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2020-09-12libata: implement ATA_HORKAGE_MAX_TRIM_128M and apply to SandisksTejun Heo1-0/+1
commit 3b5455636fe26ea21b4189d135a424a6da016418 upstream. All three generations of Sandisk SSDs lock up hard intermittently. Experiments showed that disabling NCQ lowered the failure rate significantly and the kernel has been disabling NCQ for some models of SD7's and 8's, which is obviously undesirable. Karthik worked with Sandisk to root cause the hard lockups to trim commands larger than 128M. This patch implements ATA_HORKAGE_MAX_TRIM_128M which limits max trim size to 128M and applies it to all three generations of Sandisk SSDs. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Karthik Shivaram <karthikgs@fb.com> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-12block: Move SECTOR_SIZE and SECTOR_SHIFT definitions into <linux/blkdev.h>Bart Van Assche3-14/+31
commit 233bde21aa43516baa013ef7ac33f3427056db3e upstream. It happens often while I'm preparing a patch for a block driver that I'm wondering: is a definition of SECTOR_SIZE and/or SECTOR_SHIFT available for this driver? Do I have to introduce definitions of these constants before I can use these constants? To avoid this confusion, move the existing definitions of SECTOR_SIZE and SECTOR_SHIFT into the <linux/blkdev.h> header file such that these become available for all block drivers. Make the SECTOR_SIZE definition in the uapi msdos_fs.h header file conditional to avoid that including that header file after <linux/blkdev.h> causes the compiler to complain about a SECTOR_SIZE redefinition. Note: the SECTOR_SIZE / SECTOR_SHIFT / SECTOR_BITS definitions have not been removed from uapi header files nor from NAND drivers in which these constants are used for another purpose than converting block layer offsets and sizes into a number of sectors. Cc: David S. Miller <davem@davemloft.net> Cc: Mike Snitzer <snitzer@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-12block: allow for_each_bvec to support zero len bvecMing Lei1-1/+8
commit 7e24969022cbd61ddc586f14824fc205661bb124 upstream. Block layer usually doesn't support or allow zero-length bvec. Since commit 1bdc76aea115 ("iov_iter: use bvec iterator to implement iterate_bvec()"), iterate_bvec() switches to bvec iterator. However, Al mentioned that 'Zero-length segments are not disallowed' in iov_iter. Fixes for_each_bvec() so that it can move on after seeing one zero length bvec. Fixes: 1bdc76aea115 ("iov_iter: use bvec iterator to implement iterate_bvec()") Reported-by: syzbot <syzbot+61acc40a49a3e46e25ea@syzkaller.appspotmail.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Tested-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Matthew Wilcox <willy@infradead.org> Cc: <stable@vger.kernel.org> Link: https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg2262077.html Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-12uaccess: Add non-pagefault user-space write functionDaniel Borkmann1-0/+12
[ Upstream commit 1d1585ca0f48fe7ed95c3571f3e4a82b2b5045dc ] Commit 3d7081822f7f ("uaccess: Add non-pagefault user-space read functions") missed to add probe write function, therefore factor out a probe_write_common() helper with most logic of probe_kernel_write() except setting KERNEL_DS, and add a new probe_user_write() helper so it can be used from BPF side. Again, on some archs, the user address space and kernel address space can co-exist and be overlapping, so in such case, setting KERNEL_DS would mean that the given address is treated as being in kernel address space. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Link: https://lore.kernel.org/bpf/9df2542e68141bfa3addde631441ee45503856a8.1572649915.git.daniel@iogearbox.net Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-12uaccess: Add non-pagefault user-space read functionsMasami Hiramatsu1-0/+14
[ Upstream commit 3d7081822f7f9eab867d9bcc8fd635208ec438e0 ] Add probe_user_read(), strncpy_from_unsafe_user() and strnlen_unsafe_user() which allows caller to access user-space in IRQ context. Current probe_kernel_read() and strncpy_from_unsafe() are not available for user-space memory, because it sets KERNEL_DS while accessing data. On some arch, user address space and kernel address space can be co-exist, but others can not. In that case, setting KERNEL_DS means given address is treated as a kernel address space. Also strnlen_user() is only available from user context since it can sleep if pagefault is enabled. To access user-space memory without pagefault, we need these new functions which sets USER_DS while accessing the data. Link: http://lkml.kernel.org/r/155789869802.26965.4940338412595759063.stgit@devnote2 Acked-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-12include/linux/log2.h: add missing () around n in roundup_pow_of_two()Jason Gunthorpe1-1/+1
[ Upstream commit 428fc0aff4e59399ec719ffcc1f7a5d29a4ee476 ] Otherwise gcc generates warnings if the expression is complicated. Fixes: 312a0c170945 ("[PATCH] LOG2: Alter roundup_pow_of_two() so that it can use a ilog2() on a constant") Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: https://lkml.kernel.org/r/0-v1-8a2697e3c003+41165-log_brackets_jgg@nvidia.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-12HID: core: Sanitize event code and type when mapping inputMarc Zyngier1-13/+29
commit 35556bed836f8dc07ac55f69c8d17dce3e7f0e25 upstream. When calling into hid_map_usage(), the passed event code is blindly stored as is, even if it doesn't fit in the associated bitmap. This event code can come from a variety of sources, including devices masquerading as input devices, only a bit more "programmable". Instead of taking the event code at face value, check that it actually fits the corresponding bitmap, and if it doesn't: - spit out a warning so that we know which device is acting up - NULLify the bitmap pointer so that we catch unexpected uses Code paths that can make use of untrusted inputs can now check that the mapping was indeed correct and bail out if not. Cc: stable@vger.kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-03overflow.h: Add allocation size calculation helpersKees Cook1-0/+73
commit 610b15c50e86eb1e4b77274fabcaea29ac72d6a8 upstream. In preparation for replacing unchecked overflows for memory allocations, this creates helpers for the 3 most common calculations: array_size(a, b): 2-dimensional array array3_size(a, b, c): 3-dimensional array struct_size(ptr, member, n): struct followed by n-many trailing members Each of these return SIZE_MAX on overflow instead of wrapping around. (Additionally renames a variable named "array_size" to avoid future collision.) Co-developed-by: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-03writeback: Avoid skipping inode writebackJan Kara1-2/+6
commit 5afced3bf28100d81fb2fe7e98918632a08feaf5 upstream. Inode's i_io_list list head is used to attach inode to several different lists - wb->{b_dirty, b_dirty_time, b_io, b_more_io}. When flush worker prepares a list of inodes to writeback e.g. for sync(2), it moves inodes to b_io list. Thus it is critical for sync(2) data integrity guarantees that inode is not requeued to any other writeback list when inode is queued for processing by flush worker. That's the reason why writeback_single_inode() does not touch i_io_list (unless the inode is completely clean) and why __mark_inode_dirty() does not touch i_io_list if I_SYNC flag is set. However there are two flaws in the current logic: 1) When inode has only I_DIRTY_TIME set but it is already queued in b_io list due to sync(2), concurrent __mark_inode_dirty(inode, I_DIRTY_SYNC) can still move inode back to b_dirty list resulting in skipping writeback of inode time stamps during sync(2). 2) When inode is on b_dirty_time list and writeback_single_inode() races with __mark_inode_dirty() like: writeback_single_inode() __mark_inode_dirty(inode, I_DIRTY_PAGES) inode->i_state |= I_SYNC __writeback_single_inode() inode->i_state |= I_DIRTY_PAGES; if (inode->i_state & I_SYNC) bail if (!(inode->i_state & I_DIRTY_ALL)) - not true so nothing done We end up with I_DIRTY_PAGES inode on b_dirty_time list and thus standard background writeback will not writeback this inode leading to possible dirty throttling stalls etc. (thanks to Martijn Coenen for this analysis). Fix these problems by tracking whether inode is queued in b_io or b_more_io lists in a new I_SYNC_QUEUED flag. When this flag is set, we know flush worker has queued inode and we should not touch i_io_list. On the other hand we also know that once flush worker is done with the inode it will requeue the inode to appropriate dirty list. When I_SYNC_QUEUED is not set, __mark_inode_dirty() can (and must) move inode to appropriate dirty list. Reported-by: Martijn Coenen <maco@android.com> Reviewed-by: Martijn Coenen <maco@android.com> Tested-by: Martijn Coenen <maco@android.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Fixes: 0ae45f63d4ef ("vfs: add support for a lazytime mount option") CC: stable@vger.kernel.org Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-03efi: provide empty efi_enter_virtual_mode implementationAndrey Konovalov1-0/+4
[ Upstream commit 2c547f9da0539ad1f7ef7f08c8c82036d61b011a ] When CONFIG_EFI is not enabled, we might get an undefined reference to efi_enter_virtual_mode() error, if this efi_enabled() call isn't inlined into start_kernel(). This happens in particular, if start_kernel() is annodated with __no_sanitize_address. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Ard Biesheuvel <ardb@kernel.org> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Elena Petrova <lenaptr@google.com> Cc: Marco Elver <elver@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Walter Wu <walter-zh.wu@mediatek.com> Link: http://lkml.kernel.org/r/6514652d3a32d3ed33d6eb5c91d0af63bf0d1a0c.1596544734.git.andreyknvl@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-21mm: Avoid calling build_all_zonelists_init under hotplug contextOscar Salvador1-1/+2
Recently a customer of ours experienced a crash when booting the system while enabling memory-hotplug. The problem is that Normal zones on different nodes don't get their private zone->pageset allocated, and keep sharing the initial boot_pageset. The sharing between zones is normally safe as explained by the comment for boot_pageset - it's a percpu structure, and manipulations are done with disabled interrupts, and boot_pageset is set up in a way that any page placed on its pcplist is immediately flushed to shared zone's freelist, because pcp->high == 1. However, the hotplug operation updates pcp->high to a higher value as it expects to be operating on a private pageset. The problem is in build_all_zonelists(), which is called when the first range of pages is onlined for the Normal zone of node X or Y: if (system_state == SYSTEM_BOOTING) { build_all_zonelists_init(); } else { #ifdef CONFIG_MEMORY_HOTPLUG if (zone) setup_zone_pageset(zone); #endif /* we have to stop all cpus to guarantee there is no user of zonelist */ stop_machine(__build_all_zonelists, pgdat, NULL); /* cpuset refresh routine should be here */ } When called during hotplug, it should execute the setup_zone_pageset(zone) which allocates the private pageset. However, with memhp_default_state=online, this happens early while system_state == SYSTEM_BOOTING is still true, hence this step is skipped. (and build_all_zonelists_init() is probably unsafe anyway at this point). Another hotplug operation on the same zone then leads to zone_pcp_update(zone) called from online_pages(), which updates the pcp->high for the shared boot_pageset to a value higher than 1. At that point, pages freed from Node X and Y Normal zones can end up on the same pcplist and from there they can be freed to the wrong zone's freelist, leading to the corruption and crashes. Please, note that upstream has fixed that differently (and unintentionally) by adding another boot state (SYSTEM_SCHEDULING), which is set before smp_init(). That should happen before memory hotplug events even with memhp_default_state=online. Backporting that would be too intrusive. Signed-off-by: Oscar Salvador <osalvador@suse.de> Debugged-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> # for stable trees Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-21iommu/vt-d: Enforce PASID devTLB field maskLiu Yi L1-2/+2
[ Upstream commit 5f77d6ca5ca74e4b4a5e2e010f7ff50c45dea326 ] Set proper masks to avoid invalid input spillover to reserved bits. Signed-off-by: Liu Yi L <yi.l.liu@intel.com> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Link: https://lore.kernel.org/r/20200724014925.15523-2-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-21tracepoint: Mark __tracepoint_string's __usedNick Desaulniers1-1/+1
commit f3751ad0116fb6881f2c3c957d66a9327f69cefb upstream. __tracepoint_string's have their string data stored in .rodata, and an address to that data stored in the "__tracepoint_str" section. Functions that refer to those strings refer to the symbol of the address. Compiler optimization can replace those address references with references directly to the string data. If the address doesn't appear to have other uses, then it appears dead to the compiler and is removed. This can break the /tracing/printk_formats sysfs node which iterates the addresses stored in the "__tracepoint_str" section. Like other strings stored in custom sections in this header, mark these __used to inform the compiler that there are other non-obvious users of the address, so they should still be emitted. Link: https://lkml.kernel.org/r/20200730224555.2142154-2-ndesaulniers@google.com Cc: Ingo Molnar <mingo@redhat.com> Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> Cc: stable@vger.kernel.org Fixes: 102c9323c35a8 ("tracing: Add __tracepoint_string() to export string pointers") Reported-by: Tim Murray <timmurray@google.com> Reported-by: Simon MacMullen <simonmacm@google.com> Suggested-by: Greg Hackmann <ghackmann@google.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-21xattr: break delegations in {set,remove}xattrFrank van der Linden1-0/+2
commit 08b5d5014a27e717826999ad20e394a8811aae92 upstream. set/removexattr on an exported filesystem should break NFS delegations. This is true in general, but also for the upcoming support for RFC 8726 (NFSv4 extended attribute support). Make sure that they do. Additionally, they need to grow a _locked variant, since callers might call this with i_rwsem held (like the NFS server code). Cc: stable@vger.kernel.org # v4.9+ Cc: linux-fsdevel@vger.kernel.org Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Frank van der Linden <fllinden@amazon.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-21random32: move the pseudo-random 32-bit definitions to prandom.hLinus Torvalds2-62/+82
commit c0842fbc1b18c7a044e6ff3e8fa78bfa822c7d1a upstream. The addition of percpu.h to the list of includes in random.h revealed some circular dependencies on arm64 and possibly other platforms. This include was added solely for the pseudo-random definitions, which have nothing to do with the rest of the definitions in this file but are still there for legacy reasons. This patch moves the pseudo-random parts to linux/prandom.h and the percpu.h include with it, which is now guarded by _LINUX_PRANDOM_H and protected against recursive inclusion. A further cleanup step would be to remove this from <linux/random.h> entirely, and make people who use the prandom infrastructure include just the new header file. That's a bit of a churn patch, but grepping for "prandom_" and "next_pseudo_random32" "struct rnd_state" should catch most users. But it turns out that that nice cleanup step is fairly painful, because a _lot_ of code currently seems to depend on the implicit include of <linux/random.h>, which can currently come in a lot of ways, including such fairly core headfers as <linux/net.h>. So the "nice cleanup" part may or may never happen. Fixes: 1c9df907da83 ("random: fix circular include dependency on arm64 after addition of percpu.h") Tested-by: Guenter Roeck <linux@roeck-us.net> Acked-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-21random32: remove net_rand_state from the latent entropy gcc pluginLinus Torvalds1-1/+1
commit 83bdc7275e6206f560d247be856bceba3e1ed8f2 upstream. It turns out that the plugin right now ends up being really unhappy about the change from 'static' to 'extern' storage that happened in commit f227e3ec3b5c ("random32: update the net random state on interrupt and activity"). This is probably a trivial fix for the latent_entropy plugin, but for now, just remove net_rand_state from the list of things the plugin worries about. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Emese Revfy <re.emese@gmail.com> Cc: Kees Cook <keescook@chromium.org> Cc: Willy Tarreau <w@1wt.eu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-21random: fix circular include dependency on arm64 after addition of percpu.hWilly Tarreau1-1/+1
commit 1c9df907da83812e4f33b59d3d142c864d9da57f upstream. Daniel Díaz and Kees Cook independently reported that commit f227e3ec3b5c ("random32: update the net random state on interrupt and activity") broke arm64 due to a circular dependency on include files since the addition of percpu.h in random.h. The correct fix would definitely be to move all the prandom32 stuff out of random.h but for backporting, a smaller solution is preferred. This one replaces linux/percpu.h with asm/percpu.h, and this fixes the problem on x86_64, arm64, arm, and mips. Note that moving percpu.h around didn't change anything and that removing it entirely broke differently. When backporting, such options might still be considered if this patch fails to help. [ It turns out that an alternate fix seems to be to just remove the troublesome <asm/pointer_auth.h> remove from the arm64 <asm/smp.h> that causes the circular dependency. But we might as well do the whole belt-and-suspenders thing, and minimize inclusion in <linux/random.h> too. Either will fix the problem, and both are good changes. - Linus ] Reported-by: Daniel Díaz <daniel.diaz@linaro.org> Reported-by: Kees Cook <keescook@chromium.org> Tested-by: Marc Zyngier <maz@kernel.org> Fixes: f227e3ec3b5c Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-21random32: update the net random state on interrupt and activityWilly Tarreau1-0/+3
commit f227e3ec3b5cad859ad15666874405e8c1bbc1d4 upstream. This modifies the first 32 bits out of the 128 bits of a random CPU's net_rand_state on interrupt or CPU activity to complicate remote observations that could lead to guessing the network RNG's internal state. Note that depending on some network devices' interrupt rate moderation or binding, this re-seeding might happen on every packet or even almost never. In addition, with NOHZ some CPUs might not even get timer interrupts, leaving their local state rarely updated, while they are running networked processes making use of the random state. For this reason, we also perform this update in update_process_times() in order to at least update the state when there is user or system activity, since it's the only case we care about. Reported-by: Amit Klein <aksecurity@gmail.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Eric Dumazet <edumazet@google.com> Cc: "Jason A. Donenfeld" <Jason@zx2c4.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: <stable@vger.kernel.org> Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-31tcp: allow at most one TLP probe per flightYuchung Cheng1-1/+3
[ Upstream commit 76be93fc0702322179bb0ea87295d820ee46ad14 ] Previously TLP may send multiple probes of new data in one flight. This happens when the sender is cwnd limited. After the initial TLP containing new data is sent, the sender receives another ACK that acks partial inflight. It may re-arm another TLP timer to send more, if no further ACK returns before the next TLP timeout (PTO) expires. The sender may send in theory a large amount of TLP until send queue is depleted. This only happens if the sender sees such irregular uncommon ACK pattern. But it is generally undesirable behavior during congestion especially. The original TLP design restrict only one TLP probe per inflight as published in "Reducing Web Latency: the Virtue of Gentle Aggression", SIGCOMM 2013. This patch changes TLP to send at most one probe per inflight. Note that if the sender is app-limited, TLP retransmits old data and did not have this issue. Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-31io-mapping: indicate mapping failureMichael J. Ruhl1-1/+4
commit e0b3e0b1a04367fc15c07f44e78361545b55357c upstream. The !ATOMIC_IOMAP version of io_maping_init_wc will always return success, even when the ioremap fails. Since the ATOMIC_IOMAP version returns NULL when the init fails, and callers check for a NULL return on error this is unexpected. During a device probe, where the ioremap failed, a crash can look like this: BUG: unable to handle page fault for address: 0000000000210000 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page Oops: 0002 [#1] PREEMPT SMP CPU: 0 PID: 177 Comm: RIP: 0010:fill_page_dma [i915] gen8_ppgtt_create [i915] i915_ppgtt_create [i915] intel_gt_init [i915] i915_gem_init [i915] i915_driver_probe [i915] pci_device_probe really_probe driver_probe_device The remap failure occurred much earlier in the probe. If it had been propagated, the driver would have exited with an error. Return NULL on ioremap failure. [akpm@linux-foundation.org: detect ioremap_wc() errors earlier] Fixes: cafaf14a5d8f ("io-mapping: Always create a struct to hold metadata about the io-mapping") Signed-off-by: Michael J. Ruhl <michael.j.ruhl@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/20200721171936.81563-1-michael.j.ruhl@intel.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-22usb: core: Add a helper function to check the validity of EP type in URBTakashi Iwai1-0/+2
commit e901b9873876ca30a09253731bd3a6b00c44b5b0 upstream. This patch adds a new helper function to perform a sanity check of the given URB to see whether it contains a valid endpoint. It's a light- weight version of what usb_submit_urb() does, but without the kernel warning followed by the stack trace, just returns an error code. Especially for a driver that doesn't parse the descriptor but fills the URB with the fixed endpoint (e.g. some quirks for non-compliant devices), this kind of check is preferable at the probe phase before actually submitting the urb. Tested-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-22cgroup: Fix sock_cgroup_data on big-endian.Cong Wang1-0/+2
[ Upstream commit 14b032b8f8fce03a546dcf365454bec8c4a58d7d ] In order for no_refcnt and is_data to be the lowest order two bits in the 'val' we have to pad out the bitfield of the u8. Fixes: ad0f75e5f57c ("cgroup: fix cgroup_sk_alloc() for sk_clone_lock()") Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-22cgroup: fix cgroup_sk_alloc() for sk_clone_lock()Cong Wang2-3/+7
[ Upstream commit ad0f75e5f57ccbceec13274e1e242f2b5a6397ed ] When we clone a socket in sk_clone_lock(), its sk_cgrp_data is copied, so the cgroup refcnt must be taken too. And, unlike the sk_alloc() path, sock_update_netprioidx() is not called here. Therefore, it is safe and necessary to grab the cgroup refcnt even when cgroup_sk_alloc is disabled. sk_clone_lock() is in BH context anyway, the in_interrupt() would terminate this function if called there. And for sk_alloc() skcd->val is always zero. So it's safe to factor out the code to make it more readable. The global variable 'cgroup_sk_alloc_disabled' is used to determine whether to take these reference counts. It is impossible to make the reference counting correct unless we save this bit of information in skcd->val. So, add a new bit there to record whether the socket has already taken the reference counts. This obviously relies on kmalloc() to align cgroup pointers to at least 4 bytes, ARCH_KMALLOC_MINALIGN is certainly larger than that. This bug seems to be introduced since the beginning, commit d979a39d7242 ("cgroup: duplicate cgroup reference when cloning sockets") tried to fix it but not compeletely. It seems not easy to trigger until the recent commit 090e28b229af ("netprio_cgroup: Fix unlimited memory leak of v2 cgroups") was merged. Fixes: bd1060a1d671 ("sock, cgroup: add sock->sk_cgroup") Reported-by: Cameron Berkenpas <cam@neo-zeon.de> Reported-by: Peter Geis <pgwipeout@gmail.com> Reported-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com> Reported-by: Daniël Sonck <dsonck92@gmail.com> Reported-by: Zhang Qiang <qiang.zhang@windriver.com> Tested-by: Cameron Berkenpas <cam@neo-zeon.de> Tested-by: Peter Geis <pgwipeout@gmail.com> Tested-by: Thomas Lamprecht <t.lamprecht@proxmox.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Zefan Li <lizefan@huawei.com> Cc: Tejun Heo <tj@kernel.org> Cc: Roman Gushchin <guro@fb.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-09sched/rt: Show the 'sched_rr_timeslice' SCHED_RR timeslice tuning knob in ↵Shile Zhang1-0/+1
milliseconds [ Upstream commit 975e155ed8732cb81f55c021c441ae662dd040b5 ] We added the 'sched_rr_timeslice_ms' SCHED_RR tuning knob in this commit: ce0dbbbb30ae ("sched/rt: Add a tuning knob to allow changing SCHED_RR timeslice") ... which name suggests to users that it's in milliseconds, while in reality it's being set in milliseconds but the result is shown in jiffies. This is obviously confusing when HZ is not 1000, it makes it appear like the value set failed, such as HZ=100: root# echo 100 > /proc/sys/kernel/sched_rr_timeslice_ms root# cat /proc/sys/kernel/sched_rr_timeslice_ms 10 Fix this to be milliseconds all around. Signed-off-by: Shile Zhang <shile.zhang@nokia.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.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/1485612049-20923-1-git-send-email-shile.zhang@nokia.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-30net: qed: fix left elements count calculationAlexander Lobakin1-10/+16
[ Upstream commit 97dd1abd026ae4e6a82fa68645928404ad483409 ] qed_chain_get_element_left{,_u32} returned 0 when the difference between producer and consumer page count was equal to the total page count. Fix this by conditional expanding of producer value (vs unconditional). This allowed to eliminate normalizaton against total page count, which was the cause of this bug. Misc: replace open-coded constants with common defines. Fixes: a91eb52abb50 ("qed: Revisit chain implementation") Signed-off-by: Alexander Lobakin <alobakin@marvell.com> Signed-off-by: Igor Russkikh <irusskikh@marvell.com> Signed-off-by: Michal Kalderon <michal.kalderon@marvell.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-30net: core: reduce recursion limit valueTaehee Yoo1-1/+1
[ Upstream commit fb7861d14c8d7edac65b2fcb6e8031cb138457b2 ] In the current code, ->ndo_start_xmit() can be executed recursively only 10 times because of stack memory. But, in the case of the vxlan, 10 recursion limit value results in a stack overflow. In the current code, the nested interface is limited by 8 depth. There is no critical reason that the recursion limitation value should be 10. So, it would be good to be the same value with the limitation value of nesting interface depth. Test commands: ip link add vxlan10 type vxlan vni 10 dstport 4789 srcport 4789 4789 ip link set vxlan10 up ip a a 192.168.10.1/24 dev vxlan10 ip n a 192.168.10.2 dev vxlan10 lladdr fc:22:33:44:55:66 nud permanent for i in {9..0} do let A=$i+1 ip link add vxlan$i type vxlan vni $i dstport 4789 srcport 4789 4789 ip link set vxlan$i up ip a a 192.168.$i.1/24 dev vxlan$i ip n a 192.168.$i.2 dev vxlan$i lladdr fc:22:33:44:55:66 nud permanent bridge fdb add fc:22:33:44:55:66 dev vxlan$A dst 192.168.$i.2 self done hping3 192.168.10.2 -2 -d 60000 Splat looks like: [ 103.814237][ T1127] ============================================================================= [ 103.871955][ T1127] BUG kmalloc-2k (Tainted: G B ): Padding overwritten. 0x00000000897a2e4f-0x000 [ 103.873187][ T1127] ----------------------------------------------------------------------------- [ 103.873187][ T1127] [ 103.874252][ T1127] INFO: Slab 0x000000005cccc724 objects=5 used=5 fp=0x0000000000000000 flags=0x10000000001020 [ 103.881323][ T1127] CPU: 3 PID: 1127 Comm: hping3 Tainted: G B 5.7.0+ #575 [ 103.882131][ T1127] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 103.883006][ T1127] Call Trace: [ 103.883324][ T1127] dump_stack+0x96/0xdb [ 103.883716][ T1127] slab_err+0xad/0xd0 [ 103.884106][ T1127] ? _raw_spin_unlock+0x1f/0x30 [ 103.884620][ T1127] ? get_partial_node.isra.78+0x140/0x360 [ 103.885214][ T1127] slab_pad_check.part.53+0xf7/0x160 [ 103.885769][ T1127] ? pskb_expand_head+0x110/0xe10 [ 103.886316][ T1127] check_slab+0x97/0xb0 [ 103.886763][ T1127] alloc_debug_processing+0x84/0x1a0 [ 103.887308][ T1127] ___slab_alloc+0x5a5/0x630 [ 103.887765][ T1127] ? pskb_expand_head+0x110/0xe10 [ 103.888265][ T1127] ? lock_downgrade+0x730/0x730 [ 103.888762][ T1127] ? pskb_expand_head+0x110/0xe10 [ 103.889244][ T1127] ? __slab_alloc+0x3e/0x80 [ 103.889675][ T1127] __slab_alloc+0x3e/0x80 [ 103.890108][ T1127] __kmalloc_node_track_caller+0xc7/0x420 [ ... ] Fixes: 11a766ce915f ("net: Increase xmit RECURSION_LIMIT to 10.") Signed-off-by: Taehee Yoo <ap420073@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-30mtd: rawnand: Pass a nand_chip object to nand_release()Boris Brezillon1-4/+2
[ Upstream commit 59ac276f22270fb2094910f9a734c17f41c25e70 ] Let's make the raw NAND API consistent by patching all helpers to take a nand_chip object instead of an mtd_info one. Now is nand_release()'s turn. Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-30kretprobe: Prevent triggering kretprobe from within kprobe_flush_taskJiri Olsa1-0/+4
[ Upstream commit 9b38cc704e844e41d9cf74e647bff1d249512cb3 ] Ziqian reported lockup when adding retprobe on _raw_spin_lock_irqsave. My test was also able to trigger lockdep output: ============================================ WARNING: possible recursive locking detected 5.6.0-rc6+ #6 Not tainted -------------------------------------------- sched-messaging/2767 is trying to acquire lock: ffffffff9a492798 (&(kretprobe_table_locks[i].lock)){-.-.}, at: kretprobe_hash_lock+0x52/0xa0 but task is already holding lock: ffffffff9a491a18 (&(kretprobe_table_locks[i].lock)){-.-.}, at: kretprobe_trampoline+0x0/0x50 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(kretprobe_table_locks[i].lock)); lock(&(kretprobe_table_locks[i].lock)); *** DEADLOCK *** May be due to missing lock nesting notation 1 lock held by sched-messaging/2767: #0: ffffffff9a491a18 (&(kretprobe_table_locks[i].lock)){-.-.}, at: kretprobe_trampoline+0x0/0x50 stack backtrace: CPU: 3 PID: 2767 Comm: sched-messaging Not tainted 5.6.0-rc6+ #6 Call Trace: dump_stack+0x96/0xe0 __lock_acquire.cold.57+0x173/0x2b7 ? native_queued_spin_lock_slowpath+0x42b/0x9e0 ? lockdep_hardirqs_on+0x590/0x590 ? __lock_acquire+0xf63/0x4030 lock_acquire+0x15a/0x3d0 ? kretprobe_hash_lock+0x52/0xa0 _raw_spin_lock_irqsave+0x36/0x70 ? kretprobe_hash_lock+0x52/0xa0 kretprobe_hash_lock+0x52/0xa0 trampoline_handler+0xf8/0x940 ? kprobe_fault_handler+0x380/0x380 ? find_held_lock+0x3a/0x1c0 kretprobe_trampoline+0x25/0x50 ? lock_acquired+0x392/0xbc0 ? _raw_spin_lock_irqsave+0x50/0x70 ? __get_valid_kprobe+0x1f0/0x1f0 ? _raw_spin_unlock_irqrestore+0x3b/0x40 ? finish_task_switch+0x4b9/0x6d0 ? __switch_to_asm+0x34/0x70 ? __switch_to_asm+0x40/0x70 The code within the kretprobe handler checks for probe reentrancy, so we won't trigger any _raw_spin_lock_irqsave probe in there. The problem is in outside kprobe_flush_task, where we call: kprobe_flush_task kretprobe_table_lock raw_spin_lock_irqsave _raw_spin_lock_irqsave where _raw_spin_lock_irqsave triggers the kretprobe and installs kretprobe_trampoline handler on _raw_spin_lock_irqsave return. The kretprobe_trampoline handler is then executed with already locked kretprobe_table_locks, and first thing it does is to lock kretprobe_table_locks ;-) the whole lockup path like: kprobe_flush_task kretprobe_table_lock raw_spin_lock_irqsave _raw_spin_lock_irqsave ---> probe triggered, kretprobe_trampoline installed ---> kretprobe_table_locks locked kretprobe_trampoline trampoline_handler kretprobe_hash_lock(current, &head, &flags); <--- deadlock Adding kprobe_busy_begin/end helpers that mark code with fake probe installed to prevent triggering of another kprobe within this code. Using these helpers in kprobe_flush_task, so the probe recursion protection check is hit and the probe is never set to prevent above lockup. Link: http://lkml.kernel.org/r/158927059835.27680.7011202830041561604.stgit@devnote2 Fixes: ef53d9c5e4da ("kprobes: improve kretprobe scalability with hashed locking") Cc: Ingo Molnar <mingo@kernel.org> Cc: "Gustavo A . R . Silva" <gustavoars@kernel.org> Cc: Anders Roxell <anders.roxell@linaro.org> Cc: "Naveen N . Rao" <naveen.n.rao@linux.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: David Miller <davem@davemloft.net> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: stable@vger.kernel.org Reported-by: "Ziqian SUN (Zamir)" <zsun@redhat.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-30block: nr_sects_write(): Disable preemption on seqcount writeAhmed S. Darwish1-0/+2
[ Upstream commit 15b81ce5abdc4b502aa31dff2d415b79d2349d2f ] For optimized block readers not holding a mutex, the "number of sectors" 64-bit value is protected from tearing on 32-bit architectures by a sequence counter. Disable preemption before entering that sequence counter's write side critical section. Otherwise, the read side can preempt the write side section and spin for the entire scheduler tick. If the reader belongs to a real-time scheduling class, it can spin forever and the kernel will livelock. Fixes: c83f6bf98dc1 ("block: add partition resize function to blkpg ioctl") Cc: <stable@vger.kernel.org> Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de> Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-30libata: Use per port sync for detachKai-Heng Feng1-0/+3
[ Upstream commit b5292111de9bb70cba3489075970889765302136 ] Commit 130f4caf145c ("libata: Ensure ata_port probe has completed before detach") may cause system freeze during suspend. Using async_synchronize_full() in PM callbacks is wrong, since async callbacks that are already scheduled may wait for not-yet-scheduled callbacks, causes a circular dependency. Instead of using big hammer like async_synchronize_full(), use async cookie to make sure port probe are synced, without affecting other scheduled PM callbacks. Fixes: 130f4caf145c ("libata: Ensure ata_port probe has completed before detach") Suggested-by: John Garry <john.garry@huawei.com> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com> Tested-by: John Garry <john.garry@huawei.com> BugLink: https://bugs.launchpad.net/bugs/1867983 Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-30elfnote: mark all .note sections SHF_ALLOCNick Desaulniers1-1/+1
[ Upstream commit 51da9dfb7f20911ae4e79e9b412a9c2d4c373d4b ] ELFNOTE_START allows callers to specify flags for .pushsection assembler directives. All callsites but ELF_NOTE use "a" for SHF_ALLOC. For vdso's that explicitly use ELF_NOTE_START and BUILD_SALT, the same section is specified twice after preprocessing, once with "a" flag, once without. Example: .pushsection .note.Linux, "a", @note ; .pushsection .note.Linux, "", @note ; While GNU as allows this ordering, it warns for the opposite ordering, making these directives position dependent. We'd prefer not to precisely match this behavior in Clang's integrated assembler. Instead, the non __ASSEMBLY__ definition of ELF_NOTE uses __attribute__((section(".note.Linux"))) which is created with SHF_ALLOC, so let's make the __ASSEMBLY__ definition of ELF_NOTE consistent with C and just always use "a" flag. This allows Clang to assemble a working mainline (5.6) kernel via: $ make CC=clang AS=clang Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Fangrui Song <maskray@google.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Link: https://github.com/ClangBuiltLinux/linux/issues/913 Link: http://lkml.kernel.org/r/20200325231250.99205-1-ndesaulniers@google.com Debugged-by: Ilie Halip <ilie.halip@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-30include/linux/bitops.h: avoid clang shift-count-overflow warningsArnd Bergmann1-1/+1
[ Upstream commit bd93f003b7462ae39a43c531abca37fe7073b866 ] Clang normally does not warn about certain issues in inline functions when it only happens in an eliminated code path. However if something else goes wrong, it does tend to complain about the definition of hweight_long() on 32-bit targets: include/linux/bitops.h:75:41: error: shift count >= width of type [-Werror,-Wshift-count-overflow] return sizeof(w) == 4 ? hweight32(w) : hweight64(w); ^~~~~~~~~~~~ include/asm-generic/bitops/const_hweight.h:29:49: note: expanded from macro 'hweight64' define hweight64(w) (__builtin_constant_p(w) ? __const_hweight64(w) : __arch_hweight64(w)) ^~~~~~~~~~~~~~~~~~~~ include/asm-generic/bitops/const_hweight.h:21:76: note: expanded from macro '__const_hweight64' define __const_hweight64(w) (__const_hweight32(w) + __const_hweight32((w) >> 32)) ^ ~~ include/asm-generic/bitops/const_hweight.h:20:49: note: expanded from macro '__const_hweight32' define __const_hweight32(w) (__const_hweight16(w) + __const_hweight16((w) >> 16)) ^ include/asm-generic/bitops/const_hweight.h:19:72: note: expanded from macro '__const_hweight16' define __const_hweight16(w) (__const_hweight8(w) + __const_hweight8((w) >> 8 )) ^ include/asm-generic/bitops/const_hweight.h:12:9: note: expanded from macro '__const_hweight8' (!!((w) & (1ULL << 2))) + \ Adding an explicit cast to __u64 avoids that warning and makes it easier to read other output. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Link: http://lkml.kernel.org/r/20200505135513.65265-1-arnd@arndb.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-30usb: gadget: Fix issue with config_ep_by_speed functionPawel Laszczak1-0/+3
[ Upstream commit 5d363120aa548ba52d58907a295eee25f8207ed2 ] This patch adds new config_ep_by_speed_and_alt function which extends the config_ep_by_speed about alt parameter. This additional parameter allows to find proper usb_ss_ep_comp_descriptor. Problem has appeared during testing f_tcm (BOT/UAS) driver function. f_tcm function for SS use array of headers for both BOT/UAS alternate setting: static struct usb_descriptor_header *uasp_ss_function_desc[] = { (struct usb_descriptor_header *) &bot_intf_desc, (struct usb_descriptor_header *) &uasp_ss_bi_desc, (struct usb_descriptor_header *) &bot_bi_ep_comp_desc, (struct usb_descriptor_header *) &uasp_ss_bo_desc, (struct usb_descriptor_header *) &bot_bo_ep_comp_desc, (struct usb_descriptor_header *) &uasp_intf_desc, (struct usb_descriptor_header *) &uasp_ss_bi_desc, (struct usb_descriptor_header *) &uasp_bi_ep_comp_desc, (struct usb_descriptor_header *) &uasp_bi_pipe_desc, (struct usb_descriptor_header *) &uasp_ss_bo_desc, (struct usb_descriptor_header *) &uasp_bo_ep_comp_desc, (struct usb_descriptor_header *) &uasp_bo_pipe_desc, (struct usb_descriptor_header *) &uasp_ss_status_desc, (struct usb_descriptor_header *) &uasp_status_in_ep_comp_desc, (struct usb_descriptor_header *) &uasp_status_pipe_desc, (struct usb_descriptor_header *) &uasp_ss_cmd_desc, (struct usb_descriptor_header *) &uasp_cmd_comp_desc, (struct usb_descriptor_header *) &uasp_cmd_pipe_desc, NULL, }; The first 5 descriptors are associated with BOT alternate setting, and others are associated with UAS. During handling UAS alternate setting f_tcm driver invokes config_ep_by_speed and this function sets incorrect companion endpoint descriptor in usb_ep object. Instead setting ep->comp_desc to uasp_bi_ep_comp_desc function in this case set ep->comp_desc to uasp_ss_bi_desc. This is due to the fact that it searches endpoint based on endpoint address: for_each_ep_desc(speed_desc, d_spd) { chosen_desc = (struct usb_endpoint_descriptor *)*d_spd; if (chosen_desc->bEndpoitAddress == _ep->address) goto ep_found; } And in result it uses the descriptor from BOT alternate setting instead UAS. Finally, it causes that controller driver during enabling endpoints detect that just enabled endpoint for bot. Signed-off-by: Jayshri Pawar <jpawar@cadence.com> Signed-off-by: Pawel Laszczak <pawell@cadence.com> Signed-off-by: Felipe Balbi <balbi@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-20sunrpc: clean up properly in gss_mech_unregister()NeilBrown2-1/+3
commit 24c5efe41c29ee3e55bcf5a1c9f61ca8709622e8 upstream. gss_mech_register() calls svcauth_gss_register_pseudoflavor() for each flavour, but gss_mech_unregister() does not call auth_domain_put(). This is unbalanced and makes it impossible to reload the module. Change svcauth_gss_register_pseudoflavor() to return the registered auth_domain, and save it for later release. Cc: stable@vger.kernel.org (v2.6.12+) Link: https://bugzilla.kernel.org/show_bug.cgi?id=206651 Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-20kgdb: Fix spurious true from in_dbg_master()Daniel Thompson1-1/+1
[ Upstream commit 3fec4aecb311995189217e64d725cfe84a568de3 ] Currently there is a small window where a badly timed migration could cause in_dbg_master() to spuriously return true. Specifically if we migrate to a new core after reading the processor id and the previous core takes a breakpoint then we will evaluate true if we read kgdb_active before we get the IPI to bring us to halt. Fix this by checking irqs_disabled() first. Interrupts are always disabled when we are executing the kgdb trap so this is an acceptable prerequisite. This also allows us to replace raw_smp_processor_id() with smp_processor_id() since the short circuit logic will prevent warnings from PREEMPT_DEBUG. Fixes: dcc7871128e9 ("kgdb: core changes to support kdb") Suggested-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20200506164223.2875760-1-daniel.thompson@linaro.org Reviewed-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-11x86/cpu: Add a steppings field to struct x86_cpu_idMark Gross1-0/+6
commit e9d7144597b10ff13ff2264c059f7d4a7fbc89ac upstream Intel uses the same family/model for several CPUs. Sometimes the stepping must be checked to tell them apart. On x86 there can be at most 16 steppings. Add a steppings bitmask to x86_cpu_id and a X86_MATCH_VENDOR_FAMILY_MODEL_STEPPING_FEATURE macro and support for matching against family/model/stepping. [ bp: Massage. tglx: Lightweight variant for backporting ] Signed-off-by: Mark Gross <mgross@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Tony Luck <tony.luck@intel.com> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-03netfilter: nf_conntrack_pptp: fix compilation warning with W=1 buildPablo Neira Ayuso1-1/+1
commit 4946ea5c1237036155c3b3a24f049fd5f849f8f6 upstream. >> include/linux/netfilter/nf_conntrack_pptp.h:13:20: warning: 'const' type qualifier on return type has no effect [-Wignored-qualifiers] extern const char *const pptp_msg_name(u_int16_t msg); ^~~~~~ Reported-by: kbuild test robot <lkp@intel.com> Fixes: 4c559f15efcc ("netfilter: nf_conntrack_pptp: prevent buffer overflows in debug code") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-03netfilter: nf_conntrack_pptp: prevent buffer overflows in debug codePablo Neira Ayuso1-1/+1
commit 4c559f15efcc43b996f4da528cd7f9483aaca36d upstream. Dan Carpenter says: "Smatch complains that the value for "cmd" comes from the network and can't be trusted." Add pptp_msg_name() helper function that checks for the array boundary. Fixes: f09943fefe6b ("[NETFILTER]: nf_conntrack/nf_nat: add PPTP helper port") Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-03mm: remove VM_BUG_ON(PageSlab()) from page_mapcount()Konstantin Khlebnikov1-2/+13
[ Upstream commit 6988f31d558aa8c744464a7f6d91d34ada48ad12 ] Replace superfluous VM_BUG_ON() with comment about correct usage. Technically reverts commit 1d148e218a0d ("mm: add VM_BUG_ON_PAGE() to page_mapcount()"), but context lines have changed. Function isolate_migratepages_block() runs some checks out of lru_lock when choose pages for migration. After checking PageLRU() it checks extra page references by comparing page_count() and page_mapcount(). Between these two checks page could be removed from lru, freed and taken by slab. As a result this race triggers VM_BUG_ON(PageSlab()) in page_mapcount(). Race window is tiny. For certain workload this happens around once a year. page:ffffea0105ca9380 count:1 mapcount:0 mapping:ffff88ff7712c180 index:0x0 compound_mapcount: 0 flags: 0x500000000008100(slab|head) raw: 0500000000008100 dead000000000100 dead000000000200 ffff88ff7712c180 raw: 0000000000000000 0000000080200020 00000001ffffffff 0000000000000000 page dumped because: VM_BUG_ON_PAGE(PageSlab(page)) ------------[ cut here ]------------ kernel BUG at ./include/linux/mm.h:628! invalid opcode: 0000 [#1] SMP NOPTI CPU: 77 PID: 504 Comm: kcompactd1 Tainted: G W 4.19.109-27 #1 Hardware name: Yandex T175-N41-Y3N/MY81-EX0-Y3N, BIOS R05 06/20/2019 RIP: 0010:isolate_migratepages_block+0x986/0x9b0 The code in isolate_migratepages_block() was added in commit 119d6d59dcc0 ("mm, compaction: avoid isolating pinned pages") before adding VM_BUG_ON into page_mapcount(). This race has been predicted in 2015 by Vlastimil Babka (see link below). [akpm@linux-foundation.org: comment tweaks, per Hugh] Fixes: 1d148e218a0d ("mm: add VM_BUG_ON_PAGE() to page_mapcount()") Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Hugh Dickins <hughd@google.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/159032779896.957378.7852761411265662220.stgit@buzz Link: https://lore.kernel.org/lkml/557710E1.6060103@suse.cz/ Link: https://lore.kernel.org/linux-mm/158937872515.474360.5066096871639561424.stgit@buzz/T/ (v1) Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-03net/mlx5: Add command entry handling completionMoshe Shemesh1-0/+1
[ Upstream commit 17d00e839d3b592da9659c1977d45f85b77f986a ] When FW response to commands is very slow and all command entries in use are waiting for completion we can have a race where commands can get timeout before they get out of the queue and handled. Timeout completion on uninitialized command will cause releasing command's buffers before accessing it for initialization and then we will get NULL pointer exception while trying access it. It may also cause releasing buffers of another command since we may have timeout completion before even allocating entry index for this command. Add entry handling completion to avoid this race. Fixes: e126ba97dba9 ("mlx5: Add driver for Mellanox Connect-IB adapters") Signed-off-by: Moshe Shemesh <moshe@mellanox.com> Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27l2tp: device MTU setup, tunnel socket needs a lockR. Parameswaran1-1/+1
commit 57240d007816486131bee88cd474c2a71f0fe224 upstream. The MTU overhead calculation in L2TP device set-up merged via commit b784e7ebfce8cfb16c6f95e14e8532d0768ab7ff needs to be adjusted to lock the tunnel socket while referencing the sub-data structures to derive the socket's IP overhead. Reported-by: Guillaume Nault <g.nault@alphalink.fr> Tested-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: R. Parameswaran <rparames@brocade.com> Signed-off-by: David S. Miller <davem@davemloft.net> Cc: Giuliano Procida <gprocida@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27New kernel function to get IP overhead on a socket.R. Parameswaran1-0/+3
commit 113c3075931a334f899008f6c753abe70a3a9323 upstream. A new function, kernel_sock_ip_overhead(), is provided to calculate the cumulative overhead imposed by the IP Header and IP options, if any, on a socket's payload. The new function returns an overhead of zero for sockets that do not belong to the IPv4 or IPv6 address families. This is used in the L2TP code path to compute the total outer IP overhead on the L2TP tunnel socket when calculating the default MTU for Ethernet pseudowires. Signed-off-by: R. Parameswaran <rparames@brocade.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Giuliano Procida <gprocida@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27padata: Replace delayed timer with immediate workqueue in padata_reorderHerbert Xu1-9/+4
[ Upstream commit 6fc4dbcf0276279d488c5fbbfabe94734134f4fa ] The function padata_reorder will use a timer when it cannot progress while completed jobs are outstanding (pd->reorder_objects > 0). This is suboptimal as if we do end up using the timer then it would have introduced a gratuitous delay of one second. In fact we can easily distinguish between whether completed jobs are outstanding and whether we can make progress. All we have to do is look at the next pqueue list. This patch does that by replacing pd->processed with pd->cpu so that the next pqueue is more accessible. A work queue is used instead of the original try_again to avoid hogging the CPU. Note that we don't bother removing the work queue in padata_flush_queues because the whole premise is broken. You cannot flush async crypto requests so it makes no sense to even try. A subsequent patch will fix it by replacing it with a ref counting scheme. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> [dj: - adjust context - corrected setup_timer -> timer_setup to delete hunk - skip padata_flush_queues() hunk, function already removed in 4.9] Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-27padata: ensure padata_do_serial() runs on the correct CPUMathias Krause1-0/+2
commit 350ef88e7e922354f82a931897ad4a4ce6c686ff upstream. If the algorithm we're parallelizing is asynchronous we might change CPUs between padata_do_parallel() and padata_do_serial(). However, we don't expect this to happen as we need to enqueue the padata object into the per-cpu reorder queue we took it from, i.e. the same-cpu's parallel queue. Ensure we're not switching CPUs for a given padata object by tracking the CPU within the padata object. If the serial callback gets called on the wrong CPU, defer invoking padata_reorder() via a kernel worker on the CPU we're expected to run on. Signed-off-by: Mathias Krause <minipli@googlemail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Cc: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-27padata: ensure the reorder timer callback runs on the correct CPUMathias Krause1-0/+2
commit cf5868c8a22dc2854b96e9569064bb92365549ca upstream. The reorder timer function runs on the CPU where the timer interrupt was handled which is not necessarily one of the CPUs of the 'pcpu' CPU mask set. Ensure the padata_reorder() callback runs on the correct CPU, which is one in the 'pcpu' CPU mask set and, preferrably, the next expected one. Do so by comparing the current CPU with the expected target CPU. If they match, call padata_reorder() right away. If they differ, schedule a work item on the target CPU that does the padata_reorder() call for us. Signed-off-by: Mathias Krause <minipli@googlemail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Cc: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-20x86: Fix early boot crash on gcc-10, third tryBorislav Petkov1-0/+7
commit a9a3ed1eff3601b63aea4fb462d8b3b92c7c1e7e upstream. ... or the odyssey of trying to disable the stack protector for the function which generates the stack canary value. The whole story started with Sergei reporting a boot crash with a kernel built with gcc-10: Kernel panic — not syncing: stack-protector: Kernel stack is corrupted in: start_secondary CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.6.0-rc5—00235—gfffb08b37df9 #139 Hardware name: Gigabyte Technology Co., Ltd. To be filled by O.E.M./H77M—D3H, BIOS F12 11/14/2013 Call Trace: dump_stack panic ? start_secondary __stack_chk_fail start_secondary secondary_startup_64 -—-[ end Kernel panic — not syncing: stack—protector: Kernel stack is corrupted in: start_secondary This happens because gcc-10 tail-call optimizes the last function call in start_secondary() - cpu_startup_entry() - and thus emits a stack canary check which fails because the canary value changes after the boot_init_stack_canary() call. To fix that, the initial attempt was to mark the one function which generates the stack canary with: __attribute__((optimize("-fno-stack-protector"))) ... start_secondary(void *unused) however, using the optimize attribute doesn't work cumulatively as the attribute does not add to but rather replaces previously supplied optimization options - roughly all -fxxx options. The key one among them being -fno-omit-frame-pointer and thus leading to not present frame pointer - frame pointer which the kernel needs. The next attempt to prevent compilers from tail-call optimizing the last function call cpu_startup_entry(), shy of carving out start_secondary() into a separate compilation unit and building it with -fno-stack-protector, was to add an empty asm(""). This current solution was short and sweet, and reportedly, is supported by both compilers but we didn't get very far this time: future (LTO?) optimization passes could potentially eliminate this, which leads us to the third attempt: having an actual memory barrier there which the compiler cannot ignore or move around etc. That should hold for a long time, but hey we said that about the other two solutions too so... Reported-by: Sergei Trofimovich <slyfox@gentoo.org> Signed-off-by: Borislav Petkov <bp@suse.de> Tested-by: Kalle Valo <kvalo@codeaurora.org> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20200314164451.346497-1-slyfox@gentoo.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-20gcc-10 warnings: fix low-hanging fruitLinus Torvalds2-2/+2
commit 9d82973e032e246ff5663c9805fbb5407ae932e3 upstream. Due to a bug-report that was compiler-dependent, I updated one of my machines to gcc-10. That shows a lot of new warnings. Happily they seem to be mostly the valid kind, but it's going to cause a round of churn for getting rid of them.. This is the really low-hanging fruit of removing a couple of zero-sized arrays in some core code. We have had a round of these patches before, and we'll have many more coming, and there is nothing special about these except that they were particularly trivial, and triggered more warnings than most. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-20pnp: Use list_for_each_entry() instead of open codingJason Gunthorpe1-20/+9
commit 01b2bafe57b19d9119413f138765ef57990921ce upstream. Aside from good practice, this avoids a warning from gcc 10: ./include/linux/kernel.h:997:3: warning: array subscript -31 is outside array bounds of ‘struct list_head[1]’ [-Warray-bounds] 997 | ((type *)(__mptr - offsetof(type, member))); }) | ~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ./include/linux/list.h:493:2: note: in expansion of macro ‘container_of’ 493 | container_of(ptr, type, member) | ^~~~~~~~~~~~ ./include/linux/pnp.h:275:30: note: in expansion of macro ‘list_entry’ 275 | #define global_to_pnp_dev(n) list_entry(n, struct pnp_dev, global_list) | ^~~~~~~~~~ ./include/linux/pnp.h:281:11: note: in expansion of macro ‘global_to_pnp_dev’ 281 | (dev) != global_to_pnp_dev(&pnp_global); \ | ^~~~~~~~~~~~~~~~~ arch/x86/kernel/rtc.c:189:2: note: in expansion of macro ‘pnp_for_each_dev’ 189 | pnp_for_each_dev(dev) { Because the common code doesn't cast the starting list_head to the containing struct. Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> [ rjw: Whitespace adjustments ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-20ptp: fix the race between the release of ptp_clock and cdevVladis Dronov1-8/+11
commit a33121e5487b424339636b25c35d3a180eaa5f5e upstream. In a case when a ptp chardev (like /dev/ptp0) is open but an underlying device is removed, closing this file leads to a race. This reproduces easily in a kvm virtual machine: ts# cat openptp0.c int main() { ... fp = fopen("/dev/ptp0", "r"); ... sleep(10); } ts# uname -r 5.5.0-rc3-46cf053e ts# cat /proc/cmdline ... slub_debug=FZP ts# modprobe ptp_kvm ts# ./openptp0 & [1] 670 opened /dev/ptp0, sleeping 10s... ts# rmmod ptp_kvm ts# ls /dev/ptp* ls: cannot access '/dev/ptp*': No such file or directory ts# ...woken up [ 48.010809] general protection fault: 0000 [#1] SMP [ 48.012502] CPU: 6 PID: 658 Comm: openptp0 Not tainted 5.5.0-rc3-46cf053e #25 [ 48.014624] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), ... [ 48.016270] RIP: 0010:module_put.part.0+0x7/0x80 [ 48.017939] RSP: 0018:ffffb3850073be00 EFLAGS: 00010202 [ 48.018339] RAX: 000000006b6b6b6b RBX: 6b6b6b6b6b6b6b6b RCX: ffff89a476c00ad0 [ 48.018936] RDX: fffff65a08d3ea08 RSI: 0000000000000247 RDI: 6b6b6b6b6b6b6b6b [ 48.019470] ... ^^^ a slub poison [ 48.023854] Call Trace: [ 48.024050] __fput+0x21f/0x240 [ 48.024288] task_work_run+0x79/0x90 [ 48.024555] do_exit+0x2af/0xab0 [ 48.024799] ? vfs_write+0x16a/0x190 [ 48.025082] do_group_exit+0x35/0x90 [ 48.025387] __x64_sys_exit_group+0xf/0x10 [ 48.025737] do_syscall_64+0x3d/0x130 [ 48.026056] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 48.026479] RIP: 0033:0x7f53b12082f6 [ 48.026792] ... [ 48.030945] Modules linked in: ptp i6300esb watchdog [last unloaded: ptp_kvm] [ 48.045001] Fixing recursive fault but reboot is needed! This happens in: static void __fput(struct file *file) { ... if (file->f_op->release) file->f_op->release(inode, file); <<< cdev is kfree'd here if (unlikely(S_ISCHR(inode->i_mode) && inode->i_cdev != NULL && !(mode & FMODE_PATH))) { cdev_put(inode->i_cdev); <<< cdev fields are accessed here Namely: __fput() posix_clock_release() kref_put(&clk->kref, delete_clock) <<< the last reference delete_clock() delete_ptp_clock() kfree(ptp) <<< cdev is embedded in ptp cdev_put module_put(p->owner) <<< *p is kfree'd, bang! Here cdev is embedded in posix_clock which is embedded in ptp_clock. The race happens because ptp_clock's lifetime is controlled by two refcounts: kref and cdev.kobj in posix_clock. This is wrong. Make ptp_clock's sysfs device a parent of cdev with cdev_device_add() created especially for such cases. This way the parent device with its ptp_clock is not released until all references to the cdev are released. This adds a requirement that an initialized but not exposed struct device should be provided to posix_clock_register() by a caller instead of a simple dev_t. This approach was adopted from the commit 72139dfa2464 ("watchdog: Fix the race between the release of watchdog_core_data and cdev"). See details of the implementation in the commit 233ed09d7fda ("chardev: add helper function to register char devs with a struct device"). Link: https://lore.kernel.org/linux-fsdevel/20191125125342.6189-1-vdronov@redhat.com/T/#u Analyzed-by: Stephen Johnston <sjohnsto@redhat.com> Analyzed-by: Vern Lovejoy <vlovejoy@redhat.com> Signed-off-by: Vladis Dronov <vdronov@redhat.com> Acked-by: Richard Cochran <richardcochran@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-20chardev: add helper function to register char devs with a struct deviceLogan Gunthorpe1-0/+5
commit 233ed09d7fdacf592ee91e6c97ce5f4364fbe7c0 upstream. Credit for this patch goes is shared with Dan Williams [1]. I've taken things one step further to make the helper function more useful and clean up calling code. There's a common pattern in the kernel whereby a struct cdev is placed in a structure along side a struct device which manages the life-cycle of both. In the naive approach, the reference counting is broken and the struct device can free everything before the chardev code is entirely released. Many developers have solved this problem by linking the internal kobjs in this fashion: cdev.kobj.parent = &parent_dev.kobj; The cdev code explicitly gets and puts a reference to it's kobj parent. So this seems like it was intended to be used this way. Dmitrty Torokhov first put this in place in 2012 with this commit: 2f0157f char_dev: pin parent kobject and the first instance of the fix was then done in the input subsystem in the following commit: 4a215aa Input: fix use-after-free introduced with dynamic minor changes Subsequently over the years, however, this issue seems to have tripped up multiple developers independently. For example, see these commits: 0d5b7da iio: Prevent race between IIO chardev opening and IIO device (by Lars-Peter Clausen in 2013) ba0ef85 tpm: Fix initialization of the cdev (by Jason Gunthorpe in 2015) 5b28dde [media] media: fix use-after-free in cdev_put() when app exits after driver unbind (by Shauh Khan in 2016) This technique is similarly done in at least 15 places within the kernel and probably should have been done so in another, at least, 5 places. The kobj line also looks very suspect in that one would not expect drivers to have to mess with kobject internals in this way. Even highly experienced kernel developers can be surprised by this code, as seen in [2]. To help alleviate this situation, and hopefully prevent future wasted effort on this problem, this patch introduces a helper function to register a char device along with its parent struct device. This creates a more regular API for tying a char device to its parent without the developer having to set members in the underlying kobject. This patch introduce cdev_device_add and cdev_device_del which replaces a common pattern including setting the kobj parent, calling cdev_add and then calling device_add. It also introduces cdev_set_parent for the few cases that set the kobject parent without using device_add. [1] https://lkml.org/lkml/2017/2/13/700 [2] https://lkml.org/lkml/2017/2/10/370 Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>