From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 7644 invoked by alias); 17 Feb 2015 01:37:22 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Received: (qmail 7628 invoked by uid 89); 17 Feb 2015 01:37:21 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-0.8 required=5.0 tests=AWL,BAYES_00,LIKELY_SPAM_BODY,SPF_HELO_PASS,T_RP_MATCHES_RCVD autolearn=no version=3.3.2 X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-GCM-SHA384 encrypted) ESMTPS; Tue, 17 Feb 2015 01:37:20 +0000 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id t1H1bH9r012473 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 16 Feb 2015 20:37:18 -0500 Received: from localhost (dhcp-10-15-16-169.yyz.redhat.com [10.15.16.169]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id t1H1bHHn006601 (version=TLSv1/SSLv3 cipher=AES128-GCM-SHA256 bits=128 verify=NO); Mon, 16 Feb 2015 20:37:17 -0500 From: Sergio Durigan Junior To: "Jose E. Marchesi" Cc: gdb-patches@sourceware.org Subject: Re: [PATCH V4 6/9] Support for DTrace USDT probes in x86_64 targets. References: <1422874968-382-1-git-send-email-jose.marchesi@oracle.com> <1422874968-382-7-git-send-email-jose.marchesi@oracle.com> X-URL: http://blog.sergiodj.net Date: Tue, 17 Feb 2015 01:37:00 -0000 In-Reply-To: <1422874968-382-7-git-send-email-jose.marchesi@oracle.com> (Jose E. Marchesi's message of "Mon, 2 Feb 2015 12:02:45 +0100") Message-ID: <87mw4d71yq.fsf@redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-IsSubscribed: yes X-SW-Source: 2015-02/txt/msg00378.txt.bz2 On Monday, February 02 2015, Jose E. Marchesi wrote: > This patch adds the target-specific code in order to support the > calculation of DTrace probes arguments in x86_64 targets, and also the > enabling and disabling of probes. This is done by implementing the > `dtrace_*' gdbarch handlers. Thanks for the patch. This was approved already; no further comments. OK. > gdb/ChangeLog: > > 2015-02-02 Jose E. Marchesi > > * amd64-linux-tdep.c: Include "parser-defs.h" and "user-regs.h". > (amd64_dtrace_parse_probe_argument): New function. > (amd64_dtrace_probe_is_enabled): Likewise. > (amd64_dtrace_enable_probe): Likewise. > (amd64_dtrace_disable_probe): Likewise. > (amd64_linux_init_abi): Register the > `gdbarch_dtrace_probe_argument', `gdbarch_dtrace_enable_probe', > `gdbarch_dtrace_disable_probe' and > `gdbarch_dtrace_probe_is_enabled' hooks. > (amd64_dtrace_disabled_probe_sequence_1): New constant. > (amd64_dtrace_disabled_probe_sequence_2): Likewise. > (amd64_dtrace_enable_probe_sequence): Likewise. > (amd64_dtrace_disable_probe_sequence): Likewise. > --- > gdb/ChangeLog | 16 ++++++ > gdb/amd64-linux-tdep.c | 148 ++++++++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 164 insertions(+) > > diff --git a/gdb/amd64-linux-tdep.c b/gdb/amd64-linux-tdep.c > index 42d884e..ffa85f4 100644 > --- a/gdb/amd64-linux-tdep.c > +++ b/gdb/amd64-linux-tdep.c > @@ -28,6 +28,8 @@ > #include "gdbtypes.h" > #include "reggroups.h" > #include "regset.h" > +#include "parser-defs.h" > +#include "user-regs.h" > #include "amd64-linux-tdep.h" > #include "i386-linux-tdep.h" > #include "linux-tdep.h" > @@ -1643,6 +1645,146 @@ amd64_linux_iterate_over_regset_sections (struct gdbarch *gdbarch, > &amd64_linux_xstateregset, "XSAVE extended state", cb_data); > } > > +/* The instruction sequences used in x86_64 machines for a > + disabled is-enabled probe. */ > + > +const gdb_byte amd64_dtrace_disabled_probe_sequence_1[] = { > + /* xor %rax, %rax */ 0x48, 0x33, 0xc0, > + /* nop */ 0x90, > + /* nop */ 0x90 > +}; > + > +const gdb_byte amd64_dtrace_disabled_probe_sequence_2[] = { > + /* xor %rax, %rax */ 0x48, 0x33, 0xc0, > + /* ret */ 0xc3, > + /* nop */ 0x90 > +}; > + > +/* The instruction sequence used in x86_64 machines for enabling a > + DTrace is-enabled probe. */ > + > +const gdb_byte amd64_dtrace_enable_probe_sequence[] = { > + /* mov $0x1, %eax */ 0xb8, 0x01, 0x00, 0x00, 0x00 > +}; > + > +/* The instruction sequence used in x86_64 machines for disabling a > + DTrace is-enabled probe. */ > + > +const gdb_byte amd64_dtrace_disable_probe_sequence[] = { > + /* xor %rax, %rax; nop; nop */ 0x48, 0x33, 0xC0, 0x90, 0x90 > +}; > + > +/* Implementation of `gdbarch_dtrace_probe_is_enabled', as defined in > + gdbarch.h. */ > + > +static int > +amd64_dtrace_probe_is_enabled (struct gdbarch *gdbarch, CORE_ADDR addr) > +{ > + gdb_byte buf[5]; > + > + /* This function returns 1 if the instructions at ADDR do _not_ > + follow any of the amd64_dtrace_disabled_probe_sequence_* > + patterns. > + > + Note that ADDR is offset 3 bytes from the beginning of these > + sequences. */ > + > + read_code (addr - 3, buf, 5); > + return (memcmp (buf, amd64_dtrace_disabled_probe_sequence_1, 5) != 0 > + && memcmp (buf, amd64_dtrace_disabled_probe_sequence_2, 5) != 0); > +} > + > +/* Implementation of `gdbarch_dtrace_enable_probe', as defined in > + gdbarch.h. */ > + > +static void > +amd64_dtrace_enable_probe (struct gdbarch *gdbarch, CORE_ADDR addr) > +{ > + /* Note also that ADDR is offset 3 bytes from the beginning of > + amd64_dtrace_enable_probe_sequence. */ > + > + write_memory (addr - 3, amd64_dtrace_enable_probe_sequence, 5); > +} > + > +/* Implementation of `gdbarch_dtrace_disable_probe', as defined in > + gdbarch.h. */ > + > +static void > +amd64_dtrace_disable_probe (struct gdbarch *gdbarch, CORE_ADDR addr) > +{ > + /* Note also that ADDR is offset 3 bytes from the beginning of > + amd64_dtrace_disable_probe_sequence. */ > + > + write_memory (addr - 3, amd64_dtrace_disable_probe_sequence, 5); > +} > + > +/* Implementation of `gdbarch_dtrace_parse_probe_argument', as defined > + in gdbarch.h. */ > + > +static void > +amd64_dtrace_parse_probe_argument (struct gdbarch *gdbarch, > + struct parser_state *pstate, > + int narg) > +{ > + enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); > + struct frame_info *this_frame = get_selected_frame (NULL); > + struct stoken str; > + > + /* DTrace probe arguments can be found on the ABI-defined places for > + regular arguments at the current PC. The probe abstraction > + currently supports up to 12 arguments for probes. */ > + > + if (narg < 6) > + { > + static const int arg_reg_map[6] = > + { > + AMD64_RDI_REGNUM, /* Arg 1. */ > + AMD64_RSI_REGNUM, /* Arg 2. */ > + AMD64_RDX_REGNUM, /* Arg 3. */ > + AMD64_RCX_REGNUM, /* Arg 4. */ > + AMD64_R8_REGNUM, /* Arg 5. */ > + AMD64_R9_REGNUM /* Arg 6. */ > + }; > + int regno = arg_reg_map[narg]; > + const char *regname = user_reg_map_regnum_to_name (gdbarch, regno); > + > + write_exp_elt_opcode (pstate, OP_REGISTER); > + str.ptr = regname; > + str.length = strlen (regname); > + write_exp_string (pstate, str); > + write_exp_elt_opcode (pstate, OP_REGISTER); > + } > + else > + { > + /* Additional arguments are passed on the stack. */ > + CORE_ADDR sp; > + const char *regname = user_reg_map_regnum_to_name (gdbarch, AMD64_RSP_REGNUM); > + > + /* Displacement. */ > + write_exp_elt_opcode (pstate, OP_LONG); > + write_exp_elt_type (pstate, builtin_type (gdbarch)->builtin_long); > + write_exp_elt_longcst (pstate, narg - 6); > + write_exp_elt_opcode (pstate, OP_LONG); > + > + /* Register: SP. */ > + write_exp_elt_opcode (pstate, OP_REGISTER); > + str.ptr = regname; > + str.length = strlen (regname); > + write_exp_string (pstate, str); > + write_exp_elt_opcode (pstate, OP_REGISTER); > + > + write_exp_elt_opcode (pstate, BINOP_ADD); > + > + /* Cast to long. */ > + write_exp_elt_opcode (pstate, UNOP_CAST); > + write_exp_elt_type (pstate, > + lookup_pointer_type (builtin_type (gdbarch)->builtin_long)); > + write_exp_elt_opcode (pstate, UNOP_CAST); > + > + write_exp_elt_opcode (pstate, UNOP_IND); > + } > +} > + > static void > amd64_linux_init_abi_common(struct gdbarch_info info, struct gdbarch *gdbarch) > { > @@ -1907,6 +2049,12 @@ amd64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) > /* GNU/Linux uses SVR4-style shared libraries. */ > set_solib_svr4_fetch_link_map_offsets > (gdbarch, svr4_lp64_fetch_link_map_offsets); > + > + /* Register DTrace handlers. */ > + set_gdbarch_dtrace_parse_probe_argument (gdbarch, amd64_dtrace_parse_probe_argument); > + set_gdbarch_dtrace_probe_is_enabled (gdbarch, amd64_dtrace_probe_is_enabled); > + set_gdbarch_dtrace_enable_probe (gdbarch, amd64_dtrace_enable_probe); > + set_gdbarch_dtrace_disable_probe (gdbarch, amd64_dtrace_disable_probe); > } > > static void > -- > 1.7.10.4 -- Sergio GPG key ID: 0x65FC5E36 Please send encrypted e-mail if possible http://sergiodj.net/