From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 9799 invoked by alias); 26 Sep 2014 09:43:46 -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 9477 invoked by uid 89); 26 Sep 2014 09:43:44 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.1 required=5.0 tests=AWL,BAYES_00,LIKELY_SPAM_BODY,RP_MATCHES_RCVD,SPF_PASS,UNPARSEABLE_RELAY autolearn=no version=3.3.2 X-HELO: userp1040.oracle.com Received: from userp1040.oracle.com (HELO userp1040.oracle.com) (156.151.31.81) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-SHA encrypted) ESMTPS; Fri, 26 Sep 2014 09:43:43 +0000 Received: from ucsinet22.oracle.com (ucsinet22.oracle.com [156.151.31.94]) by userp1040.oracle.com (Sentrion-MTA-4.3.2/Sentrion-MTA-4.3.2) with ESMTP id s8Q9he3P025533 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Fri, 26 Sep 2014 09:43:41 GMT Received: from userz7021.oracle.com (userz7021.oracle.com [156.151.31.85]) by ucsinet22.oracle.com (8.14.5+Sun/8.14.5) with ESMTP id s8Q9heLV011753 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=FAIL) for ; Fri, 26 Sep 2014 09:43:40 GMT Received: from abhmp0014.oracle.com (abhmp0014.oracle.com [141.146.116.20]) by userz7021.oracle.com (8.14.4+Sun/8.14.4) with ESMTP id s8Q9hdW6004596 for ; Fri, 26 Sep 2014 09:43:39 GMT Received: from localhost.localdomain (/10.175.173.100) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Fri, 26 Sep 2014 02:43:39 -0700 From: "Jose E. Marchesi" To: gdb-patches@sourceware.org Subject: [PATCH 6/9] Support for DTrace USDT probes in x86_64 targets. Date: Fri, 26 Sep 2014 09:43:00 -0000 Message-Id: <1411724905-31234-7-git-send-email-jose.marchesi@oracle.com> In-Reply-To: <1411724905-31234-1-git-send-email-jose.marchesi@oracle.com> References: <1411724905-31234-1-git-send-email-jose.marchesi@oracle.com> X-IsSubscribed: yes X-SW-Source: 2014-09/txt/msg00773.txt.bz2 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. gdb: 2014-09-26 Jose E. Marchesi * amd64-linux-tdep.h: Prototypes for `amd64_dtrace_probe_argument', `amd64_dtrace_enable_probe', `amd64_dtrace_disable_probe' and `gdbarch_dtrace_probe_is_enabled'. * amd64-linux-tdep.c (amd64_dtrace_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'. --- gdb/ChangeLog | 14 +++++ gdb/amd64-linux-tdep.c | 150 ++++++++++++++++++++++++++++++++++++++++++++++++ gdb/amd64-linux-tdep.h | 11 ++++ 3 files changed, 175 insertions(+) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index eac03e7..a32d303 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,5 +1,19 @@ 2014-09-26 Jose E. Marchesi + * amd64-linux-tdep.h: Prototypes for + `amd64_dtrace_probe_argument', `amd64_dtrace_enable_probe', + `amd64_dtrace_disable_probe' and `gdbarch_dtrace_probe_is_enabled'. + + * amd64-linux-tdep.c (amd64_dtrace_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'. + +2014-09-26 Jose E. Marchesi + * breakpoint.c (BREAK_ARGS_HELP): help string updated to mention the -probe-dtrace new vpossible value for PROBE_MODIFIER. diff --git a/gdb/amd64-linux-tdep.c b/gdb/amd64-linux-tdep.c index 850ca20..273f5c4 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" @@ -1609,6 +1611,148 @@ amd64_linux_core_read_description (struct gdbarch *gdbarch, } } +/* Implementation of `gdbarch_dtrace_probe_is_enabled', as defined in + gdbarch.h. */ + +int +amd64_dtrace_probe_is_enabled (struct gdbarch *gdbarch, CORE_ADDR addr) +{ + /* The instruction sequence used in x86_64 machines for a disabled + is-enabled probe is: + + xor %rax, %rax => 48 33 C0 + ADDR: nop => 90 + nop => 90 + + or + + xor %rax, %rax => 48 33 C0 + ADDR: ret => c3 + nop => 90 + + This function returns 1 if the instructions at ADDR do _not_ + follow any of these patterns. + + Note that ADDR is offset 3 bytes from the beginning of these + sequences. */ + + gdb_byte buf[5]; + read_memory (addr - 3, buf, 5); + + return !((buf[0] == 0x48) && (buf[1] == 0x33) && (buf[2] == 0xc0) /* xor */ + && ((buf[3] == 0x90) || (buf[3] == 0xc3)) /* nop | ret */ + && (buf[4] == 0x90)); /* nop */ +} + +/* Implementation of `gdbarch_dtrace_enable_probe', as defined in + gdbarch.h. */ + +void +amd64_dtrace_enable_probe (struct gdbarch *gdbarch, CORE_ADDR addr) +{ + /* We use the following instruction sequence for enabling an + is-enabled probe: + + mov $0x1, %eax => b8 01 00 00 00 + + Note also that ADDR is offset 3 bytes from the beginning of the + sequence. */ + + gdb_byte buf[5]; + + buf[0] = 0xb8; buf[1] = 0x01; buf[2] = 0x00; buf[3] = 0x00; buf[4] = 0x00; + write_memory (addr - 3, buf, 5); +} + +/* Implementation of `gdbarch_dtrace_disable_probe', as defined in + gdbarch.h. */ + +void +amd64_dtrace_disable_probe (struct gdbarch *gdbarch, CORE_ADDR addr) +{ + /* We use the following instruction sequence for disabling an + is-enabled probe: + + xor %rax, %rax; nop; nop => 48 33 C0 90 90 + + Note that ADDR is offset 3 bytes from the beginning of the + sequence. */ + + gdb_byte buf[5]; + + buf[0] = 0x48; buf[1] = 0x33; buf[2] = 0xc0; buf[3] = 0x90; buf[4] = 0x90; + write_memory (addr - 3, buf, 5); +} + +/* Implementation of `gdbarch_dtrace_parse_special_token', as defined in + gdbarch.h. */ + +void +amd64_dtrace_probe_argument (struct gdbarch *gdbarch, + struct parser_state *pstate, + int narg) +{ + static 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. */ + }; + + 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) + { + 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) { @@ -1872,6 +2016,12 @@ 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_probe_argument (gdbarch, amd64_dtrace_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 diff --git a/gdb/amd64-linux-tdep.h b/gdb/amd64-linux-tdep.h index 25563b8..b28dc50 100644 --- a/gdb/amd64-linux-tdep.h +++ b/gdb/amd64-linux-tdep.h @@ -594,4 +594,15 @@ enum amd64_x32_syscall { amd64_x32_sys_getsockopt = (amd64_x32_syscall_bit + 542), }; +/* DTrace related functions. */ + +extern void amd64_dtrace_probe_argument (struct gdbarch *gdbarch, + struct parser_state *pstate, + int narg); + +extern int amd64_dtrace_probe_is_enabled (struct gdbarch *gdbarch, CORE_ADDR addr); + +extern void amd64_dtrace_enable_probe (struct gdbarch *gdbarch, CORE_ADDR addr); +extern void amd64_dtrace_disable_probe (struct gdbarch *gdbarch, CORE_ADDR addr); + #endif /* amd64-linux-tdep.h */ -- 1.7.10.4