From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 22878 invoked by alias); 3 Nov 2011 21:30:48 -0000 Received: (qmail 22861 invoked by uid 22791); 3 Nov 2011 21:30:43 -0000 X-SWARE-Spam-Status: No, hits=-5.7 required=5.0 tests=AWL,BAYES_50,RCVD_IN_DNSWL_HI,RP_MATCHES_RCVD,SPF_HELO_PASS,TW_CP,TW_QX,TW_XS X-Spam-Check-By: sourceware.org Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Thu, 03 Nov 2011 21:30:20 +0000 Received: from int-mx02.intmail.prod.int.phx2.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id pA3LUGWo024714 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Thu, 3 Nov 2011 17:30:16 -0400 Received: from host1.jankratochvil.net (ovpn-116-23.ams2.redhat.com [10.36.116.23]) by int-mx02.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id pA3LUDQF029833 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Thu, 3 Nov 2011 17:30:15 -0400 Received: from host1.jankratochvil.net (localhost [127.0.0.1]) by host1.jankratochvil.net (8.14.4/8.14.4) with ESMTP id pA3LUCSJ031031; Thu, 3 Nov 2011 22:30:12 +0100 Received: (from jkratoch@localhost) by host1.jankratochvil.net (8.14.4/8.14.4/Submit) id pA3LUBho031030; Thu, 3 Nov 2011 22:30:11 +0100 Date: Thu, 03 Nov 2011 21:30:00 -0000 From: Jan Kratochvil To: Pedro Alves Cc: gdb-patches@sourceware.org, Paul Pluzhnikov Subject: [patch] Implement qXfer:libraries-svr4 for Linux/gdbserver #4 Message-ID: <20111103213010.GA2480@host1.jankratochvil.net> References: <20111003215530.GC20272@host1.jankratochvil.net> <201110062009.24796.pedro@codesourcery.com> <20111021094258.GA23101@host1.jankratochvil.net> <201110211205.06852.pedro@codesourcery.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201110211205.06852.pedro@codesourcery.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-IsSubscribed: yes 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 X-SW-Source: 2011-11/txt/msg00103.txt.bz2 On Fri, 21 Oct 2011 13:05:06 +0200, Pedro Alves wrote: > The correct solutions are: > > - Report the library list with , _and_ make gdb use solib-target.c. > What minimal extensions would solib-target.c need so that > we could make that work, without hardcoding "svr4" semantics? E.g., > is defined to _not_ return an element for the main executable. > Would we need an extension (a new element, say?) for that? Or is the > qOffsets mechanism sufficient for relocating the main executable? The main executable is relocated (for PIE) via AUXV (AT_ENTRY). But the "main-lm" attribute is needed for libthread_db access as `struct link_map *', it needs to be read out some way from the target link_map list. Thanks for the detailed description what I in fact thought about before as "solib-svr4.c split". I tried to, I do not think it would be too complicated, but I haven't found enough justification for the work when (a) you accept the solib-svr4.c specific protocol and (b) it does bring neither more functionality (c) nor protocol efficiency (as you analysed below). I understand it would be a nice code + protocol cleanup, just I have too many other serious Bugs to do to find the energy for such solib-svr4.c rework. > - Still us solib-svr4.c, but then don't abuse , but instead > add a new packet and target object to accelerate getting at the link map. > TARGET_OBJECT_SVR4_LIBRARIES or TARGET_OBJECT_SVR4_LINKMAP or something along > those lines. I used TARGET_OBJECT_LIBRARIES_SVR4 for it, it has merged link_map inside. The separate link_map XML content would be nice for the solib-target.c reuse as you designed above, I do not think it matters when a special protocol for solib-svr4.c is there by this patch anyway. > TARGET_OBJECT_SVR4_LIBRARIES -> qXfer:read:svr4libraries > TARGET_OBJECT_SVR4_LINKMAP -> qXfer:read:svr4linkmap I just chose single: TARGET_OBJECT_LIBRARIES_SVR4 -> qXfer:libraries-svr4:read If you have some reasons for the split and/or differently named objects I have no problem updating the patch. No regressions on {x86_64,x86_64-m32,i686}-fedora16pre-linux-gnu and with gdbserver. The patch uses the gdb/ change without the gdb/gdbserver/ change as in: [patch] gdbserver and its #FIXED version="1.0" http://sourceware.org/ml/gdb-patches/2011-11/msg00099.html Thanks, Jan gdb/ 2011-11-03 Paul Pluzhnikov Jan Kratochvil * Makefile.in (XMLFILES): Add library-list-svr4.dtd. * features/library-list-svr4.dtd: New file. * remote.c (PACKET_qXfer_libraries_svr4): New. (remote_protocol_features): new entry for PACKET_qXfer_libraries_svr4. (remote_xfer_partial): Handle TARGET_OBJECT_LIBRARIES_SVR4. * solib-svr4.c (struct svr4_library_list): New. [HAVE_LIBEXPAT]: Include xml-support.h. [HAVE_LIBEXPAT] (svr4_library_list_start_library) [HAVE_LIBEXPAT] (svr4_library_list_start_list, svr4_library_attributes) [HAVE_LIBEXPAT] (svr4_library_list_children) [HAVE_LIBEXPAT] (svr4_library_list_attributes) [HAVE_LIBEXPAT] (svr4_library_list_elements, svr4_parse_libraries) [HAVE_LIBEXPAT] (svr4_current_sos_via_xfer_libraries) [!HAVE_LIBEXPAT] (svr4_current_sos_via_xfer_libraries): New. (svr4_read_so_list): Extend the corruption message by addresses. (svr4_current_sos): New variable library_list, call svr4_current_sos_via_xfer_libraries. * target.h (enum target_object): New TARGET_OBJECT_LIBRARIES_SVR4. gdb/gdbserver/ 2011-10-03 Paul Pluzhnikov Jan Kratochvil * linux-low.c (get_phdr_phnum_from_proc_auxv, get_dynamic, get_r_debug) (read_one_ptr, struct link_map_offsets, linux_qxfer_libraries_svr4): New. (struct linux_target_ops): Install linux_qxfer_libraries_svr4. * linux-low.h (struct process_info_private): New member r_debug. * server.c (handle_qxfer_libraries): Call the_target->qxfer_libraries_svr4. (handle_qxfer_libraries_svr4): New function. (qxfer_packets): New entry "libraries-svr4". (handle_query): Check QXFER_LIBRARIES_SVR4 and report libraries-svr4. * target.h (struct target_ops): New member qxfer_libraries_svr4. * remote.c (remote_xfer_partial): Call add_packet_config_cmd for PACKET_qXfer_libraries_svr4. gdb/doc/ 2011-11-03 Jan Kratochvil * gdb.texinfo (Requirements, Remote Protocol): Reference also `Library List Format for SVR4 Targets'. (General Query Packets): New item qXfer:libraries-svr4:read. (Library List Format for SVR4 Targets): New node. gdb/testsuite/ 2011-10-03 Jan Kratochvil * gdb.base/solib-corrupted.exp: Suppress test on is_remote target. (corrupted list): Adjust the expectation. --- a/gdb/Makefile.in +++ b/gdb/Makefile.in @@ -495,7 +495,8 @@ RUNTESTFLAGS= # XML files to build in to GDB. XMLFILES = $(srcdir)/features/gdb-target.dtd $(srcdir)/features/xinclude.dtd \ - $(srcdir)/features/library-list.dtd $(srcdir)/features/osdata.dtd \ + $(srcdir)/features/library-list.dtd \ + $(srcdir)/features/library-list-svr4.dtd $(srcdir)/features/osdata.dtd \ $(srcdir)/features/threads.dtd $(srcdir)/features/traceframe-info.dtd # This is ser-unix.o for any system which supports a v7/BSD/SYSV/POSIX --- a/gdb/doc/gdb.texinfo +++ b/gdb/doc/gdb.texinfo @@ -32216,7 +32216,8 @@ Remote protocol memory maps (@pxref{Memory Map Format}) @item Target descriptions (@pxref{Target Descriptions}) @item -Remote shared library lists (@pxref{Library List Format}) +Remote shared library lists (@xref{Library List Format}, +or alternatively @pxref{Library List Format for SVR4 Targets}) @item MS-Windows shared libraries (@pxref{Shared Libraries}) @item @@ -33050,6 +33051,7 @@ Show the current setting of the target wait timeout. * Examples:: * File-I/O Remote Protocol Extension:: * Library List Format:: +* Library List Format for SVR4 Targets:: * Memory Map Format:: * Thread List Format:: * Traceframe Info Format:: @@ -34751,6 +34753,10 @@ The remote stub understands the @samp{qXfer:features:read} packet The remote stub understands the @samp{qXfer:libraries:read} packet (@pxref{qXfer library list read}). +@item qXfer:libraries-svr4:read +The remote stub understands the @samp{qXfer:libraries-svr4:read} packet +(@pxref{qXfer svr4 library list read}). + @item qXfer:memory-map:read The remote stub understands the @samp{qXfer:memory-map:read} packet (@pxref{qXfer memory map read}). @@ -34988,6 +34994,18 @@ the operating system manages the list of loaded libraries. This packet is not probed by default; the remote stub must request it, by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). +@item qXfer:libraries-svr4:read:@var{annex}:@var{offset},@var{length} +@anchor{qXfer svr4 library list read} +Access the target's list of loaded libraries when the target is an SVR4 +platform. @xref{Library List Format for SVR4 Targets}. The annex part +of the generic @samp{qXfer} packet must be empty (@pxref{qXfer read}). + +This packet is optional for better performance on SVR4 targets. +@value{GDBN} uses memory read packets to read the SVR4 library list otherwise. + +This packet is not probed by default; the remote stub must request it, +by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). + @item qXfer:memory-map:read::@var{offset},@var{length} @anchor{qXfer memory map read} Access the target's @dfn{memory-map}. @xref{Memory Map Format}. The @@ -37251,6 +37269,68 @@ In addition, segments and section descriptors cannot be mixed within a single library element, and you must supply at least one segment or section for each library. +@node Library List Format for SVR4 Targets +@section Library List Format for SVR4 Targets +@cindex library list format, remote protocol + +On SVR4 platforms @value{GDBN} can use the symbol table of a dynamic loader +(e.g.@: @file{ld.so}) and normal memory operations to maintain a list of +shared libraries. Still a special library list provided by this packet is +more efficient for the @value{GDBN} remote protocol. + +The @samp{qXfer:libraries-svr4:read} packet returns an XML document which lists +loaded libraries and their SVR4 linker parameters. For each library on SVR4 +target, the following parameters are reported: + +@itemize @minus +@item +@code{name}, the absolute file name from the @code{l_name} field of +@code{struct link_map}. +@item +@code{lm} with address of @code{struct link_map} used for TLS +(Thread Local Storage) access. +@item +@code{l_addr}, the displacement as read from the field @code{l_addr} of +@code{struct link_map}. For prelinked libraries this is not an absolute +memory address. It is a displacement of absolute memory address against +address the file was prelinked to during the library load. +@item +@code{l_ld}, which is memory address of the @code{PT_DYNAMIC} segment +@end itemize + +Additionally the single @code{main-lm} attribute specifies address of +@code{struct link_map} used for the main executable. This parameter is used +for TLS access and its presence is optional. + +@value{GDBN} must be linked with the Expat library to support XML +SVR4 library lists. @xref{Expat}. + +A simple memory map, with two loaded libraries (which do not use prelink), +looks like this: + +@smallexample + + + + +@end smallexample + +The format of an SVR4 library list is described by this DTD: + +@smallexample + + + + + + + + + +@end smallexample + @node Memory Map Format @section Memory Map Format @cindex memory map format --- /dev/null +++ b/gdb/features/library-list-svr4.dtd @@ -0,0 +1,16 @@ + + + + + + + + + + + + --- a/gdb/gdbserver/linux-low.c +++ b/gdb/gdbserver/linux-low.c @@ -4953,6 +4953,377 @@ linux_emit_ops (void) return NULL; } +/* Extract &phdr and num_phdr in the inferior. Return 0 on success. */ + +static int +get_phdr_phnum_from_proc_auxv (const int pid, const int is_elf64, + CORE_ADDR *phdr_memaddr, int *num_phdr) +{ + char filename[PATH_MAX]; + int fd; + const int auxv_size = is_elf64 + ? sizeof (Elf64_auxv_t) : sizeof (Elf32_auxv_t); + char buf[sizeof (Elf64_auxv_t)]; /* The larger of the two. */ + + xsnprintf (filename, sizeof filename, "/proc/%d/auxv", pid); + + fd = open (filename, O_RDONLY); + if (fd < 0) + return 1; + + *phdr_memaddr = 0; + *num_phdr = 0; + while (read (fd, buf, auxv_size) == auxv_size + && (*phdr_memaddr == 0 || *num_phdr == 0)) + { + if (is_elf64) + { + Elf64_auxv_t *const aux = (Elf64_auxv_t *) buf; + + switch (aux->a_type) + { + case AT_PHDR: + *phdr_memaddr = aux->a_un.a_val; + break; + case AT_PHNUM: + *num_phdr = aux->a_un.a_val; + break; + } + } + else + { + Elf32_auxv_t *const aux = (Elf32_auxv_t *) buf; + + switch (aux->a_type) + { + case AT_PHDR: + *phdr_memaddr = aux->a_un.a_val; + break; + case AT_PHNUM: + *num_phdr = aux->a_un.a_val; + break; + } + } + } + + close (fd); + + if (*phdr_memaddr == 0 || *num_phdr == 0) + { + warning ("Unexpected missing AT_PHDR and/or AT_PHNUM: " + "phdr_memaddr = %ld, phdr_num = %d", + (long) *phdr_memaddr, *num_phdr); + return 2; + } + + return 0; +} + +/* Return &_DYNAMIC (via PT_DYNAMIC) in the inferior, or 0 if not present. */ + +static CORE_ADDR +get_dynamic (const int pid, const int is_elf64) +{ + CORE_ADDR phdr_memaddr, relocation; + int num_phdr, i; + unsigned char *phdr_buf; + const int phdr_size = is_elf64 ? sizeof (Elf64_Phdr) : sizeof (Elf32_Phdr); + + if (get_phdr_phnum_from_proc_auxv (pid, is_elf64, &phdr_memaddr, &num_phdr)) + return 0; + + gdb_assert (num_phdr < 100); /* Basic sanity check. */ + phdr_buf = alloca (num_phdr * phdr_size); + + if (linux_read_memory (phdr_memaddr, phdr_buf, num_phdr * phdr_size)) + return 0; + + /* Compute relocation: it is expected to be 0 for "regular" executables, + non-zero for PIE ones. */ + relocation = -1; + for (i = 0; relocation == -1 && i < num_phdr; i++) + if (is_elf64) + { + Elf64_Phdr *const p = (Elf64_Phdr *) (phdr_buf + i * phdr_size); + + if (p->p_type == PT_PHDR) + relocation = phdr_memaddr - p->p_vaddr; + } + else + { + Elf32_Phdr *const p = (Elf32_Phdr *) (phdr_buf + i * phdr_size); + + if (p->p_type == PT_PHDR) + relocation = phdr_memaddr - p->p_vaddr; + } + + if (relocation == -1) + { + warning ("Unexpected missing PT_PHDR"); + return 0; + } + + for (i = 0; i < num_phdr; i++) + { + if (is_elf64) + { + Elf64_Phdr *const p = (Elf64_Phdr *) (phdr_buf + i * phdr_size); + + if (p->p_type == PT_DYNAMIC) + return p->p_vaddr + relocation; + } + else + { + Elf32_Phdr *const p = (Elf32_Phdr *) (phdr_buf + i * phdr_size); + + if (p->p_type == PT_DYNAMIC) + return p->p_vaddr + relocation; + } + } + + return 0; +} + +/* Return &_r_debug in the inferior, or -1 if not present. Return value + can be 0 if the inferior does not yet have the library list initialized. */ + +static CORE_ADDR +get_r_debug (const int pid, const int is_elf64) +{ + CORE_ADDR dynamic_memaddr; + const int dyn_size = is_elf64 ? sizeof (Elf64_Dyn) : sizeof (Elf32_Dyn); + unsigned char buf[sizeof (Elf64_Dyn)]; /* The larger of the two. */ + + dynamic_memaddr = get_dynamic (pid, is_elf64); + if (dynamic_memaddr == 0) + return (CORE_ADDR) -1; + + while (linux_read_memory (dynamic_memaddr, buf, dyn_size) == 0) + { + if (is_elf64) + { + Elf64_Dyn *const dyn = (Elf64_Dyn *) buf; + + if (dyn->d_tag == DT_DEBUG) + return dyn->d_un.d_val; + + if (dyn->d_tag == DT_NULL) + break; + } + else + { + Elf32_Dyn *const dyn = (Elf32_Dyn *) buf; + + if (dyn->d_tag == DT_DEBUG) + return dyn->d_un.d_val; + + if (dyn->d_tag == DT_NULL) + break; + } + + dynamic_memaddr += dyn_size; + } + + return (CORE_ADDR) -1; +} + +/* Read one pointer from MEMADDR in the inferior. */ + +static int +read_one_ptr (CORE_ADDR memaddr, CORE_ADDR *ptr, int ptr_size) +{ + *ptr = 0; + return linux_read_memory (memaddr, (unsigned char *) ptr, ptr_size); +} + +struct link_map_offsets + { + /* Offset and size of r_debug.r_version. */ + int r_version_offset; + + /* Offset and size of r_debug.r_map. */ + int r_map_offset; + + /* Offset to l_addr field in struct link_map. */ + int l_addr_offset; + + /* Offset to l_name field in struct link_map. */ + int l_name_offset; + + /* Offset to l_ld field in struct link_map. */ + int l_ld_offset; + + /* Offset to l_next field in struct link_map. */ + int l_next_offset; + + /* Offset to l_prev field in struct link_map. */ + int l_prev_offset; + }; + +/* Construct qXfer:libraries:read reply. */ + +static int +linux_qxfer_libraries_svr4 (const char *annex, unsigned char *readbuf, + unsigned const char *writebuf, + CORE_ADDR offset, int len) +{ + char *document; + unsigned document_len; + struct process_info_private *const priv = current_process ()->private; + char filename[PATH_MAX]; + int pid, is_elf64; + + static const struct link_map_offsets lmo_32bit_offsets = + { + 0, /* r_version offset. */ + 4, /* r_debug.r_map offset. */ + 0, /* l_addr offset in link_map. */ + 4, /* l_name offset in link_map. */ + 8, /* l_ld offset in link_map. */ + 12, /* l_next offset in link_map. */ + 16 /* l_prev offset in link_map. */ + }; + + static const struct link_map_offsets lmo_64bit_offsets = + { + 0, /* r_version offset. */ + 8, /* r_debug.r_map offset. */ + 0, /* l_addr offset in link_map. */ + 8, /* l_name offset in link_map. */ + 16, /* l_ld offset in link_map. */ + 24, /* l_next offset in link_map. */ + 32 /* l_prev offset in link_map. */ + }; + const struct link_map_offsets *lmo; + + if (writebuf != NULL) + return -2; + if (readbuf == NULL) + return -1; + + pid = lwpid_of (get_thread_lwp (current_inferior)); + xsnprintf (filename, sizeof filename, "/proc/%d/exe", pid); + is_elf64 = elf_64_file_p (filename); + lmo = is_elf64 ? &lmo_64bit_offsets : &lmo_32bit_offsets; + + if (priv->r_debug == 0) + priv->r_debug = get_r_debug (pid, is_elf64); + + if (priv->r_debug == (CORE_ADDR) -1 || priv->r_debug == 0) + { + document = xstrdup ("\n"); + } + else + { + int allocated = 1024; + char *p; + const int ptr_size = is_elf64 ? 8 : 4; + CORE_ADDR lm_addr, lm_prev, l_name, l_addr, l_ld, l_next, l_prev; + int r_version, header_done = 0; + + document = xmalloc (allocated); + strcpy (document, "r_debug + lmo->r_version_offset, + (unsigned char *) &r_version, + sizeof (r_version)) != 0 + || r_version != 1) + { + warning ("unexpected r_debug version %d", r_version); + goto done; + } + + if (read_one_ptr (priv->r_debug + lmo->r_map_offset, + &lm_addr, ptr_size) != 0) + { + warning ("unable to read r_map from 0x%lx", + (long) priv->r_debug + lmo->r_map_offset); + goto done; + } + + lm_prev = 0; + while (read_one_ptr (lm_addr + lmo->l_name_offset, + &l_name, ptr_size) == 0 + && read_one_ptr (lm_addr + lmo->l_addr_offset, + &l_addr, ptr_size) == 0 + && read_one_ptr (lm_addr + lmo->l_ld_offset, + &l_ld, ptr_size) == 0 + && read_one_ptr (lm_addr + lmo->l_prev_offset, + &l_prev, ptr_size) == 0 + && read_one_ptr (lm_addr + lmo->l_next_offset, + &l_next, ptr_size) == 0) + { + unsigned char libname[PATH_MAX]; + + if (lm_prev != l_prev) + { + warning ("Corrupted shared library list: 0x%lx != 0x%lx", + (long) lm_prev, (long) l_prev); + break; + } + + /* Not checking for error because reading may stop before + we've got PATH_MAX worth of characters. */ + libname[0] = '\0'; + linux_read_memory (l_name, libname, sizeof (libname) - 1); + libname[sizeof (libname) - 1] = '\0'; + if (libname[0] != '\0') + { + size_t len = strlen ((char *) libname); + char *name; + + if (!header_done) + { + /* Terminate `", + name, (unsigned long) lm_addr, + (unsigned long) l_addr, (unsigned long) l_ld); + free (name); + } + else if (lm_prev == 0) + { + sprintf (p, " main-lm=\"0x%lx\"", (unsigned long) lm_addr); + p = p + strlen (p); + } + + if (l_next == 0) + break; + + lm_prev = lm_addr; + lm_addr = l_next; + } + done: + strcpy (p, ""); + } + + document_len = strlen (document + offset); + if (len > document_len) + len = document_len; + + memcpy (readbuf, document + offset, len); + xfree (document); + + return len; +} + static struct target_ops linux_target_ops = { linux_create_inferior, linux_attach, @@ -5014,6 +5385,7 @@ static struct target_ops linux_target_ops = { linux_install_fast_tracepoint_jump_pad, linux_emit_ops, linux_supports_disable_randomization, + linux_qxfer_libraries_svr4 }; static void --- a/gdb/gdbserver/linux-low.h +++ b/gdb/gdbserver/linux-low.h @@ -56,6 +56,9 @@ struct process_info_private /* libthread_db-specific additions. Not NULL if this process has loaded thread_db, and it is active. */ struct thread_db *thread_db; + + /* &_r_debug. 0 if not yet determined. -1 if no PT_DYNAMIC in Phdrs. */ + CORE_ADDR r_debug; }; struct lwp_info; --- a/gdb/gdbserver/server.c +++ b/gdb/gdbserver/server.c @@ -942,6 +942,10 @@ handle_qxfer_libraries (const char *annex, if (annex[0] != '\0' || !target_running ()) return -1; + /* Do not confuse this packet with qXfer:libraries-svr4:read. */ + if (the_target->qxfer_libraries_svr4 != NULL) + return 0; + /* Over-estimate the necessary memory. Assume that every character in the library name must be escaped. */ total_len = 64; @@ -992,6 +996,23 @@ handle_qxfer_libraries (const char *annex, return len; } +/* Handle qXfer:libraries-svr4:read. */ + +static int +handle_qxfer_libraries_svr4 (const char *annex, + gdb_byte *readbuf, const gdb_byte *writebuf, + ULONGEST offset, LONGEST len) +{ + if (writebuf != NULL) + return -2; + + if (annex[0] != '\0' || !target_running () + || the_target->qxfer_libraries_svr4 == NULL) + return -1; + + return the_target->qxfer_libraries_svr4 (annex, readbuf, writebuf, offset, len); +} + /* Handle qXfer:osadata:read. */ static int @@ -1216,6 +1237,7 @@ static const struct qxfer qxfer_packets[] = { "fdpic", handle_qxfer_fdpic}, { "features", handle_qxfer_features }, { "libraries", handle_qxfer_libraries }, + { "libraries-svr4", handle_qxfer_libraries_svr4 }, { "osdata", handle_qxfer_osdata }, { "siginfo", handle_qxfer_siginfo }, { "spu", handle_qxfer_spu }, @@ -1536,9 +1558,14 @@ handle_query (char *own_buf, int packet_len, int *new_packet_len_p) sprintf (own_buf, "PacketSize=%x;QPassSignals+", PBUFSIZ - 1); - /* We do not have any hook to indicate whether the target backend - supports qXfer:libraries:read, so always report it. */ - strcat (own_buf, ";qXfer:libraries:read+"); + if (the_target->qxfer_libraries_svr4 != NULL) + strcat (own_buf, ";qXfer:libraries-svr4:read+"); + else + { + /* We do not have any hook to indicate whether the non-SVR4 target + backend supports qXfer:libraries:read, so always report it. */ + strcat (own_buf, ";qXfer:libraries:read+"); + } if (the_target->read_auxv != NULL) strcat (own_buf, ";qXfer:auxv:read+"); --- a/gdb/gdbserver/target.h +++ b/gdb/gdbserver/target.h @@ -380,6 +380,11 @@ struct target_ops /* Returns true if the target supports disabling randomization. */ int (*supports_disable_randomization) (void); + + /* Read solib info on SVR4 platforms. */ + int (*qxfer_libraries_svr4) (const char *annex, unsigned char *readbuf, + unsigned const char *writebuf, + CORE_ADDR offset, int len); }; extern struct target_ops *the_target; --- a/gdb/remote.c +++ b/gdb/remote.c @@ -1239,6 +1239,7 @@ enum { PACKET_qXfer_auxv, PACKET_qXfer_features, PACKET_qXfer_libraries, + PACKET_qXfer_libraries_svr4, PACKET_qXfer_memory_map, PACKET_qXfer_spu_read, PACKET_qXfer_spu_write, @@ -3733,6 +3734,8 @@ static struct protocol_feature remote_protocol_features[] = { PACKET_qXfer_features }, { "qXfer:libraries:read", PACKET_DISABLE, remote_supported_packet, PACKET_qXfer_libraries }, + { "qXfer:libraries-svr4:read", PACKET_DISABLE, remote_supported_packet, + PACKET_qXfer_libraries_svr4 }, { "qXfer:memory-map:read", PACKET_DISABLE, remote_supported_packet, PACKET_qXfer_memory_map }, { "qXfer:spu:read", PACKET_DISABLE, remote_supported_packet, @@ -8331,6 +8334,11 @@ remote_xfer_partial (struct target_ops *ops, enum target_object object, (ops, "libraries", annex, readbuf, offset, len, &remote_protocol_packets[PACKET_qXfer_libraries]); + case TARGET_OBJECT_LIBRARIES_SVR4: + return remote_read_qxfer + (ops, "libraries-svr4", annex, readbuf, offset, len, + &remote_protocol_packets[PACKET_qXfer_libraries_svr4]); + case TARGET_OBJECT_MEMORY_MAP: gdb_assert (annex == NULL); return remote_read_qxfer (ops, "memory-map", annex, readbuf, offset, len, @@ -10912,6 +10920,9 @@ Show the maximum size of the address (in bits) in a memory packet."), NULL, add_packet_config_cmd (&remote_protocol_packets[PACKET_qXfer_libraries], "qXfer:libraries:read", "library-info", 0); + add_packet_config_cmd (&remote_protocol_packets[PACKET_qXfer_libraries_svr4], + "qXfer:libraries-svr4:read", "library-info-svr4", 0); + add_packet_config_cmd (&remote_protocol_packets[PACKET_qXfer_memory_map], "qXfer:memory-map:read", "memory-map", 0); --- a/gdb/solib-svr4.c +++ b/gdb/solib-svr4.c @@ -949,6 +949,110 @@ open_symbol_file_object (void *from_ttyp) return 1; } +/* Data exchange structure for the XML parser as returned by + svr4_current_sos_via_xfer_libraries. */ + +struct svr4_library_list +{ + struct so_list *head, **tailp; + CORE_ADDR main_lm; +}; + +#ifdef HAVE_LIBEXPAT + +#include "xml-support.h" + +/* Handle the start of a element. Note: new elements are added + at the tail of the list, keeping the list in order. */ + +static void +library_list_start_library (struct gdb_xml_parser *parser, + const struct gdb_xml_element *element, + void *user_data, VEC(gdb_xml_value_s) *attributes) +{ + struct svr4_library_list *list = user_data; + const char *name = xml_find_attribute (attributes, "name")->value; + ULONGEST *lmp = xml_find_attribute (attributes, "lm")->value; + ULONGEST *l_addrp = xml_find_attribute (attributes, "l_addr")->value; + ULONGEST *l_ldp = xml_find_attribute (attributes, "l_ld")->value; + struct so_list *new_elem; + + new_elem = XZALLOC (struct so_list); + new_elem->lm_info = XZALLOC (struct lm_info); + new_elem->lm_info->lm_addr = *lmp; + new_elem->lm_info->l_addr_inferior = *l_addrp; + new_elem->lm_info->l_ld = *l_ldp; + + strncpy (new_elem->so_name, name, sizeof (new_elem->so_name) - 1); + new_elem->so_name[sizeof (new_elem->so_name) - 1] = 0; + strcpy (new_elem->so_original_name, new_elem->so_name); + + *list->tailp = new_elem; + list->tailp = &new_elem->next; +} + +/* Handle the start of a element. */ + +static void +svr4_library_list_start_list (struct gdb_xml_parser *parser, + const struct gdb_xml_element *element, + void *user_data, VEC(gdb_xml_value_s) *attributes) +{ + struct svr4_library_list *list = user_data; + struct gdb_xml_value *version = xml_find_attribute (attributes, "version"); + struct gdb_xml_value *main_lm = xml_find_attribute (attributes, "main-lm"); + + /* #FIXED attribute may be omitted, Expat returns NULL in such case. */ + if (version) + { + const char *string = version->value; + + if (strcmp (string, "1.0") != 0) + gdb_xml_error (parser, + _("SVR4 Library list has unsupported version \"%s\""), + version); + } + + if (main_lm) + list->main_lm = *(ULONGEST *) main_lm->value; +} + +/* The allowed elements and attributes for an XML library list. + The root element is a . */ + +static const struct gdb_xml_attribute svr4_library_attributes[] = +{ + { "name", GDB_XML_AF_NONE, NULL, NULL }, + { "lm", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL }, + { "l_addr", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL }, + { "l_ld", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL }, + { NULL, GDB_XML_AF_NONE, NULL, NULL } +}; + +static const struct gdb_xml_element svr4_library_list_children[] = +{ + { + "library", svr4_library_attributes, NULL, + GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL, + library_list_start_library, NULL + }, + { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL } +}; + +static const struct gdb_xml_attribute svr4_library_list_attributes[] = +{ + { "version", GDB_XML_AF_OPTIONAL, NULL, NULL }, + { "main-lm", GDB_XML_AF_OPTIONAL, gdb_xml_parse_attr_ulongest, NULL }, + { NULL, GDB_XML_AF_NONE, NULL, NULL } +}; + +static const struct gdb_xml_element svr4_library_list_elements[] = +{ + { "library-list-svr4", svr4_library_list_attributes, svr4_library_list_children, + GDB_XML_EF_NONE, svr4_library_list_start_list, NULL }, + { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL } +}; + /* Implementation for target_so_ops.free_so. */ static void @@ -973,6 +1077,69 @@ svr4_free_library_list (void *p_list) } } +/* Parse qXfer:libraries:read packet into *SO_LIST_RETURN. Return 1 if + + Return 0 if packet not supported, *SO_LIST_RETURN is not modified in such + case. Return 1 if *SO_LIST_RETURN contains the library list, it may be + empty, caller is responsible for freeing all its entries. */ + +static int +svr4_parse_libraries (const char *document, struct svr4_library_list *list) +{ + struct cleanup *back_to = make_cleanup (svr4_free_library_list, + &list->head); + + memset (list, 0, sizeof (*list)); + list->tailp = &list->head; + if (gdb_xml_parse_quick (_("target library list"), "library-list.dtd", + svr4_library_list_elements, document, list) == 0) + { + /* Parsed successfully, keep the result. */ + discard_cleanups (back_to); + return 1; + } + + do_cleanups (back_to); + return 0; +} + +/* Attempt to get so_list from target via qXfer:libraries:read packet. + + Return 0 if packet not supported, *SO_LIST_RETURN is not modified in such + case. Return 1 if *SO_LIST_RETURN contains the library list, it may be + empty, caller is responsible for freeing all its entries. */ + +static int +svr4_current_sos_via_xfer_libraries (struct svr4_library_list *list) +{ + char *svr4_library_document; + int result; + struct cleanup *back_to; + + /* Fetch the list of shared libraries. */ + svr4_library_document = target_read_stralloc (¤t_target, + TARGET_OBJECT_LIBRARIES_SVR4, + NULL); + if (svr4_library_document == NULL) + return 0; + + back_to = make_cleanup (xfree, svr4_library_document); + result = svr4_parse_libraries (svr4_library_document, list); + do_cleanups (back_to); + + return result; +} + +#else + +static int +svr4_current_sos_via_xfer_libraries (struct svr4_library_list *list) +{ + return 0; +} + +#endif + /* If no shared library information is available from the dynamic linker, build a fallback list from other sources. */ @@ -1032,7 +1199,9 @@ svr4_read_so_list (CORE_ADDR lm, struct so_list ***link_ptr_ptr, if (new->lm_info->l_prev != prev_lm) { - warning (_("Corrupted shared library list")); + warning (_("Corrupted shared library list: %s != %s"), + paddress (target_gdbarch, prev_lm), + paddress (target_gdbarch, new->lm_info->l_prev)); do_cleanups (old_chain); break; } @@ -1093,6 +1262,18 @@ svr4_current_sos (void) struct svr4_info *info; struct cleanup *back_to; int ignore_first; + struct svr4_library_list library_list; + + if (svr4_current_sos_via_xfer_libraries (&library_list)) + { + if (library_list.main_lm) + { + info = get_svr4_info (); + info->main_lm_addr = library_list.main_lm; + } + + return library_list.head ? library_list.head : svr4_default_sos (); + } info = get_svr4_info (); --- a/gdb/target.h +++ b/gdb/target.h @@ -255,6 +255,8 @@ enum target_object TARGET_OBJECT_AVAILABLE_FEATURES, /* Currently loaded libraries, in XML format. */ TARGET_OBJECT_LIBRARIES, + /* Currently loaded libraries specific for SVR4 systems, in XML format. */ + TARGET_OBJECT_LIBRARIES_SVR4, /* Get OS specific data. The ANNEX specifies the type (running processes, etc.). The data being transfered is expected to follow the DTD specified in features/osdata.dtd. */ --- a/gdb/testsuite/gdb.base/solib-corrupted.exp +++ b/gdb/testsuite/gdb.base/solib-corrupted.exp @@ -17,6 +17,12 @@ if {[skip_shlib_tests]} { return 0 } +if {[is_remote target]} { + # gdbserver prints the warning message but expect is parsing only the GDB + # output, not the gdbserver output. + return 0 +} + set testfile "solib-corrupted" set srcfile start.c @@ -47,4 +53,4 @@ gdb_test_multiple "p/x _r_debug->r_map->l_next = _r_debug->r_map" $test { pass $test } } -gdb_test "info sharedlibrary" "warning: Corrupted shared library list\r\n.*" "corrupted list" +gdb_test "info sharedlibrary" "warning: Corrupted shared library list: .*" "corrupted list"