From patchwork Fri Feb 16 23:54:14 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Namhyung Kim X-Patchwork-Id: 13560923 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9793514A4F3; Fri, 16 Feb 2024 23:54:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708127668; cv=none; b=frS1Xanpp6sFM++bMnVjWW2jdBA7B6fnjAPxuDOxKINPaKwenUKgU0tIYCSJnoQRHNd6ILHMUrW+w/qF7fI1xHTUzGjxNzX6DLQcMVGPINqf70fMF9vyYIRfTAgm+SkaXmmsXCYArwhK4BxceJKKVqu0HTBoGv+uRL2BuO0HF5M= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708127668; c=relaxed/simple; bh=7EAn2Z7hh95QVpxT5LLVg3XrS1iSEiXohUgQ6njH8Hg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=uJDdRo58u9MrQN2TEuECg/UKcq92Z17wCavTT/xBjy5lZMB24NXtHRoJ/Oh1gDgikMMaXsyYBXofRUAODvIYuxSYN8OZfC018B7x7tHh7QinzuU7H95ZoFcHyCwho4s1hxE529R7Q9U0cne8v9yOSUYAsgl8e/A2BhplWuTfwwA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ZeLCMDV7; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ZeLCMDV7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9DC2AC433B1; Fri, 16 Feb 2024 23:54:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1708127668; bh=7EAn2Z7hh95QVpxT5LLVg3XrS1iSEiXohUgQ6njH8Hg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZeLCMDV7bHtdsFi8sCylsREmrW9tSE3m0vzGLdXQI0OC1VxfLN81/lMqFjVzT2DpS mQqvRLFyDJut08I1lYqvTfBqf2EyCzVPeC3B63aMK2CtBSILhAz/CwXEObNRhXAP6S Y6Pc3SqQOoLYjNx2VQzj0jV9euTr3TUgLqhWFCXpbxNZTlC48BBiN7IDqfPz9HHhWQ WMUSTki/oEvwNq3LcenYTN6m6tBCxXy8nv605+fn44WeeypIakSbvNzkTatIPh4toT HFN/Y76xhbe1W4AbXKR3eX2uPtVkAOGP+uZhxKiA1PD6UVw9EUx8CoCriP/JPFyG2x ej3V0tPVkmGIA== From: Namhyung Kim To: Arnaldo Carvalho de Melo , Ian Rogers Cc: Jiri Olsa , Adrian Hunter , Peter Zijlstra , Ingo Molnar , LKML , linux-perf-users@vger.kernel.org, Linus Torvalds , Stephane Eranian , Masami Hiramatsu , linux-toolchains@vger.kernel.org, linux-trace-devel@vger.kernel.org Subject: [PATCH 05/14] perf annotate: Add annotate_get_basic_blocks() Date: Fri, 16 Feb 2024 15:54:14 -0800 Message-ID: <20240216235423.2343167-6-namhyung@kernel.org> X-Mailer: git-send-email 2.44.0.rc0.258.g7320e95886-goog In-Reply-To: <20240216235423.2343167-1-namhyung@kernel.org> References: <20240216235423.2343167-1-namhyung@kernel.org> Precedence: bulk X-Mailing-List: linux-trace-devel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 The annotate_get_basic_blocks() is to find a list of basic blocks from the source instruction to the destination instruction in a function. It'll be used to find variables in a scope. Use BFS (Breadth First Search) to find a shortest path to carry the variable/register state minimally. Also change find_disasm_line() to be used in annotate_get_basic_blocks() and add 'allow_update' argument to control if it can update the IP. Signed-off-by: Namhyung Kim --- tools/perf/util/annotate.c | 222 ++++++++++++++++++++++++++++++++++++- tools/perf/util/annotate.h | 16 +++ 2 files changed, 235 insertions(+), 3 deletions(-) diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c index cb5d4c517a4d..4ef14b3f49e4 100644 --- a/tools/perf/util/annotate.c +++ b/tools/perf/util/annotate.c @@ -3686,7 +3686,8 @@ static void symbol__ensure_annotate(struct map_symbol *ms, struct evsel *evsel) } } -static struct disasm_line *find_disasm_line(struct symbol *sym, u64 ip) +static struct disasm_line *find_disasm_line(struct symbol *sym, u64 ip, + bool allow_update) { struct disasm_line *dl; struct annotation *notes; @@ -3699,7 +3700,8 @@ static struct disasm_line *find_disasm_line(struct symbol *sym, u64 ip) * llvm-objdump places "lock" in a separate line and * in that case, we want to get the next line. */ - if (!strcmp(dl->ins.name, "lock") && *dl->ops.raw == '\0') { + if (!strcmp(dl->ins.name, "lock") && + *dl->ops.raw == '\0' && allow_update) { ip++; continue; } @@ -3815,7 +3817,7 @@ struct annotated_data_type *hist_entry__get_data_type(struct hist_entry *he) * Get a disasm to extract the location from the insn. * This is too slow... */ - dl = find_disasm_line(ms->sym, ip); + dl = find_disasm_line(ms->sym, ip, /*allow_update=*/true); if (dl == NULL) { ann_data_stat.no_insn++; return NULL; @@ -3909,3 +3911,217 @@ struct annotated_data_type *hist_entry__get_data_type(struct hist_entry *he) istat->bad++; return NULL; } + +/* Basic block traversal (BFS) data structure */ +struct basic_block_data { + struct list_head queue; + struct list_head visited; +}; + +/* + * During the traversal, it needs to know the parent block where the current + * block block started from. Note that single basic block can be parent of + * two child basic blocks (in case of condition jump). + */ +struct basic_block_link { + struct list_head node; + struct basic_block_link *parent; + struct annotated_basic_block *bb; +}; + +/* Check any of basic block in the list already has the offset */ +static bool basic_block_has_offset(struct list_head *head, s64 offset) +{ + struct basic_block_link *link; + + list_for_each_entry(link, head, node) { + s64 begin_offset = link->bb->begin->al.offset; + s64 end_offset = link->bb->end->al.offset; + + if (begin_offset <= offset && offset <= end_offset) + return true; + } + return false; +} + +static bool is_new_basic_block(struct basic_block_data *bb_data, + struct disasm_line *dl) +{ + s64 offset = dl->al.offset; + + if (basic_block_has_offset(&bb_data->visited, offset)) + return false; + if (basic_block_has_offset(&bb_data->queue, offset)) + return false; + return true; +} + +/* Add a basic block starting from dl and link it to the parent */ +static int add_basic_block(struct basic_block_data *bb_data, + struct basic_block_link *parent, + struct disasm_line *dl) +{ + struct annotated_basic_block *bb; + struct basic_block_link *link; + + if (dl == NULL) + return -1; + + if (!is_new_basic_block(bb_data, dl)) + return 0; + + bb = zalloc(sizeof(*bb)); + if (bb == NULL) + return -1; + + bb->begin = dl; + bb->end = dl; + INIT_LIST_HEAD(&bb->list); + + link = malloc(sizeof(*link)); + if (link == NULL) { + free(bb); + return -1; + } + + link->bb = bb; + link->parent = parent; + list_add_tail(&link->node, &bb_data->queue); + return 0; +} + +/* Returns true when it finds the target in the current basic block */ +static bool process_basic_block(struct basic_block_data *bb_data, + struct basic_block_link *link, + struct symbol *sym, u64 target) +{ + struct disasm_line *dl, *next_dl, *last_dl; + struct annotation *notes = symbol__annotation(sym); + bool found = false; + + dl = link->bb->begin; + /* Check if it's already visited */ + if (basic_block_has_offset(&bb_data->visited, dl->al.offset)) + return false; + + last_dl = list_last_entry(¬es->src->source, + struct disasm_line, al.node); + + list_for_each_entry_from(dl, ¬es->src->source, al.node) { + /* Found the target instruction */ + if (sym->start + dl->al.offset == target) { + found = true; + break; + } + /* End of the function, finish the block */ + if (dl == last_dl) + break; + /* 'return' instruction finishes the block */ + if (dl->ins.ops == &ret_ops) + break; + /* normal instructions are part of the basic block */ + if (dl->ins.ops != &jump_ops) + continue; + /* jump to a different function, tail call or return */ + if (dl->ops.target.outside) + break; + /* jump instruction creates new basic block(s) */ + next_dl = find_disasm_line(sym, sym->start + dl->ops.target.offset, + /*allow_update=*/false); + add_basic_block(bb_data, link, next_dl); + + /* + * FIXME: determine conditional jumps properly. + * Conditional jumps create another basic block with the + * next disasm line. + */ + if (!strstr(dl->ins.name, "jmp")) { + next_dl = list_next_entry(dl, al.node); + add_basic_block(bb_data, link, next_dl); + } + break; + + } + link->bb->end = dl; + return found; +} + +/* + * It founds a target basic block, build a proper linked list of basic blocks + * by following the link recursively. + */ +static void link_found_basic_blocks(struct basic_block_link *link, + struct list_head *head) +{ + while (link) { + struct basic_block_link *parent = link->parent; + + list_move(&link->bb->list, head); + list_del(&link->node); + free(link); + + link = parent; + } +} + +static void delete_basic_blocks(struct basic_block_data *bb_data) +{ + struct basic_block_link *link, *tmp; + + list_for_each_entry_safe(link, tmp, &bb_data->queue, node) { + list_del(&link->node); + free(link->bb); + free(link); + } + + list_for_each_entry_safe(link, tmp, &bb_data->visited, node) { + list_del(&link->node); + free(link->bb); + free(link); + } +} + +/** + * annotate_get_basic_blocks - Get basic blocks for given address range + * @sym: symbol to annotate + * @src: source address + * @dst: destination address + * @head: list head to save basic blocks + * + * This function traverses disasm_lines from @src to @dst and save them in a + * list of annotated_basic_block to @head. It uses BFS to find the shortest + * path between two. The basic_block_link is to maintain parent links so + * that it can build a list of blocks from the start. + */ +int annotate_get_basic_blocks(struct symbol *sym, s64 src, s64 dst, + struct list_head *head) +{ + struct basic_block_data bb_data = { + .queue = LIST_HEAD_INIT(bb_data.queue), + .visited = LIST_HEAD_INIT(bb_data.visited), + }; + struct basic_block_link *link; + struct disasm_line *dl; + int ret = -1; + + dl = find_disasm_line(sym, src, /*allow_update=*/false); + if (dl == NULL) + return -1; + + if (add_basic_block(&bb_data, /*parent=*/NULL, dl) < 0) + return -1; + + /* Find shortest path from src to dst using BFS */ + while (!list_empty(&bb_data.queue)) { + link = list_first_entry(&bb_data.queue, struct basic_block_link, node); + + if (process_basic_block(&bb_data, link, sym, dst)) { + link_found_basic_blocks(link, head); + ret = 0; + break; + } + list_move(&link->node, &bb_data.visited); + } + delete_basic_blocks(&bb_data); + return ret; +} diff --git a/tools/perf/util/annotate.h b/tools/perf/util/annotate.h index 94435607c958..83afbe294ab7 100644 --- a/tools/perf/util/annotate.h +++ b/tools/perf/util/annotate.h @@ -495,4 +495,20 @@ extern struct list_head ann_insn_stat; u64 annotate_calc_pcrel(struct map_symbol *ms, u64 ip, int offset, struct disasm_line *dl); +/** + * struct annotated_basic_block - Basic block of instructions + * @list: List node + * @begin: start instruction in the block + * @end: end instruction in the block + */ +struct annotated_basic_block { + struct list_head list; + struct disasm_line *begin; + struct disasm_line *end; +}; + +/* Get a list of basic blocks from src to dst addresses */ +int annotate_get_basic_blocks(struct symbol *sym, s64 src, s64 dst, + struct list_head *head); + #endif /* __PERF_ANNOTATE_H */