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| author | Alexei Starovoitov <ast@kernel.org> | 2024-04-05 16:11:33 -0700 |
|---|---|---|
| committer | Martin KaFai Lau <martin.lau@kernel.org> | 2024-04-09 10:24:26 -0700 |
| commit | d503a04f8bc0c75dc9db9452d8cc79d748afb752 (patch) | |
| tree | 54f3e9a2c1954e9e916989a454233fe56ce5ba25 /kernel/bpf/core.c | |
| parent | bb761fcb821738e8d3b720e1460d3783db74c68a (diff) | |
| download | linux-stable-d503a04f8bc0c75dc9db9452d8cc79d748afb752.tar.gz linux-stable-d503a04f8bc0c75dc9db9452d8cc79d748afb752.tar.bz2 linux-stable-d503a04f8bc0c75dc9db9452d8cc79d748afb752.zip | |
bpf: Add support for certain atomics in bpf_arena to x86 JIT
Support atomics in bpf_arena that can be JITed as a single x86 instruction.
Instructions that are JITed as loops are not supported at the moment,
since they require more complex extable and loop logic.
JITs can choose to do smarter things with bpf_jit_supports_insn().
Like arm64 may decide to support all bpf atomics instructions
when emit_lse_atomic is available and none in ll_sc mode.
bpf_jit_supports_percpu_insn(), bpf_jit_supports_ptr_xchg() and
other such callbacks can be replaced with bpf_jit_supports_insn()
in the future.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20240405231134.17274-1-alexei.starovoitov@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Diffstat (limited to 'kernel/bpf/core.c')
| -rw-r--r-- | kernel/bpf/core.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 7a33a3a7e63c..a41718eaeefe 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -2965,6 +2965,11 @@ bool __weak bpf_jit_supports_arena(void) return false; } +bool __weak bpf_jit_supports_insn(struct bpf_insn *insn, bool in_arena) +{ + return false; +} + /* Return TRUE if the JIT backend satisfies the following two conditions: * 1) JIT backend supports atomic_xchg() on pointer-sized words. * 2) Under the specific arch, the implementation of xchg() is the same |