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tools: bpf: sync uapi header bpf.h

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Sync new bpf prog load flag "BPF_F_TEST_RND_HI32" to tools/.

Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Jiong Wang 2019-05-24 23:25:17 +01:00 committed by Alexei Starovoitov
parent c240eff63a
commit 9ce33e337f
1 changed files with 18 additions and 0 deletions
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18
tools/include/uapi/linux/bpf.h
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@ -260,6 +260,24 @@ enum bpf_attach_type {
*/
#define BPF_F_ANY_ALIGNMENT (1U << 1)
/* BPF_F_TEST_RND_HI32 is used in BPF_PROG_LOAD command for testing purpose.
* Verifier does sub-register def/use analysis and identifies instructions whose
* def only matters for low 32-bit, high 32-bit is never referenced later
* through implicit zero extension. Therefore verifier notifies JIT back-ends
* that it is safe to ignore clearing high 32-bit for these instructions. This
* saves some back-ends a lot of code-gen. However such optimization is not
* necessary on some arches, for example x86_64, arm64 etc, whose JIT back-ends
* hence hasn't used verifier's analysis result. But, we really want to have a
* way to be able to verify the correctness of the described optimization on
* x86_64 on which testsuites are frequently exercised.
*
* So, this flag is introduced. Once it is set, verifier will randomize high
* 32-bit for those instructions who has been identified as safe to ignore them.
* Then, if verifier is not doing correct analysis, such randomization will
* regress tests to expose bugs.
*/
#define BPF_F_TEST_RND_HI32 (1U << 2)
/* When BPF ldimm64's insn[0].src_reg != 0 then this can have
* two extensions:
*