diff options
| author | Ido Schimmel <idosch@nvidia.com> | 2024-03-11 19:23:07 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2024-03-12 06:35:20 +0300 |
| commit | e006858f1a1c6e8ba8aeff67e9b15700f70174da (patch) | |
| tree | 2af16865282c7e43ec8927786938bfa05a56e404 /net | |
| parent | d8a21070b6e168d3800c2962a574f16020dd2951 (diff) | |
| download | linux-e006858f1a1c6e8ba8aeff67e9b15700f70174da.tar.xz | |
nexthop: Fix splat with CONFIG_DEBUG_PREEMPT=y
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>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/nexthop.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/ipv4/nexthop.c b/net/ipv4/nexthop.c index 4c6915bff31e..74928a9d1aa4 100644 --- a/net/ipv4/nexthop.c +++ b/net/ipv4/nexthop.c @@ -674,10 +674,11 @@ static void nh_grp_entry_stats_inc(struct nh_grp_entry *nhge) { struct nh_grp_entry_stats *cpu_stats; - cpu_stats = this_cpu_ptr(nhge->stats); + cpu_stats = get_cpu_ptr(nhge->stats); u64_stats_update_begin(&cpu_stats->syncp); u64_stats_inc(&cpu_stats->packets); u64_stats_update_end(&cpu_stats->syncp); + put_cpu_ptr(cpu_stats); } static void nh_grp_entry_stats_read(struct nh_grp_entry *nhge, |