diff options
| author | Yafang Shao <laoar.shao@gmail.com> | 2023-10-05 08:41:23 +0000 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2023-10-06 20:16:44 +0200 |
| commit | bc5bc309db45a7ab218ce8259ba9bc7659be61ca (patch) | |
| tree | 658e32196afca145b29b0c268385fd2a57046df1 /include/linux/bpf.h | |
| parent | 9c8c3fa3a52bc55696ccc4dfcb8a49f969b5fb0e (diff) | |
bpf: Inherit system settings for CPU security mitigations
Currently, there exists a system-wide setting related to CPU security
mitigations, denoted as 'mitigations='. When set to 'mitigations=off', it
deactivates all optional CPU mitigations. Therefore, if we implement a
system-wide 'mitigations=off' setting, it should inherently bypass Spectre
v1 and Spectre v4 in the BPF subsystem.
Please note that there is also a more specific 'nospectre_v1' setting on
x86 and ppc architectures, though it is not currently exported. For the
time being, let's disregard more fine-grained options.
This idea emerged during our discussion about potential Spectre v1 attacks
with Luis [0].
[0] https://lore.kernel.org/bpf/b4fc15f7-b204-767e-ebb9-fdb4233961fb@iogearbox.net
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Song Liu <song@kernel.org>
Acked-by: KP Singh <kpsingh@kernel.org>
Cc: Luis Gerhorst <gerhorst@cs.fau.de>
Link: https://lore.kernel.org/bpf/20231005084123.1338-1-laoar.shao@gmail.com
Diffstat (limited to 'include/linux/bpf.h')
| -rw-r--r-- | include/linux/bpf.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h index a82efd34b741..61bde4520f5c 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -2164,12 +2164,12 @@ static inline bool bpf_allow_uninit_stack(void) static inline bool bpf_bypass_spec_v1(void) { - return perfmon_capable(); + return perfmon_capable() || cpu_mitigations_off(); } static inline bool bpf_bypass_spec_v4(void) { - return perfmon_capable(); + return perfmon_capable() || cpu_mitigations_off(); } int bpf_map_new_fd(struct bpf_map *map, int flags); |