[ 26.767879] BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:974 [ 26.767881] in_atomic(): 1, irqs_disabled(): 0, pid: 1401, name: cryptomgr_test [ 26.767883] Preemption disabled at: [ 26.767895] [<ffff00000849941c>] scomp_acomp_comp_decomp+0x34/0x1a0 [ 26.767902] CPU: 21 PID: 1401 Comm: cryptomgr_test Tainted: G W 4.16.18-rt9-rt #1 [ 26.767903] Hardware name: www.cavium.com crb-1s/crb-1s, BIOS 0.3 Apr 25 2017 [ 26.767905] Call trace: [ 26.767908] dump_backtrace+0x0/0x1c8 [ 26.767910] show_stack+0x24/0x30 [ 26.767916] dump_stack+0xac/0xe8 [ 26.767923] ___might_sleep+0x124/0x188 [ 26.767927] rt_spin_lock+0x40/0x88 [ 26.767939] zip_load_instr+0x44/0x170 [thunderx_zip] [ 26.767950] zip_deflate+0x184/0x378 [thunderx_zip] [ 26.767956] zip_compress+0xb0/0x130 [thunderx_zip] [ 26.767968] zip_scomp_compress+0x48/0x60 [thunderx_zip] [ 26.767974] scomp_acomp_comp_decomp+0xd8/0x1a0 [ 26.767976] scomp_acomp_compress+0x24/0x30 [ 26.767978] test_acomp+0x15c/0x558 [ 26.767981] alg_test_comp+0xc0/0x128 [ 26.767988] alg_test.part.6+0x120/0x2c0 [ 26.767990] alg_test+0x6c/0xa0 [ 26.767992] cryptomgr_test+0x50/0x58 [ 26.767995] kthread+0x134/0x138 [ 26.767998] ret_from_fork+0x10/0x18 Mainline disables preemption to serialize percpu scratch buffer access, causing the splat above. Serialize with a local lock for RT instead. Signed-off-by: Mike Galbraith <efault@xxxxxx> --- crypto/scompress.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/crypto/scompress.c +++ b/crypto/scompress.c @@ -24,6 +24,7 @@ #include <linux/cryptouser.h> #include <net/netlink.h> #include <linux/scatterlist.h> +#include <linux/locallock.h> #include <crypto/scatterwalk.h> #include <crypto/internal/acompress.h> #include <crypto/internal/scompress.h> @@ -34,6 +35,7 @@ static void * __percpu *scomp_src_scratc static void * __percpu *scomp_dst_scratches; static int scomp_scratch_users; static DEFINE_MUTEX(scomp_lock); +static DEFINE_LOCAL_IRQ_LOCK(scomp_scratches_lock); #ifdef CONFIG_NET static int crypto_scomp_report(struct sk_buff *skb, struct crypto_alg *alg) @@ -146,7 +148,7 @@ static int scomp_acomp_comp_decomp(struc void **tfm_ctx = acomp_tfm_ctx(tfm); struct crypto_scomp *scomp = *tfm_ctx; void **ctx = acomp_request_ctx(req); - const int cpu = get_cpu(); + const int cpu = local_lock_cpu(scomp_scratches_lock); u8 *scratch_src = *per_cpu_ptr(scomp_src_scratches, cpu); u8 *scratch_dst = *per_cpu_ptr(scomp_dst_scratches, cpu); int ret; @@ -181,7 +183,7 @@ static int scomp_acomp_comp_decomp(struc 1); } out: - put_cpu(); + local_unlock_cpu(scomp_scratches_lock); return ret; } -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html