Commit 1471e962 authored Nov 01, 2020 by Vasily Gorbik Committed by Greg Kroah-Hartman Nov 10, 2020

lib/crc32test: remove extra local_irq_disable/enable



commit aa4e460f0976351fddd2f5ac6e08b74320c277a1 upstream.

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: 5fb7f874 ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent d4fea27f

lib/crc32test.c

+0 −4

Original line number	Original line	Diff line number	Diff line
	@@ -683,7 +683,6 @@ static int __init crc32c_test(void)

	/* reduce OS noise */		/* reduce OS noise */
	local_irq_save(flags);		local_irq_save(flags);
	local_irq_disable();

	nsec = ktime_get_ns();		nsec = ktime_get_ns();
	for (i = 0; i < 100; i++) {		for (i = 0; i < 100; i++) {
	@@ -694,7 +693,6 @@ static int __init crc32c_test(void)
	nsec = ktime_get_ns() - nsec;		nsec = ktime_get_ns() - nsec;

	local_irq_restore(flags);		local_irq_restore(flags);
	local_irq_enable();

	pr_info("crc32c: CRC_LE_BITS = %d\n", CRC_LE_BITS);		pr_info("crc32c: CRC_LE_BITS = %d\n", CRC_LE_BITS);

	@@ -768,7 +766,6 @@ static int __init crc32_test(void)

	/* reduce OS noise */		/* reduce OS noise */
	local_irq_save(flags);		local_irq_save(flags);
	local_irq_disable();

	nsec = ktime_get_ns();		nsec = ktime_get_ns();
	for (i = 0; i < 100; i++) {		for (i = 0; i < 100; i++) {
	@@ -783,7 +780,6 @@ static int __init crc32_test(void)
	nsec = ktime_get_ns() - nsec;		nsec = ktime_get_ns() - nsec;

	local_irq_restore(flags);		local_irq_restore(flags);
	local_irq_enable();

	pr_info("crc32: CRC_LE_BITS = %d, CRC_BE BITS = %d\n",		pr_info("crc32: CRC_LE_BITS = %d, CRC_BE BITS = %d\n",
	CRC_LE_BITS, CRC_BE_BITS);		CRC_LE_BITS, CRC_BE_BITS);