From: Mike Galbraith Date: Wed, 11 Jul 2018 17:14:47 +0200 Subject: [PATCH 223/351] crypto: scompress - serialize RT percpu scratch buffer access with a local lock Origin: https://git.kernel.org/cgit/linux/kernel/git/rt/linux-stable-rt.git/commit?id=18eaf07ec37f2f06619b6b90d309748e0e86dc94 | BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:974 | in_atomic(): 1, irqs_disabled(): 0, pid: 1401, name: cryptomgr_test | Preemption disabled at: | [] scomp_acomp_comp_decomp+0x34/0x1a0 | CPU: 21 PID: 1401 Comm: cryptomgr_test Tainted: G W 4.16.18-rt9-rt #1 | Hardware name: www.cavium.com crb-1s/crb-1s, BIOS 0.3 Apr 25 2017 | Call trace: | dump_backtrace+0x0/0x1c8 | show_stack+0x24/0x30 | dump_stack+0xac/0xe8 | ___might_sleep+0x124/0x188 | rt_spin_lock+0x40/0x88 | zip_load_instr+0x44/0x170 [thunderx_zip] | zip_deflate+0x184/0x378 [thunderx_zip] | zip_compress+0xb0/0x130 [thunderx_zip] | zip_scomp_compress+0x48/0x60 [thunderx_zip] | scomp_acomp_comp_decomp+0xd8/0x1a0 | scomp_acomp_compress+0x24/0x30 | test_acomp+0x15c/0x558 | alg_test_comp+0xc0/0x128 | alg_test.part.6+0x120/0x2c0 | alg_test+0x6c/0xa0 | cryptomgr_test+0x50/0x58 | kthread+0x134/0x138 | 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 Signed-off-by: Sebastian Andrzej Siewior --- crypto/scompress.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/crypto/scompress.c b/crypto/scompress.c index 968bbcf65c94..c2f0077e0801 100644 --- a/crypto/scompress.c +++ b/crypto/scompress.c @@ -24,6 +24,7 @@ #include #include #include +#include #include #include #include @@ -34,6 +35,7 @@ static void * __percpu *scomp_src_scratches; 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(struct acomp_req *req, int dir) 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(struct acomp_req *req, int dir) 1); } out: - put_cpu(); + local_unlock_cpu(scomp_scratches_lock); return ret; }