From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 87120 invoked by alias); 4 Dec 2015 02:27:01 -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 87076 invoked by uid 89); 4 Dec 2015 02:27:01 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.2 required=5.0 tests=AWL,BAYES_50,SPF_HELO_PASS,T_RP_MATCHES_RCVD autolearn=ham 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; Fri, 04 Dec 2015 02:26:53 +0000 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) by mx1.redhat.com (Postfix) with ESMTPS id 848FA915A3; Fri, 4 Dec 2015 02:26:52 +0000 (UTC) Received: from moya.redhat.com (ovpn-113-175.phx2.redhat.com [10.3.113.175]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id tB42Qn4X016719; Thu, 3 Dec 2015 21:26:51 -0500 From: Josh Stone To: gdb-patches@sourceware.org Cc: philippe.waroquiers@skynet.be, sergiodj@redhat.com, palves@redhat.com, eliz@gnu.org, xdje42@gmail.com, Josh Stone Subject: [PATCH v3 2/2] Implement 'catch syscall' for gdbserver Date: Fri, 04 Dec 2015 02:27:00 -0000 Message-Id: <1449196006-13759-2-git-send-email-jistone@redhat.com> In-Reply-To: <1449196006-13759-1-git-send-email-jistone@redhat.com> References: <1448506425-24691-1-git-send-email-jistone@redhat.com> <1449196006-13759-1-git-send-email-jistone@redhat.com> X-SW-Source: 2015-12/txt/msg00062.txt.bz2 This adds a new QCatchSyscalls packet to enable 'catch syscall', and new stop reasons "syscall_entry" and "syscall_return" for those events. It is currently only supported on Linux x86 and x86_64. gdb/ChangeLog: 2015-12-03 Josh Stone Philippe Waroquiers * NEWS (Changes since GDB 7.10): Mention QCatchSyscalls and new GDBserver support for catch syscall. * remote.c (PACKET_QCatchSyscalls): New enum. (remote_set_syscall_catchpoint): New function. (remote_protocol_features): New element for QCatchSyscalls. (remote_parse_stop_reply): Parse syscall_entry/return stops. (init_remote_ops): Install remote_set_syscall_catchpoint. (_initialize_remote): Config QCatchSyscalls. * linux-nat.h (struct lwp_info) : Comment typo. gdb/doc/ChangeLog: 2015-12-03 Josh Stone Philippe Waroquiers * gdb.texinfo (Remote Configuration): List the QCatchSyscalls packet. (Stop Reply Packets): List the syscall entry and return stop reasons. (General Query Packets): Describe QCatchSyscalls, and add it to the table and detailed list of stub features. gdb/gdbserver/ChangeLog: 2015-12-03 Josh Stone Philippe Waroquiers * inferiors.h: Include "gdb_vecs.h". (struct process_info): Add syscalls_to_catch. * inferiors.c (remove_process): Free syscalls_to_catch. * remote-utils.c (prepare_resume_reply): Report syscall_entry and syscall_return stops. * server.h (UNKNOWN_SYSCALL, ANY_SYSCALL): Define. * server.c (handle_general_set): Handle QCatchSyscalls. (handle_query): Report support for QCatchSyscalls. * target.h (struct target_ops): Add supports_catch_syscall. (target_supports_catch_syscall): New macro. * linux-low.h (struct linux_target_ops): Add get_syscall_trapinfo. (struct lwp_info): Add syscall_state. * linux-low.c (handle_extended_wait): Mark syscall_state as an entry. (get_syscall_trapinfo): New function, proxy to the_low_target. (linux_low_ptrace_options): Enable PTRACE_O_TRACESYSGOOD. (linux_low_filter_event): Toggle syscall_state entry/return for syscall traps, and set it ignored for all others. (gdb_catching_syscalls_p): New function. (gdb_catch_this_syscall_p): New function. (linux_wait_1): Handle SYSCALL_SIGTRAP. (linux_resume_one_lwp_throw): Add PTRACE_SYSCALL possibility. (linux_supports_catch_syscall): New function. (linux_target_ops): Install it. * linux-x86-low.c (x86_get_syscall_trapinfo): New function. (the_low_target): Install it. * nto-low.c (nto_target_ops): Install NULL supports_catch_syscall. * spu-low.c (spu_target_ops): Likewise. * win32-low.c (win32_target_ops): Likewise. gdb/testsuite/ChangeLog: 2015-12-03 Josh Stone Philippe Waroquiers * gdb.base/catch-syscall.exp: Enable testing for x86 and x86_64 linux remote targets. (do_syscall_tests): Only test mid-vfork on local or extended-remote. --- gdb/NEWS | 10 +++ gdb/doc/gdb.texinfo | 56 +++++++++++++ gdb/gdbserver/inferiors.c | 1 + gdb/gdbserver/inferiors.h | 5 ++ gdb/gdbserver/linux-low.c | 140 ++++++++++++++++++++++++++++++- gdb/gdbserver/linux-low.h | 13 +++ gdb/gdbserver/linux-x86-low.c | 26 ++++++ gdb/gdbserver/nto-low.c | 1 + gdb/gdbserver/remote-utils.c | 12 +++ gdb/gdbserver/server.c | 49 +++++++++++ gdb/gdbserver/server.h | 6 ++ gdb/gdbserver/spu-low.c | 1 + gdb/gdbserver/target.h | 8 ++ gdb/gdbserver/win32-low.c | 1 + gdb/linux-nat.h | 2 +- gdb/remote.c | 116 +++++++++++++++++++++++++ gdb/testsuite/gdb.base/catch-syscall.exp | 15 +++- 17 files changed, 456 insertions(+), 6 deletions(-) diff --git a/gdb/NEWS b/gdb/NEWS index a222dfb491f0..1917523d8249 100644 --- a/gdb/NEWS +++ b/gdb/NEWS @@ -112,6 +112,11 @@ N stop reply threads are stopped). The remote stub reports support for this stop reply to GDB's qSupported query. +QCatchSyscalls:1 [;SYSNO]... +QCatchSyscalls:0 + Enable ("QCatchSyscalls:1") or disable ("QCatchSyscalls:0") + catching syscalls from the inferior process. + * Extended-remote exec events ** GDB now has support for exec events on extended-remote Linux targets. @@ -127,6 +132,11 @@ show remote exec-event-feature-packet The reply to qXfer:threads:read may now include a name attribute for each thread. +* New features in the GDB remote stub, GDBserver + + ** GDBserver now supports catch syscall. Currently enabled + on x86/x86_64 GNU/Linux targets. + *** Changes in GDB 7.10 * Support for process record-replay and reverse debugging on aarch64*-linux* diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo index b82f3c67a8a6..99865d9cef98 100644 --- a/gdb/doc/gdb.texinfo +++ b/gdb/doc/gdb.texinfo @@ -20135,6 +20135,10 @@ are: @tab @code{qSupported} @tab Remote communications parameters +@item @code{catch-syscalls} +@tab @code{QCatchSyscalls} +@tab @code{catch syscall} + @item @code{pass-signals} @tab @code{QPassSignals} @tab @code{handle @var{signal}} @@ -35458,6 +35462,11 @@ The currently defined stop reasons are: The packet indicates a watchpoint hit, and @var{r} is the data address, in hex. +@item syscall_entry +@itemx syscall_return +The packet indicates a syscall entry or return, and @var{r} is the +syscall number, in hex. + @cindex shared library events, remote reply @item library The packet indicates that the loaded libraries have changed. @@ -35950,6 +35959,44 @@ by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). Use of this packet is controlled by the @code{set non-stop} command; @pxref{Non-Stop Mode}. +@item QCatchSyscalls:1 @r{[};@var{sysno}@r{]}@dots{} +@itemx QCatchSyscalls:0 +@cindex catch syscalls from inferior, remote request +@cindex @samp{QCatchSyscalls} packet +@anchor{QCatchSyscalls} +Enable (@samp{QCatchSyscalls:1}) or disable (@samp{QCatchSyscalls:0}) +catching syscalls from the inferior process. + +For @samp{QCatchSyscalls:1}, each listed syscall @var{sysno} (encoded +in hex) should be reported to @value{GDBN}. If no syscall @var{sysno} +is listed, every system call should be reported. + +Note that if a syscall not in the list is reported, @value{GDBN} will +still filter the event according to its own list from all corresponding +@code{catch syscall} commands. However, it is more efficient to only +report the requested syscalls. + +Multiple @samp{QCatchSyscalls:1} packets do not combine; any earlier +@samp{QCatchSyscalls:1} list is completely replaced by the new list. + +Reply: +@table @samp +@item OK +The request succeeded. + +@item E @var{nn} +An error occurred. @var{nn} are hex digits. + +@item @w{} +An empty reply indicates that @samp{QCatchSyscalls} is not supported by +the stub. +@end table + +Use of this packet is controlled by the @code{set remote catch-syscalls} +command (@pxref{Remote Configuration, set remote catch-syscalls}). +This packet is not probed by default; the remote stub must request it, +by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}). + @item QPassSignals: @var{signal} @r{[};@var{signal}@r{]}@dots{} @cindex pass signals to inferior, remote request @cindex @samp{QPassSignals} packet @@ -36401,6 +36448,11 @@ These are the currently defined stub features and their properties: @tab @samp{-} @tab Yes +@item @samp{QCatchSyscalls} +@tab No +@tab @samp{-} +@tab Yes + @item @samp{QPassSignals} @tab No @tab @samp{-} @@ -36604,6 +36656,10 @@ packet (@pxref{qXfer fdpic loadmap read}). The remote stub understands the @samp{QNonStop} packet (@pxref{QNonStop}). +@item QCatchSyscalls +The remote stub understands the @samp{QCatchSyscalls} packet +(@pxref{QCatchSyscalls}). + @item QPassSignals The remote stub understands the @samp{QPassSignals} packet (@pxref{QPassSignals}). diff --git a/gdb/gdbserver/inferiors.c b/gdb/gdbserver/inferiors.c index 95f3ad03ab08..1c736b62650a 100644 --- a/gdb/gdbserver/inferiors.c +++ b/gdb/gdbserver/inferiors.c @@ -339,6 +339,7 @@ remove_process (struct process_info *process) free_all_breakpoints (process); gdb_assert (find_thread_process (process) == NULL); remove_inferior (&all_processes, &process->entry); + VEC_free (int, process->syscalls_to_catch); free (process); } diff --git a/gdb/gdbserver/inferiors.h b/gdb/gdbserver/inferiors.h index d7226163c0e8..43fc869f6612 100644 --- a/gdb/gdbserver/inferiors.h +++ b/gdb/gdbserver/inferiors.h @@ -19,6 +19,8 @@ #ifndef INFERIORS_H #define INFERIORS_H +#include "gdb_vecs.h" + /* Generic information for tracking a list of ``inferiors'' - threads, processes, etc. */ struct inferior_list @@ -67,6 +69,9 @@ struct process_info /* The list of installed fast tracepoints. */ struct fast_tracepoint_jump *fast_tracepoint_jumps; + /* The list of syscalls to report, or just ANY_SYSCALL. */ + VEC (int) *syscalls_to_catch; + const struct target_desc *tdesc; /* Private target data. */ diff --git a/gdb/gdbserver/linux-low.c b/gdb/gdbserver/linux-low.c index 5e2dc5857a8d..cceede6fe408 100644 --- a/gdb/gdbserver/linux-low.c +++ b/gdb/gdbserver/linux-low.c @@ -461,6 +461,11 @@ handle_extended_wait (struct lwp_info **orig_event_lwp, int wstat) gdb_assert (event_lwp->waitstatus.kind == TARGET_WAITKIND_IGNORE); + /* All extended events we currently use are mid-syscall. Only + PTRACE_EVENT_STOP is delivered more like a signal-stop, but + you have to be using PTRACE_SEIZE to get that. */ + event_lwp->syscall_state = TARGET_WAITKIND_SYSCALL_ENTRY; + if ((event == PTRACE_EVENT_FORK) || (event == PTRACE_EVENT_VFORK) || (event == PTRACE_EVENT_CLONE)) { @@ -682,6 +687,40 @@ get_pc (struct lwp_info *lwp) return pc; } +/* This function should only be called if LWP got a SYSCALL_SIGTRAP. + Fill *SYSNO with the syscall nr trapped. Fill *SYSRET with the + return code. */ + +static void +get_syscall_trapinfo (struct lwp_info *lwp, int *sysno, int *sysret) +{ + struct thread_info *saved_thread; + struct regcache *regcache; + + if (the_low_target.get_syscall_trapinfo == NULL) + { + /* If we cannot get the syscall trapinfo, report an unknown + system call number and -ENOSYS return value. */ + *sysno = UNKNOWN_SYSCALL; + *sysret = -ENOSYS; + return; + } + + saved_thread = current_thread; + current_thread = get_lwp_thread (lwp); + + regcache = get_thread_regcache (current_thread, 1); + (*the_low_target.get_syscall_trapinfo) (regcache, sysno, sysret); + + if (debug_threads) + { + debug_printf ("get_syscall_trapinfo sysno %d sysret %d\n", + *sysno, *sysret); + } + + current_thread = saved_thread; +} + /* This function should only be called if LWP got a SIGTRAP. The SIGTRAP could mean several things. @@ -2241,6 +2280,8 @@ linux_low_ptrace_options (int attached) if (report_exec_events) options |= PTRACE_O_TRACEEXEC; + options |= PTRACE_O_TRACESYSGOOD; + return options; } @@ -2369,6 +2410,21 @@ linux_low_filter_event (int lwpid, int wstat) child->must_set_ptrace_flags = 0; } + /* Always update syscall_state, even if it will be filtered later. */ + if (WIFSTOPPED (wstat) && WSTOPSIG (wstat) == SYSCALL_SIGTRAP) + { + child->syscall_state + = (child->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY + ? TARGET_WAITKIND_SYSCALL_RETURN + : TARGET_WAITKIND_SYSCALL_ENTRY); + } + else + { + /* Almost all other ptrace-stops are known to be outside of system + calls, with further exceptions in handle_extended_wait. */ + child->syscall_state = TARGET_WAITKIND_IGNORE; + } + /* Be careful to not overwrite stop_pc until check_stopped_by_breakpoint is called. */ if (WIFSTOPPED (wstat) && WSTOPSIG (wstat) == SIGTRAP @@ -2978,6 +3034,44 @@ filter_exit_event (struct lwp_info *event_child, return ptid; } +/* Returns 1 if GDB is interested in any event_child syscalls. */ + +static int +gdb_catching_syscalls_p (struct lwp_info *event_child) +{ + struct thread_info *thread = get_lwp_thread (event_child); + struct process_info *proc = get_thread_process (thread); + + return !VEC_empty (int, proc->syscalls_to_catch); +} + +/* Returns 1 if GDB is interested in the event_child syscall. + Only to be called when stopped reason is SYSCALL_SIGTRAP. */ + +static int +gdb_catch_this_syscall_p (struct lwp_info *event_child) +{ + int i, iter; + int sysno, sysret; + struct thread_info *thread = get_lwp_thread (event_child); + struct process_info *proc = get_thread_process (thread); + + if (VEC_empty (int, proc->syscalls_to_catch)) + return 0; + + if (VEC_index (int, proc->syscalls_to_catch, 0) == ANY_SYSCALL) + return 1; + + get_syscall_trapinfo (event_child, &sysno, &sysret); + for (i = 0; + VEC_iterate (int, proc->syscalls_to_catch, i, iter); + i++) + if (iter == sysno) + return 1; + + return 0; +} + /* Wait for process, returns status. */ static ptid_t @@ -3312,6 +3406,22 @@ linux_wait_1 (ptid_t ptid, /* Check whether GDB would be interested in this event. */ + /* Check if GDB is interested in this syscall. */ + if (WIFSTOPPED (w) + && WSTOPSIG (w) == SYSCALL_SIGTRAP + && !gdb_catch_this_syscall_p (event_child)) + { + if (debug_threads) + { + debug_printf ("Ignored syscall for LWP %ld.\n", + lwpid_of (current_thread)); + } + + linux_resume_one_lwp (event_child, event_child->stepping, + 0, NULL); + return ignore_event (ourstatus); + } + /* If GDB is not interested in this signal, don't stop other threads, and don't report it to GDB. Just resume the inferior right away. We do this for threading-related signals as well as @@ -3566,8 +3676,16 @@ linux_wait_1 (ptid_t ptid, } } - if (current_thread->last_resume_kind == resume_stop - && WSTOPSIG (w) == SIGSTOP) + if (WSTOPSIG (w) == SYSCALL_SIGTRAP) + { + int sysret; + + get_syscall_trapinfo (event_child, + &ourstatus->value.syscall_number, &sysret); + ourstatus->kind = event_child->syscall_state; + } + else if (current_thread->last_resume_kind == resume_stop + && WSTOPSIG (w) == SIGSTOP) { /* A thread that has been requested to stop by GDB with vCont;t, and it stopped cleanly, so report as SIG0. The use of @@ -3987,6 +4105,7 @@ linux_resume_one_lwp_throw (struct lwp_info *lwp, struct thread_info *thread = get_lwp_thread (lwp); struct thread_info *saved_thread; int fast_tp_collecting; + int ptrace_request; struct process_info *proc = get_thread_process (thread); /* Note that target description may not be initialised @@ -4174,7 +4293,14 @@ linux_resume_one_lwp_throw (struct lwp_info *lwp, regcache_invalidate_thread (thread); errno = 0; lwp->stepping = step; - ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, lwpid_of (thread), + if (step) + ptrace_request = PTRACE_SINGLESTEP; + else if (gdb_catching_syscalls_p (lwp)) + ptrace_request = PTRACE_SYSCALL; + else + ptrace_request = PTRACE_CONT; + ptrace (ptrace_request, + lwpid_of (thread), (PTRACE_TYPE_ARG3) 0, /* Coerce to a uintptr_t first to avoid potential gcc warning of coercing an 8 byte integer to a 4 byte pointer. */ @@ -6270,6 +6396,13 @@ linux_process_qsupported (char **features, int count) } static int +linux_supports_catch_syscall (void) +{ + return (the_low_target.get_syscall_trapinfo != NULL + && linux_supports_tracesysgood()); +} + +static int linux_supports_tracepoints (void) { if (*the_low_target.supports_tracepoints == NULL) @@ -7157,6 +7290,7 @@ static struct target_ops linux_target_ops = { linux_common_core_of_thread, linux_read_loadmap, linux_process_qsupported, + linux_supports_catch_syscall, linux_supports_tracepoints, linux_read_pc, linux_write_pc, diff --git a/gdb/gdbserver/linux-low.h b/gdb/gdbserver/linux-low.h index c211a37d280a..45fffcd3208c 100644 --- a/gdb/gdbserver/linux-low.h +++ b/gdb/gdbserver/linux-low.h @@ -201,6 +201,12 @@ struct linux_target_ops /* Hook to support target specific qSupported. */ void (*process_qsupported) (char **, int count); + /* Fill *SYSNO with the syscall nr trapped. Fill *SYSRET with the + return code. Only to be called when inferior is stopped + due to SYSCALL_SIGTRAP. */ + void (*get_syscall_trapinfo) (struct regcache *regcache, + int *sysno, int *sysret); + /* Returns true if the low target supports tracepoints. */ int (*supports_tracepoints) (void); @@ -277,6 +283,13 @@ struct lwp_info event already received in a wait()). */ int stopped; + /* Signal whether we are in a SYSCALL_ENTRY or + in a SYSCALL_RETURN event. + Values: + - TARGET_WAITKIND_SYSCALL_ENTRY + - TARGET_WAITKIND_SYSCALL_RETURN */ + enum target_waitkind syscall_state; + /* When stopped is set, the last wait status recorded for this lwp. */ int last_status; diff --git a/gdb/gdbserver/linux-x86-low.c b/gdb/gdbserver/linux-x86-low.c index 18adf5ee7d17..1caf71edf485 100644 --- a/gdb/gdbserver/linux-x86-low.c +++ b/gdb/gdbserver/linux-x86-low.c @@ -1438,6 +1438,31 @@ x86_arch_setup (void) current_process ()->tdesc = x86_linux_read_description (); } +/* Fill *SYSNO and *SYSRET with the syscall nr trapped and the syscall return + code. This should only be called if LWP got a SYSCALL_SIGTRAP. */ + +static void +x86_get_syscall_trapinfo (struct regcache *regcache, int *sysno, int *sysret) +{ + int use_64bit = register_size (regcache->tdesc, 0) == 8; + + if (use_64bit) + { + long l_sysno; + long l_sysret; + + collect_register_by_name (regcache, "orig_rax", &l_sysno); + collect_register_by_name (regcache, "rax", &l_sysret); + *sysno = (int) l_sysno; + *sysret = (int) l_sysret; + } + else + { + collect_register_by_name (regcache, "orig_eax", sysno); + collect_register_by_name (regcache, "eax", sysret); + } +} + static int x86_supports_tracepoints (void) { @@ -3307,6 +3332,7 @@ struct linux_target_ops the_low_target = x86_linux_new_fork, x86_linux_prepare_to_resume, x86_linux_process_qsupported, + x86_get_syscall_trapinfo, x86_supports_tracepoints, x86_get_thread_area, x86_install_fast_tracepoint_jump_pad, diff --git a/gdb/gdbserver/nto-low.c b/gdb/gdbserver/nto-low.c index ee043b120830..2783c1a8b375 100644 --- a/gdb/gdbserver/nto-low.c +++ b/gdb/gdbserver/nto-low.c @@ -979,6 +979,7 @@ static struct target_ops nto_target_ops = { NULL, /* core_of_thread */ NULL, /* read_loadmap */ NULL, /* process_qsupported */ + NULL, /* supports_catch_syscall */ NULL, /* supports_tracepoints */ NULL, /* read_pc */ NULL, /* write_pc */ diff --git a/gdb/gdbserver/remote-utils.c b/gdb/gdbserver/remote-utils.c index 05e3d635f597..52fc12fa1013 100644 --- a/gdb/gdbserver/remote-utils.c +++ b/gdb/gdbserver/remote-utils.c @@ -1123,6 +1123,8 @@ prepare_resume_reply (char *buf, ptid_t ptid, case TARGET_WAITKIND_VFORK_DONE: case TARGET_WAITKIND_EXECD: case TARGET_WAITKIND_THREAD_CREATED: + case TARGET_WAITKIND_SYSCALL_ENTRY: + case TARGET_WAITKIND_SYSCALL_RETURN: { struct thread_info *saved_thread; const char **regp; @@ -1172,6 +1174,16 @@ prepare_resume_reply (char *buf, ptid_t ptid, sprintf (buf, "T%02xcreate:;", signal); } + else if ((status->kind == TARGET_WAITKIND_SYSCALL_ENTRY) + || (status->kind == TARGET_WAITKIND_SYSCALL_RETURN)) + { + enum gdb_signal signal = GDB_SIGNAL_TRAP; + const char *event = (status->kind == TARGET_WAITKIND_SYSCALL_ENTRY + ? "syscall_entry" : "syscall_return"); + + sprintf (buf, "T%02x%s:%x;", signal, event, + status->value.syscall_number); + } else sprintf (buf, "T%02x", status->value.sig); diff --git a/gdb/gdbserver/server.c b/gdb/gdbserver/server.c index 6d151ee35d39..e63656b9c0f6 100644 --- a/gdb/gdbserver/server.c +++ b/gdb/gdbserver/server.c @@ -597,6 +597,52 @@ handle_general_set (char *own_buf) return; } + if (startswith (own_buf, "QCatchSyscalls:1")) + { + const char *p; + CORE_ADDR sysno; + struct process_info *process; + + if (!target_running () || !target_supports_catch_syscall ()) + { + write_enn (own_buf); + return; + } + + process = current_process (); + + VEC_truncate (int, process->syscalls_to_catch, 0); + + p = own_buf + strlen("QCatchSyscalls:1"); + if (*p == ';') + { + p += 1; + while (*p) + { + p = decode_address_to_semicolon (&sysno, p); + VEC_safe_push (int, process->syscalls_to_catch, (int) sysno); + } + } + else + VEC_safe_push (int, process->syscalls_to_catch, ANY_SYSCALL); + + write_ok (own_buf); + return; + } + + if (strcmp ("QCatchSyscalls:0", own_buf) == 0) + { + if (!target_running () || !target_supports_catch_syscall ()) + { + write_enn (own_buf); + return; + } + + VEC_free (int, current_process ()->syscalls_to_catch); + write_ok (own_buf); + return; + } + if (startswith (own_buf, "QProgramSignals:")) { int numsigs = (int) GDB_SIGNAL_LAST, i; @@ -2219,6 +2265,9 @@ handle_query (char *own_buf, int packet_len, int *new_packet_len_p) "PacketSize=%x;QPassSignals+;QProgramSignals+", PBUFSIZ - 1); + if (target_supports_catch_syscall ()) + strcat (own_buf, ";QCatchSyscalls+"); + if (the_target->qxfer_libraries_svr4 != NULL) strcat (own_buf, ";qXfer:libraries-svr4:read+" ";augmented-libraries-svr4-read+"); diff --git a/gdb/gdbserver/server.h b/gdb/gdbserver/server.h index dc0361fdcd14..bc2abd5f50c8 100644 --- a/gdb/gdbserver/server.h +++ b/gdb/gdbserver/server.h @@ -134,4 +134,10 @@ extern void discard_queued_stop_replies (ptid_t ptid); as large as the largest register set supported by gdbserver. */ #define PBUFSIZ 16384 +/* Definition for an unknown syscall, used basically in error-cases. */ +#define UNKNOWN_SYSCALL (-1) + +/* Definition for any syscall, used for unfiltered syscall reporting. */ +#define ANY_SYSCALL (-2) + #endif /* SERVER_H */ diff --git a/gdb/gdbserver/spu-low.c b/gdb/gdbserver/spu-low.c index 64a440cf7ea2..9b3e84e33f52 100644 --- a/gdb/gdbserver/spu-low.c +++ b/gdb/gdbserver/spu-low.c @@ -699,6 +699,7 @@ static struct target_ops spu_target_ops = { NULL, /* core_of_thread */ NULL, /* read_loadmap */ NULL, /* process_qsupported */ + NULL, /* supports_catch_syscall */ NULL, /* supports_tracepoints */ NULL, /* read_pc */ NULL, /* write_pc */ diff --git a/gdb/gdbserver/target.h b/gdb/gdbserver/target.h index 1a38b2052c2c..a13c94163d38 100644 --- a/gdb/gdbserver/target.h +++ b/gdb/gdbserver/target.h @@ -312,6 +312,10 @@ struct target_ops features with COUNT elements. */ void (*process_qsupported) (char **features, int count); + /* Return 1 if the target supports catch syscall, 0 (or leave the + callback NULL) otherwise. */ + int (*supports_catch_syscall) (void); + /* Return 1 if the target supports tracepoints, 0 (or leave the callback NULL) otherwise. */ int (*supports_tracepoints) (void); @@ -542,6 +546,10 @@ int kill_inferior (int); the_target->process_qsupported (features, count); \ } while (0) +#define target_supports_catch_syscall() \ + (the_target->supports_catch_syscall ? \ + (*the_target->supports_catch_syscall) () : 0) + #define target_supports_tracepoints() \ (the_target->supports_tracepoints \ ? (*the_target->supports_tracepoints) () : 0) diff --git a/gdb/gdbserver/win32-low.c b/gdb/gdbserver/win32-low.c index ba20aea35a71..78d0c80b2c62 100644 --- a/gdb/gdbserver/win32-low.c +++ b/gdb/gdbserver/win32-low.c @@ -1844,6 +1844,7 @@ static struct target_ops win32_target_ops = { NULL, /* core_of_thread */ NULL, /* read_loadmap */ NULL, /* process_qsupported */ + NULL, /* supports_catch_syscall */ NULL, /* supports_tracepoints */ NULL, /* read_pc */ NULL, /* write_pc */ diff --git a/gdb/linux-nat.h b/gdb/linux-nat.h index f7b45f7bc693..1c5a4a92a05a 100644 --- a/gdb/linux-nat.h +++ b/gdb/linux-nat.h @@ -93,7 +93,7 @@ struct lwp_info or to a local variable in lin_lwp_wait. */ struct target_waitstatus waitstatus; - /* Signal wether we are in a SYSCALL_ENTRY or + /* Signal whether we are in a SYSCALL_ENTRY or in a SYSCALL_RETURN event. Values: - TARGET_WAITKIND_SYSCALL_ENTRY diff --git a/gdb/remote.c b/gdb/remote.c index 52c5df84c41d..66e2cc9b8faa 100644 --- a/gdb/remote.c +++ b/gdb/remote.c @@ -1392,6 +1392,7 @@ enum { PACKET_qSupported, PACKET_qTStatus, PACKET_QPassSignals, + PACKET_QCatchSyscalls, PACKET_QProgramSignals, PACKET_qCRC, PACKET_qSearch_memory, @@ -1986,6 +1987,99 @@ remote_pass_signals (struct target_ops *self, } } +/* If 'QCatchSyscalls' is supported, tell the remote stub + to report syscalls to GDB. */ + +static int +remote_set_syscall_catchpoint (struct target_ops *self, + int pid, int needed, int any_count, + int table_size, int *table) +{ + char *catch_packet, *p; + enum packet_result result; + int n_sysno = 0; + + if (remote_protocol_packets[PACKET_QCatchSyscalls].support == PACKET_DISABLE) + { + /* Not supported. */ + return 1; + } + + if (needed && !any_count) + { + int i; + + /* Count how many syscalls are to be caught (table[sysno] != 0). */ + for (i = 0; i < table_size; i++) + { + if (table[i]) + n_sysno++; + } + } + + if (remote_debug) + { + fprintf_unfiltered (gdb_stdlog, + "remote_set_syscall_catchpoint " + "pid %d needed %d any_count %d n_sysno %d\n", + pid, needed, any_count, n_sysno); + } + + if (needed) + { + /* Prepare a packet with the sysno list, assuming max 8+1 + characters for a sysno. If the resulting packet size is too + big, fallback on the non selective packet. */ + const int maxpktsz = strlen ("QCatchSyscalls:1") + n_sysno * 9 + 1; + + catch_packet = xmalloc (maxpktsz); + strcpy (catch_packet, "QCatchSyscalls:1"); + if (!any_count) + { + int i; + char *p; + + p = catch_packet; + p += strlen (p); + + /* Add in catch_packet each syscall to be caught (table[i] != 0). */ + for (i = 0; i < table_size; i++) + { + if (table[i]) + { + xsnprintf (p, catch_packet + maxpktsz - p, ";%x", i); + p += strlen (p); + } + } + } + if (strlen (catch_packet) > get_remote_packet_size ()) + { + /* catch_packet too big. Fallback to less efficient + non selective mode, with GDB doing the filtering. */ + catch_packet[strlen ("QCatchSyscalls:1")] = 0; + } + } + else + { + catch_packet = xmalloc (strlen ("QCatchSyscalls:0") + 1); + strcpy (catch_packet, "QCatchSyscalls:0"); + } + + { + struct remote_state *rs = get_remote_state (); + char *buf = rs->buf; + + putpkt (catch_packet); + getpkt (&rs->buf, &rs->buf_size, 0); + result = packet_ok (buf, &remote_protocol_packets[PACKET_QCatchSyscalls]); + xfree (catch_packet); + if (result == PACKET_OK) + return 0; + else + return -1; + } +} + /* If 'QProgramSignals' is supported, tell the remote stub what signals it should pass through to the inferior when detaching. */ @@ -4466,6 +4560,8 @@ static const struct protocol_feature remote_protocol_features[] = { PACKET_qXfer_traceframe_info }, { "QPassSignals", PACKET_DISABLE, remote_supported_packet, PACKET_QPassSignals }, + { "QCatchSyscalls", PACKET_DISABLE, remote_supported_packet, + PACKET_QCatchSyscalls }, { "QProgramSignals", PACKET_DISABLE, remote_supported_packet, PACKET_QProgramSignals }, { "QStartNoAckMode", PACKET_DISABLE, remote_supported_packet, @@ -6371,6 +6467,22 @@ Packet: '%s'\n"), if (strprefix (p, p1, "thread")) event->ptid = read_ptid (++p1, &p); + else if (strprefix (p, p1, "syscall_entry")) + { + ULONGEST sysno; + + event->ws.kind = TARGET_WAITKIND_SYSCALL_ENTRY; + p = unpack_varlen_hex (++p1, &sysno); + event->ws.value.syscall_number = (int) sysno; + } + else if (strprefix (p, p1, "syscall_return")) + { + ULONGEST sysno; + + event->ws.kind = TARGET_WAITKIND_SYSCALL_RETURN; + p = unpack_varlen_hex (++p1, &sysno); + event->ws.value.syscall_number = (int) sysno; + } else if (strprefix (p, p1, "watch") || strprefix (p, p1, "rwatch") || strprefix (p, p1, "awatch")) @@ -12975,6 +13087,7 @@ Specify the serial device it is connected to\n\ remote_ops.to_load = remote_load; remote_ops.to_mourn_inferior = remote_mourn; remote_ops.to_pass_signals = remote_pass_signals; + remote_ops.to_set_syscall_catchpoint = remote_set_syscall_catchpoint; remote_ops.to_program_signals = remote_program_signals; remote_ops.to_thread_alive = remote_thread_alive; remote_ops.to_thread_name = remote_thread_name; @@ -13549,6 +13662,9 @@ Show the maximum size of the address (in bits) in a memory packet."), NULL, add_packet_config_cmd (&remote_protocol_packets[PACKET_QPassSignals], "QPassSignals", "pass-signals", 0); + add_packet_config_cmd (&remote_protocol_packets[PACKET_QCatchSyscalls], + "QCatchSyscalls", "catch-syscalls", 0); + add_packet_config_cmd (&remote_protocol_packets[PACKET_QProgramSignals], "QProgramSignals", "program-signals", 0); diff --git a/gdb/testsuite/gdb.base/catch-syscall.exp b/gdb/testsuite/gdb.base/catch-syscall.exp index c1cfe23cdddb..0ba078db22ac 100644 --- a/gdb/testsuite/gdb.base/catch-syscall.exp +++ b/gdb/testsuite/gdb.base/catch-syscall.exp @@ -19,7 +19,15 @@ # It was written by Sergio Durigan Junior # on September/2008. -if { [is_remote target] || ![isnative] } then { +if { ![isnative] } then { + continue +} + +# This shall be updated whenever QCatchSyscalls packet support is implemented +# on some gdbserver architecture. +if { [is_remote target] + && ![istarget "x86_64-*-linux*"] + && ![istarget "i\[34567\]86-*-linux*"] } { continue } @@ -390,7 +398,10 @@ proc do_syscall_tests {} { if [runto_main] then { test_catch_syscall_skipping_return } # Testing the 'catch syscall' command starting mid-vfork. - if [runto_main] then { test_catch_syscall_mid_vfork } + # (Only local or extended-remote can use "catch vfork".) + if { ![is_remote target] || [target_info gdb_protocol] == "extended-remote" } { + if [runto_main] then { test_catch_syscall_mid_vfork } + } # Testing if the 'catch syscall' command works when switching to # different architectures on-the-fly (PR gdb/10737). -- 2.5.0