On 8/12/2020 7:14 PM, Kamal Heib wrote:
To avoid the following kernel panic when calling kmem_cache_create() with a NULL pointer from pool_cache(),
What is the root cause of this kernel panic? Zhu Yanjun
move the rxe_cache_init() to the context of device creation. BUG: unable to handle kernel NULL pointer dereference at 000000000000000b PGD 0 P4D 0 Oops: 0000 [#1] SMP NOPTI CPU: 4 PID: 8512 Comm: modprobe Kdump: loaded Not tainted 4.18.0-231.el8.x86_64 #1 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 10/02/2018 RIP: 0010:kmem_cache_alloc+0xd1/0x1b0 Code: 8b 57 18 45 8b 77 1c 48 8b 5c 24 30 0f 1f 44 00 00 5b 48 89 e8 5d 41 5c 41 5d 41 5e 41 5f c3 81 e3 00 00 10 00 75 0e 4d 89 fe <41> f6 47 0b 04 0f 84 6c ff ff ff 4c 89 ff e8 cc da 01 00 49 89 c6 RSP: 0018:ffffa2b8c773f9d0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000005 RDX: 0000000000000004 RSI: 00000000006080c0 RDI: 0000000000000000 RBP: ffff8ea0a8634fd0 R08: ffffa2b8c773f988 R09: 00000000006000c0 R10: 0000000000000000 R11: 0000000000000230 R12: 00000000006080c0 R13: ffffffffc0a97fc8 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f9138ed9740(0000) GS:ffff8ea4ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000000000b CR3: 000000046d59a000 CR4: 00000000003406e0 Call Trace: rxe_alloc+0xc8/0x160 [rdma_rxe] rxe_get_dma_mr+0x25/0xb0 [rdma_rxe] __ib_alloc_pd+0xcb/0x160 [ib_core] ib_mad_init_device+0x296/0x8b0 [ib_core] add_client_context+0x11a/0x160 [ib_core] enable_device_and_get+0xdc/0x1d0 [ib_core] ib_register_device+0x572/0x6b0 [ib_core] ? crypto_create_tfm+0x32/0xe0 ? crypto_create_tfm+0x7a/0xe0 ? crypto_alloc_tfm+0x58/0xf0 rxe_register_device+0x19d/0x1c0 [rdma_rxe] rxe_net_add+0x3d/0x70 [rdma_rxe] ? dev_get_by_name_rcu+0x73/0x90 rxe_param_set_add+0xaf/0xc0 [rdma_rxe] parse_args+0x179/0x370 ? ref_module+0x1b0/0x1b0 load_module+0x135e/0x17e0 ? ref_module+0x1b0/0x1b0 ? __do_sys_init_module+0x13b/0x180 __do_sys_init_module+0x13b/0x180 do_syscall_64+0x5b/0x1a0 entry_SYSCALL_64_after_hwframe+0x65/0xca RIP: 0033:0x7f9137ed296e Fixes: 8700e3e7c485 ("Soft RoCE driver") Signed-off-by: Kamal Heib <kamalheib1@xxxxxxxxx> --- drivers/infiniband/sw/rxe/rxe.c | 14 +++++++------- drivers/infiniband/sw/rxe/rxe_pool.c | 3 +++ drivers/infiniband/sw/rxe/rxe_sysfs.c | 7 +++++++ 3 files changed, 17 insertions(+), 7 deletions(-) diff --git a/drivers/infiniband/sw/rxe/rxe.c b/drivers/infiniband/sw/rxe/rxe.c index 5642eefb4ba1..60d5086dd34d 100644 --- a/drivers/infiniband/sw/rxe/rxe.c +++ b/drivers/infiniband/sw/rxe/rxe.c @@ -318,6 +318,13 @@ static int rxe_newlink(const char *ibdev_name, struct net_device *ndev) goto err; }+ /* initialize slab caches for managed objects */+ err = rxe_cache_init(); + if (err) { + pr_err("unable to init object pools\n"); + goto err; + } + err = rxe_net_add(ibdev_name, ndev); if (err) { pr_err("failed to add %s\n", ndev->name); @@ -336,13 +343,6 @@ static int __init rxe_module_init(void) { int err;- /* initialize slab caches for managed objects */- err = rxe_cache_init(); - if (err) { - pr_err("unable to init object pools\n"); - return err; - } - err = rxe_net_init(); if (err) return err; diff --git a/drivers/infiniband/sw/rxe/rxe_pool.c b/drivers/infiniband/sw/rxe/rxe_pool.c index fbcbac52290b..06c6d1f835b7 100644 --- a/drivers/infiniband/sw/rxe/rxe_pool.c +++ b/drivers/infiniband/sw/rxe/rxe_pool.c @@ -139,6 +139,9 @@ int rxe_cache_init(void) for (i = 0; i < RXE_NUM_TYPES; i++) { type = &rxe_type_info[i]; size = ALIGN(type->size, RXE_POOL_ALIGN); + if (type->cache) + continue; + if (!(type->flags & RXE_POOL_NO_ALLOC)) { type->cache = kmem_cache_create(type->name, size, diff --git a/drivers/infiniband/sw/rxe/rxe_sysfs.c b/drivers/infiniband/sw/rxe/rxe_sysfs.c index ccda5f5a3bc0..d0af48ba0110 100644 --- a/drivers/infiniband/sw/rxe/rxe_sysfs.c +++ b/drivers/infiniband/sw/rxe/rxe_sysfs.c @@ -81,6 +81,13 @@ static int rxe_param_set_add(const char *val, const struct kernel_param *kp) goto err; }+ /* initialize slab caches for managed objects */+ err = rxe_cache_init(); + if (err) { + pr_err("unable to init object pools\n"); + goto err; + } + err = rxe_net_add("rxe%d", ndev); if (err) { pr_err("failed to add %s\n", intf);
