Qian Cai 60d60c8fbd net/mlx5e: always initialize frag->last_in_page
The commit 069d11465a ("net/mlx5e: RX, Enhance legacy Receive Queue
memory scheme") introduced an undefined behaviour below due to
"frag->last_in_page" is only initialized in mlx5e_init_frags_partition()
when,

if (next_frag.offset + frag_info[f].frag_stride > PAGE_SIZE)

or after bailed out the loop,

for (i = 0; i < mlx5_wq_cyc_get_size(&rq->wqe.wq); i++)

As the result, there could be some "frag" have uninitialized
value of "last_in_page".

Later, get_frag() obtains those "frag" and check "frag->last_in_page" in
mlx5e_put_rx_frag() and triggers the error during boot. Fix it by always
initializing "frag->last_in_page" to "false" in
mlx5e_init_frags_partition().

UBSAN: Undefined behaviour in
drivers/net/ethernet/mellanox/mlx5/core/en_rx.c:325:12
load of value 170 is not a valid value for type 'bool' (aka '_Bool')
Call trace:
 dump_backtrace+0x0/0x264
 show_stack+0x20/0x2c
 dump_stack+0xb0/0x104
 __ubsan_handle_load_invalid_value+0x104/0x128
 mlx5e_handle_rx_cqe+0x8e8/0x12cc [mlx5_core]
 mlx5e_poll_rx_cq+0xca8/0x1a94 [mlx5_core]
 mlx5e_napi_poll+0x17c/0xa30 [mlx5_core]
 net_rx_action+0x248/0x940
 __do_softirq+0x350/0x7b8
 irq_exit+0x200/0x26c
 __handle_domain_irq+0xc8/0x128
 gic_handle_irq+0x138/0x228
 el1_irq+0xb8/0x140
 arch_cpu_idle+0x1a4/0x348
 do_idle+0x114/0x1b0
 cpu_startup_entry+0x24/0x28
 rest_init+0x1ac/0x1dc
 arch_call_rest_init+0x10/0x18
 start_kernel+0x4d4/0x57c

Fixes: 069d11465a ("net/mlx5e: RX, Enhance legacy Receive Queue memory scheme")
Signed-off-by: Qian Cai <cai@lca.pw>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-05 11:13:05 -07:00
2019-06-18 14:37:27 +01:00
2019-07-19 12:22:04 -07:00
2019-07-21 14:05:38 -07:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
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