linux-stable.git/include/linux, branch v5.4.95

iommu/vt-d: Don't dereference iommu_device if IOMMU_API is not built

2021-02-03T22:26:01+00:00

commit 9def3b1a07c41e21c68a0eb353e3e569fdd1d2b1 upstream.

Since commit c40aaaac1018 ("iommu/vt-d: Gracefully handle DMAR units
with no supported address widths") dmar.c needs struct iommu_device to
be selected. We can drop this dependency by not dereferencing struct
iommu_device if IOMMU_API is not selected and by reusing the information
stored in iommu->drhd->ignored instead.

This fixes the following build error when IOMMU_API is not selected:

drivers/iommu/dmar.c: In function ‘free_iommu’:
drivers/iommu/dmar.c:1139:41: error: ‘struct iommu_device’ has no member named ‘ops’
 1139 |  if (intel_iommu_enabled && iommu->iommu.ops) {
                                                ^

Fixes: c40aaaac1018 ("iommu/vt-d: Gracefully handle DMAR units with no supported address widths")
Signed-off-by: Bartosz Golaszewski 
Acked-by: Lu Baolu 
Acked-by: David Woodhouse 
Link: https://lore.kernel.org/r/20201013073055.11262-1-brgl@bgdev.pl
Signed-off-by: Joerg Roedel 
[ - context change due to moving drivers/iommu/dmar.c to
    drivers/iommu/intel/dmar.c
  - set the drhr in the iommu like in upstream commit b1012ca8dc4f
    ("iommu/vt-d: Skip TE disabling on quirky gfx dedicated iommu") ]
Signed-off-by: Filippo Sironi 
Signed-off-by: Greg Kroah-Hartman

writeback: Drop I_DIRTY_TIME_EXPIRE

2021-01-30T12:54:11+00:00

commit 5fcd57505c002efc5823a7355e21f48dd02d5a51 upstream.

The only use of I_DIRTY_TIME_EXPIRE is to detect in
__writeback_single_inode() that inode got there because flush worker
decided it's time to writeback the dirty inode time stamps (either
because we are syncing or because of age). However we can detect this
directly in __writeback_single_inode() and there's no need for the
strange propagation with I_DIRTY_TIME_EXPIRE flag.

Reviewed-by: Christoph Hellwig 
Signed-off-by: Jan Kara 
Cc: Eric Biggers 
Signed-off-by: Greg Kroah-Hartman

net: skbuff: disambiguate argument and member for skb_list_walk_safe helper

2021-01-23T14:57:57+00:00

commit 5eee7bd7e245914e4e050c413dfe864e31805207 upstream.

This worked before, because we made all callers name their next pointer
"next". But in trying to be more "drop-in" ready, the silliness here is
revealed. This commit fixes the problem by making the macro argument and
the member use different names.

Signed-off-by: Jason A. Donenfeld 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: introduce skb_list_walk_safe for skb segment walking

2021-01-23T14:57:57+00:00

commit dcfea72e79b0aa7a057c8f6024169d86a1bbc84b upstream.

As part of the continual effort to remove direct usage of skb->next and
skb->prev, this patch adds a helper for iterating through the
singly-linked variant of skb lists, which are used for lists of GSO
packet. The name "skb_list_..." has been chosen to match the existing
function, "kfree_skb_list, which also operates on these singly-linked
lists, and the "..._walk_safe" part is the same idiom as elsewhere in
the kernel.

This patch removes the helper from wireguard and puts it into
linux/skbuff.h, while making it a bit more robust for general usage. In
particular, parenthesis are added around the macro argument usage, and it
now accounts for trying to iterate through an already-null skb pointer,
which will simply run the iteration zero times. This latter enhancement
means it can be used to replace both do { ... } while and while (...)
open-coded idioms.

This should take care of these three possible usages, which match all
current methods of iterations.

skb_list_walk_safe(segs, skb, next) { ... }
skb_list_walk_safe(skb, skb, next) { ... }
skb_list_walk_safe(segs, skb, segs) { ... }

Gcc appears to generate efficient code for each of these.

Signed-off-by: Jason A. Donenfeld 
Signed-off-by: David S. Miller 
[ Just the skbuff.h changes for backporting - gregkh]
Signed-off-by: Greg Kroah-Hartman

elfcore: fix building with clang

2021-01-23T14:57:55+00:00

commit 6e7b64b9dd6d96537d816ea07ec26b7dedd397b9 upstream.

kernel/elfcore.c only contains weak symbols, which triggers a bug with
clang in combination with recordmcount:

  Cannot find symbol for section 2: .text.
  kernel/elfcore.o: failed

Move the empty stubs into linux/elfcore.h as inline functions.  As only
two architectures use these, just use the architecture specific Kconfig
symbols to key off the declaration.

Link: https://lkml.kernel.org/r/20201204165742.3815221-2-arnd@kernel.org
Signed-off-by: Arnd Bergmann 
Cc: Nathan Chancellor 
Cc: Nick Desaulniers 
Cc: Barret Rhoden 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Cc: Jian Cai 
Signed-off-by: Greg Kroah-Hartman

compiler.h: Raise minimum version of GCC to 5.1 for arm64

2021-01-23T14:57:55+00:00

commit dca5244d2f5b94f1809f0c02a549edf41ccd5493 upstream.

GCC versions >= 4.9 and < 5.1 have been shown to emit memory references
beyond the stack pointer, resulting in memory corruption if an interrupt
is taken after the stack pointer has been adjusted but before the
reference has been executed. This leads to subtle, infrequent data
corruption such as the EXT4 problems reported by Russell King at the
link below.

Life is too short for buggy compilers, so raise the minimum GCC version
required by arm64 to 5.1.

Reported-by: Russell King 
Suggested-by: Arnd Bergmann 
Signed-off-by: Will Deacon 
Tested-by: Nathan Chancellor 
Reviewed-by: Nick Desaulniers 
Reviewed-by: Nathan Chancellor 
Acked-by: Linus Torvalds 
Cc: 
Cc: Theodore Ts'o 
Cc: Florian Weimer 
Cc: Peter Zijlstra 
Cc: Nick Desaulniers 
Link: https://lore.kernel.org/r/20210105154726.GD1551@shell.armlinux.org.uk
Link: https://lore.kernel.org/r/20210112224832.10980-1-will@kernel.org
Signed-off-by: Catalin Marinas 
[will: backport to 4.19.y/5.4.y]
Signed-off-by: Will Deacon 
Signed-off-by: Greg Kroah-Hartman

ACPI: scan: add stub acpi_create_platform_device() for !CONFIG_ACPI

2021-01-19T17:26:16+00:00

[ Upstream commit ee61cfd955a64a58ed35cbcfc54068fcbd486945 ]

It adds a stub acpi_create_platform_device() for !CONFIG_ACPI build, so
that caller doesn't have to deal with !CONFIG_ACPI build issue.

Reported-by: kernel test robot 
Signed-off-by: Shawn Guo 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin

dm integrity: fix flush with external metadata device

2021-01-19T17:26:13+00:00

[ Upstream commit 9b5948267adc9e689da609eb61cf7ed49cae5fa8 ]

With external metadata device, flush requests are not passed down to the
data device.

Fix this by submitting the flush request in dm_integrity_flush_buffers. In
order to not degrade performance, we overlap the data device flush with
the metadata device flush.

Reported-by: Lukas Straub 
Signed-off-by: Mikulas Patocka 
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer 
Signed-off-by: Sasha Levin

proc: fix lookup in /proc/net subdirectories after setns(2)

2021-01-12T19:16:10+00:00

[ Upstream commit c6c75deda81344c3a95d1d1f606d5cee109e5d54 ]

Commit 1fde6f21d90f ("proc: fix /proc/net/* after setns(2)") only forced
revalidation of regular files under /proc/net/

However, /proc/net/ is unusual in the sense of /proc/net/foo handlers
take netns pointer from parent directory which is old netns.

Steps to reproduce:

	(void)open("/proc/net/sctp/snmp", O_RDONLY);
	unshare(CLONE_NEWNET);

	int fd = open("/proc/net/sctp/snmp", O_RDONLY);
	read(fd, &c, 1);

Read will read wrong data from original netns.

Patch forces lookup on every directory under /proc/net .

Link: https://lkml.kernel.org/r/20201205160916.GA109739@localhost.localdomain
Fixes: 1da4d377f943 ("proc: revalidate misc dentries")
Signed-off-by: Alexey Dobriyan 
Reported-by: "Rantala, Tommi T. (Nokia - FI/Espoo)" 
Cc: Al Viro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin

exec: Transform exec_update_mutex into a rw_semaphore

2021-01-09T12:44:55+00:00

[ Upstream commit f7cfd871ae0c5008d94b6f66834e7845caa93c15 ]

Recently syzbot reported[0] that there is a deadlock amongst the users
of exec_update_mutex.  The problematic lock ordering found by lockdep
was:

   perf_event_open  (exec_update_mutex -> ovl_i_mutex)
   chown            (ovl_i_mutex       -> sb_writes)
   sendfile         (sb_writes         -> p->lock)
     by reading from a proc file and writing to overlayfs
   proc_pid_syscall (p->lock           -> exec_update_mutex)

While looking at possible solutions it occured to me that all of the
users and possible users involved only wanted to state of the given
process to remain the same.  They are all readers.  The only writer is
exec.

There is no reason for readers to block on each other.  So fix
this deadlock by transforming exec_update_mutex into a rw_semaphore
named exec_update_lock that only exec takes for writing.

Cc: Jann Horn 
Cc: Vasiliy Kulikov 
Cc: Al Viro 
Cc: Bernd Edlinger 
Cc: Oleg Nesterov 
Cc: Christopher Yeoh 
Cc: Cyrill Gorcunov 
Cc: Sargun Dhillon 
Cc: Christian Brauner 
Cc: Arnd Bergmann 
Cc: Peter Zijlstra 
Cc: Ingo Molnar 
Cc: Arnaldo Carvalho de Melo 
Fixes: eea9673250db ("exec: Add exec_update_mutex to replace cred_guard_mutex")
[0] https://lkml.kernel.org/r/00000000000063640c05ade8e3de@google.com
Reported-by: syzbot+db9cdf3dd1f64252c6ef@syzkaller.appspotmail.com
Link: https://lkml.kernel.org/r/87ft4mbqen.fsf@x220.int.ebiederm.org
Signed-off-by: Eric W. Biederman 
Signed-off-by: Sasha Levin