diff mbox series

[for-rc] RDMA/rxe: Fix panic when calling kmem_cache_create()

Message ID 20200812111447.256822-1-kamalheib1@gmail.com (mailing list archive)
State Superseded
Headers show
Series [for-rc] RDMA/rxe: Fix panic when calling kmem_cache_create() | expand

Commit Message

Kamal Heib Aug. 12, 2020, 11:14 a.m. UTC
To avoid the following kernel panic when calling kmem_cache_create()
with a NULL pointer from pool_cache(), 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@gmail.com>
---
 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(-)

Comments

Zhu Yanjun Aug. 15, 2020, 6:58 a.m. UTC | #1
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@gmail.com>
> ---
>   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);
Kamal Heib Aug. 16, 2020, 10:12 p.m. UTC | #2
On Sat, Aug 15, 2020 at 02:58:45PM +0800, Zhu Yanjun wrote:
> 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?
>

The kernel panic is triggered using the following command and it happen
because the cache is not getting initialized.

modprobe rdma_rxe add=eno1

Thanks,
Kamal

> 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@gmail.com>
> > ---
> >   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);
> 
>
Zhu Yanjun Aug. 18, 2020, 1:48 a.m. UTC | #3
On 8/17/2020 6:12 AM, Kamal Heib wrote:
> On Sat, Aug 15, 2020 at 02:58:45PM +0800, Zhu Yanjun wrote:
>> 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?
>>
> The kernel panic is triggered using the following command and it happen
> because the cache is not getting initialized.
>
> modprobe rdma_rxe add=eno1
>
> Thanks,
> Kamal
>
>> 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@gmail.com>
>>> ---
>>>    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();

When modprobe rdma_rxe, rxe_module_init should be called. Then 
rxe_cache_init should be also called.

Why does the above call trace occur?

Zhu Yanjun

>>> -	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);
>>
Kamal Heib Aug. 18, 2020, 5:50 a.m. UTC | #4
On Tue, Aug 18, 2020 at 09:48:43AM +0800, Zhu Yanjun wrote:
> On 8/17/2020 6:12 AM, Kamal Heib wrote:
> > On Sat, Aug 15, 2020 at 02:58:45PM +0800, Zhu Yanjun wrote:
> > > 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?
> > > 
> > The kernel panic is triggered using the following command and it happen
> > because the cache is not getting initialized.
> > 
> > modprobe rdma_rxe add=eno1
> > 
> > Thanks,
> > Kamal
> > 
> > > 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@gmail.com>
> > > > ---
> > > >    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();
> 
> When modprobe rdma_rxe, rxe_module_init should be called. Then
> rxe_cache_init should be also called.
> 
> Why does the above call trace occur?
> 
> Zhu Yanjun
>

As you can see in the call trace attached to the commit message, When
running the "modprobe rdma_rxe add=eno1" command the rxe_param_set_add()
is called before rxe_module_init() (without init the caches), so the
call trace occurs when trying to register the allocated rxe device from
the context of rxe_param_set_add() without initialize the caches.

Thanks,
Kamal

> > > > -	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);
> > > 
>
Leon Romanovsky Aug. 18, 2020, 7:49 a.m. UTC | #5
On Tue, Aug 18, 2020 at 08:50:57AM +0300, Kamal Heib wrote:
> On Tue, Aug 18, 2020 at 09:48:43AM +0800, Zhu Yanjun wrote:
> > On 8/17/2020 6:12 AM, Kamal Heib wrote:
> > > On Sat, Aug 15, 2020 at 02:58:45PM +0800, Zhu Yanjun wrote:
> > > > 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?
> > > >
> > > The kernel panic is triggered using the following command and it happen
> > > because the cache is not getting initialized.
> > >
> > > modprobe rdma_rxe add=eno1
> > >
> > > Thanks,
> > > Kamal
> > >
> > > > 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@gmail.com>
> > > > > ---
> > > > >    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();
> >
> > When modprobe rdma_rxe, rxe_module_init should be called. Then
> > rxe_cache_init should be also called.
> >
> > Why does the above call trace occur?
> >
> > Zhu Yanjun
> >
>
> As you can see in the call trace attached to the commit message, When
> running the "modprobe rdma_rxe add=eno1" command the rxe_param_set_add()
> is called before rxe_module_init() (without init the caches), so the
> call trace occurs when trying to register the allocated rxe device from
> the context of rxe_param_set_add() without initialize the caches.

I would expect the fix being in rxe_init() instead of putting calls to
rxe_cache_init() in all places.

Thanks
Kamal Heib Aug. 18, 2020, 2:18 p.m. UTC | #6
On Tue, Aug 18, 2020 at 10:49:56AM +0300, Leon Romanovsky wrote:
> On Tue, Aug 18, 2020 at 08:50:57AM +0300, Kamal Heib wrote:
> > On Tue, Aug 18, 2020 at 09:48:43AM +0800, Zhu Yanjun wrote:
> > > On 8/17/2020 6:12 AM, Kamal Heib wrote:
> > > > On Sat, Aug 15, 2020 at 02:58:45PM +0800, Zhu Yanjun wrote:
> > > > > 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?
> > > > >
> > > > The kernel panic is triggered using the following command and it happen
> > > > because the cache is not getting initialized.
> > > >
> > > > modprobe rdma_rxe add=eno1
> > > >
> > > > Thanks,
> > > > Kamal
> > > >
> > > > > 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@gmail.com>
> > > > > > ---
> > > > > >    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();
> > >
> > > When modprobe rdma_rxe, rxe_module_init should be called. Then
> > > rxe_cache_init should be also called.
> > >
> > > Why does the above call trace occur?
> > >
> > > Zhu Yanjun
> > >
> >
> > As you can see in the call trace attached to the commit message, When
> > running the "modprobe rdma_rxe add=eno1" command the rxe_param_set_add()
> > is called before rxe_module_init() (without init the caches), so the
> > call trace occurs when trying to register the allocated rxe device from
> > the context of rxe_param_set_add() without initialize the caches.
> 
> I would expect the fix being in rxe_init() instead of putting calls to
> rxe_cache_init() in all places.
> 
> Thanks

OK, I agree.
I'll post v2.

Thanks,
Kamal
Zhu Yanjun Aug. 19, 2020, 3:07 a.m. UTC | #7
On 8/18/2020 3:49 PM, Leon Romanovsky wrote:
> On Tue, Aug 18, 2020 at 08:50:57AM +0300, Kamal Heib wrote:
>> On Tue, Aug 18, 2020 at 09:48:43AM +0800, Zhu Yanjun wrote:
>>> On 8/17/2020 6:12 AM, Kamal Heib wrote:
>>>> On Sat, Aug 15, 2020 at 02:58:45PM +0800, Zhu Yanjun wrote:
>>>>> 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?
>>>>>
>>>> The kernel panic is triggered using the following command and it happen
>>>> because the cache is not getting initialized.
>>>>
>>>> modprobe rdma_rxe add=eno1
>>>>
>>>> Thanks,
>>>> Kamal
>>>>
>>>>> 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@gmail.com>
>>>>>> ---
>>>>>>     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();
>>> When modprobe rdma_rxe, rxe_module_init should be called. Then
>>> rxe_cache_init should be also called.
>>>
>>> Why does the above call trace occur?
>>>
>>> Zhu Yanjun
>>>
>> As you can see in the call trace attached to the commit message, When
>> running the "modprobe rdma_rxe add=eno1" command the rxe_param_set_add()
>> is called before rxe_module_init() (without init the caches), so the
>> call trace occurs when trying to register the allocated rxe device from
>> the context of rxe_param_set_add() without initialize the caches.
> I would expect the fix being in rxe_init() instead of putting calls to
> rxe_cache_init() in all places.

I agree with you.

Is it possible to make rxe_module_init be called before rxe_param_set_add?

Thanks

>
> Thanks
Leon Romanovsky Aug. 19, 2020, 4:58 a.m. UTC | #8
On Wed, Aug 19, 2020 at 11:07:56AM +0800, Zhu Yanjun wrote:
> On 8/18/2020 3:49 PM, Leon Romanovsky wrote:
> > On Tue, Aug 18, 2020 at 08:50:57AM +0300, Kamal Heib wrote:
> > > On Tue, Aug 18, 2020 at 09:48:43AM +0800, Zhu Yanjun wrote:
> > > > On 8/17/2020 6:12 AM, Kamal Heib wrote:
> > > > > On Sat, Aug 15, 2020 at 02:58:45PM +0800, Zhu Yanjun wrote:
> > > > > > 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?
> > > > > >
> > > > > The kernel panic is triggered using the following command and it happen
> > > > > because the cache is not getting initialized.
> > > > >
> > > > > modprobe rdma_rxe add=eno1
> > > > >
> > > > > Thanks,
> > > > > Kamal
> > > > >
> > > > > > 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@gmail.com>
> > > > > > > ---
> > > > > > >     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();
> > > > When modprobe rdma_rxe, rxe_module_init should be called. Then
> > > > rxe_cache_init should be also called.
> > > >
> > > > Why does the above call trace occur?
> > > >
> > > > Zhu Yanjun
> > > >
> > > As you can see in the call trace attached to the commit message, When
> > > running the "modprobe rdma_rxe add=eno1" command the rxe_param_set_add()
> > > is called before rxe_module_init() (without init the caches), so the
> > > call trace occurs when trying to register the allocated rxe device from
> > > the context of rxe_param_set_add() without initialize the caches.
> > I would expect the fix being in rxe_init() instead of putting calls to
> > rxe_cache_init() in all places.
>
> I agree with you.
>
> Is it possible to make rxe_module_init be called before rxe_param_set_add?

The best solution will be to delete module_parameters() from RXE.

Thanks

>
> Thanks
>
> >
> > Thanks
>
>
Zhu Yanjun Aug. 19, 2020, 6:19 a.m. UTC | #9
On Wed, Aug 19, 2020 at 12:58 PM Leon Romanovsky <leon@kernel.org> wrote:
>
> On Wed, Aug 19, 2020 at 11:07:56AM +0800, Zhu Yanjun wrote:
> > On 8/18/2020 3:49 PM, Leon Romanovsky wrote:
> > > On Tue, Aug 18, 2020 at 08:50:57AM +0300, Kamal Heib wrote:
> > > > On Tue, Aug 18, 2020 at 09:48:43AM +0800, Zhu Yanjun wrote:
> > > > > On 8/17/2020 6:12 AM, Kamal Heib wrote:
> > > > > > On Sat, Aug 15, 2020 at 02:58:45PM +0800, Zhu Yanjun wrote:
> > > > > > > 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?
> > > > > > >
> > > > > > The kernel panic is triggered using the following command and it happen
> > > > > > because the cache is not getting initialized.
> > > > > >
> > > > > > modprobe rdma_rxe add=eno1
> > > > > >
> > > > > > Thanks,
> > > > > > Kamal
> > > > > >
> > > > > > > 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@gmail.com>
> > > > > > > > ---
> > > > > > > >     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();
> > > > > When modprobe rdma_rxe, rxe_module_init should be called. Then
> > > > > rxe_cache_init should be also called.
> > > > >
> > > > > Why does the above call trace occur?
> > > > >
> > > > > Zhu Yanjun
> > > > >
> > > > As you can see in the call trace attached to the commit message, When
> > > > running the "modprobe rdma_rxe add=eno1" command the rxe_param_set_add()
> > > > is called before rxe_module_init() (without init the caches), so the
> > > > call trace occurs when trying to register the allocated rxe device from
> > > > the context of rxe_param_set_add() without initialize the caches.
> > > I would expect the fix being in rxe_init() instead of putting calls to
> > > rxe_cache_init() in all places.
> >
> > I agree with you.
> >
> > Is it possible to make rxe_module_init be called before rxe_param_set_add?
>
> The best solution will be to delete module_parameters() from RXE.

Sure. I am curious why the parameters are set before rxe_module_init.
Is this a bug?

Zhu Yanjun
>
> Thanks
>
> >
> > Thanks
> >
> > >
> > > Thanks
> >
> >
Leon Romanovsky Aug. 19, 2020, 7:20 a.m. UTC | #10
On Wed, Aug 19, 2020 at 02:19:20PM +0800, Zhu Yanjun wrote:
> On Wed, Aug 19, 2020 at 12:58 PM Leon Romanovsky <leon@kernel.org> wrote:
> >
> > On Wed, Aug 19, 2020 at 11:07:56AM +0800, Zhu Yanjun wrote:
> > > On 8/18/2020 3:49 PM, Leon Romanovsky wrote:
> > > > On Tue, Aug 18, 2020 at 08:50:57AM +0300, Kamal Heib wrote:
> > > > > On Tue, Aug 18, 2020 at 09:48:43AM +0800, Zhu Yanjun wrote:
> > > > > > On 8/17/2020 6:12 AM, Kamal Heib wrote:
> > > > > > > On Sat, Aug 15, 2020 at 02:58:45PM +0800, Zhu Yanjun wrote:
> > > > > > > > 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?
> > > > > > > >
> > > > > > > The kernel panic is triggered using the following command and it happen
> > > > > > > because the cache is not getting initialized.
> > > > > > >
> > > > > > > modprobe rdma_rxe add=eno1
> > > > > > >
> > > > > > > Thanks,
> > > > > > > Kamal
> > > > > > >
> > > > > > > > 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@gmail.com>
> > > > > > > > > ---
> > > > > > > > >     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();
> > > > > > When modprobe rdma_rxe, rxe_module_init should be called. Then
> > > > > > rxe_cache_init should be also called.
> > > > > >
> > > > > > Why does the above call trace occur?
> > > > > >
> > > > > > Zhu Yanjun
> > > > > >
> > > > > As you can see in the call trace attached to the commit message, When
> > > > > running the "modprobe rdma_rxe add=eno1" command the rxe_param_set_add()
> > > > > is called before rxe_module_init() (without init the caches), so the
> > > > > call trace occurs when trying to register the allocated rxe device from
> > > > > the context of rxe_param_set_add() without initialize the caches.
> > > > I would expect the fix being in rxe_init() instead of putting calls to
> > > > rxe_cache_init() in all places.
> > >
> > > I agree with you.
> > >
> > > Is it possible to make rxe_module_init be called before rxe_param_set_add?
> >
> > The best solution will be to delete module_parameters() from RXE.
>
> Sure. I am curious why the parameters are set before rxe_module_init.
> Is this a bug?

Yes and no.

The part of receiving user input is correct and it should be done before
rxe_module_init(), so RXE can initialize properly based on the input.

The call to rxe_net_add() later inside of rxe_param_set_add() is wrong.
It should be done after rxe_module_init() finishes.

Thanks

>
> Zhu Yanjun
> >
> > Thanks
> >
> > >
> > > Thanks
> > >
> > > >
> > > > Thanks
> > >
> > >
diff mbox series

Patch

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);