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authorChen Zhongjin <chenzhongjin@huawei.com>2022-05-10 17:46:39 +0800
committerPaul E. McKenney <paulmck@kernel.org>2022-07-19 11:40:00 -0700
commit9c9b26b0df270d4f9246e483a44686fca951a29c (patch)
tree2b0fc8209d4682c2284fafdfc9ada6d0099c52c9 /kernel/smp.c
parentb3ade95b8ee507d650d9e163abfdf645a9f3886d (diff)
locking/csd_lock: Change csdlock_debug from early_param to __setup
The csdlock_debug kernel-boot parameter is parsed by the early_param() function csdlock_debug(). If set, csdlock_debug() invokes static_branch_enable() to enable csd_lock_wait feature, which triggers a panic on arm64 for kernels built with CONFIG_SPARSEMEM=y and CONFIG_SPARSEMEM_VMEMMAP=n. With CONFIG_SPARSEMEM_VMEMMAP=n, __nr_to_section is called in static_key_enable() and returns NULL, resulting in a NULL dereference because mem_section is initialized only later in sparse_init(). This is also a problem for powerpc because early_param() functions are invoked earlier than jump_label_init(), also resulting in static_key_enable() failures. These failures cause the warning "static key 'xxx' used before call to jump_label_init()". Thus, early_param is too early for csd_lock_wait to run static_branch_enable(), so changes it to __setup to fix these. Fixes: 8d0968cc6b8f ("locking/csd_lock: Add boot parameter for controlling CSD lock debugging") Cc: stable@vger.kernel.org Reported-by: Chen jingwen <chenjingwen6@huawei.com> Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel/smp.c')
-rw-r--r--kernel/smp.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/smp.c b/kernel/smp.c
index dd215f439426..650810a6f29b 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -174,9 +174,9 @@ static int __init csdlock_debug(char *str)
if (val)
static_branch_enable(&csdlock_debug_enabled);
- return 0;
+ return 1;
}
-early_param("csdlock_debug", csdlock_debug);
+__setup("csdlock_debug=", csdlock_debug);
static DEFINE_PER_CPU(call_single_data_t *, cur_csd);
static DEFINE_PER_CPU(smp_call_func_t, cur_csd_func);