Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux

lib/crc32test: remove extra local_irq_disable/enable

Commit 4d004099a668 ("lockdep: Fix lockdep recursion") uncovered the
following issue in lib/crc32test reported on s390:

BUG: using __this_cpu_read() in preemptible [00000000] code: swapper/0/1
caller is lockdep_hardirqs_on_prepare+0x48/0x270
CPU: 6 PID: 1 Comm: swapper/0 Not tainted 5.9.0-next-20201015-15164-g03d992bd2de6 #19
Hardware name: IBM 3906 M04 704 (LPAR)
Call Trace:
lockdep_hardirqs_on_prepare+0x48/0x270
trace_hardirqs_on+0x9c/0x1b8
crc32_test.isra.0+0x170/0x1c0
crc32test_init+0x1c/0x40
do_one_initcall+0x40/0x130
do_initcalls+0x126/0x150
kernel_init_freeable+0x1f6/0x230
kernel_init+0x22/0x150
ret_from_fork+0x24/0x2c
no locks held by swapper/0/1.

Remove extra local_irq_disable/local_irq_enable helpers calls.

Fixes: 5fb7f87408f1 ("lib: add module support to crc32 tests")
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lkml.kernel.org/r/patch.git-4369da00c06e.your-ad-here.call-01602859837-ext-1679@work.hours
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

authored by

Vasily Gorbik and committed by
Linus Torvalds
aa4e460f 7b3c36fc

-4
-4
lib/crc32test.c
··· 683 683 684 684 /* reduce OS noise */ 685 685 local_irq_save(flags); 686 - local_irq_disable(); 687 686 688 687 nsec = ktime_get_ns(); 689 688 for (i = 0; i < 100; i++) { ··· 693 694 nsec = ktime_get_ns() - nsec; 694 695 695 696 local_irq_restore(flags); 696 - local_irq_enable(); 697 697 698 698 pr_info("crc32c: CRC_LE_BITS = %d\n", CRC_LE_BITS); 699 699 ··· 766 768 767 769 /* reduce OS noise */ 768 770 local_irq_save(flags); 769 - local_irq_disable(); 770 771 771 772 nsec = ktime_get_ns(); 772 773 for (i = 0; i < 100; i++) { ··· 780 783 nsec = ktime_get_ns() - nsec; 781 784 782 785 local_irq_restore(flags); 783 - local_irq_enable(); 784 786 785 787 pr_info("crc32: CRC_LE_BITS = %d, CRC_BE BITS = %d\n", 786 788 CRC_LE_BITS, CRC_BE_BITS);