From: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Subject: 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:
[<0000000000d54870>] show_stack+0x90/0xf8
[<0000000000d675d2>] dump_stack+0xa2/0xd8
[<0000000000d6c9ac>] check_preemption_disabled+0xe4/0xe8
[<00000000001d6098>] lockdep_hardirqs_on_prepare+0x48/0x270
[<00000000002ac274>] trace_hardirqs_on+0x9c/0x1b8
[<0000000001441430>] crc32_test.isra.0+0x170/0x1c0
[<0000000001441764>] crc32test_init+0x1c/0x40
[<0000000000100cd0>] do_one_initcall+0x40/0x130
[<0000000001411586>] do_initcalls+0x126/0x150
[<0000000001411826>] kernel_init_freeable+0x1f6/0x230
[<0000000000d6cc92>] kernel_init+0x22/0x150
[<0000000000d7bcc4>] ret_from_fork+0x24/0x2c
no locks held by swapper/0/1.
Remove extra local_irq_disable/local_irq_enable helpers calls.
Link: https://lkml.kernel.org/r/patch.git-4369da00c06e.your-ad-here.call-01602859837-ext-1679@work.hours
Fixes: 5fb7f87408f1 ("lib: add module support to crc32 tests")
Signed-off-by: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/crc32test.c | 4 ----
1 file changed, 4 deletions(-)
--- a/lib/crc32test.c~lib-crc32test-remove-extra-local_irq_disable-enable
+++ a/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);
_
