From aa4e460f0976351fddd2f5ac6e08b74320c277a1 Mon Sep 17 00:00:00 2001 From: Vasily Gorbik Date: Sun, 1 Nov 2020 17:07:47 -0800 Subject: [PATCH] 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 Signed-off-by: Andrew Morton Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Greg Kroah-Hartman Link: https://lkml.kernel.org/r/patch.git-4369da00c06e.your-ad-here.call-01602859837-ext-1679@work.hours Signed-off-by: Linus Torvalds --- lib/crc32test.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/lib/crc32test.c b/lib/crc32test.c index 97d6a57..61ddce2 100644 --- a/lib/crc32test.c +++ b/lib/crc32test.c @@ -683,7 +683,6 @@ static int __init crc32c_test(void) /* reduce OS noise */ local_irq_save(flags); - local_irq_disable(); nsec = ktime_get_ns(); for (i = 0; i < 100; i++) { @@ -694,7 +693,6 @@ static int __init crc32c_test(void) nsec = ktime_get_ns() - nsec; local_irq_restore(flags); - local_irq_enable(); pr_info("crc32c: CRC_LE_BITS = %d\n", CRC_LE_BITS); @@ -768,7 +766,6 @@ static int __init crc32_test(void) /* reduce OS noise */ local_irq_save(flags); - local_irq_disable(); nsec = ktime_get_ns(); for (i = 0; i < 100; i++) { @@ -783,7 +780,6 @@ static int __init crc32_test(void) nsec = ktime_get_ns() - nsec; local_irq_restore(flags); - local_irq_enable(); pr_info("crc32: CRC_LE_BITS = %d, CRC_BE BITS = %d\n", CRC_LE_BITS, CRC_BE_BITS); -- 2.7.4