From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ot1-x333.google.com (mail-ot1-x333.google.com [IPv6:2607:f8b0:4864:20::333]) by sourceware.org (Postfix) with ESMTPS id C3E2F388553D for ; Sat, 26 Nov 2022 02:05:30 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org C3E2F388553D Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=linaro.org Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=linaro.org Received: by mail-ot1-x333.google.com with SMTP id g51-20020a9d12b6000000b0066dbea0d203so3667303otg.6 for ; Fri, 25 Nov 2022 18:05:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=yxs5m0ICOUI8UResuPr+3K3lWWkmctogWLT2EGjmofw=; b=BPP7462knqG+ZbMqxsR7uZHEskz4/FYOwp13YDVzcYAdJpRgDoCMjlDGNhC/m0PaV7 WvAKAf3MR2I2zj5UbO7E2Q5cXhBE+HGj73GkUoglrSASIlRMUSBx/3nN5zLynOF+B75J xbNTh1TOc3g8/L1L0AK0oOY1/hmvheChbnEdmDEpMOYTDZQvV7Rfht3dIS0W7Psf1Rjn VvaMyXJGlUkQcWy1qptHKYK6G2LF/6SqOjoVxb7rYqhOZ6La6qULmAwdy7DJhwy9UrLR 0juf30mcVXCWoF61yAQTWgTtHtHbOUXQifIIwREIKQMoL1TLsUKvaQTMeRSQZ0aNjqx3 RjjA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=yxs5m0ICOUI8UResuPr+3K3lWWkmctogWLT2EGjmofw=; b=hyr/43tgsbFWcDqIZqKGgG1pne+hYm20HleDe9wR4hBat6YTxuLPFmmiFThIz8abwh 8xw1ISed7D/z5sfJB7oCjWZFX3IOqV4hKa7QvTLwZkWxOjKOae4o05dEdUPISmsbbxrZ m+6JakkhTnBzv+pt9xl6UMcSPBh4HX41bKYj6C44SBl/6cli2GA5qg3n37f7j9n/4Bn2 4BlPay2mcGM1Q9ayAxNo361h3iUDNV+RMvgOmGISpVmFrhnb3FlBm8yfSt45IEhq+N5R XyYfwRuW49aFlKRsGhN+h6EdEH96xbrudUfluUtU36vVp6f/XHQKvT0mWObfDrdHepbS HyJA== X-Gm-Message-State: ANoB5plek3lbTPKLHJDy7/Phdix/p0RPwopXdxdY6JWql+x3BMnOQlrO 2RtaLHAvMgo2DYp80FzdtRd+UHUqSZqh5Q== X-Google-Smtp-Source: AA0mqf579N0KyPDnx6w2QPDddAMFW9mTOdnrmQzqnaZ1h0uLSpVZrXmLtMQfrTOw2zXDqLX3UVmyIw== X-Received: by 2002:a9d:6486:0:b0:66d:ca7a:8b1a with SMTP id g6-20020a9d6486000000b0066dca7a8b1amr12324745otl.55.1669428330034; Fri, 25 Nov 2022 18:05:30 -0800 (PST) Received: from localhost ([2804:14d:7e39:8470:41ee:c7fc:c991:eee6]) by smtp.gmail.com with ESMTPSA id a22-20020a9d6e96000000b0066c45517c8fsm2291520otr.52.2022.11.25.18.05.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 25 Nov 2022 18:05:29 -0800 (PST) From: Thiago Jung Bauermann To: gdb-patches@sourceware.org Cc: Luis Machado , Thiago Jung Bauermann Subject: [PATCH v2 6/6] gdb/aarch64: Detect vector length changes when debugging remotely Date: Sat, 26 Nov 2022 02:04:52 +0000 Message-Id: <20221126020452.1686509-7-thiago.bauermann@linaro.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221126020452.1686509-1-thiago.bauermann@linaro.org> References: <20221126020452.1686509-1-thiago.bauermann@linaro.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-11.3 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,GIT_PATCH_0,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: If the remote target provides an expedited VG register, use it to update the thread's gdbarch. This allows debugging programs that change their SVE vector length during runtime. This is accomplished by implementing the thread_architecture method in remote_target, which returns the gdbarch corresponding to the expedited registers provided by the last stop reply. To allow changing the architecture based on the expedited registers, add a new gdbarch method to allow arch-specific code to make the adjustment. --- gdb/aarch64-tdep.c | 26 +++++++++++++++++++++++- gdb/arch-utils.c | 9 +++++++++ gdb/arch-utils.h | 5 +++++ gdb/gdbarch-components.py | 16 +++++++++++++++ gdb/gdbarch-gen.h | 11 ++++++++++ gdb/gdbarch.c | 22 ++++++++++++++++++++ gdb/remote.c | 42 +++++++++++++++++++++++++++++++++++++++ 7 files changed, 130 insertions(+), 1 deletion(-) diff --git a/gdb/aarch64-tdep.c b/gdb/aarch64-tdep.c index ffc128d91f60..764f693aee8d 100644 --- a/gdb/aarch64-tdep.c +++ b/gdb/aarch64-tdep.c @@ -3486,7 +3486,8 @@ aarch64_cannot_store_register (struct gdbarch *gdbarch, int regnum) || regnum == AARCH64_PAUTH_CMASK_REGNUM (tdep->pauth_reg_base)); } -/* Helper function for the "thread_architecture" target_ops method. +/* Helper function for both the "update_architecture" gdbarch method and the + "thread_architecture" target_ops method. Returns a new gdbarch that is equivalent to the given gdbarch, but with SVE registers reflecting the given vq value. */ @@ -3521,6 +3522,28 @@ aarch64_update_gdbarch (struct gdbarch *gdbarch, uint64_t vq) return gdbarch_find_by_info (info); } +/* Implement the "update_architecture" gdbarch method. */ + +static struct gdbarch * +aarch64_update_architecture (struct gdbarch *gdbarch, + const std::vector ®cache) +{ + /* Look for the VG register. */ + auto it = find_if (regcache.cbegin (), regcache.cend (), + [] (const cached_reg_t ®) { + return reg.num == AARCH64_SVE_VG_REGNUM; + }); + + /* No VG register was provided. Don't change gdbarch. */ + if (it == regcache.cend ()) + return gdbarch; + + ULONGEST vg = extract_unsigned_integer (it->data, 8, + gdbarch_byte_order (gdbarch)); + + return aarch64_update_gdbarch (gdbarch, sve_vq_from_vg (vg)); +} + /* Implement the stack_frame_destroyed_p gdbarch method. */ static int @@ -3742,6 +3765,7 @@ aarch64_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches) set_tdesc_pseudo_register_reggroup_p (gdbarch, aarch64_pseudo_register_reggroup_p); set_gdbarch_cannot_store_register (gdbarch, aarch64_cannot_store_register); + set_gdbarch_update_architecture (gdbarch, aarch64_update_architecture); /* ABI */ set_gdbarch_short_bit (gdbarch, 16); diff --git a/gdb/arch-utils.c b/gdb/arch-utils.c index 7b84daf046e2..2315aacb4bbe 100644 --- a/gdb/arch-utils.c +++ b/gdb/arch-utils.c @@ -1090,6 +1090,15 @@ default_get_return_buf_addr (struct type *val_type, frame_info_ptr cur_frame) return 0; } +/* See arch-utils.h. */ + +struct gdbarch * +default_update_architecture (struct gdbarch *gdbarch, + const std::vector ®cache) +{ + return gdbarch; +} + /* Non-zero if we want to trace architecture code. */ #ifndef GDBARCH_DEBUG diff --git a/gdb/arch-utils.h b/gdb/arch-utils.h index 46018a6fbbb6..e68a91f6753d 100644 --- a/gdb/arch-utils.h +++ b/gdb/arch-utils.h @@ -304,4 +304,9 @@ extern void default_read_core_file_mappings /* Default implementation of gdbarch default_get_return_buf_addr method. */ extern CORE_ADDR default_get_return_buf_addr (struct type *val_typegdbarch, frame_info_ptr cur_frame); + +/* Default implementation of gdbarch update_architecture method. */ +extern struct gdbarch * +default_update_architecture (struct gdbarch *gdbarch, + const std::vector ®cache); #endif /* ARCH_UTILS_H */ diff --git a/gdb/gdbarch-components.py b/gdb/gdbarch-components.py index 9b688998a7bd..fbb32c5e5853 100644 --- a/gdb/gdbarch-components.py +++ b/gdb/gdbarch-components.py @@ -2698,3 +2698,19 @@ Read core file mappings predefault="default_read_core_file_mappings", invalid=False, ) + +Method( + comment=""" +An architecture may change based on the current contents of its registers. +For instance, the length of the vector registers in AArch64's Scalable Vector +Extension is given by the contents of the VL pseudo-register. + +This method allows an architecture to provide a new gdbarch corresponding to +the registers in the given regcache. +""", + type="struct gdbarch *", + name="update_architecture", + params=[("const std::vector &", "regcache")], + predefault="default_update_architecture", + invalid=False, +) diff --git a/gdb/gdbarch-gen.h b/gdb/gdbarch-gen.h index a663316df166..a65699e7241f 100644 --- a/gdb/gdbarch-gen.h +++ b/gdb/gdbarch-gen.h @@ -1649,3 +1649,14 @@ extern void set_gdbarch_get_pc_address_flags (struct gdbarch *gdbarch, gdbarch_g typedef void (gdbarch_read_core_file_mappings_ftype) (struct gdbarch *gdbarch, struct bfd *cbfd, read_core_file_mappings_pre_loop_ftype pre_loop_cb, read_core_file_mappings_loop_ftype loop_cb); extern void gdbarch_read_core_file_mappings (struct gdbarch *gdbarch, struct bfd *cbfd, read_core_file_mappings_pre_loop_ftype pre_loop_cb, read_core_file_mappings_loop_ftype loop_cb); extern void set_gdbarch_read_core_file_mappings (struct gdbarch *gdbarch, gdbarch_read_core_file_mappings_ftype *read_core_file_mappings); + +/* An architecture may change based on the current contents of its registers. + For instance, the length of the vector registers in AArch64's Scalable Vector + Extension is given by the contents of the VL pseudo-register. + + This method allows an architecture to provide a new gdbarch corresponding to + the registers in the given regcache. */ + +typedef struct gdbarch * (gdbarch_update_architecture_ftype) (struct gdbarch *gdbarch, const std::vector ®cache); +extern struct gdbarch * gdbarch_update_architecture (struct gdbarch *gdbarch, const std::vector ®cache); +extern void set_gdbarch_update_architecture (struct gdbarch *gdbarch, gdbarch_update_architecture_ftype *update_architecture); diff --git a/gdb/gdbarch.c b/gdb/gdbarch.c index 3227e9458801..1b0a2c70db4c 100644 --- a/gdb/gdbarch.c +++ b/gdb/gdbarch.c @@ -255,6 +255,7 @@ struct gdbarch gdbarch_type_align_ftype *type_align = default_type_align; gdbarch_get_pc_address_flags_ftype *get_pc_address_flags = default_get_pc_address_flags; gdbarch_read_core_file_mappings_ftype *read_core_file_mappings = default_read_core_file_mappings; + gdbarch_update_architecture_ftype *update_architecture = default_update_architecture; }; /* Create a new ``struct gdbarch'' based on information provided by @@ -514,6 +515,7 @@ verify_gdbarch (struct gdbarch *gdbarch) /* Skip verify of type_align, invalid_p == 0 */ /* Skip verify of get_pc_address_flags, invalid_p == 0 */ /* Skip verify of read_core_file_mappings, invalid_p == 0 */ + /* Skip verify of update_architecture, invalid_p == 0 */ if (!log.empty ()) internal_error (_("verify_gdbarch: the following are invalid ...%s"), log.c_str ()); @@ -1352,6 +1354,9 @@ gdbarch_dump (struct gdbarch *gdbarch, struct ui_file *file) gdb_printf (file, "gdbarch_dump: read_core_file_mappings = <%s>\n", host_address_to_string (gdbarch->read_core_file_mappings)); + gdb_printf (file, + "gdbarch_dump: update_architecture = <%s>\n", + host_address_to_string (gdbarch->update_architecture)); if (gdbarch->dump_tdep != NULL) gdbarch->dump_tdep (gdbarch, file); } @@ -5314,3 +5319,20 @@ set_gdbarch_read_core_file_mappings (struct gdbarch *gdbarch, { gdbarch->read_core_file_mappings = read_core_file_mappings; } + +struct gdbarch * +gdbarch_update_architecture (struct gdbarch *gdbarch, const std::vector ®cache) +{ + gdb_assert (gdbarch != NULL); + gdb_assert (gdbarch->update_architecture != NULL); + if (gdbarch_debug >= 2) + gdb_printf (gdb_stdlog, "gdbarch_update_architecture called\n"); + return gdbarch->update_architecture (gdbarch, regcache); +} + +void +set_gdbarch_update_architecture (struct gdbarch *gdbarch, + gdbarch_update_architecture_ftype update_architecture) +{ + gdbarch->update_architecture = update_architecture; +} diff --git a/gdb/remote.c b/gdb/remote.c index 5118ecd0a312..eb60ed51585b 100644 --- a/gdb/remote.c +++ b/gdb/remote.c @@ -491,6 +491,8 @@ class remote_target : public process_stratum_target gdb::byte_vector thread_info_to_thread_handle (struct thread_info *tp) override; + struct gdbarch *thread_architecture (ptid_t ptid) override; + void stop (ptid_t) override; void interrupt () override; @@ -1150,6 +1152,10 @@ struct remote_thread_info : public private_thread_info to stop for a watchpoint. */ CORE_ADDR watch_data_address = 0; + /* The architecture corresponding to the expedited registers returned + in the last stop reply. */ + struct gdbarch *expedited_arch = nullptr; + /* Get the thread's resume state. */ enum resume_state get_resume_state () const { @@ -1168,6 +1174,8 @@ struct remote_thread_info : public private_thread_info m_resume_state = resume_state::RESUMED_PENDING_VCONT; m_resumed_pending_vcont_info.step = step; m_resumed_pending_vcont_info.sig = sig; + + expedited_arch = nullptr; } /* Get the information this thread's pending vCont-resumption. @@ -1185,6 +1193,8 @@ struct remote_thread_info : public private_thread_info void set_resumed () { m_resume_state = resume_state::RESUMED; + + expedited_arch = nullptr; } private: @@ -8068,6 +8078,21 @@ remote_target::process_stop_reply (struct stop_reply *stop_reply, /* Expedited registers. */ if (!stop_reply->regcache.empty ()) { + /* If GDB already knows about this thread, we can give the + architecture-specific code a chance to update the gdbarch based on + the expedited registers. */ + if (find_thread_ptid (this, ptid) != nullptr) + { + stop_reply->arch = gdbarch_update_architecture (stop_reply->arch, + stop_reply->regcache); + + /* Save stop_reply->arch so that it can be returned by the + thread_architecture method. */ + remote_thread_info *remote_thr = get_remote_thread_info (this, + ptid); + remote_thr->expedited_arch = stop_reply->arch; + } + struct regcache *regcache = get_thread_arch_regcache (this, ptid, stop_reply->arch); @@ -14382,6 +14407,23 @@ remote_target::thread_info_to_thread_handle (struct thread_info *tp) return priv->thread_handle; } +struct gdbarch * +remote_target::thread_architecture (ptid_t ptid) +{ + thread_info *thr = find_thread_ptid (this, ptid); + remote_thread_info *remote_thr = nullptr; + + if (thr != nullptr) + remote_thr = get_remote_thread_info (thr); + + if (remote_thr == nullptr || remote_thr->expedited_arch == nullptr) + /* The default thread_architecture implementation is the one from + process_stratum_target. */ + return process_stratum_target::thread_architecture(ptid); + + return remote_thr->expedited_arch; +} + bool remote_target::can_async_p () {