kernel/linux.git/drivers/misc/cxl, branch v4.14.286

cxl: Fix kobject memleak

2020-08-21T07:48:08+00:00

[ Upstream commit 85c5cbeba8f4fb28e6b9bfb3e467718385f78f76 ] Currently the error return path from kobject_init_and_add() is not followed by a call to kobject_put() - which means we are leaking the kobject. Fix it by adding a call to kobject_put() in the error path of kobject_init_and_add(). Fixes: b087e6190ddc ("cxl: Export optional AFU configuration record in sysfs") Reported-by: Hulk Robot Signed-off-by: Wang Hai Acked-by: Andrew Donnellan Acked-by: Frederic Barrat Link: https://lore.kernel.org/r/20200602120733.5943-1-wanghai38@huawei.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

misc: cxl: Fix possible null pointer dereference

2019-11-24T07:23:32+00:00

[ Upstream commit 3dac3583bf1a61db6aaf31dfd752c677a4400afd ] It is not safe to dereference an object before a null test. It is not needed and just remove them. Ftrace can be used instead. Signed-off-by: zhong jiang Acked-by: Andrew Donnellan Acked-by: Frederic Barrat Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

cxl: Wrap iterations over afu slices inside 'afu_list_lock'

2019-03-23T13:35:23+00:00

commit edeb304f659792fb5bab90d7d6f3408b4c7301fb upstream. Within cxl module, iteration over array 'adapter->afu' may be racy at few points as it might be simultaneously read during an EEH and its contents being set to NULL while driver is being unloaded or unbound from the adapter. This might result in a NULL pointer to 'struct afu' being de-referenced during an EEH thereby causing a kernel oops. This patch fixes this by making sure that all access to the array 'adapter->afu' is wrapped within the context of spin-lock 'adapter->afu_list_lock'. Fixes: 9e8df8a21963 ("cxl: EEH support") Cc: stable@vger.kernel.org # v4.3+ Acked-by: Andrew Donnellan Acked-by: Frederic Barrat Acked-by: Christophe Lombard Signed-off-by: Vaibhav Jain Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

cxl: Fix wrong comparison in cxl_adapter_context_get()

2018-09-09T17:55:54+00:00

commit ef6cb5f1a048fdf91ccee6d63d2bfa293338502d upstream. Function atomic_inc_unless_negative() returns a bool to indicate success/failure. However cxl_adapter_context_get() wrongly compares the return value against '>=0' which will always be true. The patch fixes this comparison to '==0' there by also fixing this compile time warning: drivers/misc/cxl/main.c:290 cxl_adapter_context_get() warn: 'atomic_inc_unless_negative(&adapter->contexts_num)' is unsigned Fixes: 70b565bbdb91 ("cxl: Prevent adapter reset if an active context exists") Cc: stable@vger.kernel.org # v4.9+ Reported-by: Dan Carpenter Signed-off-by: Vaibhav Jain Acked-by: Andrew Donnellan Acked-by: Frederic Barrat Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

cxl_getfile(): fix double-iput() on alloc_file() failures

2018-07-25T09:25:11+00:00

commit d202797f480c0e5918e7642d6716cdc62b3ab5c9 upstream. Doing iput() after path_put() is wrong. Cc: stable@vger.kernel.org Acked-by: Linus Torvalds Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman

cxl: Disable prefault_mode in Radix mode

2018-07-03T09:24:51+00:00

commit b6c84ba22ff3a198eb8d5552cf9b8fda1d792e54 upstream. Currently we see a kernel-oops reported on Power-9 while attaching a context to an AFU, with radix-mode and sysfs attr 'prefault_mode' set to anything other than 'none'. The backtrace of the oops is of this form: Unable to handle kernel paging request for data at address 0x00000080 Faulting instruction address: 0xc00800000bcf3b20 cpu 0x1: Vector: 300 (Data Access) at [c00000037f003800] pc: c00800000bcf3b20: cxl_load_segment+0x178/0x290 [cxl] lr: c00800000bcf39f0: cxl_load_segment+0x48/0x290 [cxl] sp: c00000037f003a80 msr: 9000000000009033 dar: 80 dsisr: 40000000 current = 0xc00000037f280000 paca = 0xc0000003ffffe600 softe: 3 irq_happened: 0x01 pid = 3529, comm = afp_no_int cxl_prefault+0xfc/0x248 [cxl] process_element_entry_psl9+0xd8/0x1a0 [cxl] cxl_attach_dedicated_process_psl9+0x44/0x130 [cxl] native_attach_process+0xc0/0x130 [cxl] afu_ioctl+0x3f4/0x5e0 [cxl] do_vfs_ioctl+0xdc/0x890 ksys_ioctl+0x68/0xf0 sys_ioctl+0x40/0xa0 system_call+0x58/0x6c The issue is caused as on Power-8 the AFU attr 'prefault_mode' was used to improve initial storage fault performance by prefaulting process segments. However on Power-9 with radix mode we don't have Storage-Segments that we can prefault. Also prefaulting process Pages will be too costly and fine-grained. Hence, since the prefaulting mechanism doesn't makes sense of radix-mode, this patch updates prefault_mode_store() to not allow any other value apart from CXL_PREFAULT_NONE when radix mode is enabled. Fixes: f24be42aab37 ("cxl: Add psl9 specific code") Cc: stable@vger.kernel.org # v4.12+ Signed-off-by: Vaibhav Jain Acked-by: Frederic Barrat Acked-by: Andrew Donnellan Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

cxl: Check if PSL data-cache is available before issue flush request

2018-05-30T05:52:33+00:00

[ Upstream commit 94322ed8e857e3b2a33cf75118051af9baaa110f ] PSL9D doesn't have a data-cache that needs to be flushed before resetting the card. However when cxl tries to flush data-cache on such a card, it times-out as PSL_Control register never indicates flush operation complete due to missing data-cache. This is usually indicated in the kernel logs with this message: "WARNING: cache flush timed out" To fix this the patch checks PSL_Debug register CDC-Field(BIT:27) which indicates the absence of a data-cache and sets a flag 'no_data_cache' in 'struct cxl_native' to indicate this. When cxl_data_cache_flush() is called it checks the flag and if set bails out early without requesting a data-cache flush operation to the PSL. Signed-off-by: Vaibhav Jain Acked-by: Andrew Donnellan Acked-by: Frederic Barrat Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

cxl: Fix possible deadlock when processing page faults from cxllib

2018-04-24T07:36:32+00:00

commit ad7b4e8022b9864c075fe71e1328b1d25cad82f6 upstream. cxllib_handle_fault() is called by an external driver when it needs to have the host resolve page faults for a buffer. The buffer can cover several pages and VMAs. The function iterates over all the pages used by the buffer, based on the page size of the VMA. To ensure some stability while processing the faults, the thread T1 grabs the mm->mmap_sem semaphore with read access (R1). However, when processing a page fault for a single page, one of the underlying functions, copro_handle_mm_fault(), also grabs the same semaphore with read access (R2). So the thread T1 takes the semaphore twice. If another thread T2 tries to access the semaphore in write mode W1 (say, because it wants to allocate memory and calls 'brk'), then that thread T2 will have to wait because there's a reader (R1). If the thread T1 is processing a new page at that time, it won't get an automatic grant at R2, because there's now a writer thread waiting (T2). And we have a deadlock. The timeline is: 1. thread T1 owns the semaphore with read access R1 2. thread T2 requests write access W1 and waits 3. thread T1 requests read access R2 and waits The fix is for the thread T1 to release the semaphore R1 once it got the information it needs from the current VMA. The address space/VMAs could evolve while T1 iterates over the full buffer, but in the unlikely case where T1 misses a page, the external driver will raise a new page fault when retrying the memory access. Fixes: 3ced8d730063 ("cxl: Export library to support IBM XSL") Cc: stable@vger.kernel.org # 4.13+ Signed-off-by: Frederic Barrat Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

cxl: Check if vphb exists before iterating over AFU devices

2017-12-05T10:26:34+00:00

commit 12841f87b7a8ceb3d54f171660f72a86941bfcb3 upstream. During an eeh a kernel-oops is reported if no vPHB is allocated to the AFU. This happens as during AFU init, an error in creation of vPHB is a non-fatal error. Hence afu->phb should always be checked for NULL before iterating over it for the virtual AFU pci devices. This patch fixes the kenel-oops by adding a NULL pointer check for afu->phb before it is dereferenced. Fixes: 9e8df8a21963 ("cxl: EEH support") Signed-off-by: Vaibhav Jain Acked-by: Andrew Donnellan Acked-by: Frederic Barrat Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55+00:00

Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman