leak is real.

We may have to do something different if it turns out that people have
valid reasons to want the old semantics, and if we can limit the
information leak sanely.

Cc: Kevin Easton <kevin@guarana.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Masatake YAMATO <yamato@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      574823bf
    • Linus Torvalds's avatar
      Fix 'acccess_ok()' on alpha and SH · 94bd8a05
      Linus Torvalds authored 
      Commit 594cc251 ("make 'user_access_begin()' do 'access_ok()'")
broke both alpha and SH booting in qemu, as noticed by Guenter Roeck.

It turns out that the bug wasn't actually in that commit itself (which
would have been surprising: it was mostly a no-op), but in how the
addition of access_ok() to the strncpy_from_user() and strnlen_user()
functions now triggered the case where those functions would test the
access of the very last byte of the user address space.

The string functions actually did that user range test before too, but
they did it manually by just comparing against user_addr_max().  But
with user_access_begin() doing the check (using "access_ok()"), it now
exposed problems in the architecture implementations of that function.

For example, on alpha, the access_ok() helper macro looked like this:

  #define __access_ok(addr, size) \
        ((get_fs().seg & (addr | size | (addr+size))) == 0)

and what it basically tests is of any of the high bits get set (the
USER_DS masking value is 0xfffffc0000000000).

And that's completely wrong for the "addr+size" check.  Because it's
off-by-one for the case where we check to the very end of the user
address space, which is exactly what the strn*_user() functions do.

Why? Because "addr+size" will be exactly the size of the address space,
so trying to access the last byte of the user address space will fail
the __access_ok() check, even though it shouldn't.  As a result, the
user string accessor functions failed consistently - because they
literally don't know how long the string is going to be, and the max
access is going to be that last byte of the user address space.

Side note: that alpha macro is buggy for another reason too - it re-uses
the arguments twice.

And SH has another version of almost the exact same bug:

  #define __addr_ok(addr) \
        ((unsigned long __force)(addr) < current_thread_info()->addr_limit.seg)

so far so good: yes, a user address must be below the limit.  But then:

  #define __access_ok(addr, size)         \
        (__addr_ok((addr) + (size)))

is wrong with the exact same off-by-one case: the case when "addr+size"
is exactly _equal_ to the limit is actually perfectly fine (think "one
byte access at the last address of the user address space")

The SH version is actually seriously buggy in another way: it doesn't
actually check for overflow, even though it did copy the _comment_ that
talks about overflow.

So it turns out that both SH and alpha actually have completely buggy
implementations of access_ok(), but they happened to work in practice
(although the SH overflow one is a serious serious security bug, not
that anybody likely cares about SH security).

This fixes the problems by using a similar macro on both alpha and SH.
It isn't trying to be clever, the end address is based on this logic:

        unsigned long __ao_end = __ao_a + __ao_b - !!__ao_b;

which basically says "add start and length, and then subtract one unless
the length was zero".  We can't subtract one for a zero length, or we'd
just hit an underflow instead.

For a lot of access_ok() users the length is a constant, so this isn't
actually as expensive as it initially looks.
Reported-and-tested-by: default avatarGuenter Roeck <linux@roeck-us.net>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      94bd8a05
    • Linus Torvalds's avatar
      Merge tag 'fscrypt_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/fscrypt · baa67073
      Linus Torvalds authored 
      Pull fscrypt updates from Ted Ts'o:
 "Add Adiantum support for fscrypt"

* tag 'fscrypt_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/fscrypt:
  fscrypt: add Adiantum support
      baa67073
    • Linus Torvalds's avatar
      Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 · 21524046
      Linus Torvalds authored 
      Pull ext4 bug fixes from Ted Ts'o:
 "Fix a number of ext4 bugs"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: fix special inode number checks in __ext4_iget()
  ext4: track writeback errors using the generic tracking infrastructure
  ext4: use ext4_write_inode() when fsyncing w/o a journal
  ext4: avoid kernel warning when writing the superblock to a dead device
  ext4: fix a potential fiemap/page fault deadlock w/ inline_data
  ext4: make sure enough credits are reserved for dioread_nolock writes
      21524046
    • Linus Torvalds's avatar
      Merge tag 'dma-mapping-4.21-1' of git://git.infradead.org/users/hch/dma-mapping · e2b745f4
      Linus Torvalds authored 
      Pull dma-mapping fixes from Christoph Hellwig:
 "Fix various regressions introduced in this cycles:

   - fix dma-debug tracking for the map_page / map_single
     consolidatation

   - properly stub out DMA mapping symbols for !HAS_DMA builds to avoid
     link failures

   - fix AMD Gart direct mappings

   - setup the dma address for no kernel mappings using the remap
     allocator"

* tag 'dma-mapping-4.21-1' of git://git.infradead.org/users/hch/dma-mapping:
  dma-direct: fix DMA_ATTR_NO_KERNEL_MAPPING for remapped allocations
  x86/amd_gart: fix unmapping of non-GART mappings
  dma-mapping: remove a few unused exports
  dma-mapping: properly stub out the DMA API for !CONFIG_HAS_DMA
  dma-mapping: remove dmam_{declare,release}_coherent_memory
  dma-mapping: implement dmam_alloc_coherent using dmam_alloc_attrs
  dma-mapping: implement dma_map_single_attrs using dma_map_page_attrs
      e2b745f4
    • Linus Torvalds's avatar
      Merge tag 'tag-chrome-platform-for-v4.21' of... · 12133258
      Linus Torvalds authored 
      Merge tag 'tag-chrome-platform-for-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/bleung/chrome-platform

Pull chrome platform updates from Benson Leung:

 - Changes for EC_MKBP_EVENT_SENSOR_FIFO handling.

 - Also, maintainership changes. Olofj out, Enric balletbo in.

* tag 'tag-chrome-platform-for-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/bleung/chrome-platform:
  MAINTAINERS: add maintainers for ChromeOS EC sub-drivers
  MAINTAINERS: platform/chrome: Add Enric as a maintainer
  MAINTAINERS: platform/chrome: remove myself as maintainer
  platform/chrome: don't report EC_MKBP_EVENT_SENSOR_FIFO as wakeup
  platform/chrome: straighten out cros_ec_get_{next,host}_event() error codes
      12133258
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