On 12/17/24 8:58 PM, Andrea Righi wrote:
On x86-64 calling bpf_get_smp_processor_id() in a kernel with CONFIG_SMP
disabled can trigger the following bug, as pcpu_hot is unavailable:
[ 8.471774] BUG: unable to handle page fault for address: 00000000936a290c
[ 8.471849] #PF: supervisor read access in kernel mode
[ 8.471881] #PF: error_code(0x0000) - not-present page
Fix by inlining a return 0 in the !CONFIG_SMP case.
Fixes: 1ae6921009e5 ("bpf: inline bpf_get_smp_processor_id() helper")
Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Cc: Andrii Nakryiko <andrii.nakryiko@xxxxxxxxx>
Signed-off-by: Andrea Righi <arighi@xxxxxxxxxx>
Acked-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
