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git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent
Pull perf/urgent fix from Arnaldo Carvalho de Melo:
- Fix symbols__fixup_end heuristic for corner cases, such as JITted eBPF
programs, that are loaded at page aligned addresses, just after the
kernel proper (Daniel Borkmann)
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
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The current symbols__fixup_end() heuristic for the last entry in the rb
tree is suboptimal as it leads to not being able to recognize the symbol
in the call graph in a couple of corner cases, for example:
i) If the symbol has a start address (f.e. exposed via kallsyms)
that is at a page boundary, then the roundup(curr->start, 4096)
for the last entry will result in curr->start == curr->end with
a symbol length of zero.
ii) If the symbol has a start address that is shortly before a page
boundary, then also here, curr->end - curr->start will just be
very few bytes, where it's unrealistic that we could perform a
match against.
Instead, change the heuristic to roundup(curr->start, 4096) + 4096, so
that we can catch such corner cases and have a better chance to find
that specific symbol. It's still just best effort as the real end of the
symbol is unknown to us (and could even be at a larger offset than the
current range), but better than the current situation.
Alexei reported that he recently run into case i) with a JITed eBPF
program (these are all page aligned) as the last symbol which wasn't
properly shown in the call graph (while other eBPF program symbols in
the rb tree were displayed correctly). Since this is a generic issue,
lets try to improve the heuristic a bit.
Reported-and-Tested-by: Alexei Starovoitov <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Fixes: 2e538c4a1847 ("perf tools: Improve kernel/modules symbol lookup")
Link: http://lkml.kernel.org/r/bb5c80d27743be6f12afc68405f1956a330e1bc9.1489614365.git.daniel@iogearbox.net
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
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When an interrupt occurs on an MCP23S08 chip, the INTF register will only
contain one bit as causing the interrupt. If more than two pins change at
the same time on the chip, this causes one of the pins to not be reported.
This patch fixes the logic for checking if a pin has changed, so that
multiple pins will always cause more than one change.
Cc: [email protected]
Signed-off-by: Robert Middleton <[email protected]>
Tested-by: Phil Reid <[email protected]>
Signed-off-by: Linus Walleij <[email protected]>
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Naively, it looks racy, but ->mmap_sem saves it. Add a comment and a
lockdep assertion.
Signed-off-by: Andy Lutomirski <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vince Weaver <[email protected]>
Link: http://lkml.kernel.org/r/03a1e629063899168dfc4707f3bb6e581e21f5c6.1489694270.git.luto@kernel.org
Signed-off-by: Ingo Molnar <[email protected]>
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If one thread mmaps a perf event while another thread in the same mm
is in some context where active_mm != mm (which can happen in the
scheduler, for example), refresh_pce() would write the wrong value
to CR4.PCE. This broke some PAPI tests.
Reported-and-tested-by: Vince Weaver <[email protected]>
Signed-off-by: Andy Lutomirski <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Fixes: 7911d3f7af14 ("perf/x86: Only allow rdpmc if a perf_event is mapped")
Link: http://lkml.kernel.org/r/0c5b38a76ea50e405f9abe07a13dfaef87c173a1.1489694270.git.luto@kernel.org
Signed-off-by: Ingo Molnar <[email protected]>
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As of commit 438cc81a41e8 ("powerpc/pseries: Automatically resize HPT
for memory hot add/remove"), when running on the pseries platform, we
always attempt to use the PAPR extension to resize the hashed page
table (HPT) when we add or remove memory.
This is fine, but when the extension is not available we'll give a
harmless, but scary warning. Instead check if the firmware supports HPT
resizing before populating the mmu_hash_ops.resize_hpt pointer.
Signed-off-by: David Gibson <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
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Merge fixes from Andrew Morton:
"6 fixes"
* emailed patches from Andrew Morton <[email protected]>:
drivers core: remove assert_held_device_hotplug()
mm: add private lock to serialize memory hotplug operations
mm: don't warn when vmalloc() fails due to a fatal signal
mm, x86: fix native_pud_clear build error
kasan: add a prototype of task_struct to avoid warning
z3fold: fix spinlock unlocking in page reclaim
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The last caller of assert_held_device_hotplug() is gone, so remove it again.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Heiko Carstens <[email protected]>
Acked-by: Dan Williams <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
Cc: Vladimir Davydov <[email protected]>
Cc: Ben Hutchings <[email protected]>
Cc: Gerald Schaefer <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: Sebastian Ott <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Commit bfc8c90139eb ("mem-hotplug: implement get/put_online_mems")
introduced new functions get/put_online_mems() and mem_hotplug_begin/end()
in order to allow similar semantics for memory hotplug like for cpu
hotplug.
The corresponding functions for cpu hotplug are get/put_online_cpus()
and cpu_hotplug_begin/done() for cpu hotplug.
The commit however missed to introduce functions that would serialize
memory hotplug operations like they are done for cpu hotplug with
cpu_maps_update_begin/done().
This basically leaves mem_hotplug.active_writer unprotected and allows
concurrent writers to modify it, which may lead to problems as outlined
by commit f931ab479dd2 ("mm: fix devm_memremap_pages crash, use
mem_hotplug_{begin, done}").
That commit was extended again with commit b5d24fda9c3d ("mm,
devm_memremap_pages: hold device_hotplug lock over mem_hotplug_{begin,
done}") which serializes memory hotplug operations for some call sites
by using the device_hotplug lock.
In addition with commit 3fc21924100b ("mm: validate device_hotplug is held
for memory hotplug") a sanity check was added to mem_hotplug_begin() to
verify that the device_hotplug lock is held.
This in turn triggers the following warning on s390:
WARNING: CPU: 6 PID: 1 at drivers/base/core.c:643 assert_held_device_hotplug+0x4a/0x58
Call Trace:
assert_held_device_hotplug+0x40/0x58)
mem_hotplug_begin+0x34/0xc8
add_memory_resource+0x7e/0x1f8
add_memory+0xda/0x130
add_memory_merged+0x15c/0x178
sclp_detect_standby_memory+0x2ae/0x2f8
do_one_initcall+0xa2/0x150
kernel_init_freeable+0x228/0x2d8
kernel_init+0x2a/0x140
kernel_thread_starter+0x6/0xc
One possible fix would be to add more lock_device_hotplug() and
unlock_device_hotplug() calls around each call site of
mem_hotplug_begin/end(). But that would give the device_hotplug lock
additional semantics it better should not have (serialize memory hotplug
operations).
Instead add a new memory_add_remove_lock which has the similar semantics
like cpu_add_remove_lock for cpu hotplug.
To keep things hopefully a bit easier the lock will be locked and unlocked
within the mem_hotplug_begin/end() functions.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Heiko Carstens <[email protected]>
Reported-by: Sebastian Ott <[email protected]>
Acked-by: Dan Williams <[email protected]>
Acked-by: Rafael J. Wysocki <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Vladimir Davydov <[email protected]>
Cc: Ben Hutchings <[email protected]>
Cc: Gerald Schaefer <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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When vmalloc() fails it prints a very lengthy message with all the
details about memory consumption assuming that it happened due to OOM.
However, vmalloc() can also fail due to fatal signal pending. In such
case the message is quite confusing because it suggests that it is OOM
but the numbers suggest otherwise. The messages can also pollute
console considerably.
Don't warn when vmalloc() fails due to fatal signal pending.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Dmitry Vyukov <[email protected]>
Reviewed-by: Matthew Wilcox <[email protected]>
Acked-by: Kirill A. Shutemov <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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We still get a build error in random configurations, after this has been
modified a few times:
In file included from include/linux/mm.h:68:0,
from include/linux/suspend.h:8,
from arch/x86/kernel/asm-offsets.c:12:
arch/x86/include/asm/pgtable.h:66:26: error: redefinition of 'native_pud_clear'
#define pud_clear(pud) native_pud_clear(pud)
My interpretation is that the build error comes from a typo in
__PAGETABLE_PUD_FOLDED, so fix that typo now, and remove the incorrect
#ifdef around the native_pud_clear definition.
Fixes: 3e761a42e19c ("mm, x86: fix HIGHMEM64 && PARAVIRT build config for native_pud_clear()")
Fixes: a00cc7d9dd93 ("mm, x86: add support for PUD-sized transparent hugepages")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnd Bergmann <[email protected]>
Ackedy-by: Dave Jiang <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Thomas Garnier <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Borislav Petkov <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Add a prototype of task_struct to fix below warning on arm64.
In file included from arch/arm64/kernel/probes/kprobes.c:19:0:
include/linux/kasan.h:81:132: error: 'struct task_struct' declared inside parameter list will not be visible outside of this definition or declaration [-Werror]
static inline void kasan_unpoison_task_stack(struct task_struct *task) {}
As same as other types (kmem_cache, page, and vm_struct) this adds a
prototype of task_struct data structure on top of kasan.h.
[arnd] A related warning was fixed before, but now appears in a
different line in the same file in v4.11-rc2. The patch from Masami
Hiramatsu still seems appropriate, so let's take his version.
Fixes: 71af2ed5eeea ("kasan, sched/headers: Remove <linux/sched.h> from <linux/kasan.h>")
Link: https://patchwork.kernel.org/patch/9569839/
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnd Bergmann <[email protected]>
Signed-off-by: Masami Hiramatsu <[email protected]>
Acked-by: Alexander Potapenko <[email protected]>
Acked-by: Andrey Ryabinin <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Commmit 5a27aa822029 ("z3fold: add kref refcounting") introduced a bug
in z3fold_reclaim_page() with function exit that may leave pool->lock
spinlock held. Here comes the trivial fix.
Fixes: 5a27aa822029 ("z3fold: add kref refcounting")
Link: http://lkml.kernel.org/r/[email protected]
Reported-by: Alexey Khoroshilov <[email protected]>
Signed-off-by: Vitaly Wool <[email protected]>
Cc: Dan Streetman <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Pull xfs fix from Darrick Wong:
"Here's a single fix for -rc3 to improve input validation on inline
directory data to prevent buffer overruns due to corrupt metadata"
* tag 'xfs-4.11-fixes-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
xfs: verify inline directory data forks
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git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 fixes/cleanups from Catalin Marinas:
"In Will's absence I'm sending the arm64 fixes he queued for 4.11-rc3:
- fix arm64 kernel boot warning when DEBUG_VIRTUAL and KASAN are
enabled
- enable KEYS_COMPAT for keyctl compat support
- use cpus_have_const_cap() for system_uses_ttbr0_pan() (slight
performance improvement)
- update kerneldoc for cpu_suspend() rename
- remove the arm64-specific kprobe_exceptions_notify (weak generic
variant defined)"
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64: kernel: Update kerneldoc for cpu_suspend() rename
arm64: use const cap for system_uses_ttbr0_pan()
arm64: support keyctl() system call in 32-bit mode
arm64: kasan: avoid bad virt_to_pfn()
arm64: kprobes: remove kprobe_exceptions_notify
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git://git.kernel.org/pub/scm/linux/kernel/git/shli/md
Pull MD fixes from Shaohua Li:
- fix a parity calculation bug of raid5 cache by Song
- fix a potential deadlock issue by me
- fix two endian issues by Jason
- fix a disk limitation issue by Neil
- other small fixes and cleanup
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md:
md/raid1: fix a trivial typo in comments
md/r5cache: fix set_syndrome_sources() for data in cache
md: fix incorrect use of lexx_to_cpu in does_sb_need_changing
md: fix super_offset endianness in super_1_rdev_size_change
md/raid1/10: fix potential deadlock
md: don't impose the MD_SB_DISKS limit on arrays without metadata.
md: move funcs from pers->resize to update_size
md-cluster: remove useless memset from gather_all_resync_info
md-cluster: free md_cluster_info if node leave cluster
md: delete dead code
md/raid10: submit bio directly to replacement disk
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Drop the page lock before waiting for page writeback.
Signed-off-by: David Howells <[email protected]>
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The ->writepage() op shouldn't call clear_page_dirty_for_io() as that has
already been called by the caller.
Fix afs_writepage() by moving the call out of
afs_write_back_from_locked_page() to afs_writepages_region() where it is
needed.
Signed-off-by: David Howells <[email protected]>
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Fix the way in which a call that's in progress and being waited for is
aborted in the case that EINTR is detected. We should be sending
RX_USER_ABORT rather than RX_CALL_DEAD as the abort code.
Note that since the only two ways out of the loop are if the call completes
or if a signal happens, the kill-the-call clause after the loop has
finished can only happen in the case of EINTR. This means that we only
have one abort case to deal with, not two, and the "KWC" case can never
happen and so can be deleted.
Note further that simply aborting the call isn't necessarily the best thing
here since at this point: the request has been entirely sent and it's
likely the server will do the operation anyway - whether we abort it or
not. In future, we should punt the handling of the remainder of the call
off to a background thread.
Reported-by: Marc Dionne <[email protected]>
Signed-off-by: David Howells <[email protected]>
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afs_send_pages() should only put the call into the AFS_CALL_AWAIT_REPLY
state if it has sent all the pages - but the check it makes is incorrect
and sometimes it will finish the loop early.
Signed-off-by: David Howells <[email protected]>
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Fix afs_kill_pages() in two ways:
(1) If a writeback has been partially flushed, then if we try and kill the
pages it contains, some of them may no longer be undergoing writeback
and end_page_writeback() will assert.
Fix this by checking to see whether the page in question is actually
undergoing writeback before ending that writeback.
(2) The loop that scans for pages to kill doesn't increase the first page
index, and so the loop may not terminate, but it will try to process
the same pages over and over again.
Fix this by increasing the first page index to one after the last page
we processed.
Signed-off-by: David Howells <[email protected]>
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afs_write_begin() leaks a ref and a lock on a page if afs_fill_page()
fails. Fix the leak by unlocking and releasing the page in the error path.
Signed-off-by: David Howells <[email protected]>
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Don't set PG_error on a page if we get local EINTR or ENOMEM when filling a
page for writing.
Signed-off-by: David Howells <[email protected]>
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The inode timestamps should be set from the client time
in the status received from the server, rather than the
server time which is meant for internal server use.
Set AFS_SET_MTIME and populate the mtime for operations
that take an input status, such as file/dir creation
and StoreData. If an input time is not provided the
server will set the vnode times based on the current server
time.
In a situation where the server has some skew with the
client, this could lead to the client seeing a timestamp
in the future for a file that it just created or wrote.
Signed-off-by: Marc Dionne <[email protected]>
Signed-off-by: David Howells <[email protected]>
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If we receive a network error, a remote abort or a protocol error whilst
we're still transmitting data, make sure we return an appropriate error to
the caller rather than ESHUTDOWN or ECONNABORTED.
Signed-off-by: David Howells <[email protected]>
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When we are given an invalid operation ID, we should abort that with
RXGEN_OPCODE rather than RX_INVALID_OPERATION.
Also map RXGEN_OPCODE to -ENOTSUPP.
Signed-off-by: David Howells <[email protected]>
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afs_fs_store_data() works out of the size of the write it's going to make,
but it uses 32-bit unsigned subtraction in one place that gets
automatically cast to loff_t.
However, if to < offset, then the number goes negative, but as the result
isn't signed, this doesn't get sign-extended to 64-bits when placed in a
loff_t.
Fix by casting the operands to loff_t.
Signed-off-by: David Howells <[email protected]>
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Use a bvec rather than a kvec in afs_send_pages() as we don't then have to
call kmap() in advance. This allows us to pass the array of contiguous
pages that we extracted through to rxrpc in one go rather than passing a
single page at a time.
Signed-off-by: David Howells <[email protected]>
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Make struct afs_read::remain 64-bit so that it can handle huge transfers if
we ever request them or the server decides to give us a bit extra data (the
other fields there are already 64-bit).
Signed-off-by: David Howells <[email protected]>
Tested-by: Marc Dionne <[email protected]>
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Fix a bug in AFS read whereby the request page afs_read::index isn't
incremented after calling ->page_done() if ->remain reaches 0, indicating
that the data read is complete.
Without this a NULL pointer exception happens when ->page_done() is called
twice for the last page because the page clearing loop will call it also
and afs_readpages_page_done() clears the current entry in the page list.
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: afs_readpages_page_done+0x21/0xa4 [kafs]
PGD 0
Oops: 0002 [#1] SMP
Modules linked in: kafs(E)
CPU: 2 PID: 3002 Comm: md5sum Tainted: G E 4.10.0-fscache #485
Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014
task: ffff8804017d86c0 task.stack: ffff8803fc1d8000
RIP: 0010:afs_readpages_page_done+0x21/0xa4 [kafs]
RSP: 0018:ffff8803fc1db978 EFLAGS: 00010282
RAX: ffff880405d39af8 RBX: 0000000000000000 RCX: ffff880407d83ed4
RDX: 0000000000000000 RSI: ffff880405d39a00 RDI: ffff880405c6f400
RBP: ffff8803fc1db988 R08: 0000000000000000 R09: 0000000000000001
R10: ffff8803fc1db820 R11: ffff88040cf56000 R12: ffff8804088f1780
R13: ffff8804017d86c0 R14: ffff8804088f1780 R15: 0000000000003840
FS: 00007f8154469700(0000) GS:ffff88041fb00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000004016ec000 CR4: 00000000001406e0
Call Trace:
afs_deliver_fs_fetch_data+0x5b9/0x60e [kafs]
? afs_make_call+0x316/0x4e8 [kafs]
? afs_make_call+0x359/0x4e8 [kafs]
afs_deliver_to_call+0x173/0x2e8 [kafs]
? afs_make_call+0x316/0x4e8 [kafs]
afs_make_call+0x37a/0x4e8 [kafs]
? wake_up_q+0x4f/0x4f
? __init_waitqueue_head+0x36/0x49
afs_fs_fetch_data+0x21c/0x227 [kafs]
? afs_fs_fetch_data+0x21c/0x227 [kafs]
afs_vnode_fetch_data+0xf3/0x1d2 [kafs]
afs_readpages+0x314/0x3fd [kafs]
__do_page_cache_readahead+0x208/0x2c5
ondemand_readahead+0x3a2/0x3b7
? ondemand_readahead+0x3a2/0x3b7
page_cache_async_readahead+0x5e/0x67
generic_file_read_iter+0x23b/0x70c
? __inode_security_revalidate+0x2f/0x62
__vfs_read+0xc4/0xe8
vfs_read+0xd1/0x15a
SyS_read+0x4c/0x89
do_syscall_64+0x80/0x191
entry_SYSCALL64_slow_path+0x25/0x25
Reported-by: Marc Dionne <[email protected]>
Signed-off-by: David Howells <[email protected]>
Tested-by: Marc Dionne <[email protected]>
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get_seconds() returns real wall-clock seconds. On 32-bit systems
this value will overflow in year 2038 and beyond. This patch changes
afs_vnode record to use ktime_get_real_seconds() instead, for the
fields cb_expires and cb_expires_at.
Signed-off-by: Tina Ruchandani <[email protected]>
Signed-off-by: David Howells <[email protected]>
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get_seconds() returns real wall-clock seconds. On 32-bit systems
this value will overflow in year 2038 and beyond. This patch changes
afs's vlocation record to use ktime_get_real_seconds() instead, for the
fields time_of_death and update_at.
Signed-off-by: Tina Ruchandani <[email protected]>
Signed-off-by: David Howells <[email protected]>
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The use of "rcu_assign_pointer()" is NULLing out the pointer.
According to RCU_INIT_POINTER()'s block comment:
"1. This use of RCU_INIT_POINTER() is NULLing out the pointer"
it is better to use it instead of rcu_assign_pointer() because it has a
smaller overhead.
The following Coccinelle semantic patch was used:
@@
@@
- rcu_assign_pointer
+ RCU_INIT_POINTER
(..., NULL)
Signed-off-by: Andreea-Cristina Bernat <[email protected]>
Signed-off-by: David Howells <[email protected]>
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The use of "rcu_assign_pointer()" is NULLing out the pointer.
According to RCU_INIT_POINTER()'s block comment:
"1. This use of RCU_INIT_POINTER() is NULLing out the pointer"
it is better to use it instead of rcu_assign_pointer() because it has a
smaller overhead.
The following Coccinelle semantic patch was used:
@@
@@
- rcu_assign_pointer
+ RCU_INIT_POINTER
(..., NULL)
Signed-off-by: Andreea-Cristina Bernat <[email protected]>
Signed-off-by: David Howells <[email protected]>
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In AFS, mountpoints appear as symlinks with mode 0644 and normal symlinks
have mode 0777, so use this to distinguish them rather than reading the
content and parsing it. In the case of a mountpoint, the symlink body is a
formatted string indicating the location of the target volume.
Note that with this, kAFS no longer 'pre-fetches' the contents of symlinks,
so afs_readpage() may fail with an access-denial because when the VFS calls
d_automount(), it wraps the call in an credentials override that sets the
initial creds - thereby preventing access to the caller's keyrings and the
authentication keys held therein.
To this end, a patch reverting that change to the VFS is required also.
Reported-by: Jeffrey Altman <[email protected]>
Signed-off-by: David Howells <[email protected]>
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Flush outstanding writes in afs when an fd is closed. This is what NFS and
CIFS do.
Reported-by: Marc Dionne <[email protected]>
Signed-off-by: David Howells <[email protected]>
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Handle the situation where afs_write_begin() is told to expect that a
full-page write will be made, but this doesn't happen (EFAULT, CTRL-C,
etc.), and so afs_write_end() sees a partial write took place. Currently,
no attempt is to deal with the discrepency.
Fix this by loading the gap from the server.
Reported-by: Al Viro <[email protected]>
Signed-off-by: David Howells <[email protected]>
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Kill struct afs_read::pg_offset as nothing uses it. It's unnecessary as pos
can be masked off.
Signed-off-by: David Howells <[email protected]>
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When an AFS server is given an FS.FetchData{,64} request to read data from
a file, it is permitted by the protocol to return more or less than was
requested. kafs currently relies on the latter behaviour in readpage{,s}
to handle a partial page at the end of the file (we just ask for a whole
page and clear space beyond the short read).
However, we don't handle all cases. Add:
(1) Handle excess data by discarding it rather than aborting. Note that
we use a common static buffer to discard into so that the decryption
algorithm advances the PCBC state.
(2) Handle a short read that affects more than just the last page.
Note that if a read comes up unexpectedly short of long, it's possible that
the server's copy of the file changed - in which case the data version
number will have been incremented and the callback will have been broken -
in which case all the pages currently attached to the inode will be zapped
anyway at some point.
Signed-off-by: David Howells <[email protected]>
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Servers may send a callback array that is the same size as
the FID array, or an empty array. If the callback count is
0, the code would attempt to read (fid_count * 12) bytes of
data, which would fail and result in an unmarshalling error.
This would lead to stale data for remotely modified files
or directories.
Store the callback array size in the internal afs_call
structure and use that to determine the amount of data to
read.
Signed-off-by: Marc Dionne <[email protected]>
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Mode bits for an afs file should not be enforced in the usual
way.
For files, the absence of user bits can restrict file access
with respect to what is granted by the server.
These bits apply regardless of the owner or the current uid; the
rest of the mode bits (group, other) are ignored.
Signed-off-by: Marc Dionne <[email protected]>
Signed-off-by: David Howells <[email protected]>
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The group was hard coded to GLOBAL_ROOT_GID; use the group
ID that was received from the server.
Signed-off-by: Marc Dionne <[email protected]>
Signed-off-by: David Howells <[email protected]>
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afs_fill_page() loads the page it wants to fill into the afs_read request
without incrementing its refcount - but then calls afs_put_read() to clean
up afterwards, which then releases a ref on the page.
Fix this by getting a ref on the page before calling
afs_vnode_fetch_data().
This causes sync after a write to hang in afs_writepages_region() because
find_get_pages_tag() gets confused and doesn't return.
Fixes: 196ee9cd2d04 ("afs: Make afs_fs_fetch_data() take a list of pages")
Reported-by: Marc Dionne <[email protected]>
Signed-off-by: David Howells <[email protected]>
Tested-by: Marc Dionne <[email protected]>
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In afs_writepages_region(), inside the loop where we find dirty pages to
deal with, one of the if-statements is missing a put_page().
Signed-off-by: David Howells <[email protected]>
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While going through the event inheritance code Oleg got confused.
Add some comments to better explain the silent dissapearance of
orphaned events.
So what happens is that at perf_event_release_kernel() time; when an
event looses its connection to userspace (and ceases to exist from the
user's perspective) we can still have an arbitrary amount of inherited
copies of the event. We want to synchronously find and remove all
these child events.
Since that requires a bit of lock juggling, there is the possibility
that concurrent clone()s will create new child events. Therefore we
first mark the parent event as DEAD, which marks all the extant child
events as orphaned.
We then avoid copying orphaned events; in order to avoid getting more
of them.
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vince Weaver <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
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We have ctx->event_list that contains all events; no need to
repeatedly iterate the group lists to find them all.
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vince Weaver <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
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While hunting for clues to a use-after-free, Oleg spotted that
perf_event_init_context() can loose an error value with the result
that fork() can succeed even though we did not fully inherit the perf
event context.
Spotted-by: Oleg Nesterov <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vince Weaver <[email protected]>
Cc: [email protected]
Cc: [email protected]
Fixes: 889ff0150661 ("perf/core: Split context's event group list into pinned and non-pinned lists")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
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Dmitry reported syzcaller tripped a use-after-free in perf_release().
After much puzzlement Oleg spotted the below scenario:
Task1 Task2
fork()
perf_event_init_task()
/* ... */
goto bad_fork_$foo;
/* ... */
perf_event_free_task()
mutex_lock(ctx->lock)
perf_free_event(B)
perf_event_release_kernel(A)
mutex_lock(A->child_mutex)
list_for_each_entry(child, ...) {
/* child == B */
ctx = B->ctx;
get_ctx(ctx);
mutex_unlock(A->child_mutex);
mutex_lock(A->child_mutex)
list_del_init(B->child_list)
mutex_unlock(A->child_mutex)
/* ... */
mutex_unlock(ctx->lock);
put_ctx() /* >0 */
free_task();
mutex_lock(ctx->lock);
mutex_lock(A->child_mutex);
/* ... */
mutex_unlock(A->child_mutex);
mutex_unlock(ctx->lock)
put_ctx() /* 0 */
ctx->task && !TOMBSTONE
put_task_struct() /* UAF */
This patch closes the hole by making perf_event_free_task() destroy the
task <-> ctx relation such that perf_event_release_kernel() will no longer
observe the now dead task.
Spotted-by: Oleg Nesterov <[email protected]>
Reported-by: Dmitry Vyukov <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vince Weaver <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Fixes: c6e5b73242d2 ("perf: Synchronously clean up child events")
Link: http://lkml.kernel.org/r/20170314155949.GE32474@worktop
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
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Test runs on a ppc64 BE guest succeeded. linux/samples/statx/test-statx
program was executed on the following file types,
1. Regular file
2. Directory
3. device file
4. symlink
5. Named pipe
The test run also included invoking test-statx with the runtime options
provided in the main() function of test-statx.c
Signed-off-by: Chandan Rajendra <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
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I was testing Daniel's changes with his test case, and tweaked it a
little. Instead of having the runtime equal to the deadline, I
increased the deadline ten fold.
Daniel's test case had:
attr.sched_runtime = 2 * 1000 * 1000; /* 2 ms */
attr.sched_deadline = 2 * 1000 * 1000; /* 2 ms */
attr.sched_period = 2 * 1000 * 1000 * 1000; /* 2 s */
To make it more interesting, I changed it to:
attr.sched_runtime = 2 * 1000 * 1000; /* 2 ms */
attr.sched_deadline = 20 * 1000 * 1000; /* 20 ms */
attr.sched_period = 2 * 1000 * 1000 * 1000; /* 2 s */
The results were rather surprising. The behavior that Daniel's patch
was fixing came back. The task started using much more than .1% of the
CPU. More like 20%.
Looking into this I found that it was due to the dl_entity_overflow()
constantly returning true. That's because it uses the relative period
against relative runtime vs the absolute deadline against absolute
runtime.
runtime / (deadline - t) > dl_runtime / dl_period
There's even a comment mentioning this, and saying that when relative
deadline equals relative period, that the equation is the same as using
deadline instead of period. That comment is backwards! What we really
want is:
runtime / (deadline - t) > dl_runtime / dl_deadline
We care about if the runtime can make its deadline, not its period. And
then we can say "when the deadline equals the period, the equation is
the same as using dl_period instead of dl_deadline".
After correcting this, now when the task gets enqueued, it can throttle
correctly, and Daniel's fix to the throttling of sleeping deadline
tasks works even when the runtime and deadline are not the same.
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Daniel Bristot de Oliveira <[email protected]>
Cc: Juri Lelli <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Luca Abeni <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Romulo Silva de Oliveira <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Tommaso Cucinotta <[email protected]>
Link: http://lkml.kernel.org/r/02135a27f1ae3fe5fd032568a5a2f370e190e8d7.1488392936.git.bristot@redhat.com
Signed-off-by: Ingo Molnar <[email protected]>
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