From nobody Mon Sep 15 14:45:03 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DAA50C46467 for ; Thu, 12 Jan 2023 00:37:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235942AbjALAhp (ORCPT ); Wed, 11 Jan 2023 19:37:45 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58246 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235898AbjALAhJ (ORCPT ); Wed, 11 Jan 2023 19:37:09 -0500 Received: from loongson.cn (mail.loongson.cn [114.242.206.163]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id D3ADF3C707 for ; Wed, 11 Jan 2023 16:36:57 -0800 (PST) Received: from loongson.cn (unknown [111.9.175.10]) by gateway (Coremail) with SMTP id _____8Cxe+ooVr9j4BIBAA--.3177S3; Thu, 12 Jan 2023 08:36:56 +0800 (CST) Received: from localhost.localdomain (unknown [111.9.175.10]) by localhost.localdomain (Coremail) with SMTP id AQAAf8DxbL4kVr9jLyEYAA--.43573S4; Thu, 12 Jan 2023 08:36:55 +0800 (CST) From: Jinyang He To: Huacai Chen , WANG Xuerui , Qing Zhang Cc: loongarch@lists.linux.dev, linux-kernel@vger.kernel.org, Steven Rostedt , Masami Hiramatsu , Mark Rutland Subject: [PATCH v3 2/5] LoongArch: Use correct sp value to get graph addr in unwinder guess Date: Thu, 12 Jan 2023 08:36:24 +0800 Message-Id: <20230112003627.26111-3-hejinyang@loongson.cn> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20230112003627.26111-1-hejinyang@loongson.cn> References: <20230112003627.26111-1-hejinyang@loongson.cn> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: AQAAf8DxbL4kVr9jLyEYAA--.43573S4 X-CM-SenderInfo: pkhmx0p1dqwqxorr0wxvrqhubq/ X-Coremail-Antispam: 1Uk129KBjvJXoW3Gw1fAFWUCF43CF43XFWfuFg_yoWxJr4kpF 9xCas3GrWxWryqgrnrXr1jvrn5Crn2kw12gFyDJ34FkFnrXry3Grn0v3yqvF4DJ3y8Wr48 XFn5GrW5KanrG3JanT9S1TB71UUUUjUqnTZGkaVYY2UrUUUUj1kv1TuYvTs0mT0YCTnIWj qI5I8CrVACY4xI64kE6c02F40Ex7xfYxn0WfASr-VFAUDa7-sFnT9fnUUIcSsGvfJTRUUU bfkYFVCjjxCrM7AC8VAFwI0_Jr0_Gr1l1xkIjI8I6I8E6xAIw20EY4v20xvaj40_Wr0E3s 1l1IIY67AEw4v_Jrv_JF1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxSw2x7M28EF7xv wVC0I7IYx2IY67AKxVW8JVW5JwA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxVW8JVWxJwA2z4 x0Y4vEx4A2jsIE14v26r4j6F4UM28EF7xvwVC2z280aVCY1x0267AKxVW8JVW8Jr1ln4kS 14v26r1Y6r17M2AIxVAIcxkEcVAq07x20xvEncxIr21l57IF6xkI12xvs2x26I8E6xACxx 1l5I8CrVACY4xI64kE6c02F40Ex7xfMcIj6xIIjxv20xvE14v26r1q6rW5McIj6I8E87Iv 67AKxVW8JVWxJwAm72CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41lc7CjxVAaw2 AFwI0_JF0_Jw1l42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1l4IxYO2xF xVAFwI0_Jrv_JF1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWw C2zVAF1VAY17CE14v26r1q6r43MIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Gr0_ Xr1lIxAIcVC0I7IYx2IY6xkF7I0E14v26r4j6F4UMIIF0xvE42xK8VAvwI8IcIk0rVWUJV WUCwCI42IY6I8E87Iv67AKxVW8JVWxJwCI42IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIY CTnIWIevJa73UjIFyTuYvjxUxhiSDUUUU Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" The stack frame when function_graph enable like follows, --------- <- function sp_on_entry | | | FAKE_RA <- sp_on_entry - sizeof(pt_regs) + PT_R1 | --------- <- sp_on_entry - sizeof(pt_regs) So if we want to get the &FAKE_RA we should get sp_on_entry first. In unwinder_prologue case, we can get the sp_on_entry as state->sp, because we try to calculate each CFA and the ra saved address. But in unwinder_guess case, we cannot get it because we do not try to calculate the CFA. Although LoongArch have not fixed frame, the $ra is saved at CFA - 8 in most cases, we can try guess, too. As we store the pc in state, we not need to dereference state->sp, too. Signed-off-by: Jinyang He --- arch/loongarch/include/asm/ftrace.h | 2 -- arch/loongarch/include/asm/unwind.h | 9 +++++++++ arch/loongarch/kernel/unwind_guess.c | 12 ++++-------- arch/loongarch/kernel/unwind_prologue.c | 22 ++++++---------------- 4 files changed, 19 insertions(+), 26 deletions(-) diff --git a/arch/loongarch/include/asm/ftrace.h b/arch/loongarch/include/a= sm/ftrace.h index 90f9d3399b2a..3418d32d4fc7 100644 --- a/arch/loongarch/include/asm/ftrace.h +++ b/arch/loongarch/include/asm/ftrace.h @@ -10,8 +10,6 @@ #define FTRACE_REGS_PLT_IDX 1 #define NR_FTRACE_PLTS 2 =20 -#define GRAPH_FAKE_OFFSET (sizeof(struct pt_regs) - offsetof(struct pt_reg= s, regs[1])) - #ifdef CONFIG_FUNCTION_TRACER =20 #define MCOUNT_INSN_SIZE 4 /* sizeof mcount call */ diff --git a/arch/loongarch/include/asm/unwind.h b/arch/loongarch/include/a= sm/unwind.h index f2b52b9ea93d..6ece48f0ff77 100644 --- a/arch/loongarch/include/asm/unwind.h +++ b/arch/loongarch/include/asm/unwind.h @@ -7,8 +7,10 @@ #ifndef _ASM_UNWIND_H #define _ASM_UNWIND_H =20 +#include #include =20 +#include #include =20 enum unwinder_type { @@ -40,4 +42,11 @@ static inline bool unwind_error(struct unwind_state *sta= te) return state->error; } =20 +#define GRAPH_FAKE_OFFSET (sizeof(struct pt_regs) - offsetof(struct pt_reg= s, regs[1])) +static inline unsigned long unwind_graph_addr(struct unwind_state *state, + unsigned long pc, unsigned long cfa) +{ + return ftrace_graph_ret_addr(state->task, &state->graph_idx, + pc, (unsigned long *)(cfa - GRAPH_FAKE_OFFSET)); +} #endif /* _ASM_UNWIND_H */ diff --git a/arch/loongarch/kernel/unwind_guess.c b/arch/loongarch/kernel/u= nwind_guess.c index a1bc7c852000..935d24f8c95c 100644 --- a/arch/loongarch/kernel/unwind_guess.c +++ b/arch/loongarch/kernel/unwind_guess.c @@ -11,10 +11,7 @@ unsigned long unwind_get_return_address(struct unwind_st= ate *state) { if (unwind_done(state)) return 0; - else if (state->first) - return state->pc; - - return *(unsigned long *)(state->sp); + return state->pc; } EXPORT_SYMBOL_GPL(unwind_get_return_address); =20 @@ -36,7 +33,7 @@ void unwind_start(struct unwind_state *state, struct task= _struct *task, =20 state->task =3D task; state->first =3D true; - + state->pc =3D unwind_graph_addr(state, state->pc, state->sp); get_stack_info(state->sp, state->task, &state->stack_info); =20 if (!unwind_done(state) && !__kernel_text_address(state->pc)) @@ -60,9 +57,8 @@ bool unwind_next_frame(struct unwind_state *state) state->sp < info->end; state->sp +=3D sizeof(unsigned long)) { addr =3D *(unsigned long *)(state->sp); - state->pc =3D ftrace_graph_ret_addr(state->task, &state->graph_idx, - addr, (unsigned long *)(state->sp - GRAPH_FAKE_OFFSET)); - if (__kernel_text_address(addr)) + state->pc =3D unwind_graph_addr(state, addr, state->sp + 8); + if (__kernel_text_address(state->pc)) return true; } =20 diff --git a/arch/loongarch/kernel/unwind_prologue.c b/arch/loongarch/kerne= l/unwind_prologue.c index b8b830b69a48..3fbb9c65d64e 100644 --- a/arch/loongarch/kernel/unwind_prologue.c +++ b/arch/loongarch/kernel/unwind_prologue.c @@ -21,16 +21,9 @@ static inline void unwind_state_fixup(struct unwind_stat= e *state) =20 unsigned long unwind_get_return_address(struct unwind_state *state) { - if (unwind_done(state)) return 0; - else if (state->type) - return state->pc; - else if (state->first) - return state->pc; - - return *(unsigned long *)(state->sp); - + return state->pc; } EXPORT_SYMBOL_GPL(unwind_get_return_address); =20 @@ -43,9 +36,8 @@ static bool unwind_by_guess(struct unwind_state *state) state->sp < info->end; state->sp +=3D sizeof(unsigned long)) { addr =3D *(unsigned long *)(state->sp); - state->pc =3D ftrace_graph_ret_addr(state->task, &state->graph_idx, - addr, (unsigned long *)(state->sp - GRAPH_FAKE_OFFSET)); - if (__kernel_text_address(addr)) + state->pc =3D unwind_graph_addr(state, addr, state->sp + 8); + if (__kernel_text_address(state->pc)) return true; } =20 @@ -161,7 +153,7 @@ void unwind_start(struct unwind_state *state, struct ta= sk_struct *task, =20 state->task =3D task; state->first =3D true; - + state->pc =3D unwind_graph_addr(state, state->pc, state->sp); get_stack_info(state->sp, state->task, &state->stack_info); =20 if (!unwind_done(state) && !__kernel_text_address(state->pc)) @@ -188,8 +180,7 @@ bool unwind_next_frame(struct unwind_state *state) =20 case UNWINDER_PROLOGUE: if (unwind_by_prologue(state)) { - state->pc =3D ftrace_graph_ret_addr(state->task, &state->graph_idx, - state->pc, (unsigned long *)(state->sp - GRAPH_FAKE_OFFSET)); + state->pc =3D unwind_graph_addr(state, state->pc, state->sp); return true; } =20 @@ -204,8 +195,7 @@ bool unwind_next_frame(struct unwind_state *state) state->first =3D true; state->ra =3D regs->regs[1]; state->sp =3D regs->regs[3]; - state->pc =3D ftrace_graph_ret_addr(state->task, &state->graph_idx, - pc, (unsigned long *)(state->sp - GRAPH_FAKE_OFFSET)); + state->pc =3D pc; get_stack_info(state->sp, state->task, info); =20 return true; --=20 2.34.3