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Commit Graph

1706 Commits

Author SHA1 Message Date
Heiko Carstens
d0290bc20d fs/proc/kcore.c: use probe_kernel_read() instead of memcpy()
Commit df04abfd18 ("fs/proc/kcore.c: Add bounce buffer for ktext
data") added a bounce buffer to avoid hardened usercopy checks.  Copying
to the bounce buffer was implemented with a simple memcpy() assuming
that it is always valid to read from kernel memory iff the
kern_addr_valid() check passed.

A simple, but pointless, test case like "dd if=/proc/kcore of=/dev/null"
now can easily crash the kernel, since the former execption handling on
invalid kernel addresses now doesn't work anymore.

Also adding a kern_addr_valid() implementation wouldn't help here.  Most
architectures simply return 1 here, while a couple implemented a page
table walk to figure out if something is mapped at the address in
question.

With DEBUG_PAGEALLOC active mappings are established and removed all the
time, so that relying on the result of kern_addr_valid() before
executing the memcpy() also doesn't work.

Therefore simply use probe_kernel_read() to copy to the bounce buffer.
This also allows to simplify read_kcore().

At least on s390 this fixes the observed crashes and doesn't introduce
warnings that were removed with df04abfd18 ("fs/proc/kcore.c: Add
bounce buffer for ktext data"), even though the generic
probe_kernel_read() implementation uses uaccess functions.

While looking into this I'm also wondering if kern_addr_valid() could be
completely removed...(?)

Link: http://lkml.kernel.org/r/20171202132739.99971-1-heiko.carstens@de.ibm.com
Fixes: df04abfd18 ("fs/proc/kcore.c: Add bounce buffer for ktext data")
Fixes: f5509cc18d ("mm: Hardened usercopy")
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-06 18:32:43 -08:00
Alexey Dobriyan
171ef917df fs/proc/array.c: delete children_seq_release()
It is 1:1 wrapper around seq_release().

Link: http://lkml.kernel.org/r/20171122171510.GA12161@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-06 18:32:43 -08:00
Alexey Dobriyan
20d28cde55 proc: less memory for /proc/*/map_files readdir
dentry name can be evaluated later, right before calling into VFS.

Also, spend less time under ->mmap_sem.

Link: http://lkml.kernel.org/r/20171110163034.GA2534@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-06 18:32:43 -08:00
Alexey Dobriyan
593bc695a1 fs/proc/vmcore.c: simpler /proc/vmcore cleanup
Iterators aren't necessary as you can just grab the first entry and delete
it until no entries left.

Link: http://lkml.kernel.org/r/20171121191121.GA20757@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-06 18:32:43 -08:00
Alexey Dobriyan
ac7f1061c2 proc: fix /proc/*/map_files lookup
Current code does:

	if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2)

However sscanf() is broken garbage.

It silently accepts whitespace between format specifiers
(did you know that?).

It silently accepts valid strings which result in integer overflow.

Do not use sscanf() for any even remotely reliable parsing code.

	OK
	# readlink '/proc/1/map_files/55a23af39000-55a23b05b000'
	/lib/systemd/systemd

	broken
	# readlink '/proc/1/map_files/               55a23af39000-55a23b05b000'
	/lib/systemd/systemd

	broken
	# readlink '/proc/1/map_files/55a23af39000-55a23b05b000    '
	/lib/systemd/systemd

	very broken
	# readlink '/proc/1/map_files/1000000000000000055a23af39000-55a23b05b000'
	/lib/systemd/systemd

Andrei said:

: This patch breaks criu.  It was a bug in criu.  And this bug is on a minor
: path, which works when memfd_create() isn't available.  It is a reason why
: I ask to not backport this patch to stable kernels.
:
: In CRIU this bug can be triggered, only if this patch will be backported
: to a kernel which version is lower than v3.16.

Link: http://lkml.kernel.org/r/20171120212706.GA14325@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Andrei Vagin <avagin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-06 18:32:43 -08:00
Alexey Dobriyan
9f7118b200 proc: don't use READ_ONCE/WRITE_ONCE for /proc/*/fail-nth
READ_ONCE and WRITE_ONCE are useless when there is only one read/write
is being made.

Link: http://lkml.kernel.org/r/20171120204033.GA9446@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-06 18:32:43 -08:00
Alexey Dobriyan
e3912ac37e proc: use %u for pid printing and slightly less stack
PROC_NUMBUF is 13 which is enough for "negative int + \n + \0".

However PIDs and TGIDs are never negative and newline is not a concern,
so use just 10 per integer.

Link: http://lkml.kernel.org/r/20171120203005.GA27743@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Alexander Viro <viro@ftp.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-06 18:32:43 -08:00
Kirill A. Shutemov
a3cf988fcb mm: use updated pmdp_invalidate() interface to track dirty/accessed bits
Use the modifed pmdp_invalidate() that returns the previous value of pmd
to transfer dirty and accessed bits.

Link: http://lkml.kernel.org/r/20171213105756.69879-12-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Daney <david.daney@cavium.com>
Cc: David Miller <davem@davemloft.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Nitin Gupta <nitin.m.gupta@oracle.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-01-31 17:18:38 -08:00
Konstantin Khlebnikov
8526d84f81 fs/proc/task_mmu.c: do not show VmExe bigger than total executable virtual memory
If start_code / end_code pointers are screwed then "VmExe" could be
bigger than total executable virtual memory and "VmLib" becomes
negative:

  VmExe:	  294320 kB
  VmLib:	18446744073709327564 kB

VmExe and VmLib documented as text segment and shared library code size.

Now their sum will be always equal to mm->exec_vm which sums size of
executable and not writable and not stack areas.

I've seen this for huge (>2Gb) statically linked binary which has whole
world inside.  For it start_code ..  end_code range also covers one of
rodata sections.  Probably this is bug in customized linker, elf loader
or both.

Anyway CONFIG_CHECKPOINT_RESTORE allows to change these pointers, thus
we cannot trust them without validation.

Link: http://lkml.kernel.org/r/150728955451.743749.11276392315459539583.stgit@buzz
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-01-31 17:18:37 -08:00
Linus Torvalds
168fe32a07 Merge branch 'misc.poll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull poll annotations from Al Viro:
 "This introduces a __bitwise type for POLL### bitmap, and propagates
  the annotations through the tree. Most of that stuff is as simple as
  'make ->poll() instances return __poll_t and do the same to local
  variables used to hold the future return value'.

  Some of the obvious brainos found in process are fixed (e.g. POLLIN
  misspelled as POLL_IN). At that point the amount of sparse warnings is
  low and most of them are for genuine bugs - e.g. ->poll() instance
  deciding to return -EINVAL instead of a bitmap. I hadn't touched those
  in this series - it's large enough as it is.

  Another problem it has caught was eventpoll() ABI mess; select.c and
  eventpoll.c assumed that corresponding POLL### and EPOLL### were
  equal. That's true for some, but not all of them - EPOLL### are
  arch-independent, but POLL### are not.

  The last commit in this series separates userland POLL### values from
  the (now arch-independent) kernel-side ones, converting between them
  in the few places where they are copied to/from userland. AFAICS, this
  is the least disruptive fix preserving poll(2) ABI and making epoll()
  work on all architectures.

  As it is, it's simply broken on sparc - try to give it EPOLLWRNORM and
  it will trigger only on what would've triggered EPOLLWRBAND on other
  architectures. EPOLLWRBAND and EPOLLRDHUP, OTOH, are never triggered
  at all on sparc. With this patch they should work consistently on all
  architectures"

* 'misc.poll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (37 commits)
  make kernel-side POLL... arch-independent
  eventpoll: no need to mask the result of epi_item_poll() again
  eventpoll: constify struct epoll_event pointers
  debugging printk in sg_poll() uses %x to print POLL... bitmap
  annotate poll(2) guts
  9p: untangle ->poll() mess
  ->si_band gets POLL... bitmap stored into a user-visible long field
  ring_buffer_poll_wait() return value used as return value of ->poll()
  the rest of drivers/*: annotate ->poll() instances
  media: annotate ->poll() instances
  fs: annotate ->poll() instances
  ipc, kernel, mm: annotate ->poll() instances
  net: annotate ->poll() instances
  apparmor: annotate ->poll() instances
  tomoyo: annotate ->poll() instances
  sound: annotate ->poll() instances
  acpi: annotate ->poll() instances
  crypto: annotate ->poll() instances
  block: annotate ->poll() instances
  x86: annotate ->poll() instances
  ...
2018-01-30 17:58:07 -08:00
Alexey Dobriyan
8bb2ee192e proc: fix coredump vs read /proc/*/stat race
do_task_stat() accesses IP and SP of a task without bumping reference
count of a stack (which became an entity with independent lifetime at
some point).

Steps to reproduce:

    #include <stdio.h>
    #include <sys/types.h>
    #include <sys/stat.h>
    #include <fcntl.h>
    #include <sys/time.h>
    #include <sys/resource.h>
    #include <unistd.h>
    #include <sys/wait.h>

    int main(void)
    {
    	setrlimit(RLIMIT_CORE, &(struct rlimit){});

    	while (1) {
    		char buf[64];
    		char buf2[4096];
    		pid_t pid;
    		int fd;

    		pid = fork();
    		if (pid == 0) {
    			*(volatile int *)0 = 0;
    		}

    		snprintf(buf, sizeof(buf), "/proc/%u/stat", pid);
    		fd = open(buf, O_RDONLY);
    		read(fd, buf2, sizeof(buf2));
    		close(fd);

    		waitpid(pid, NULL, 0);
    	}
    	return 0;
    }

    BUG: unable to handle kernel paging request at 0000000000003fd8
    IP: do_task_stat+0x8b4/0xaf0
    PGD 800000003d73e067 P4D 800000003d73e067 PUD 3d558067 PMD 0
    Oops: 0000 [#1] PREEMPT SMP PTI
    CPU: 0 PID: 1417 Comm: a.out Not tainted 4.15.0-rc8-dirty #2
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1.fc27 04/01/2014
    RIP: 0010:do_task_stat+0x8b4/0xaf0
    Call Trace:
     proc_single_show+0x43/0x70
     seq_read+0xe6/0x3b0
     __vfs_read+0x1e/0x120
     vfs_read+0x84/0x110
     SyS_read+0x3d/0xa0
     entry_SYSCALL_64_fastpath+0x13/0x6c
    RIP: 0033:0x7f4d7928cba0
    RSP: 002b:00007ffddb245158 EFLAGS: 00000246
    Code: 03 b7 a0 01 00 00 4c 8b 4c 24 70 4c 8b 44 24 78 4c 89 74 24 18 e9 91 f9 ff ff f6 45 4d 02 0f 84 fd f7 ff ff 48 8b 45 40 48 89 ef <48> 8b 80 d8 3f 00 00 48 89 44 24 20 e8 9b 97 eb ff 48 89 44 24
    RIP: do_task_stat+0x8b4/0xaf0 RSP: ffffc90000607cc8
    CR2: 0000000000003fd8

John Ogness said: for my tests I added an else case to verify that the
race is hit and correctly mitigated.

Link: http://lkml.kernel.org/r/20180116175054.GA11513@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reported-by: "Kohli, Gaurav" <gkohli@codeaurora.org>
Tested-by: John Ogness <john.ogness@linutronix.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-01-19 10:09:41 -08:00
Linus Torvalds
ba3edf1f77 proc: show si_ptr in /proc/<pid>/timers without hashing
It's a user pointer, and while the permissions of the file are pretty
questionable (should it really be readable to everybody), hashing the
pointer isn't going to be the solution.

We should take a closer look at more of the /proc/<pid> file permissions
in general.  Sure, we do want many of them to often be readable (for
'ps' and friends), but I think we should probably do a few conversions
from S_IRUGO to S_IRUSR.

Reported-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-12-06 18:23:27 -08:00
Linus Torvalds
8f5abe842e proc: don't report kernel addresses in /proc/<pid>/stack
This just changes the file to report them as zero, although maybe even
that could be removed.  I checked, and at least procps doesn't actually
seem to parse the 'stack' file at all.

And since the file doesn't necessarily even exist (it requires
CONFIG_STACKTRACE), possibly other tools don't really use it either.

That said, in case somebody parses it with tools, just having that zero
there should keep such tools happy.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-27 16:45:56 -08:00
Al Viro
076ccb76e1 fs: annotate ->poll() instances
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-11-27 16:20:05 -05:00
Al Viro
e6c8adca20 anntotate the places where ->poll() return values go
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-11-27 16:19:53 -05:00
Al Viro
a3f8683bf7 ->poll() methods should return __poll_t
The most common place to find POLL... bitmaps: return values
of ->poll() and its subsystem counterparts.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-11-27 16:19:52 -05:00
Linus Torvalds
1751e8a6cb Rename superblock flags (MS_xyz -> SB_xyz)
This is a pure automated search-and-replace of the internal kernel
superblock flags.

The s_flags are now called SB_*, with the names and the values for the
moment mirroring the MS_* flags that they're equivalent to.

Note how the MS_xyz flags are the ones passed to the mount system call,
while the SB_xyz flags are what we then use in sb->s_flags.

The script to do this was:

    # places to look in; re security/*: it generally should *not* be
    # touched (that stuff parses mount(2) arguments directly), but
    # there are two places where we really deal with superblock flags.
    FILES="drivers/mtd drivers/staging/lustre fs ipc mm \
            include/linux/fs.h include/uapi/linux/bfs_fs.h \
            security/apparmor/apparmorfs.c security/apparmor/include/lib.h"
    # the list of MS_... constants
    SYMS="RDONLY NOSUID NODEV NOEXEC SYNCHRONOUS REMOUNT MANDLOCK \
          DIRSYNC NOATIME NODIRATIME BIND MOVE REC VERBOSE SILENT \
          POSIXACL UNBINDABLE PRIVATE SLAVE SHARED RELATIME KERNMOUNT \
          I_VERSION STRICTATIME LAZYTIME SUBMOUNT NOREMOTELOCK NOSEC BORN \
          ACTIVE NOUSER"

    SED_PROG=
    for i in $SYMS; do SED_PROG="$SED_PROG -e s/MS_$i/SB_$i/g"; done

    # we want files that contain at least one of MS_...,
    # with fs/namespace.c and fs/pnode.c excluded.
    L=$(for i in $SYMS; do git grep -w -l MS_$i $FILES; done| sort|uniq|grep -v '^fs/namespace.c'|grep -v '^fs/pnode.c')

    for f in $L; do sed -i $f $SED_PROG; done

Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-27 13:05:09 -08:00
Linus Torvalds
275327851e Merge branch 'work.whack-a-mole' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull mode_t whack-a-mole from Al Viro:
 "For all internal uses we want umode_t, which is arch-independent;
  mode_t (or __kernel_mode_t, for that matter) is wrong outside of
  userland ABI.

  Unfortunately, that crap keeps coming back and needs to be put down
  from time to time..."

* 'work.whack-a-mole' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  mode_t whack-a-mole: task_dump_owner()
2017-11-22 20:20:02 -10:00
Linus Torvalds
fa7f578076 Merge branch 'akpm' (patches from Andrew)
Merge more updates from Andrew Morton:

 - a bit more MM

 - procfs updates

 - dynamic-debug fixes

 - lib/ updates

 - checkpatch

 - epoll

 - nilfs2

 - signals

 - rapidio

 - PID management cleanup and optimization

 - kcov updates

 - sysvipc updates

 - quite a few misc things all over the place

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (94 commits)
  EXPERT Kconfig menu: fix broken EXPERT menu
  include/asm-generic/topology.h: remove unused parent_node() macro
  arch/tile/include/asm/topology.h: remove unused parent_node() macro
  arch/sparc/include/asm/topology_64.h: remove unused parent_node() macro
  arch/sh/include/asm/topology.h: remove unused parent_node() macro
  arch/ia64/include/asm/topology.h: remove unused parent_node() macro
  drivers/pcmcia/sa1111_badge4.c: avoid unused function warning
  mm: add infrastructure for get_user_pages_fast() benchmarking
  sysvipc: make get_maxid O(1) again
  sysvipc: properly name ipc_addid() limit parameter
  sysvipc: duplicate lock comments wrt ipc_addid()
  sysvipc: unteach ids->next_id for !CHECKPOINT_RESTORE
  initramfs: use time64_t timestamps
  drivers/watchdog: make use of devm_register_reboot_notifier()
  kernel/reboot.c: add devm_register_reboot_notifier()
  kcov: update documentation
  Makefile: support flag -fsanitizer-coverage=trace-cmp
  kcov: support comparison operands collection
  kcov: remove pointless current != NULL check
  kernel/panic.c: add TAINT_AUX
  ...
2017-11-17 16:56:17 -08:00
Gargi Sharma
95846ecf9d pid: replace pid bitmap implementation with IDR API
Patch series "Replacing PID bitmap implementation with IDR API", v4.

This series replaces kernel bitmap implementation of PID allocation with
IDR API.  These patches are written to simplify the kernel by replacing
custom code with calls to generic code.

The following are the stats for pid and pid_namespace object files
before and after the replacement.  There is a noteworthy change between
the IDR and bitmap implementation.

Before
   text       data        bss        dec        hex    filename
   8447       3894         64      12405       3075    kernel/pid.o
After
   text       data        bss        dec        hex    filename
   3397        304          0       3701        e75    kernel/pid.o

Before
   text       data        bss        dec        hex    filename
   5692       1842        192       7726       1e2e    kernel/pid_namespace.o
After
   text       data        bss        dec        hex    filename
   2854        216         16       3086        c0e    kernel/pid_namespace.o

The following are the stats for ps, pstree and calling readdir on /proc
for 10,000 processes.

ps:
        With IDR API    With bitmap
real    0m1.479s        0m2.319s
user    0m0.070s        0m0.060s
sys     0m0.289s        0m0.516s

pstree:
        With IDR API    With bitmap
real    0m1.024s        0m1.794s
user    0m0.348s        0m0.612s
sys     0m0.184s        0m0.264s

proc:
        With IDR API    With bitmap
real    0m0.059s        0m0.074s
user    0m0.000s        0m0.004s
sys     0m0.016s        0m0.016s

This patch (of 2):

Replace the current bitmap implementation for Process ID allocation.
Functions that are no longer required, for example, free_pidmap(),
alloc_pidmap(), etc.  are removed.  The rest of the functions are
modified to use the IDR API.  The change was made to make the PID
allocation less complex by replacing custom code with calls to generic
API.

[gs051095@gmail.com: v6]
  Link: http://lkml.kernel.org/r/1507760379-21662-2-git-send-email-gs051095@gmail.com
[avagin@openvz.org: restore the old behaviour of the ns_last_pid sysctl]
  Link: http://lkml.kernel.org/r/20171106183144.16368-1-avagin@openvz.org
Link: http://lkml.kernel.org/r/1507583624-22146-2-git-send-email-gs051095@gmail.com
Signed-off-by: Gargi Sharma <gs051095@gmail.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Julia Lawall <julia.lawall@lip6.fr>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17 16:10:03 -08:00
Alexey Dobriyan
0746a0bc6e proc: use do-while in name_to_int()
Gcc doesn't know that "len" is guaranteed to be >=1 by dcache and
generates standard while-loop prologue duplicating loop condition.

	add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-27 (-27)
	function                                     old     new   delta
	name_to_int                                  104      77     -27

Link: http://lkml.kernel.org/r/20170912195213.GB17730@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17 16:10:00 -08:00
Alexey Dobriyan
3ee2a19908 proc: : uninline name_to_int()
Save ~360 bytes.

	add/remove: 1/0 grow/shrink: 0/4 up/down: 104/-463 (-359)
	function                                     old     new   delta
	name_to_int                                    -     104    +104
	proc_pid_lookup                              217     126     -91
	proc_lookupfd_common                         212     121     -91
	proc_task_lookup                             289     194     -95
	__proc_create                                588     402    -186

Link: http://lkml.kernel.org/r/20170912194850.GA17730@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17 16:10:00 -08:00
Roman Gushchin
c643401218 proc, coredump: add CoreDumping flag to /proc/pid/status
Right now there is no convenient way to check if a process is being
coredumped at the moment.

It might be necessary to recognize such state to prevent killing the
process and getting a broken coredump.  Writing a large core might take
significant time, and the process is unresponsive during it, so it might
be killed by timeout, if another process is monitoring and
killing/restarting hanging tasks.

We're getting a significant number of corrupted coredump files on
machines in our fleet, just because processes are being killed by
timeout in the middle of the core writing process.

We do have a process health check, and some agent is responsible for
restarting processes which are not responding for health check requests.
Writing a large coredump to the disk can easily exceed the reasonable
timeout (especially on an overloaded machine).

This flag will allow the agent to distinguish processes which are being
coredumped, extend the timeout for them, and let them produce a full
coredump file.

To provide an ability to detect if a process is in the state of being
coredumped, we can expose a boolean CoreDumping flag in
/proc/pid/status.

Example:
$ cat core.sh
  #!/bin/sh

  echo "|/usr/bin/sleep 10" > /proc/sys/kernel/core_pattern
  sleep 1000 &
  PID=$!

  cat /proc/$PID/status | grep CoreDumping
  kill -ABRT $PID
  sleep 1
  cat /proc/$PID/status | grep CoreDumping

$ ./core.sh
  CoreDumping:	0
  CoreDumping:	1

[guro@fb.com: document CoreDumping flag in /proc/<pid>/status]
  Link: http://lkml.kernel.org/r/20170928135357.GA8470@castle.DHCP.thefacebook.com
Link: http://lkml.kernel.org/r/20170920230634.31572-1-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17 16:10:00 -08:00
Linus Torvalds
e75080f185 Two power management fixes for v4.15-rc1
This is the change making /proc/cpuinfo on x86 report current
 CPU frequency in "cpu MHz" again in all cases and an additional
 one dealing with an overzealous check in one of the helper
 routines in the runtime PM framework.
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Merge tag 'pm-fixes-4.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull two power management fixes from Rafael Wysocki:
 "This is the change making /proc/cpuinfo on x86 report current CPU
  frequency in "cpu MHz" again in all cases and an additional one
  dealing with an overzealous check in one of the helper routines in the
  runtime PM framework"

* tag 'pm-fixes-4.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PM / runtime: Drop children check from __pm_runtime_set_status()
  x86 / CPU: Always show current CPU frequency in /proc/cpuinfo
2017-11-17 14:49:25 -08:00
Linus Torvalds
a3841f94c7 libnvdimm for 4.15
* Introduce MAP_SYNC and MAP_SHARED_VALIDATE, a mechanism to enable
  'userspace flush' of persistent memory updates via filesystem-dax
   mappings. It arranges for any filesystem metadata updates that may be
   required to satisfy a write fault to also be flushed ("on disk") before
   the kernel returns to userspace from the fault handler. Effectively
   every write-fault that dirties metadata completes an fsync() before
   returning from the fault handler. The new MAP_SHARED_VALIDATE mapping
   type guarantees that the MAP_SYNC flag is validated as supported by the
   filesystem's ->mmap() file operation.
 
 * Add support for the standard ACPI 6.2 label access methods that
   replace the NVDIMM_FAMILY_INTEL (vendor specific) label methods. This
   enables interoperability with environments that only implement the
   standardized methods.
 
 * Add support for the ACPI 6.2 NVDIMM media error injection methods.
 
 * Add support for the NVDIMM_FAMILY_INTEL v1.6 DIMM commands for latch
   last shutdown status, firmware update, SMART error injection, and
   SMART alarm threshold control.
 
 * Cleanup physical address information disclosures to be root-only.
 
 * Fix revalidation of the DIMM "locked label area" status to support
   dynamic unlock of the label area.
 
 * Expand unit test infrastructure to mock the ACPI 6.2 Translate SPA
   (system-physical-address) command and error injection commands.
 
 Acknowledgements that came after the commits were pushed to -next:
 
 957ac8c421 dax: fix PMD faults on zero-length files
 Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
 
 a39e596baa xfs: support for synchronous DAX faults
 Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
 
 7b565c9f96 xfs: Implement xfs_filemap_pfn_mkwrite() using __xfs_filemap_fault()
 Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
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Merge tag 'libnvdimm-for-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm and dax updates from Dan Williams:
 "Save for a few late fixes, all of these commits have shipped in -next
  releases since before the merge window opened, and 0day has given a
  build success notification.

  The ext4 touches came from Jan, and the xfs touches have Darrick's
  reviewed-by. An xfstest for the MAP_SYNC feature has been through
  a few round of reviews and is on track to be merged.

   - Introduce MAP_SYNC and MAP_SHARED_VALIDATE, a mechanism to enable
     'userspace flush' of persistent memory updates via filesystem-dax
     mappings. It arranges for any filesystem metadata updates that may
     be required to satisfy a write fault to also be flushed ("on disk")
     before the kernel returns to userspace from the fault handler.
     Effectively every write-fault that dirties metadata completes an
     fsync() before returning from the fault handler. The new
     MAP_SHARED_VALIDATE mapping type guarantees that the MAP_SYNC flag
     is validated as supported by the filesystem's ->mmap() file
     operation.

   - Add support for the standard ACPI 6.2 label access methods that
     replace the NVDIMM_FAMILY_INTEL (vendor specific) label methods.
     This enables interoperability with environments that only implement
     the standardized methods.

   - Add support for the ACPI 6.2 NVDIMM media error injection methods.

   - Add support for the NVDIMM_FAMILY_INTEL v1.6 DIMM commands for
     latch last shutdown status, firmware update, SMART error injection,
     and SMART alarm threshold control.

   - Cleanup physical address information disclosures to be root-only.

   - Fix revalidation of the DIMM "locked label area" status to support
     dynamic unlock of the label area.

   - Expand unit test infrastructure to mock the ACPI 6.2 Translate SPA
     (system-physical-address) command and error injection commands.

  Acknowledgements that came after the commits were pushed to -next:

   - 957ac8c421 ("dax: fix PMD faults on zero-length files"):
       Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>

   - a39e596baa ("xfs: support for synchronous DAX faults") and
     7b565c9f96 ("xfs: Implement xfs_filemap_pfn_mkwrite() using __xfs_filemap_fault()")
        Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>"

* tag 'libnvdimm-for-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (49 commits)
  acpi, nfit: add 'Enable Latch System Shutdown Status' command support
  dax: fix general protection fault in dax_alloc_inode
  dax: fix PMD faults on zero-length files
  dax: stop requiring a live device for dax_flush()
  brd: remove dax support
  dax: quiet bdev_dax_supported()
  fs, dax: unify IOMAP_F_DIRTY read vs write handling policy in the dax core
  tools/testing/nvdimm: unit test clear-error commands
  acpi, nfit: validate commands against the device type
  tools/testing/nvdimm: stricter bounds checking for error injection commands
  xfs: support for synchronous DAX faults
  xfs: Implement xfs_filemap_pfn_mkwrite() using __xfs_filemap_fault()
  ext4: Support for synchronous DAX faults
  ext4: Simplify error handling in ext4_dax_huge_fault()
  dax: Implement dax_finish_sync_fault()
  dax, iomap: Add support for synchronous faults
  mm: Define MAP_SYNC and VM_SYNC flags
  dax: Allow tuning whether dax_insert_mapping_entry() dirties entry
  dax: Allow dax_iomap_fault() to return pfn
  dax: Fix comment describing dax_iomap_fault()
  ...
2017-11-17 09:51:57 -08:00
Kirill A. Shutemov
af5b0f6a09 mm: consolidate page table accounting
Currently, we account page tables separately for each page table level,
but that's redundant -- we only make use of total memory allocated to
page tables for oom_badness calculation.  We also provide the
information to userspace, but it has dubious value there too.

This patch switches page table accounting to single counter.

mm->pgtables_bytes is now used to account all page table levels.  We use
bytes, because page table size for different levels of page table tree
may be different.

The change has user-visible effect: we don't have VmPMD and VmPUD
reported in /proc/[pid]/status.  Not sure if anybody uses them.  (As
alternative, we can always report 0 kB for them.)

OOM-killer report is also slightly changed: we now report pgtables_bytes
instead of nr_ptes, nr_pmd, nr_puds.

Apart from reducing number of counters per-mm, the benefit is that we
now calculate oom_badness() more correctly for machines which have
different size of page tables depending on level or where page tables
are less than a page in size.

The only downside can be debuggability because we do not know which page
table level could leak.  But I do not remember many bugs that would be
caught by separate counters so I wouldn't lose sleep over this.

[akpm@linux-foundation.org: fix mm/huge_memory.c]
Link: http://lkml.kernel.org/r/20171006100651.44742-2-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
[kirill.shutemov@linux.intel.com: fix build]
  Link: http://lkml.kernel.org/r/20171016150113.ikfxy3e7zzfvsr4w@black.fi.intel.com
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-15 18:21:04 -08:00
Kirill A. Shutemov
c4812909f5 mm: introduce wrappers to access mm->nr_ptes
Let's add wrappers for ->nr_ptes with the same interface as for nr_pmd
and nr_pud.

The patch also makes nr_ptes accounting dependent onto CONFIG_MMU.  Page
table accounting doesn't make sense if you don't have page tables.

It's preparation for consolidation of page-table counters in mm_struct.

Link: http://lkml.kernel.org/r/20171006100651.44742-1-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-15 18:21:04 -08:00
Kirill A. Shutemov
b4e98d9ac7 mm: account pud page tables
On a machine with 5-level paging support a process can allocate
significant amount of memory and stay unnoticed by oom-killer and memory
cgroup.  The trick is to allocate a lot of PUD page tables.  We don't
account PUD page tables, only PMD and PTE.

We already addressed the same issue for PMD page tables, see commit
dc6c9a35b6 ("mm: account pmd page tables to the process").
Introduction of 5-level paging brings the same issue for PUD page
tables.

The patch expands accounting to PUD level.

[kirill.shutemov@linux.intel.com: s/pmd_t/pud_t/]
  Link: http://lkml.kernel.org/r/20171004074305.x35eh5u7ybbt5kar@black.fi.intel.com
[heiko.carstens@de.ibm.com: s390/mm: fix pud table accounting]
  Link: http://lkml.kernel.org/r/20171103090551.18231-1-heiko.carstens@de.ibm.com
Link: http://lkml.kernel.org/r/20171002080427.3320-1-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-15 18:21:04 -08:00
Rafael J. Wysocki
7d5905dc14 x86 / CPU: Always show current CPU frequency in /proc/cpuinfo
After commit 890da9cf09 (Revert "x86: do not use cpufreq_quick_get()
for /proc/cpuinfo "cpu MHz"") the "cpu MHz" number in /proc/cpuinfo
on x86 can be either the nominal CPU frequency (which is constant)
or the frequency most recently requested by a scaling governor in
cpufreq, depending on the cpufreq configuration.  That is somewhat
inconsistent and is different from what it was before 4.13, so in
order to restore the previous behavior, make it report the current
CPU frequency like the scaling_cur_freq sysfs file in cpufreq.

To that end, modify the /proc/cpuinfo implementation on x86 to use
aperfmperf_snapshot_khz() to snapshot the APERF and MPERF feedback
registers, if available, and use their values to compute the CPU
frequency to be reported as "cpu MHz".

However, do that carefully enough to avoid accumulating delays that
lead to unacceptable access times for /proc/cpuinfo on systems with
many CPUs.  Run aperfmperf_snapshot_khz() once on all CPUs
asynchronously at the /proc/cpuinfo open time, add a single delay
upfront (if necessary) at that point and simply compute the current
frequency while running show_cpuinfo() for each individual CPU.

Also, to avoid slowing down /proc/cpuinfo accesses too much, reduce
the default delay between consecutive APERF and MPERF reads to 10 ms,
which should be sufficient to get large enough numbers for the
frequency computation in all cases.

Fixes: 890da9cf09 (Revert "x86: do not use cpufreq_quick_get() for /proc/cpuinfo "cpu MHz"")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
2017-11-15 19:46:50 +01:00
Linus Torvalds
fb0255fb29 TTY/Serial patches for 4.15-rc1
Here is the big tty/serial driver pull request for 4.15-rc1.
 
 Lots of serial driver updates in here, some small vt cleanups, and a
 raft of SPDX and license boilerplate cleanups, messing up the diffstat a
 bit.
 
 Nothing major, with no realy functional changes except better hardware
 support for some platforms.
 
 All of these have been in linux-next for a while with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-4.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial updates from Greg KH:
 "Here is the big tty/serial driver pull request for 4.15-rc1.

  Lots of serial driver updates in here, some small vt cleanups, and a
  raft of SPDX and license boilerplate cleanups, messing up the diffstat
  a bit.

  Nothing major, with no realy functional changes except better hardware
  support for some platforms.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'tty-4.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (110 commits)
  tty: ehv_bytechan: fix spelling mistake
  tty: serial: meson: allow baud-rates lower than 9600
  serial: 8250_fintek: Fix crash with baud rate B0
  serial: 8250_fintek: Disable delays for ports != 0
  serial: 8250_fintek: Return -EINVAL on invalid configuration
  tty: Remove redundant license text
  tty: serdev: Remove redundant license text
  tty: hvc: Remove redundant license text
  tty: serial: Remove redundant license text
  tty: add SPDX identifiers to all remaining files in drivers/tty/
  tty: serial: jsm: remove redundant pointer ts
  tty: serial: jsm: add space before the open parenthesis '('
  tty: serial: jsm: fix coding style
  tty: serial: jsm: delete space between function name and '('
  tty: serial: jsm: add blank line after declarations
  tty: serial: jsm: change the type of local variable
  tty: serial: imx: remove dead code imx_dma_rxint
  tty: serial: imx: disable ageing timer interrupt if dma in use
  serial: 8250: fix potential deadlock in rs485-mode
  serial: m32r_sio: Drop redundant .data assignment
  ...
2017-11-13 21:05:31 -08:00
Linus Torvalds
3e2014637c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
 "The main updates in this cycle were:

   - Group balancing enhancements and cleanups (Brendan Jackman)

   - Move CPU isolation related functionality into its separate
     kernel/sched/isolation.c file, with related 'housekeeping_*()'
     namespace and nomenclature et al. (Frederic Weisbecker)

   - Improve the interactive/cpu-intense fairness calculation (Josef
     Bacik)

   - Improve the PELT code and related cleanups (Peter Zijlstra)

   - Improve the logic of pick_next_task_fair() (Uladzislau Rezki)

   - Improve the RT IPI based balancing logic (Steven Rostedt)

   - Various micro-optimizations:

   - better !CONFIG_SCHED_DEBUG optimizations (Patrick Bellasi)

   - better idle loop (Cheng Jian)

   - ... plus misc fixes, cleanups and updates"

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (54 commits)
  sched/core: Optimize sched_feat() for !CONFIG_SCHED_DEBUG builds
  sched/sysctl: Fix attributes of some extern declarations
  sched/isolation: Document isolcpus= boot parameter flags, mark it deprecated
  sched/isolation: Add basic isolcpus flags
  sched/isolation: Move isolcpus= handling to the housekeeping code
  sched/isolation: Handle the nohz_full= parameter
  sched/isolation: Introduce housekeeping flags
  sched/isolation: Split out new CONFIG_CPU_ISOLATION=y config from CONFIG_NO_HZ_FULL
  sched/isolation: Rename is_housekeeping_cpu() to housekeeping_cpu()
  sched/isolation: Use its own static key
  sched/isolation: Make the housekeeping cpumask private
  sched/isolation: Provide a dynamic off-case to housekeeping_any_cpu()
  sched/isolation, watchdog: Use housekeeping_cpumask() instead of ad-hoc version
  sched/isolation: Move housekeeping related code to its own file
  sched/idle: Micro-optimize the idle loop
  sched/isolcpus: Fix "isolcpus=" boot parameter handling when !CONFIG_CPUMASK_OFFSTACK
  x86/tsc: Append the 'tsc=' description for the 'tsc=unstable' boot parameter
  sched/rt: Simplify the IPI based RT balancing logic
  block/ioprio: Use a helper to check for RT prio
  sched/rt: Add a helper to test for a RT task
  ...
2017-11-13 13:37:52 -08:00
Ingo Molnar
8a103df440 Merge branch 'linus' into sched/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-08 10:17:15 +01:00
Ingo Molnar
8c5db92a70 Merge branch 'linus' into locking/core, to resolve conflicts
Conflicts:
	include/linux/compiler-clang.h
	include/linux/compiler-gcc.h
	include/linux/compiler-intel.h
	include/uapi/linux/stddef.h

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-07 10:32:44 +01:00
Huang Ying
b83d7e4323 mm, /proc/pid/pagemap: fix soft dirty marking for PMD migration entry
When the pagetable is walked in the implementation of /proc/<pid>/pagemap,
pmd_soft_dirty() is used for both the PMD huge page map and the PMD
migration entries.  That is wrong, pmd_swp_soft_dirty() should be used
for the PMD migration entries instead because the different page table
entry flag is used.

As a result, /proc/pid/pagemap may report incorrect soft dirty information
for PMD migration entries.

Link: http://lkml.kernel.org/r/20171017081818.31795-1-ying.huang@intel.com
Fixes: 84c3fc4e9c ("mm: thp: check pmd migration entry in common path")
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: Daniel Colascione <dancol@google.com>
Cc: Zi Yan <zi.yan@cs.rutgers.edu>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-03 07:39:19 -07:00
Jan Kara
b6fb293f24 mm: Define MAP_SYNC and VM_SYNC flags
Define new MAP_SYNC flag and corresponding VMA VM_SYNC flag. As the
MAP_SYNC flag is not part of LEGACY_MAP_MASK, currently it will be
refused by all MAP_SHARED_VALIDATE map attempts and silently ignored for
everything else.

Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-11-03 06:26:25 -07:00
Greg Kroah-Hartman
b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00
Mark Rutland
6aa7de0591 locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns to READ_ONCE()/WRITE_ONCE()
Please do not apply this to mainline directly, instead please re-run the
coccinelle script shown below and apply its output.

For several reasons, it is desirable to use {READ,WRITE}_ONCE() in
preference to ACCESS_ONCE(), and new code is expected to use one of the
former. So far, there's been no reason to change most existing uses of
ACCESS_ONCE(), as these aren't harmful, and changing them results in
churn.

However, for some features, the read/write distinction is critical to
correct operation. To distinguish these cases, separate read/write
accessors must be used. This patch migrates (most) remaining
ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following
coccinelle script:

----
// Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and
// WRITE_ONCE()

// $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch

virtual patch

@ depends on patch @
expression E1, E2;
@@

- ACCESS_ONCE(E1) = E2
+ WRITE_ONCE(E1, E2)

@ depends on patch @
expression E;
@@

- ACCESS_ONCE(E)
+ READ_ONCE(E)
----

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: davem@davemloft.net
Cc: linux-arch@vger.kernel.org
Cc: mpe@ellerman.id.au
Cc: shuah@kernel.org
Cc: snitzer@redhat.com
Cc: thor.thayer@linux.intel.com
Cc: tj@kernel.org
Cc: viro@zeniv.linux.org.uk
Cc: will.deacon@arm.com
Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-25 11:01:08 +02:00
nixiaoming
c79dde629d tty fix oops when rmmod 8250
After rmmod 8250.ko
tty_kref_put starts kwork (release_one_tty) to release proc interface
oops when accessing driver->driver_name in proc_tty_unregister_driver

Use jprobe, found driver->driver_name point to 8250.ko
static static struct uart_driver serial8250_reg
.driver_name= serial,

Use name in proc_dir_entry instead of driver->driver_name to fix oops

test on linux 4.1.12:

BUG: unable to handle kernel paging request at ffffffffa01979de
IP: [<ffffffff81310f40>] strchr+0x0/0x30
PGD 1a0d067 PUD 1a0e063 PMD 851c1f067 PTE 0
Oops: 0000 [#1] PREEMPT SMP
Modules linked in: ... ...  [last unloaded: 8250]
CPU: 7 PID: 116 Comm: kworker/7:1 Tainted: G           O    4.1.12 #1
Hardware name: Insyde RiverForest/Type2 - Board Product Name1, BIOS NE5KV904 12/21/2015
Workqueue: events release_one_tty
task: ffff88085b684960 ti: ffff880852884000 task.ti: ffff880852884000
RIP: 0010:[<ffffffff81310f40>]  [<ffffffff81310f40>] strchr+0x0/0x30
RSP: 0018:ffff880852887c90  EFLAGS: 00010282
RAX: ffffffff81a5eca0 RBX: ffffffffa01979de RCX: 0000000000000004
RDX: ffff880852887d10 RSI: 000000000000002f RDI: ffffffffa01979de
RBP: ffff880852887cd8 R08: 0000000000000000 R09: ffff88085f5d94d0
R10: 0000000000000195 R11: 0000000000000000 R12: ffffffffa01979de
R13: ffff880852887d00 R14: ffffffffa01979de R15: ffff88085f02e840
FS:  0000000000000000(0000) GS:ffff88085f5c0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffa01979de CR3: 0000000001a0c000 CR4: 00000000001406e0
Stack:
 ffffffff812349b1 ffff880852887cb8 ffff880852887d10 ffff88085f5cd6c2
 ffff880852800a80 ffffffffa01979de ffff880852800a84 0000000000000010
 ffff88085bb28bd8 ffff880852887d38 ffffffff812354f0 ffff880852887d08
Call Trace:
 [<ffffffff812349b1>] ? __xlate_proc_name+0x71/0xd0
 [<ffffffff812354f0>] remove_proc_entry+0x40/0x180
 [<ffffffff815f6811>] ? _raw_spin_lock_irqsave+0x41/0x60
 [<ffffffff813be520>] ? destruct_tty_driver+0x60/0xe0
 [<ffffffff81237c68>] proc_tty_unregister_driver+0x28/0x40
 [<ffffffff813be548>] destruct_tty_driver+0x88/0xe0
 [<ffffffff813be5bd>] tty_driver_kref_put+0x1d/0x20
 [<ffffffff813becca>] release_one_tty+0x5a/0xd0
 [<ffffffff81074159>] process_one_work+0x139/0x420
 [<ffffffff810745a1>] worker_thread+0x121/0x450
 [<ffffffff81074480>] ? process_scheduled_works+0x40/0x40
 [<ffffffff8107a16c>] kthread+0xec/0x110
 [<ffffffff81080000>] ? tg_rt_schedulable+0x210/0x220
 [<ffffffff8107a080>] ? kthread_freezable_should_stop+0x80/0x80
 [<ffffffff815f7292>] ret_from_fork+0x42/0x70
 [<ffffffff8107a080>] ? kthread_freezable_should_stop+0x80/0x80

Signed-off-by: nixiaoming <nixiaoming@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-20 14:06:45 +02:00
Peter Zijlstra
1d48b080bc sched/debug: Rename task-state printing helpers
Steve requested better names for the new task-state helper functions.

So introduce the concept of task-state index for the printing and
rename __get_task_state() to task_state_index() and
__task_state_to_char() to task_index_to_char().

Requested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170929115016.pzlqc7ss3ccystyg@hirez.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-10 11:43:29 +02:00
Al Viro
c6eb50d279 mode_t whack-a-mole: task_dump_owner()
should be umode_t...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-09-30 14:45:42 -04:00
Peter Zijlstra
8ef9925b02 sched/debug: Add explicit TASK_PARKED printing
Currently TASK_PARKED is masqueraded as TASK_INTERRUPTIBLE, give it
its own print state because it will not in fact get woken by regular
wakeups and is a long-term state.

This requires moving TASK_PARKED into the TASK_REPORT mask, and since
that latter needs to be a contiguous bitmask, we need to shuffle the
bits around a bit.

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: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-29 11:02:57 +02:00
Peter Zijlstra
06eb61844d sched/debug: Add explicit TASK_IDLE printing
Markus reported that kthreads that idle using TASK_IDLE instead of
TASK_INTERRUPTIBLE are reported in as TASK_UNINTERRUPTIBLE and things
like htop mark those red.

This is undesirable, so add an explicit state for TASK_IDLE.

Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de>
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: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-29 11:02:56 +02:00
Peter Zijlstra
1593baab91 sched/debug: Implement consistent task-state printing
Currently get_task_state() and task_state_to_char() report different
states, create a number of common helpers and unify the reported state
space.

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: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-29 10:09:08 +02:00
John Ogness
fd7d56270b fs/proc: Report eip/esp in /prod/PID/stat for coredumping
Commit 0a1eb2d474 ("fs/proc: Stop reporting eip and esp in
/proc/PID/stat") stopped reporting eip/esp because it is
racy and dangerous for executing tasks. The comment adds:

    As far as I know, there are no use programs that make any
    material use of these fields, so just get rid of them.

However, existing userspace core-dump-handler applications (for
example, minicoredumper) are using these fields since they
provide an excellent cross-platform interface to these valuable
pointers. So that commit introduced a user space visible
regression.

Partially revert the change and make the readout possible for
tasks with the proper permissions and only if the target task
has the PF_DUMPCORE flag set.

Fixes: 0a1eb2d474 ("fs/proc: Stop reporting eip and esp in> /proc/PID/stat")
Reported-by: Marco Felsch <marco.felsch@preh.de>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Cc: Tycho Andersen <tycho.andersen@canonical.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: stable@vger.kernel.org
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Linux API <linux-api@vger.kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/87poatfwg6.fsf@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-09-15 23:31:16 +02:00
Michal Hocko
0ee931c4e3 mm: treewide: remove GFP_TEMPORARY allocation flag
GFP_TEMPORARY was introduced by commit e12ba74d8f ("Group short-lived
and reclaimable kernel allocations") along with __GFP_RECLAIMABLE.  It's
primary motivation was to allow users to tell that an allocation is
short lived and so the allocator can try to place such allocations close
together and prevent long term fragmentation.  As much as this sounds
like a reasonable semantic it becomes much less clear when to use the
highlevel GFP_TEMPORARY allocation flag.  How long is temporary? Can the
context holding that memory sleep? Can it take locks? It seems there is
no good answer for those questions.

The current implementation of GFP_TEMPORARY is basically GFP_KERNEL |
__GFP_RECLAIMABLE which in itself is tricky because basically none of
the existing caller provide a way to reclaim the allocated memory.  So
this is rather misleading and hard to evaluate for any benefits.

I have checked some random users and none of them has added the flag
with a specific justification.  I suspect most of them just copied from
other existing users and others just thought it might be a good idea to
use without any measuring.  This suggests that GFP_TEMPORARY just
motivates for cargo cult usage without any reasoning.

I believe that our gfp flags are quite complex already and especially
those with highlevel semantic should be clearly defined to prevent from
confusion and abuse.  Therefore I propose dropping GFP_TEMPORARY and
replace all existing users to simply use GFP_KERNEL.  Please note that
SLAB users with shrinkers will still get __GFP_RECLAIMABLE heuristic and
so they will be placed properly for memory fragmentation prevention.

I can see reasons we might want some gfp flag to reflect shorterm
allocations but I propose starting from a clear semantic definition and
only then add users with proper justification.

This was been brought up before LSF this year by Matthew [1] and it
turned out that GFP_TEMPORARY really doesn't have a clear semantic.  It
seems to be a heuristic without any measured advantage for most (if not
all) its current users.  The follow up discussion has revealed that
opinions on what might be temporary allocation differ a lot between
developers.  So rather than trying to tweak existing users into a
semantic which they haven't expected I propose to simply remove the flag
and start from scratch if we really need a semantic for short term
allocations.

[1] http://lkml.kernel.org/r/20170118054945.GD18349@bombadil.infradead.org

[akpm@linux-foundation.org: fix typo]
[akpm@linux-foundation.org: coding-style fixes]
[sfr@canb.auug.org.au: drm/i915: fix up]
  Link: http://lkml.kernel.org/r/20170816144703.378d4f4d@canb.auug.org.au
Link: http://lkml.kernel.org/r/20170728091904.14627-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Mel Gorman <mgorman@suse.de>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Neil Brown <neilb@suse.de>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-13 18:53:16 -07:00
Arnd Bergmann
6dec0dd4a6 procfs: remove unused variable
In NOMMU configurations, we get a warning about a variable that has become
unused:

  fs/proc/task_nommu.c: In function 'nommu_vma_show':
  fs/proc/task_nommu.c:148:28: error: unused variable 'priv' [-Werror=unused-variable]

Link: http://lkml.kernel.org/r/20170911200231.3171415-1-arnd@arndb.de
Fixes: 1240ea0dc3 ("fs, proc: remove priv argument from is_stack")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-13 18:53:15 -07:00
Davidlohr Bueso
410bd5ecb2 procfs: use faster rb_first_cached()
...  such that we can avoid the tree walks to get the node with the
smallest key.  Semantically the same, as the previously used rb_first(),
but O(1).  The main overhead is the extra footprint for the cached rb_node
pointer, which should not matter for procfs.

Link: http://lkml.kernel.org/r/20170719014603.19029-14-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:49 -07:00
David Rientjes
1403830294 fs, proc: unconditional cond_resched when reading smaps
If there are large numbers of hugepages to iterate while reading
/proc/pid/smaps, the page walk never does cond_resched().  On archs
without split pmd locks, there can be significant and observable
contention on mm->page_table_lock which cause lengthy delays without
rescheduling.

Always reschedule in smaps_pte_range() if necessary since the pagewalk
iteration can be expensive.

Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1708211405520.131071@chino.kir.corp.google.com
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:47 -07:00
Alexey Dobriyan
855d97657d proc: uninline proc_create()
Save some code from ~320 invocations all clearing last argument.

	add/remove: 3/0 grow/shrink: 0/158 up/down: 45/-702 (-657)
	function                                     old     new   delta
	proc_create                                    -      17     +17
	__ksymtab_proc_create                          -      16     +16
	__kstrtab_proc_create                          -      12     +12
	yam_init_driver                              301     298      -3

		...

	cifs_proc_init                               249     228     -21
	via_fb_pci_probe                            2304    2280     -24

Link: http://lkml.kernel.org/r/20170819094702.GA27864@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:47 -07:00
Michal Hocko
1240ea0dc3 fs, proc: remove priv argument from is_stack
Commit b18cb64ead ("fs/proc: Stop trying to report thread stacks")
removed the priv parameter user in is_stack so the argument is
redundant.  Drop it.

[arnd@arndb.de: remove unused variable]
  Link: http://lkml.kernel.org/r/20170801120150.1520051-1-arnd@arndb.de
Link: http://lkml.kernel.org/r/20170728075833.7241-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:47 -07:00