From 1c8f9b91c456f5b47a377a0c8c5d4130fc39433a Mon Sep 17 00:00:00 2001 From: Yauheni Kaliuta Date: Wed, 28 Aug 2019 21:28:46 +0300 Subject: bpf: s390: add JIT support for multi-function programs This adds support for bpf-to-bpf function calls in the s390 JIT compiler. The JIT compiler converts the bpf call instructions to native branch instructions. After a round of the usual passes, the start addresses of the JITed images for the callee functions are known. Finally, to fixup the branch target addresses, we need to perform an extra pass. Because of the address range in which JITed images are allocated on s390, the offsets of the start addresses of these images from __bpf_call_base are as large as 64 bits. So, for a function call, the imm field of the instruction cannot be used to determine the callee's address. Use bpf_jit_get_func_addr() helper instead. The patch borrows a lot from: commit 8c11ea5ce13d ("bpf, arm64: fix getting subprog addr from aux for calls") commit e2c95a61656d ("bpf, ppc64: generalize fetching subprog into bpf_jit_get_func_addr") commit 8484ce8306f9 ("bpf: powerpc64: add JIT support for multi-function programs") (including the commit message). test_verifier (5.3-rc6 with CONFIG_BPF_JIT_ALWAYS_ON=y): without patch: Summary: 1501 PASSED, 0 SKIPPED, 47 FAILED with patch: Summary: 1540 PASSED, 0 SKIPPED, 8 FAILED Signed-off-by: Yauheni Kaliuta Acked-by: Ilya Leoshkevich Tested-by: Ilya Leoshkevich Signed-off-by: Daniel Borkmann --- arch/s390/net/bpf_jit_comp.c | 66 ++++++++++++++++++++++++++++++++++++-------- 1 file changed, 55 insertions(+), 11 deletions(-) (limited to 'arch/s390/net/bpf_jit_comp.c') diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c index e636728ab452..a76cbe4cc7cc 100644 --- a/arch/s390/net/bpf_jit_comp.c +++ b/arch/s390/net/bpf_jit_comp.c @@ -502,7 +502,8 @@ static void bpf_jit_epilogue(struct bpf_jit *jit, u32 stack_depth) * NOTE: Use noinline because for gcov (-fprofile-arcs) gcc allocates a lot of * stack space for the large switch statement. */ -static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i) +static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, + int i, bool extra_pass) { struct bpf_insn *insn = &fp->insnsi[i]; int jmp_off, last, insn_count = 1; @@ -1011,10 +1012,14 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i */ case BPF_JMP | BPF_CALL: { - /* - * b0 = (__bpf_call_base + imm)(b1, b2, b3, b4, b5) - */ - const u64 func = (u64)__bpf_call_base + imm; + u64 func; + bool func_addr_fixed; + int ret; + + ret = bpf_jit_get_func_addr(fp, insn, extra_pass, + &func, &func_addr_fixed); + if (ret < 0) + return -1; REG_SET_SEEN(BPF_REG_5); jit->seen |= SEEN_FUNC; @@ -1281,7 +1286,8 @@ branch_oc: /* * Compile eBPF program into s390x code */ -static int bpf_jit_prog(struct bpf_jit *jit, struct bpf_prog *fp) +static int bpf_jit_prog(struct bpf_jit *jit, struct bpf_prog *fp, + bool extra_pass) { int i, insn_count; @@ -1290,7 +1296,7 @@ static int bpf_jit_prog(struct bpf_jit *jit, struct bpf_prog *fp) bpf_jit_prologue(jit, fp->aux->stack_depth); for (i = 0; i < fp->len; i += insn_count) { - insn_count = bpf_jit_insn(jit, fp, i); + insn_count = bpf_jit_insn(jit, fp, i, extra_pass); if (insn_count < 0) return -1; /* Next instruction address */ @@ -1309,6 +1315,12 @@ bool bpf_jit_needs_zext(void) return true; } +struct s390_jit_data { + struct bpf_binary_header *header; + struct bpf_jit ctx; + int pass; +}; + /* * Compile eBPF program "fp" */ @@ -1316,7 +1328,9 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp) { struct bpf_prog *tmp, *orig_fp = fp; struct bpf_binary_header *header; + struct s390_jit_data *jit_data; bool tmp_blinded = false; + bool extra_pass = false; struct bpf_jit jit; int pass; @@ -1335,6 +1349,23 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp) fp = tmp; } + jit_data = fp->aux->jit_data; + if (!jit_data) { + jit_data = kzalloc(sizeof(*jit_data), GFP_KERNEL); + if (!jit_data) { + fp = orig_fp; + goto out; + } + fp->aux->jit_data = jit_data; + } + if (jit_data->ctx.addrs) { + jit = jit_data->ctx; + header = jit_data->header; + extra_pass = true; + pass = jit_data->pass + 1; + goto skip_init_ctx; + } + memset(&jit, 0, sizeof(jit)); jit.addrs = kcalloc(fp->len + 1, sizeof(*jit.addrs), GFP_KERNEL); if (jit.addrs == NULL) { @@ -1347,7 +1378,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp) * - 3: Calculate program size and addrs arrray */ for (pass = 1; pass <= 3; pass++) { - if (bpf_jit_prog(&jit, fp)) { + if (bpf_jit_prog(&jit, fp, extra_pass)) { fp = orig_fp; goto free_addrs; } @@ -1359,12 +1390,14 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp) fp = orig_fp; goto free_addrs; } + header = bpf_jit_binary_alloc(jit.size, &jit.prg_buf, 2, jit_fill_hole); if (!header) { fp = orig_fp; goto free_addrs; } - if (bpf_jit_prog(&jit, fp)) { +skip_init_ctx: + if (bpf_jit_prog(&jit, fp, extra_pass)) { bpf_jit_binary_free(header); fp = orig_fp; goto free_addrs; @@ -1373,12 +1406,23 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp) bpf_jit_dump(fp->len, jit.size, pass, jit.prg_buf); print_fn_code(jit.prg_buf, jit.size_prg); } - bpf_jit_binary_lock_ro(header); + if (!fp->is_func || extra_pass) { + bpf_jit_binary_lock_ro(header); + } else { + jit_data->header = header; + jit_data->ctx = jit; + jit_data->pass = pass; + } fp->bpf_func = (void *) jit.prg_buf; fp->jited = 1; fp->jited_len = jit.size; + + if (!fp->is_func || extra_pass) { free_addrs: - kfree(jit.addrs); + kfree(jit.addrs); + kfree(jit_data); + fp->aux->jit_data = NULL; + } out: if (tmp_blinded) bpf_jit_prog_release_other(fp, fp == orig_fp ? -- cgit v1.2.3 From 53092f7e074936df43aa4dbf4b6c3df812f3dab9 Mon Sep 17 00:00:00 2001 From: Yauheni Kaliuta Date: Fri, 30 Aug 2019 14:51:09 +0300 Subject: bpf: s390: add JIT support for bpf line info This adds support for generating bpf line info for JITed programs like commit 6f20c71d8505 ("bpf: powerpc64: add JIT support for bpf line info") does for powerpc, but it should pass the array starting from 1. This fixes test_btf. Signed-off-by: Yauheni Kaliuta Acked-by: Ilya Leoshkevich Tested-by: Ilya Leoshkevich Signed-off-by: Daniel Borkmann --- arch/s390/net/bpf_jit_comp.c | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/s390/net/bpf_jit_comp.c') diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c index a76cbe4cc7cc..e3615e55e7ef 100644 --- a/arch/s390/net/bpf_jit_comp.c +++ b/arch/s390/net/bpf_jit_comp.c @@ -1418,6 +1418,7 @@ skip_init_ctx: fp->jited_len = jit.size; if (!fp->is_func || extra_pass) { + bpf_prog_fill_jited_linfo(fp, jit.addrs + 1); free_addrs: kfree(jit.addrs); kfree(jit_data); -- cgit v1.2.3