Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751649AbbEXIag (ORCPT ); Sun, 24 May 2015 04:30:36 -0400 Received: from szxga03-in.huawei.com ([119.145.14.66]:28110 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750870AbbEXI2h (ORCPT ); Sun, 24 May 2015 04:28:37 -0400 From: He Kuang To: , , , , , , , , , , , CC: , Subject: [RFC PATCH v2 11/15] perf bpf: Synthesize vars to generate bpf prologue Date: Sun, 24 May 2015 08:28:07 +0000 Message-ID: <1432456091-73384-12-git-send-email-hekuang@huawei.com> X-Mailer: git-send-email 1.8.3.4 In-Reply-To: <1432456091-73384-1-git-send-email-hekuang@huawei.com> References: <1432456091-73384-1-git-send-email-hekuang@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.107.197.210] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020206.55618BB2.0098,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2013-05-26 15:14:31, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: fbbe4e1a3b86aed8cb6a30e010b2384c Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3165 Lines: 125 After gethered all vars represented in trace_probe_arg, we can now use functions in libbpf to generate the args prologue. Signed-off-by: He Kuang --- tools/perf/util/probe-finder.c | 83 +++++++++++++++++++++++++++++++++++++++++- 1 file changed, 81 insertions(+), 2 deletions(-) diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c index 6785eab..455ff0f 100644 --- a/tools/perf/util/probe-finder.c +++ b/tools/perf/util/probe-finder.c @@ -1242,6 +1242,67 @@ end: return ret; } +/* + * Convert args to bpf prologue + * 1) First pass for calculating the new program length: + * synthesize_probe_bpf(arg, nargs, NULL, &new_len); + * + * 2) 2nd pass do the actually convert + * new_prog = malloc(sizeof(struct bpf_insn) * new_len); + * synthesize_probe_bpf(arg, nargs, new_prog, &new_len); + */ +static int synthesize_probe_bpf(struct probe_trace_arg *arg, + int nargs, + char *new_prog, + int *new_len) +{ + int i; + char *new_insn = new_prog; + + if (nargs == 0) { + *new_len = 0; + return 0; + } + + new_insn += bpf_prologue_begin(new_prog); + /* Find each argument */ + for (i = 0; i < nargs; i++) { + struct probe_trace_arg_ref *ref = arg[i].ref; + unsigned int regn = arg[i].regn; + + /* Print argument value */ + if (arg[i].value[0] == '@' && ref) { + /* TODO parse other arguments */ + pr_debug("%d%+ld", regn, ref->offset); + } else { + int depth = 0; + + new_insn += bpf_prologue_arg_deref( + get_arch_reg_offset(regn), + i + 1, + depth++, + new_prog ? new_insn : NULL, + !ref); + + while (ref) { + new_insn += bpf_prologue_arg_deref( + ref->offset, + i + 1, + depth++, + new_prog ? new_insn : NULL, + !ref->next); + ref = ref->next; + } + } + } + + new_insn += bpf_prologue_end(new_prog ? new_insn : NULL, + nargs); + *new_len = new_insn - new_prog; + + return 0; +} + /* Add a found probe point into trace event list */ static int add_probe_trace_event(Dwarf_Die *sc_die, struct probe_finder *pf) { @@ -1335,6 +1396,8 @@ int debuginfo__find_bpf_prologue(struct debuginfo *dbg, .pf = {.pev = pev, .callback = generate_bpf_prologue}, .mod = dbg->mod, .max_tevs = BPF_MAX_TEVS}; struct probe_trace_event *tevs; + struct probe_trace_event *tev; + char *new_prog; int ret; /* Allocate result tevs array */ @@ -1347,9 +1410,25 @@ int debuginfo__find_bpf_prologue(struct debuginfo *dbg, ret = debuginfo__find_probes(dbg, &tf.pf); - *result = NULL; - *count = 0; + tev = &tevs[0]; + + synthesize_probe_bpf(tev->args, tev->nargs, NULL, count); + if (*count == 0) + goto end; + + new_prog = malloc(*count); + if (!new_prog) { + ret = -ENOMEM; + goto end; + } + synthesize_probe_bpf(tev->args, tev->nargs, new_prog, count); + + /* assign result to tvar */ + *result = (char *)new_prog; + +end: + /* release tevs */ free(tevs); return ret; } -- 1.8.5.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/