Commit Graph

870983 Commits

Author SHA1 Message Date
Valdis Kletnieks
8e72a7a44d lib/extable.c: add missing prototypes
When building with W=1, a number of warnings are issued:

  CC      lib/extable.o
lib/extable.c:63:6: warning: no previous prototype for 'sort_extable' [-Wmissing-prototypes]
   63 | void sort_extable(struct exception_table_entry *start,
      |      ^~~~~~~~~~~~
lib/extable.c:75:6: warning: no previous prototype for 'trim_init_extable' [-Wmissing-prototypes]
   75 | void trim_init_extable(struct module *m)
      |      ^~~~~~~~~~~~~~~~~
lib/extable.c:115:1: warning: no previous prototype for 'search_extable' [-Wmissing-prototypes]
  115 | search_extable(const struct exception_table_entry *base,
      | ^~~~~~~~~~~~~~

Add the missing #include for the prototypes.

Link: http://lkml.kernel.org/r/45574.1565235784@turing-police
Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-25 17:51:39 -07:00
Valdis Kletnieks
e3f4faa420 lib/generic-radix-tree.c: make 2 functions static inline
When building with W=1, we get some warnings:

l  CC      lib/generic-radix-tree.o
lib/generic-radix-tree.c:39:10: warning: no previous prototype for 'genradix_root_to_depth' [-Wmissing-prototypes]
   39 | unsigned genradix_root_to_depth(struct genradix_root *r)
      |          ^~~~~~~~~~~~~~~~~~~~~~
lib/generic-radix-tree.c:44:23: warning: no previous prototype for 'genradix_root_to_node' [-Wmissing-prototypes]
   44 | struct genradix_node *genradix_root_to_node(struct genradix_root *r)
      |                       ^~~~~~~~~~~~~~~~~~~~~

They're not used anywhere else, so make them static inline.

Link: http://lkml.kernel.org/r/46923.1565236485@turing-police
Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-25 17:51:39 -07:00
Kees Cook
9a15646614 strscpy: reject buffer sizes larger than INT_MAX
As already done for snprintf(), add a check in strscpy() for giant (i.e.
likely negative and/or miscalculated) copy sizes, WARN, and error out.

Link: http://lkml.kernel.org/r/201907260928.23DE35406@keescook
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Joe Perches <joe@perches.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Yann Droneaud <ydroneaud@opteya.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Stephen Kitt <steve@sk2.org>
Cc: Jann Horn <jannh@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-25 17:51:39 -07:00
Qian Cai
d1a445d3b8 include/trace/events/writeback.h: fix -Wstringop-truncation warnings
There are many of those warnings.

In file included from ./arch/powerpc/include/asm/paca.h:15,
                 from ./arch/powerpc/include/asm/current.h:13,
                 from ./include/linux/thread_info.h:21,
                 from ./include/asm-generic/preempt.h:5,
                 from ./arch/powerpc/include/generated/asm/preempt.h:1,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from fs/fs-writeback.c:19:
In function 'strncpy',
    inlined from 'perf_trace_writeback_page_template' at
./include/trace/events/writeback.h:56:1:
./include/linux/string.h:260:9: warning: '__builtin_strncpy' specified
bound 32 equals destination size [-Wstringop-truncation]
  return __builtin_strncpy(p, q, size);
         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Fix it by using the new strscpy_pad() which was introduced in "lib/string:
Add strscpy_pad() function" and will always be NUL-terminated instead of
strncpy().  Also, change strlcpy() to use strscpy_pad() in this file for
consistency.

Link: http://lkml.kernel.org/r/1564075099-27750-1-git-send-email-cai@lca.pw
Fixes: 455b286468 ("writeback: Initial tracing support")
Fixes: 028c2dd184 ("writeback: Add tracing to balance_dirty_pages")
Fixes: e84d0a4f8e ("writeback: trace event writeback_queue_io")
Fixes: b48c104d22 ("writeback: trace event bdi_dirty_ratelimit")
Fixes: cc1676d917 ("writeback: Move requeueing when I_SYNC set to writeback_sb_inodes()")
Fixes: 9fb0a7da0c ("writeback: add more tracepoints")
Signed-off-by: Qian Cai <cai@lca.pw>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Tobin C. Harding <tobin@kernel.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Joe Perches <joe@perches.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Jann Horn <jannh@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Nitin Gote <nitin.r.gote@intel.com>
Cc: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Cc: Stephen Kitt <steve@sk2.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-25 17:51:39 -07:00
Joe Perches
917cda2790 kernel-doc: core-api: include string.h into core-api
core-api should show all the various string functions including the newly
added stracpy and stracpy_pad.

Miscellanea:

o Update the Returns: value for strscpy
o fix a defect with %NUL)

[joe@perches.com: correct return of -E2BIG descriptions]
  Link: http://lkml.kernel.org/r/29f998b4c1a9d69fbeae70500ba0daa4b340c546.1563889130.git.joe@perches.com
Link: http://lkml.kernel.org/r/224a6ebf39955f4107c0c376d66155d970e46733.1563841972.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Stephen Kitt <steve@sk2.org>
Cc: Nitin Gote <nitin.r.gote@intel.com>
Cc: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Cc: Jann Horn <jannh@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-25 17:51:39 -07:00
Michel Lespinasse
6d2052d188 augmented rbtree: rework the RB_DECLARE_CALLBACKS macro definition
Change the definition of the RBCOMPUTE function.  The propagate callback
repeatedly calls RBCOMPUTE as it moves from leaf to root.  it wants to
stop recomputing once the augmented subtree information doesn't change.
This was previously checked using the == operator, but that only works
when the augmented subtree information is a scalar field.  This commit
modifies the RBCOMPUTE function so that it now sets the augmented subtree
information instead of returning it, and returns a boolean value
indicating if the propagate callback should stop.

The motivation for this change is that I want to introduce augmented
rbtree uses where the augmented data for the subtree is a struct instead
of a scalar.

Link: http://lkml.kernel.org/r/20190703040156.56953-4-walken@google.com
Signed-off-by: Michel Lespinasse <walken@google.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Uladzislau Rezki <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-25 17:51:39 -07:00
Michel Lespinasse
315cc066b8 augmented rbtree: add new RB_DECLARE_CALLBACKS_MAX macro
Add RB_DECLARE_CALLBACKS_MAX, which generates augmented rbtree callbacks
for the case where the augmented value is a scalar whose definition
follows a max(f(node)) pattern.  This actually covers all present uses of
RB_DECLARE_CALLBACKS, and saves some (source) code duplication in the
various RBCOMPUTE function definitions.

[walken@google.com: fix mm/vmalloc.c]
  Link: http://lkml.kernel.org/r/CANN689FXgK13wDYNh1zKxdipeTuALG4eKvKpsdZqKFJ-rvtGiQ@mail.gmail.com
[walken@google.com: re-add check to check_augmented()]
  Link: http://lkml.kernel.org/r/20190727022027.GA86863@google.com
Link: http://lkml.kernel.org/r/20190703040156.56953-3-walken@google.com
Signed-off-by: Michel Lespinasse <walken@google.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Uladzislau Rezki <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-25 17:51:39 -07:00
Michel Lespinasse
444b8a83f1 augmented rbtree: add comments for RB_DECLARE_CALLBACKS macro
Patch series "make RB_DECLARE_CALLBACKS more generic", v3.

These changes are intended to make the RB_DECLARE_CALLBACKS macro more
generic (allowing the aubmented subtree information to be a struct instead
of a scalar).

I have verified the compiled lib/interval_tree.o and mm/mmap.o files to
check that they didn't change.  This held as expected for interval_tree.o;
mmap.o did have some changes which could be reverted by marking
__vma_link_rb as noinline.  I did not add such a change to the patchset; I
felt it was reasonable enough to leave the inlining decision up to the
compiler.

This patch (of 3):

Add a short comment summarizing the arguments to RB_DECLARE_CALLBACKS.
The arguments are also now capitalized.  This copies the style of the
INTERVAL_TREE_DEFINE macro.

No functional changes in this commit, only comments and capitalization.

Link: http://lkml.kernel.org/r/20190703040156.56953-2-walken@google.com
Signed-off-by: Michel Lespinasse <walken@google.com>
Acked-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Uladzislau Rezki <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-25 17:51:39 -07:00
Michel Lespinasse
c7d4f7eeb6 rbtree: avoid generating code twice for the cached versions (tools copy)
As was already noted in rbtree.h, the logic to cache rb_first (or
rb_last) can easily be implemented externally to the core rbtree api.

This commit takes the changes applied to the include/linux/ and lib/
rbtree files in 9f973cb380 ("lib/rbtree: avoid generating code twice
for the cached versions"), and applies these to the
tools/include/linux/ and tools/lib/ files as well to keep them
synchronized.

Link: http://lkml.kernel.org/r/20190703034812.53002-1-walken@google.com
Signed-off-by: Michel Lespinasse <walken@google.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-25 17:51:39 -07:00
Valdis Kletnieks
0f74914071 kernel/elfcore.c: include proper prototypes
When building with W=1, gcc properly complains that there's no prototypes:

  CC      kernel/elfcore.o
kernel/elfcore.c:7:17: warning: no previous prototype for 'elf_core_extra_phdrs' [-Wmissing-prototypes]
    7 | Elf_Half __weak elf_core_extra_phdrs(void)
      |                 ^~~~~~~~~~~~~~~~~~~~
kernel/elfcore.c:12:12: warning: no previous prototype for 'elf_core_write_extra_phdrs' [-Wmissing-prototypes]
   12 | int __weak elf_core_write_extra_phdrs(struct coredump_params *cprm, loff_t offset)
      |            ^~~~~~~~~~~~~~~~~~~~~~~~~~
kernel/elfcore.c:17:12: warning: no previous prototype for 'elf_core_write_extra_data' [-Wmissing-prototypes]
   17 | int __weak elf_core_write_extra_data(struct coredump_params *cprm)
      |            ^~~~~~~~~~~~~~~~~~~~~~~~~
kernel/elfcore.c:22:15: warning: no previous prototype for 'elf_core_extra_data_size' [-Wmissing-prototypes]
   22 | size_t __weak elf_core_extra_data_size(void)
      |               ^~~~~~~~~~~~~~~~~~~~~~~~

Provide the include file so gcc is happy, and we don't have potential code drift

Link: http://lkml.kernel.org/r/29875.1565224705@turing-police
Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-25 17:51:39 -07:00
Masahiro Yamada
541be05095 linux/coff.h: add include guard
Add a header include guard just in case.

My motivation is to allow Kbuild to detect missing include guard:

https://patchwork.kernel.org/patch/11063011/

Before I enable this checker I want to fix as many headers as possible.

Link: http://lkml.kernel.org/r/20190728154728.11126-1-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-25 17:51:39 -07:00
Michal Hocko
e55d9d9bfb memcg, kmem: do not fail __GFP_NOFAIL charges
Thomas has noticed the following NULL ptr dereference when using cgroup
v1 kmem limit:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
PGD 0
P4D 0
Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 3 PID: 16923 Comm: gtk-update-icon Not tainted 4.19.51 #42
Hardware name: Gigabyte Technology Co., Ltd. Z97X-Gaming G1/Z97X-Gaming G1, BIOS F9 07/31/2015
RIP: 0010:create_empty_buffers+0x24/0x100
Code: cd 0f 1f 44 00 00 0f 1f 44 00 00 41 54 49 89 d4 ba 01 00 00 00 55 53 48 89 fb e8 97 fe ff ff 48 89 c5 48 89 c2 eb 03 48 89 ca <48> 8b 4a 08 4c 09 22 48 85 c9 75 f1 48 89 6a 08 48 8b 43 18 48 8d
RSP: 0018:ffff927ac1b37bf8 EFLAGS: 00010286
RAX: 0000000000000000 RBX: fffff2d4429fd740 RCX: 0000000100097149
RDX: 0000000000000000 RSI: 0000000000000082 RDI: ffff9075a99fbe00
RBP: 0000000000000000 R08: fffff2d440949cc8 R09: 00000000000960c0
R10: 0000000000000002 R11: 0000000000000000 R12: 0000000000000000
R13: ffff907601f18360 R14: 0000000000002000 R15: 0000000000001000
FS:  00007fb55b288bc0(0000) GS:ffff90761f8c0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000008 CR3: 000000007aebc002 CR4: 00000000001606e0
Call Trace:
 create_page_buffers+0x4d/0x60
 __block_write_begin_int+0x8e/0x5a0
 ? ext4_inode_attach_jinode.part.82+0xb0/0xb0
 ? jbd2__journal_start+0xd7/0x1f0
 ext4_da_write_begin+0x112/0x3d0
 generic_perform_write+0xf1/0x1b0
 ? file_update_time+0x70/0x140
 __generic_file_write_iter+0x141/0x1a0
 ext4_file_write_iter+0xef/0x3b0
 __vfs_write+0x17e/0x1e0
 vfs_write+0xa5/0x1a0
 ksys_write+0x57/0xd0
 do_syscall_64+0x55/0x160
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Tetsuo then noticed that this is because the __memcg_kmem_charge_memcg
fails __GFP_NOFAIL charge when the kmem limit is reached.  This is a wrong
behavior because nofail allocations are not allowed to fail.  Normal
charge path simply forces the charge even if that means to cross the
limit.  Kmem accounting should be doing the same.

Link: http://lkml.kernel.org/r/20190906125608.32129-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Thomas Lindroth <thomas.lindroth@gmail.com>
Debugged-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Thomas Lindroth <thomas.lindroth@gmail.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-25 17:51:39 -07:00
Dave Airlie
da3fce4af7 - Multiple panfrost fixes for regulator support and page fault handling
- Some cleanups and fixes in the self-refresh helpers
  - Some cleanups and fixes in the atomic helpers
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYIAB0WIQRcEzekXsqa64kGDp7j7w1vZxhRxQUCXYjuIAAKCRDj7w1vZxhR
 xfNKAP9dlMLleLnjvAnCpI/Q2YZAktGCC9mIvqSzXJz52mwXNQEA5avYLerwa2+J
 P5xmO7mr2/9gzeeeWE1xaufQwZnYrwY=
 =Z99W
 -----END PGP SIGNATURE-----

Merge tag 'drm-misc-next-fixes-2019-09-23' of git://anongit.freedesktop.org/drm/drm-misc into drm-next

 - Multiple panfrost fixes for regulator support and page fault handling
 - Some cleanups and fixes in the self-refresh helpers
 - Some cleanups and fixes in the atomic helpers

Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Maxime Ripard <mripard@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190923160946.nvaqiw5j7fpcdhc7@gilmour
2019-09-26 08:48:23 +10:00
Andrii Nakryiko
4670d68b92 selftests/bpf: adjust strobemeta loop to satisfy latest clang
Some recent changes in latest Clang started causing the following
warning when unrolling strobemeta test case main loop:

  progs/strobemeta.h:416:2: warning: loop not unrolled: the optimizer was
  unable to perform the requested transformation; the transformation might
  be disabled or specified as part of an unsupported transformation
  ordering [-Wpass-failed=transform-warning]

This patch simplifies loop's exit condition to depend only on constant
max iteration number (STROBE_MAX_MAP_ENTRIES), while moving early
termination logic inside the loop body. The changes are equivalent from
program logic standpoint, but fixes the warning. It also appears to
improve generated BPF code, as it fixes previously failing non-unrolled
strobemeta test cases.

Cc: Alexei Starovoitov <ast@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-09-25 22:17:11 +02:00
Andrii Nakryiko
d778c30a05 selftests/bpf: delete unused variables in test_sysctl
Remove no longer used variables and avoid compiler warnings.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-09-25 22:16:17 +02:00
Andrii Nakryiko
aef70a1f44 libbpf: fix false uninitialized variable warning
Some compilers emit warning for potential uninitialized next_id usage.
The code is correct, but control flow is too complicated for some
compilers to figure this out. Re-initialize next_id to satisfy
compiler.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-09-25 22:15:02 +02:00
Jonathan Lemon
fcd30ae066 bpf/xskmap: Return ERR_PTR for failure case instead of NULL.
When kzalloc() failed, NULL was returned to the caller, which
tested the pointer with IS_ERR(), which didn't match, so the
pointer was used later, resulting in a NULL dereference.

Return ERR_PTR(-ENOMEM) instead of NULL.

Reported-by: syzbot+491c1b7565ba9069ecae@syzkaller.appspotmail.com
Fixes: 0402acd683 ("xsk: remove AF_XDP socket from map when the socket is released")
Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-09-25 22:14:16 +02:00
Stanislav Fomichev
8a03222f50 selftests/bpf: test_progs: fix client/server race in tcp_rtt
This is the same problem I found earlier in test_sockopt_inherit:
there is a race between server thread doing accept() and client
thread doing connect(). Let's explicitly synchronize them via
pthread conditional variable.

v2:
* don't exit from server_thread without signaling condvar,
  fixes possible issue where main() would wait forever (Andrii Nakryiko)

Fixes: b55873984d ("selftests/bpf: test BPF_SOCK_OPS_RTT_CB")
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-09-25 22:13:45 +02:00
Navid Emamdoost
104c307147 drm/amd/display: prevent memory leak
In dcn*_create_resource_pool the allocated memory should be released if
construct pool fails.

Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2019-09-25 14:58:38 -05:00
Arnaldo Carvalho de Melo
d6840d87b2 perf parser: Remove needless include directives
They go on accumulating there like the debug.h one, that was introduced
here:

  f23610245c ("perf list: Add debug support for outputing alias string")

But then, when that need is removed via:

  2073ad3326 ("perf tools: Factor out PMU matching in parser")

The thing stays there, so continue the house cleaning spree...

list.h not needed, no macros from there are used, and 'struct
list_head' is in linux/types.h, ditto for util.h, no need for that as
well.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-zkxr3mf6inun8m5mbnil4u0d@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-09-25 16:26:41 -03:00
Thomas Richter
815c1560bf perf build: Add detection of java-11-openjdk-devel package
With Java 11 there is no seperate JRE anymore.

Details:

  https://coderanch.com/t/701603/java/JRE-JDK

Therefore the detection of the JRE needs to be adapted.

This change works for s390 and x86.  I have not tested other platforms.

Committer testing:

Continues to work with the OpenJDK 8:

  $ rm -f ~acme/lib64/libperf-jvmti.so
  $ rpm -qa | grep jdk-devel
  java-1.8.0-openjdk-devel-1.8.0.222.b10-0.fc30.x86_64
  $ git log --oneline -1
  a51937170f33 (HEAD -> perf/core) perf build: Add detection of java-11-openjdk-devel package
  $ rm -rf /tmp/build/perf ; mkdir -p /tmp/build/perf ; make -C tools/perf O=/tmp/build/perf install > /dev/null 2>1
  $ ls -la ~acme/lib64/libperf-jvmti.so
  -rwxr-xr-x. 1 acme acme 230744 Sep 24 16:46 /home/acme/lib64/libperf-jvmti.so
  $

Suggested-by: Andreas Krebbel <krebbel@linux.ibm.com>
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Hendrik Brueckner <brueckner@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Link: http://lore.kernel.org/lkml/20190909114116.50469-4-tmricht@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-09-25 16:26:41 -03:00
Thomas Richter
61bf4ee29d perf jvmti: Include JVMTI support for s390
Enable JVMTI support for s390 perf tool chain.

Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Hendrik Brueckner <brueckner@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Link: http://lore.kernel.org/lkml/20190909114116.50469-3-tmricht@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-09-25 16:26:41 -03:00
Mamatha Inamdar
28b951760c perf vendor events: Remove P8 HW events which are not supported
This patch is to remove following hardware events
from JSON file which are not supported on POWER8.

pm_l3_p0_grp_pump
pm_l3_p0_lco_data
pm_l3_p0_lco_no_data
pm_l3_p0_lco_rty

  Note: Unfortunately power8 event list is not publicly available.

Fixes: c3b4d5c4af ("perf vendor events: Remove P8 HW events which are not supported")
Signed-off-by: Mamatha Inamdar <mamatha4@linux.vnet.ibm.com>
Acked-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20190909065624.11956.3992.stgit@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-09-25 16:26:40 -03:00
Andi Kleen
7834fa948b perf evlist: Fix access of freed id arrays
I'm not fully sure if this is the correct fix, but without this I get
crashes on more complex perf stat metric usages. The problem is that
part of the state gets freed when a weak group fails, but then is later
still used. Just don't free the ids, we're going to reuse them anyways
on the weak group retry.

For example:

  % perf stat -M IpB,IpCall,IpTB,IPC,Retiring_SMT,Frontend_Bound_SMT,Kernel_Utilization,CPU_Utilization --metric-only -a -I 1000 sleep 2

  crashes and gives in valgrind:

  =21527== Invalid write of size 8
  ==21527==    at 0x4EE582: hlist_add_head (list.h:644)
  ==21527==    by 0x4EFD3C: perf_evlist__id_hash (evlist.c:477)
  ==21527==    by 0x4EFD99: perf_evlist__id_add (evlist.c:483)
  ==21527==    by 0x4EFF15: perf_evlist__id_add_fd (evlist.c:524)
  ==21527==    by 0x4FC693: store_evsel_ids (evsel.c:2969)
  ==21527==    by 0x4FC76C: perf_evsel__store_ids (evsel.c:2986)
  ==21527==    by 0x450DA7: __run_perf_stat (builtin-stat.c:519)
  ==21527==    by 0x451285: run_perf_stat (builtin-stat.c:636)
  ==21527==    by 0x454619: cmd_stat (builtin-stat.c:1966)
  ==21527==    by 0x4D557D: run_builtin (perf.c:310)
  ==21527==    by 0x4D57EA: handle_internal_command (perf.c:362)
  ==21527==    by 0x4D5931: run_argv (perf.c:406)
  ==21527==  Address 0x12e3f008 is 104 bytes inside a block of size 2,056 free'd
  ==21527==    at 0x4839A0C: free (vg_replace_malloc.c:540)
  ==21527==    by 0x627139: xyarray__delete (xyarray.c:32)
  ==21527==    by 0x4F6BE4: perf_evsel__free_id (evsel.c:1253)
  ==21527==    by 0x4FA11F: evsel__close (evsel.c:1994)
  ==21527==    by 0x4F30A3: perf_evlist__reset_weak_group (evlist.c:1783)
  ==21527==    by 0x450B47: __run_perf_stat (builtin-stat.c:466)
  ==21527==    by 0x451285: run_perf_stat (builtin-stat.c:636)
  ==21527==    by 0x454619: cmd_stat (builtin-stat.c:1966)
  ==21527==    by 0x4D557D: run_builtin (perf.c:310)
  ==21527==    by 0x4D57EA: handle_internal_command (perf.c:362)
  ==21527==    by 0x4D5931: run_argv (perf.c:406)
  ==21527==    by 0x4D5CAE: main (perf.c:531)
  ==21527==  Block was alloc'd at
  ==21527==    at 0x483AB1A: calloc (vg_replace_malloc.c:762)
  ==21527==    by 0x627024: zalloc (zalloc.c:8)
  ==21527==    by 0x627088: xyarray__new (xyarray.c:10)
  ==21527==    by 0x4F6B20: perf_evsel__alloc_id (evsel.c:1237)
  ==21527==    by 0x4FC74E: perf_evsel__store_ids (evsel.c:2983)
  ==21527==    by 0x450DA7: __run_perf_stat (builtin-stat.c:519)
  ==21527==    by 0x451285: run_perf_stat (builtin-stat.c:636)
  ==21527==    by 0x454619: cmd_stat (builtin-stat.c:1966)
  ==21527==    by 0x4D557D: run_builtin (perf.c:310)
  ==21527==    by 0x4D57EA: handle_internal_command (perf.c:362)
  ==21527==    by 0x4D5931: run_argv (perf.c:406)
  ==21527==    by 0x4D5CAE: main (perf.c:531)

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: http://lore.kernel.org/lkml/20190923233339.25326-1-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-09-25 16:26:40 -03:00
Andi Kleen
6f6473c37d perf stat: Fix free memory access / memory leaks in metrics
Make sure to not free the name passed in by the caller, but free all the
allocated ids when parsing expressions.

The loop at the end knows that the first entry shouldn't be freed, so
make sure the caller name is the first entry.

Fixes

  % perf stat -M IpB,IpCall,IpTB,IPC,Retiring_SMT,Frontend_Bound_SMT,Kernel_Utilization,CPU_Utilization --metric-only -a -I 1000 sleep 2

  valgrind:
       1.009943231 ==21527== Invalid read of size 1
  ==21527==    at 0x483CB74: strcmp (vg_replace_strmem.c:849)
  ==21527==    by 0x582CF8: collect_all_aliases (stat-display.c:554)
  ==21527==    by 0x582EB3: collect_data (stat-display.c:577)
  ==21527==    by 0x583A32: print_counter_aggr (stat-display.c:806)
  ==21527==    by 0x584FAD: perf_evlist__print_counters (stat-display.c:1200)
  ==21527==    by 0x45133A: print_counters (builtin-stat.c:655)
  ==21527==    by 0x450629: process_interval (builtin-stat.c:353)
  ==21527==    by 0x450FBD: __run_perf_stat (builtin-stat.c:564)
  ==21527==    by 0x451285: run_perf_stat (builtin-stat.c:636)
  ==21527==    by 0x454619: cmd_stat (builtin-stat.c:1966)
  ==21527==    by 0x4D557D: run_builtin (perf.c:310)
  ==21527==    by 0x4D57EA: handle_internal_command (perf.c:362)
  ==21527==  Address 0x12826cd0 is 0 bytes inside a block of size 25 free'd
  ==21527==    at 0x4839A0C: free (vg_replace_malloc.c:540)
  ==21527==    by 0x627041: __zfree (zalloc.c:13)
  ==21527==    by 0x57F66A: generic_metric (stat-shadow.c:814)
  ==21527==    by 0x580B21: perf_stat__print_shadow_stats (stat-shadow.c:1057)
  ==21527==    by 0x58418E: print_metric_headers (stat-display.c:943)
  ==21527==    by 0x5844BC: print_interval (stat-display.c:1004)
  ==21527==    by 0x584DEB: perf_evlist__print_counters (stat-display.c:1172)
  ==21527==    by 0x45133A: print_counters (builtin-stat.c:655)
  ==21527==    by 0x450629: process_interval (builtin-stat.c:353)
  ==21527==    by 0x450FBD: __run_perf_stat (builtin-stat.c:564)
  ==21527==    by 0x451285: run_perf_stat (builtin-stat.c:636)
  ==21527==    by 0x454619: cmd_stat (builtin-stat.c:1966)
  ==21527==  Block was alloc'd at
  ==21527==    at 0x483880B: malloc (vg_replace_malloc.c:309)
  ==21527==    by 0x51677DE: strdup (in /usr/lib64/libc-2.29.so)
  ==21527==    by 0x506457: parse_events_name (parse-events.c:1754)
  ==21527==    by 0x5550BB: parse_events_parse (parse-events.y:214)
  ==21527==    by 0x50694D: parse_events__scanner (parse-events.c:1887)
  ==21527==    by 0x506AEF: parse_events (parse-events.c:1927)
  ==21527==    by 0x521D8B: metricgroup__parse_groups (metricgroup.c:527)
  ==21527==    by 0x45156F: parse_metric_groups (builtin-stat.c:721)
  ==21527==    by 0x6228A9: get_value (parse-options.c:243)
  ==21527==    by 0x62363F: parse_short_opt (parse-options.c:348)
  ==21527==    by 0x62363F: parse_options_step (parse-options.c:536)
  ==21527==    by 0x62363F: parse_options_subcommand (parse-options.c:651)
  ==21527==    by 0x453C1D: cmd_stat (builtin-stat.c:1718)
  ==21527==    by 0x4D557D: run_builtin (perf.c:310)

and also a leak report.

Committer testing:

Before:

  # perf stat -M IpB,IpCall,IpTB,IPC,Retiring_SMT,Frontend_Bound_SMT,Kernel_Utilization,CPU_Utilization --metric-only -a -I 1000 sleep 2
  #           time      CPU_Utilization
       1.000470810                      free(): double free detected in tcache 2
  Aborted (core dumped)
  #

After:

  # perf stat -M IpB,IpCall,IpTB,IPC,Retiring_SMT,Frontend_Bound_SMT,Kernel_Utilization,CPU_Utilization --metric-only -a -I 1000 sleep 2
  #           time      CPU_Utilization
       1.000494752                  0.1
       2.001105112                  0.1
  #

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: http://lore.kernel.org/lkml/20190923233339.25326-3-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-09-25 16:26:40 -03:00
Arnaldo Carvalho de Melo
252a2fdc74 perf tools: Replace needless mmap.h with what is needed, event.h
The perf_sample struct definition and the event_attr_init() are in
util/event.h, but some places were getting it thru an otherwise needless
util/mmap.h header, fix it by including util/event.h directly.

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-p1anwyjdbbvghrkl9dlxv7h5@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-09-25 16:26:40 -03:00
Arnaldo Carvalho de Melo
95be9d197d perf evsel: Move config terms to a separate header
Further reducing the size of util/evsel.h.

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-20zr7di9eynm0272mtjfdhfc@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-09-25 16:26:40 -03:00
Arnaldo Carvalho de Melo
bd70462062 perf evlist: Remove unused perf_evlist__fprintf() method
Ditch it, noone is using it, one more stdio.h include in a hot header.

Fix the fallout in parse-events.y, where we end up using a FILE pointer,
I think due to YYDEBUG being set and in some places, like Amazon Linux 1
we don't get stdio.h included by luck, like in most other places, add a
explicit stdio.h include directive.

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-37k5q0lhdbo2hvvfbnnzn7og@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-09-25 16:26:40 -03:00
Arnaldo Carvalho de Melo
ca1252779f perf evsel: Introduce evsel_fprintf.h
We already had evsel_fprintf.c, add its counterpart, so that we can
reduce evsel.h a bit more.

We needed a new perf_event_attr_fprintf.c file so as to have a separate
object to link with the python binding in tools/perf/util/python-ext-sources
and not drag symbol_conf, etc into the python binding.

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-06bdmt1062d9unzgqmxwlv88@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-09-25 16:26:34 -03:00
Arnaldo Carvalho de Melo
9620bc361a perf evsel: Remove need for symbol_conf in evsel_fprintf.c
So that we an later link it to the python binding without having to
drag the symbol object files.

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-8823tveyasocnuoelq4qopwf@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-09-25 15:06:59 -03:00
Paolo Bonzini
fd3edd4a90 KVM: nVMX: cleanup and fix host 64-bit mode checks
KVM was incorrectly checking vmcs12->host_ia32_efer even if the "load
IA32_EFER" exit control was reset.  Also, some checks were not using
the new CC macro for tracing.

Cleanup everything so that the vCPU's 64-bit mode is determined
directly from EFER_LMA and the VMCS checks are based on that, which
matches section 26.2.4 of the SDM.

Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Fixes: 5845038c11
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-25 19:22:33 +02:00
Linus Torvalds
f41def3971 The highlights are:
- automatic recovery of a blacklisted filesystem session (Zheng Yan).
   This is disabled by default and can be enabled by mounting with the
   new "recover_session=clean" option.
 
 - serialize buffered reads and O_DIRECT writes (Jeff Layton).  Care is
   taken to avoid serializing O_DIRECT reads and writes with each other,
   this is based on the exclusion scheme from NFS.
 
 - handle large osdmaps better in the face of fragmented memory (myself)
 
 - don't limit what security.* xattrs can be get or set (Jeff Layton).
   We were overly restrictive here, unnecessarily preventing things like
   file capability sets stored in security.capability from working.
 
 - allow copy_file_range() within the same inode and across different
   filesystems within the same cluster (Luis Henriques)
 -----BEGIN PGP SIGNATURE-----
 
 iQFHBAABCAAxFiEEydHwtzie9C7TfviiSn/eOAIR84sFAl2LoD8THGlkcnlvbW92
 QGdtYWlsLmNvbQAKCRBKf944AhHzixRYB/9H5S4fif8Pn9eiXkIJiT9UZR/o7S1k
 ikfQNPeDxlBLKnoZXpDp2HqCu1/YuCcJ0zpZzPGGrKECZb7r+NaayxhmEXAZ+Vsg
 YwsO3eNHBbb58pe9T4oiHp19sflwcTOeNwg8wlvmvrgfBupFz2pU8Xm72EdFyoYm
 tP0QNTOCAuQK3pJcgozaptAO1TzBL3LomyVM0YzAKcumgMg47zALpaSLWJLGtDLM
 5+5WLvcVfBGLVv60h4B62ldS39eBxqTsFodcRMUaqAsnhLK70HVfKlwR3GgtZggr
 PDqbsuIfw/O3b65U2XDKZt1P9dyG3OE/ucueduXUxJPYNGmooEE+PpE+
 =DRVP
 -----END PGP SIGNATURE-----

Merge tag 'ceph-for-5.4-rc1' of git://github.com/ceph/ceph-client

Pull ceph updates from Ilya Dryomov:
 "The highlights are:

   - automatic recovery of a blacklisted filesystem session (Zheng Yan).
     This is disabled by default and can be enabled by mounting with the
     new "recover_session=clean" option.

   - serialize buffered reads and O_DIRECT writes (Jeff Layton). Care is
     taken to avoid serializing O_DIRECT reads and writes with each
     other, this is based on the exclusion scheme from NFS.

   - handle large osdmaps better in the face of fragmented memory
     (myself)

   - don't limit what security.* xattrs can be get or set (Jeff Layton).
     We were overly restrictive here, unnecessarily preventing things
     like file capability sets stored in security.capability from
     working.

   - allow copy_file_range() within the same inode and across different
     filesystems within the same cluster (Luis Henriques)"

* tag 'ceph-for-5.4-rc1' of git://github.com/ceph/ceph-client: (41 commits)
  ceph: call ceph_mdsc_destroy from destroy_fs_client
  libceph: use ceph_kvmalloc() for osdmap arrays
  libceph: avoid a __vmalloc() deadlock in ceph_kvmalloc()
  ceph: allow object copies across different filesystems in the same cluster
  ceph: include ceph_debug.h in cache.c
  ceph: move static keyword to the front of declarations
  rbd: pull rbd_img_request_create() dout out into the callers
  ceph: reconnect connection if session hang in opening state
  libceph: drop unused con parameter of calc_target()
  ceph: use release_pages() directly
  rbd: fix response length parameter for encoded strings
  ceph: allow arbitrary security.* xattrs
  ceph: only set CEPH_I_SEC_INITED if we got a MAC label
  ceph: turn ceph_security_invalidate_secctx into static inline
  ceph: add buffered/direct exclusionary locking for reads and writes
  libceph: handle OSD op ceph_pagelist_append() errors
  ceph: don't return a value from void function
  ceph: don't freeze during write page faults
  ceph: update the mtime when truncating up
  ceph: fix indentation in __get_snap_name()
  ...
2019-09-25 10:21:13 -07:00
Linus Torvalds
7b1373dd6e fuse update for 5.4
-----BEGIN PGP SIGNATURE-----
 
 iHUEABYIAB0WIQSQHSd0lITzzeNWNm3h3BK/laaZPAUCXYod6wAKCRDh3BK/laaZ
 PG3fAP9WXuvUeYh3X7ThQPa2D33VCIMJRd6t+1TVSSc/H8P3dAD/ehN5HIWjnmzz
 iZFc3zDtO9UCJUe23IZomblxOQbu6Qk=
 =I0S2
 -----END PGP SIGNATURE-----

Merge tag 'fuse-update-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse

Pull fuse updates from Miklos Szeredi:

 - Continue separating the transport (user/kernel communication) and the
   filesystem layers of fuse. Getting rid of most layering violations
   will allow for easier cleanup and optimization later on.

 - Prepare for the addition of the virtio-fs filesystem. The actual
   filesystem will be introduced by a separate pull request.

 - Convert to new mount API.

 - Various fixes, optimizations and cleanups.

* tag 'fuse-update-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: (55 commits)
  fuse: Make fuse_args_to_req static
  fuse: fix memleak in cuse_channel_open
  fuse: fix beyond-end-of-page access in fuse_parse_cache()
  fuse: unexport fuse_put_request
  fuse: kmemcg account fs data
  fuse: on 64-bit store time in d_fsdata directly
  fuse: fix missing unlock_page in fuse_writepage()
  fuse: reserve byteswapped init opcodes
  fuse: allow skipping control interface and forced unmount
  fuse: dissociate DESTROY from fuseblk
  fuse: delete dentry if timeout is zero
  fuse: separate fuse device allocation and installation in fuse_conn
  fuse: add fuse_iqueue_ops callbacks
  fuse: extract fuse_fill_super_common()
  fuse: export fuse_dequeue_forget() function
  fuse: export fuse_get_unique()
  fuse: export fuse_send_init_request()
  fuse: export fuse_len_args()
  fuse: export fuse_end_request()
  fuse: fix request limit
  ...
2019-09-25 09:55:59 -07:00
Linus Torvalds
301310c6d2 tpmdd fixes for Linux v5.4
-----BEGIN PGP SIGNATURE-----
 
 iJYEABYIAD4WIQRE6pSOnaBC00OEHEIaerohdGur0gUCXYqr6iAcamFya2tvLnNh
 a2tpbmVuQGxpbnV4LmludGVsLmNvbQAKCRAaerohdGur0pspAP9pmSqIde7M2BJD
 kRmkiannjbl55Ss5+RX+oqOLwtezewEAzgK/vQkm/AWZPqix274qdOMTOX1jjwUZ
 JnvsxZrEuQc=
 =l6Vw
 -----END PGP SIGNATURE-----

Merge tag 'tpmdd-next-20190925' of git://git.infradead.org/users/jjs/linux-tpmdd

Pull tpm fixes from Jarkko Sakkinen.

* tag 'tpmdd-next-20190925' of git://git.infradead.org/users/jjs/linux-tpmdd:
  tpm: Wrap the buffer from the caller to tpm_buf in tpm_send()
  MAINTAINERS: keys: Update path to trusted.h
  KEYS: trusted: correctly initialize digests and fix locking issue
  selftests/tpm2: Add log and *.pyc to .gitignore
  selftests/tpm2: Add the missing TEST_FILES assignment
2019-09-25 09:40:24 -07:00
Linus Torvalds
4ef5b13a29 New code for 5.4:
- Report both io errors and short io results to the directio endio
   handler.
 - Allow directio callers to pass an ops structure to iomap_dio_rw.
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEUzaAxoMeQq6m2jMV+H93GTRKtOsFAl2EQBwACgkQ+H93GTRK
 tOvZ0w//R00Dya3pZmO+HQX/Kovo/AOKCct/gPaLvRf4DVvWZ3ZH5lPtDUSKCHBV
 Pw+potTuabwtp//mZrQ84ZMoQYOmxBmxchquJ2L49qWT/mZ1BDqBA2sxQOCehffO
 Dlv715eOPVhkVHOEAHv+BsatxlFDkuKgGcwUqxE4LNHWGrvmjm6rBWPCnxQMTwX9
 BhGo/0WG6D0leWFSMoUIpcD4Oj302/O43RX4lJsyl0Jd5pKJD/RFtaKqwIeE+pj9
 36MnoQYtT5e9BTm1/zzHRVpGgLDDWTY+IClgZNlZprU/Em+TtOGMWitWzob3wWcU
 QHj5bJ9NiWBT6QJ192i0+I0thSTwW/peOAJrkBOW3YhBkH3UIKSzaPiwCBoSEUKS
 fuIOJkRHFW7HTjKSw6wUCJJ6ShD+rNPOoaJ9Ivzz7x2HGEqb1al3EIumu6oDJgyq
 BdnLEecN/JSxPnakpSGAnvlCjZiYbJ95E0JfapzMy7HYpMXfbzZZ4JO9Ld0hQflR
 sMrGwL82tqE9ish1yRr+2nNEY5PqVJqV0XXU3dZz3HVknNuAvqrqXDXgIZT142zS
 s9vGAW+2XphyUKHH9pImQKw142n2xiZK+Pd2AuiO4I06E0EkAvN/n9CN7oJ4Cr4F
 z9rQKNXNx8OSjFtryYe6+IzQ0qQtl2OP7o88K91jYArKP17D8ds=
 =zkFp
 -----END PGP SIGNATURE-----

Merge tag 'iomap-5.4-merge-6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull iomap updates from Darrick Wong:
 "After last week's failed pull request attempt, I scuttled everything
  in the branch except for the directio endio api changes, which were
  trivial. Everything else will simply have to wait for the next cycle.

  Summary:

   - Report both io errors and short io results to the directio endio
     handler.

   - Allow directio callers to pass an ops structure to iomap_dio_rw"

* tag 'iomap-5.4-merge-6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  iomap: move the iomap_dio_rw ->end_io callback into a structure
  iomap: split size and error for iomap_dio_rw ->end_io
2019-09-25 09:01:43 -07:00
Quentin Perret
4892f51ad5 sched/fair: Avoid redundant EAS calculation
The EAS wake-up path computes the system energy for several CPU
candidates: the CPU with maximum spare capacity in each performance
domain, and the prev_cpu. However, if prev_cpu also happens to be the
CPU with maximum spare capacity in its performance domain, the energy
calculation is still done twice, unnecessarily.

Add a condition to filter out this corner case before doing the energy
calculation.

Reported-by: Pavan Kondeti <pkondeti@codeaurora.org>
Signed-off-by: Quentin Perret <qperret@qperret.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dietmar.eggemann@arm.com
Cc: juri.lelli@redhat.com
Cc: morten.rasmussen@arm.com
Cc: qais.yousef@arm.com
Cc: rjw@rjwysocki.net
Cc: tkjos@google.com
Cc: valentin.schneider@arm.com
Cc: vincent.guittot@linaro.org
Fixes: eb92692b25 ("sched/fair: Speed-up energy-aware wake-ups")
Link: https://lkml.kernel.org/r/20190920094115.GA11503@qperret.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-09-25 17:42:32 +02:00
Valentin Schneider
9fc41acc89 sched/core: Remove double update_max_interval() call on CPU startup
update_max_interval() is called in both CPUHP_AP_SCHED_STARTING's startup
and teardown callbacks, but it turns out it's also called at the end of
the startup callback of CPUHP_AP_ACTIVE (which is further down the
startup sequence).

There's no point in repeating this interval update in the startup sequence
since the CPU will remain online until it goes down the teardown path.

Remove the redundant call in sched_cpu_activate() (CPUHP_AP_ACTIVE).

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dietmar.eggemann@arm.com
Cc: juri.lelli@redhat.com
Cc: vincent.guittot@linaro.org
Link: https://lkml.kernel.org/r/20190923093017.11755-1-valentin.schneider@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-09-25 17:42:32 +02:00
Valentin Schneider
a49b4f4012 sched/core: Fix preempt_schedule() interrupt return comment
preempt_schedule_irq() is the one that should be called on return from
interrupt, clean up the comment to avoid any ambiguity.

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-m68k@lists.linux-m68k.org
Cc: linux-riscv@lists.infradead.org
Cc: uclinux-h8-devel@lists.sourceforge.jp
Link: https://lkml.kernel.org/r/20190923143620.29334-2-valentin.schneider@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-09-25 17:42:32 +02:00
Qian Cai
763a9ec06c sched/fair: Fix -Wunused-but-set-variable warnings
Commit:

   de53fd7aed ("sched/fair: Fix low cpu usage with high throttling by removing expiration of cpu-local slices")

introduced a few compilation warnings:

  kernel/sched/fair.c: In function '__refill_cfs_bandwidth_runtime':
  kernel/sched/fair.c:4365:6: warning: variable 'now' set but not used [-Wunused-but-set-variable]
  kernel/sched/fair.c: In function 'start_cfs_bandwidth':
  kernel/sched/fair.c:4992:6: warning: variable 'overrun' set but not used [-Wunused-but-set-variable]

Also, __refill_cfs_bandwidth_runtime() does no longer update the
expiration time, so fix the comments accordingly.

Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ben Segall <bsegall@google.com>
Reviewed-by: Dave Chiluk <chiluk+linux@indeed.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: pauld@redhat.com
Fixes: de53fd7aed ("sched/fair: Fix low cpu usage with high throttling by removing expiration of cpu-local slices")
Link: https://lkml.kernel.org/r/1566326455-8038-1-git-send-email-cai@lca.pw
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-09-25 17:42:31 +02:00
KeMeng Shi
714e501e16 sched/core: Fix migration to invalid CPU in __set_cpus_allowed_ptr()
An oops can be triggered in the scheduler when running qemu on arm64:

 Unable to handle kernel paging request at virtual address ffff000008effe40
 Internal error: Oops: 96000007 [#1] SMP
 Process migration/0 (pid: 12, stack limit = 0x00000000084e3736)
 pstate: 20000085 (nzCv daIf -PAN -UAO)
 pc : __ll_sc___cmpxchg_case_acq_4+0x4/0x20
 lr : move_queued_task.isra.21+0x124/0x298
 ...
 Call trace:
  __ll_sc___cmpxchg_case_acq_4+0x4/0x20
  __migrate_task+0xc8/0xe0
  migration_cpu_stop+0x170/0x180
  cpu_stopper_thread+0xec/0x178
  smpboot_thread_fn+0x1ac/0x1e8
  kthread+0x134/0x138
  ret_from_fork+0x10/0x18

__set_cpus_allowed_ptr() will choose an active dest_cpu in affinity mask to
migrage the process if process is not currently running on any one of the
CPUs specified in affinity mask. __set_cpus_allowed_ptr() will choose an
invalid dest_cpu (dest_cpu >= nr_cpu_ids, 1024 in my virtual machine) if
CPUS in an affinity mask are deactived by cpu_down after cpumask_intersects
check. cpumask_test_cpu() of dest_cpu afterwards is overflown and may pass if
corresponding bit is coincidentally set. As a consequence, kernel will
access an invalid rq address associate with the invalid CPU in
migration_cpu_stop->__migrate_task->move_queued_task and the Oops occurs.

The reproduce the crash:

  1) A process repeatedly binds itself to cpu0 and cpu1 in turn by calling
  sched_setaffinity.

  2) A shell script repeatedly does "echo 0 > /sys/devices/system/cpu/cpu1/online"
  and "echo 1 > /sys/devices/system/cpu/cpu1/online" in turn.

  3) Oops appears if the invalid CPU is set in memory after tested cpumask.

Signed-off-by: KeMeng Shi <shikemeng@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/1568616808-16808-1-git-send-email-shikemeng@huawei.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-09-25 17:42:31 +02:00
Mathieu Desnoyers
c172e0a3e8 sched/membarrier: Return -ENOMEM to userspace on memory allocation failure
Remove the IPI fallback code from membarrier to deal with very
infrequent cpumask memory allocation failure. Use GFP_KERNEL rather
than GFP_NOWAIT, and relax the blocking guarantees for the expedited
membarrier system call commands, allowing it to block if waiting for
memory to be made available.

In addition, now -ENOMEM can be returned to user-space if the cpumask
memory allocation fails.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kirill Tkhai <tkhai@yandex.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190919173705.2181-8-mathieu.desnoyers@efficios.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-09-25 17:42:31 +02:00
Mathieu Desnoyers
c6d68c1c4a sched/membarrier: Skip IPIs when mm->mm_users == 1
If there is only a single mm_user for the mm, the private expedited
membarrier command can skip the IPIs, because only a single thread
is using the mm.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kirill Tkhai <tkhai@yandex.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190919173705.2181-7-mathieu.desnoyers@efficios.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-09-25 17:42:31 +02:00
Mathieu Desnoyers
19a4ff534b selftests, sched/membarrier: Add multi-threaded test
membarrier commands cover very different code paths if they are in
a single-threaded vs multi-threaded process. Therefore, exercise both
scenarios in the kernel selftests to increase coverage of this selftest.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kirill Tkhai <tkhai@yandex.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190919173705.2181-6-mathieu.desnoyers@efficios.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-09-25 17:42:31 +02:00
Mathieu Desnoyers
227a4aadc7 sched/membarrier: Fix p->mm->membarrier_state racy load
The membarrier_state field is located within the mm_struct, which
is not guaranteed to exist when used from runqueue-lock-free iteration
on runqueues by the membarrier system call.

Copy the membarrier_state from the mm_struct into the scheduler runqueue
when the scheduler switches between mm.

When registering membarrier for mm, after setting the registration bit
in the mm membarrier state, issue a synchronize_rcu() to ensure the
scheduler observes the change. In order to take care of the case
where a runqueue keeps executing the target mm without swapping to
other mm, iterate over each runqueue and issue an IPI to copy the
membarrier_state from the mm_struct into each runqueue which have the
same mm which state has just been modified.

Move the mm membarrier_state field closer to pgd in mm_struct to use
a cache line already touched by the scheduler switch_mm.

The membarrier_execve() (now membarrier_exec_mmap) hook now needs to
clear the runqueue's membarrier state in addition to clear the mm
membarrier state, so move its implementation into the scheduler
membarrier code so it can access the runqueue structure.

Add memory barrier in membarrier_exec_mmap() prior to clearing
the membarrier state, ensuring memory accesses executed prior to exec
are not reordered with the stores clearing the membarrier state.

As suggested by Linus, move all membarrier.c RCU read-side locks outside
of the for each cpu loops.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kirill Tkhai <tkhai@yandex.ru>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190919173705.2181-5-mathieu.desnoyers@efficios.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-09-25 17:42:30 +02:00
Mathieu Desnoyers
2840cf02fa sched/membarrier: Call sync_core only before usermode for same mm
When the prev and next task's mm change, switch_mm() provides the core
serializing guarantees before returning to usermode. The only case
where an explicit core serialization is needed is when the scheduler
keeps the same mm for prev and next.

Suggested-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kirill Tkhai <tkhai@yandex.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190919173705.2181-4-mathieu.desnoyers@efficios.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-09-25 17:42:30 +02:00
Mathieu Desnoyers
09554009c0 sched/membarrier: Remove redundant check
Checking that the number of threads is 1 is redundant with checking
mm_users == 1.

No change in functionality intended.

Suggested-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kirill Tkhai <tkhai@yandex.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190919173705.2181-3-mathieu.desnoyers@efficios.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-09-25 17:42:30 +02:00
Mathieu Desnoyers
fc0d77387c sched/membarrier: Fix private expedited registration check
Fix a logic flaw in the way membarrier_register_private_expedited()
handles ready state checks for private expedited sync core and private
expedited registrations.

If a private expedited membarrier registration is first performed, and
then a private expedited sync_core registration is performed, the ready
state check will skip the second registration when it really should not.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kirill Tkhai <tkhai@yandex.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190919173705.2181-2-mathieu.desnoyers@efficios.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-09-25 17:42:30 +02:00
Eric W. Biederman
5311a98fef tasks, sched/core: RCUify the assignment of rq->curr
The current task on the runqueue is currently read with rcu_dereference().

To obtain ordinary RCU semantics for an rcu_dereference() of rq->curr it needs
to be paired with rcu_assign_pointer() of rq->curr.  Which provides the
memory barrier necessary to order assignments to the task_struct
and the assignment to rq->curr.

Unfortunately the assignment of rq->curr in __schedule is a hot path,
and it has already been show that additional barriers in that code
will reduce the performance of the scheduler.  So I will attempt to
describe below why you can effectively have ordinary RCU semantics
without any additional barriers.

The assignment of rq->curr in init_idle is a slow path called once
per cpu and that can use rcu_assign_pointer() without any concerns.

As I write this there are effectively two users of rcu_dereference() on
rq->curr.  There is the membarrier code in kernel/sched/membarrier.c
that only looks at "->mm" after the rcu_dereference().  Then there is
task_numa_compare() in kernel/sched/fair.c.  My best reading of the
code shows that task_numa_compare only access: "->flags",
"->cpus_ptr", "->numa_group", "->numa_faults[]",
"->total_numa_faults", and "->se.cfs_rq".

The code in __schedule() essentially does:
	rq_lock(...);
	smp_mb__after_spinlock();

	next = pick_next_task(...);
	rq->curr = next;

	context_switch(prev, next);

At the start of the function the rq_lock/smp_mb__after_spinlock
pair provides a full memory barrier.  Further there is a full memory barrier
in context_switch().

This means that any task that has already run and modified itself (the
common case) has already seen two memory barriers before __schedule()
runs and begins executing.  A task that modifies itself then sees a
third full memory barrier pair with the rq_lock();

For a brand new task that is enqueued with wake_up_new_task() there
are the memory barriers present from the taking and release the
pi_lock and the rq_lock as the processes is enqueued as well as the
full memory barrier at the start of __schedule() assuming __schedule()
happens on the same cpu.

This means that by the time we reach the assignment of rq->curr
except for values on the task struct modified in pick_next_task
the code has the same guarantees as if it used rcu_assign_pointer().

Reading through all of the implementations of pick_next_task it
appears pick_next_task is limited to modifying the task_struct fields
"->se", "->rt", "->dl".  These fields are the sched_entity structures
of the varies schedulers.

Further "->se.cfs_rq" is only changed in cgroup attach/move operations
initialized by userspace.

Unless I have missed something this means that in practice that the
users of "rcu_dereference(rq->curr)" get normal RCU semantics of
rcu_dereference() for the fields the care about, despite the
assignment of rq->curr in __schedule() ot using rcu_assign_pointer.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Kirill Tkhai <tkhai@yandex.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20190903200603.GW2349@hirez.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-09-25 17:42:29 +02:00
Eric W. Biederman
154abafc68 tasks, sched/core: With a grace period after finish_task_switch(), remove unnecessary code
Remove work arounds that were written before there was a grace period
after tasks left the runqueue in finish_task_switch().

In particular now that there tasks exiting the runqueue exprience
a RCU grace period none of the work performed by task_rcu_dereference()
excpet the rcu_dereference() is necessary so replace task_rcu_dereference()
with rcu_dereference().

Remove the code in rcuwait_wait_event() that checks to ensure the current
task has not exited.  It is no longer necessary as it is guaranteed
that any running task will experience a RCU grace period after it
leaves the run queueue.

Remove the comment in rcuwait_wake_up() as it is no longer relevant.

Ref: 8f95c90ceb ("sched/wait, RCU: Introduce rcuwait machinery")
Ref: 150593bf86 ("sched/api: Introduce task_rcu_dereference() and try_get_task_struct()")
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Kirill Tkhai <tkhai@yandex.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/87lfurdpk9.fsf_-_@x220.int.ebiederm.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-09-25 17:42:29 +02:00
Eric W. Biederman
0ff7b2cfba tasks, sched/core: Ensure tasks are available for a grace period after leaving the runqueue
In the ordinary case today the RCU grace period for a task_struct is
triggered when another process wait's for it's zombine and causes the
kernel to call release_task().  As the waiting task has to receive a
signal and then act upon it before this happens, typically this will
occur after the original task as been removed from the runqueue.

Unfortunaty in some cases such as self reaping tasks it can be shown
that release_task() will be called starting the grace period for
task_struct long before the task leaves the runqueue.

Therefore use put_task_struct_rcu_user() in finish_task_switch() to
guarantee that the there is a RCU lifetime after the task
leaves the runqueue.

Besides the change in the start of the RCU grace period for the
task_struct this change may cause perf_event_delayed_put and
trace_sched_process_free.  The function perf_event_delayed_put boils
down to just a WARN_ON for cases that I assume never show happen.  So
I don't see any problem with delaying it.

The function trace_sched_process_free is a trace point and thus
visible to user space.  Occassionally userspace has the strangest
dependencies so this has a miniscule chance of causing a regression.
This change only changes the timing of when the tracepoint is called.
The change in timing arguably gives userspace a more accurate picture
of what is going on.  So I don't expect there to be a regression.

In the case where a task self reaps we are pretty much guaranteed that
the RCU grace period is delayed.  So we should get quite a bit of
coverage in of this worst case for the change in a normal threaded
workload.  So I expect any issues to turn up quickly or not at all.

I have lightly tested this change and everything appears to work
fine.

Inspired-by: Linus Torvalds <torvalds@linux-foundation.org>
Inspired-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Kirill Tkhai <tkhai@yandex.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/87r24jdpl5.fsf_-_@x220.int.ebiederm.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-09-25 17:42:29 +02:00