4749228f02
In crc32c_vpmsum() we call enable_kernel_altivec() without first disabling preemption, which is not allowed: WARNING: CPU: 9 PID: 2949 at ../arch/powerpc/kernel/process.c:277 enable_kernel_altivec+0x100/0x120 Modules linked in: dm_thin_pool dm_persistent_data dm_bio_prison dm_bufio libcrc32c vmx_crypto ... CPU: 9 PID: 2949 Comm: docker Not tainted 4.11.0-rc5-compiler_gcc-6.3.1-00033-g308ac7563944 #381 ... NIP [c00000000001e320] enable_kernel_altivec+0x100/0x120 LR [d000000003df0910] crc32c_vpmsum+0x108/0x150 [crc32c_vpmsum] Call Trace: 0xc138fd09 (unreliable) crc32c_vpmsum+0x108/0x150 [crc32c_vpmsum] crc32c_vpmsum_update+0x3c/0x60 [crc32c_vpmsum] crypto_shash_update+0x88/0x1c0 crc32c+0x64/0x90 [libcrc32c] dm_bm_checksum+0x48/0x80 [dm_persistent_data] sb_check+0x84/0x120 [dm_thin_pool] dm_bm_validate_buffer.isra.0+0xc0/0x1b0 [dm_persistent_data] dm_bm_read_lock+0x80/0xf0 [dm_persistent_data] __create_persistent_data_objects+0x16c/0x810 [dm_thin_pool] dm_pool_metadata_open+0xb0/0x1a0 [dm_thin_pool] pool_ctr+0x4cc/0xb60 [dm_thin_pool] dm_table_add_target+0x16c/0x3c0 table_load+0x184/0x400 ctl_ioctl+0x2f0/0x560 dm_ctl_ioctl+0x38/0x50 do_vfs_ioctl+0xd8/0x920 SyS_ioctl+0x68/0xc0 system_call+0x38/0xfc It used to be sufficient just to call pagefault_disable(), because that also disabled preemption. But the two were decoupled in commit 8222dbe21e79 ("sched/preempt, mm/fault: Decouple preemption from the page fault logic") in mid 2015. So add the missing preempt_disable/enable(). We should also call disable_kernel_fp(), although it does nothing by default, there is a debug switch to make it active and all enables should be paired with disables. Fixes: 6dd7a82cc54e ("crypto: powerpc - Add POWER8 optimised crc32c") Cc: stable@vger.kernel.org # v4.8+ Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.