lkml.org 
[lkml]   [2018]   [Sep]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    Subject[PATCH RT 17/22] crypto: scompress - serialize RT percpu scratch buffer access with a local lock
    4.14.63-rt41-rc1 stable review patch.
    If anyone has any objections, please let me know.

    ------------------

    From: Mike Galbraith <efault@gmx.de>

    [ Upstream commit 1a4eff3f8e743d149be26a414822710aef07fe14 ]

    | 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:
    | [<ffff00000849941c>] 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 <efault@gmx.de>
    Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
    Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
    ---
    crypto/scompress.c | 6 ++++--
    1 file changed, 4 insertions(+), 2 deletions(-)

    diff --git a/crypto/scompress.c b/crypto/scompress.c
    index 2075e2c4e7df..c6b4e265c6bf 100644
    --- 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_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)
    @@ -193,7 +195,7 @@ 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;
    @@ -228,7 +230,7 @@ static int scomp_acomp_comp_decomp(struct acomp_req *req, int dir)
    1);
    }
    out:
    - put_cpu();
    + local_unlock_cpu(scomp_scratches_lock);
    return ret;
    }

    --
    2.18.0

    \
     
     \ /
      Last update: 2018-09-05 14:29    [W:4.093 / U:0.056 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site