e006858f1a
Locally generated packets can increment the new nexthop statistics from process context, resulting in the following splat [1] due to preemption being enabled. Fix by using get_cpu_ptr() / put_cpu_ptr() which will which take care of disabling / enabling preemption. BUG: using smp_processor_id() in preemptible [00000000] code: ping/949 caller is nexthop_select_path+0xcf8/0x1e30 CPU: 12 PID: 949 Comm: ping Not tainted 6.8.0-rc7-custom-gcb450f605fae #11 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-1.fc38 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0xbd/0xe0 check_preemption_disabled+0xce/0xe0 nexthop_select_path+0xcf8/0x1e30 fib_select_multipath+0x865/0x18b0 fib_select_path+0x311/0x1160 ip_route_output_key_hash_rcu+0xe54/0x2720 ip_route_output_key_hash+0x193/0x380 ip_route_output_flow+0x25/0x130 raw_sendmsg+0xbab/0x34a0 inet_sendmsg+0xa2/0xe0 __sys_sendto+0x2ad/0x430 __x64_sys_sendto+0xe5/0x1c0 do_syscall_64+0xc5/0x1d0 entry_SYSCALL_64_after_hwframe+0x63/0x6b [...] Fixes: f4676ea74b85 ("net: nexthop: Add nexthop group entry stats") Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20240311162307.545385-5-idosch@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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.