diff options
Diffstat (limited to 'llvm/lib/Support/Host.cpp')
| -rw-r--r-- | llvm/lib/Support/Host.cpp | 31 |
1 files changed, 28 insertions, 3 deletions
diff --git a/llvm/lib/Support/Host.cpp b/llvm/lib/Support/Host.cpp index c81b1f14647..1b907bc6284 100644 --- a/llvm/lib/Support/Host.cpp +++ b/llvm/lib/Support/Host.cpp @@ -330,7 +330,19 @@ StringRef sys::detail::getHostCPUNameForBPF() { #if !defined(__linux__) || !defined(__x86_64__) return "generic"; #else - uint8_t insns[40] __attribute__ ((aligned (8))) = + uint8_t v3_insns[40] __attribute__ ((aligned (8))) = + /* BPF_MOV64_IMM(BPF_REG_0, 0) */ + { 0xb7, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, + /* BPF_MOV64_IMM(BPF_REG_2, 1) */ + 0xb7, 0x2, 0x0, 0x0, 0x1, 0x0, 0x0, 0x0, + /* BPF_JMP32_REG(BPF_JLT, BPF_REG_0, BPF_REG_2, 1) */ + 0xae, 0x20, 0x1, 0x0, 0x0, 0x0, 0x0, 0x0, + /* BPF_MOV64_IMM(BPF_REG_0, 1) */ + 0xb7, 0x0, 0x0, 0x0, 0x1, 0x0, 0x0, 0x0, + /* BPF_EXIT_INSN() */ + 0x95, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0 }; + + uint8_t v2_insns[40] __attribute__ ((aligned (8))) = /* BPF_MOV64_IMM(BPF_REG_0, 0) */ { 0xb7, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, /* BPF_MOV64_IMM(BPF_REG_2, 1) */ @@ -355,10 +367,23 @@ StringRef sys::detail::getHostCPUNameForBPF() { } attr = {}; attr.prog_type = 1; /* BPF_PROG_TYPE_SOCKET_FILTER */ attr.insn_cnt = 5; - attr.insns = (uint64_t)insns; + attr.insns = (uint64_t)v3_insns; attr.license = (uint64_t)"DUMMY"; - int fd = syscall(321 /* __NR_bpf */, 5 /* BPF_PROG_LOAD */, &attr, sizeof(attr)); + int fd = syscall(321 /* __NR_bpf */, 5 /* BPF_PROG_LOAD */, &attr, + sizeof(attr)); + if (fd >= 0) { + close(fd); + return "v3"; + } + + /* Clear the whole attr in case its content changed by syscall. */ + memset(&attr, 0, sizeof(attr)); + attr.prog_type = 1; /* BPF_PROG_TYPE_SOCKET_FILTER */ + attr.insn_cnt = 5; + attr.insns = (uint64_t)v2_insns; + attr.license = (uint64_t)"DUMMY"; + fd = syscall(321 /* __NR_bpf */, 5 /* BPF_PROG_LOAD */, &attr, sizeof(attr)); if (fd >= 0) { close(fd); return "v2"; |
