diff options
| -rw-r--r-- | gdb/NEWS | 9 | ||||
| -rw-r--r-- | gdb/doc/gdb.texinfo | 31 | ||||
| -rw-r--r-- | gdb/infcall.c | 78 | ||||
| -rw-r--r-- | gdb/testsuite/gdb.base/infcall-timeout.exp | 63 | ||||
| -rw-r--r-- | gdb/testsuite/gdb.threads/infcall-from-bp-cond-timeout.exp | 69 |
5 files changed, 194 insertions, 56 deletions
@@ -72,6 +72,15 @@ show indirect-call-timeout ignored, GDB will wait indefinitely for an inferior function to complete, unless interrupted by the user using Ctrl-C. +set unwind-on-timeout on|off +show unwind-on-timeout + These commands control whether GDB should unwind the stack when a + timeout occurs during an inferior function call. The default is + off, in which case the inferior will remain in the frame where the + timeout occurred. When on, GDB will unwind the stack removing the + dummy frame that was added for the inferior call, and restoring the + inferior state to how it was before the inferior call started. + * New features in the GDB remote stub, GDBserver ** The --remote-debug and --event-loop-debug command line options diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo index 5df88be5..f87c2c7 100644 --- a/gdb/doc/gdb.texinfo +++ b/gdb/doc/gdb.texinfo @@ -20949,6 +20949,22 @@ the default C@t{++} exception handler and the inferior terminated. Show the current setting of stack unwinding in the functions called by @value{GDBN}. +@anchor{set unwind-on-timeout} +@item set unwind-on-timeout +@kindex set unwind-on-timeout +@cindex unwind stack in called functions when timing out +@cindex call dummy stack unwinding on timeout. +Set unwinding of the stack if a function called from @value{GDBN} +times out. If set to @code{off} (the default), @value{GDBN} stops in +the frame where the timeout occurred. If set to @code{on}, +@value{GDBN} unwinds the stack it created for the call and restores +the context to what it was before the call. + +@item show unwind-on-timeout +@kindex show unwind-on-timeout +Show whether @value{GDBN} will unwind the stack if a function called +from @value{GDBN} times out. + @item set may-call-functions @kindex set may-call-functions @cindex disabling calling functions in the program @@ -20980,11 +20996,11 @@ call by typing the interrupt character (often @kbd{Ctrl-c}). If a called function is interrupted for any reason, including hitting a breakpoint, or triggering a watchpoint, and the stack is not unwound -due to @code{set unwind-on-terminating-exception on} or @code{set -unwindonsignal on} (@pxref{stack unwind settings}), -then the dummy-frame, created by @value{GDBN} to facilitate the call -to the program function, will be visible in the backtrace, for example -frame @code{#3} in the following backtrace: +due to @code{set unwind-on-terminating-exception on}, @code{set +unwind-on-timeout on}, or @code{set unwindonsignal on} (@pxref{stack +unwind settings}), then the dummy-frame, created by @value{GDBN} to +facilitate the call to the program function, will be visible in the +backtrace, for example frame @code{#3} in the following backtrace: @smallexample (@value{GDBP}) backtrace @@ -21009,6 +21025,11 @@ Execution}) @value{GDBN} can place a timeout on any functions called from @value{GDBN}. If the timeout expires and the function call is still ongoing, then @value{GDBN} will interrupt the program. +If a function called from @value{GDBN} is interrupted by a timeout, +then by default the inferior is left in the frame where the timeout +occurred, this behaviour can be adjusted with @samp{set +unwind-on-timeout} (@pxref{set unwind-on-timeout}). + For targets that don't support asynchronous execution (@pxref{Background Execution}) then timeouts for functions called from @value{GDBN} are not supported, the timeout settings described below diff --git a/gdb/infcall.c b/gdb/infcall.c index 7dc1324..bbe9064 100644 --- a/gdb/infcall.c +++ b/gdb/infcall.c @@ -218,6 +218,27 @@ show_unwind_on_terminating_exception_p (struct ui_file *file, int from_tty, value); } +/* This boolean tells GDB what to do if an inferior function, called from + GDB, times out. If true, GDB unwinds the stack and restores the context + to what it was before the call. When false, GDB leaves the thread as it + is at the point of the timeout. + + The default is to stop in the frame where the timeout occurred. */ + +static bool unwind_on_timeout_p = false; + +/* Implement 'show unwind-on-timeout'. */ + +static void +show_unwind_on_timeout_p (struct ui_file *file, int from_tty, + struct cmd_list_element *c, const char *value) +{ + gdb_printf (file, + _("Unwinding of stack if a timeout occurs " + "while in a call dummy is %s.\n"), + value); +} + /* Perform the standard coercions that are specified for arguments to be passed to C, Ada or Fortran functions. @@ -574,6 +595,16 @@ struct call_thread_fsm : public thread_fsm bool should_stop (struct thread_info *thread) override; bool should_notify_stop () override; + + /* Record that this thread timed out while performing an infcall. */ + void timed_out () + { + m_timed_out = true; + } + +private: + /* Set true if the thread timed out while performing an infcall. */ + bool m_timed_out = false; }; /* Allocate a new call_thread_fsm object. */ @@ -649,7 +680,8 @@ call_thread_fsm::should_notify_stop () infcall_debug_printf ("inferior call didn't complete fully"); - if (stopped_by_random_signal && unwind_on_signal_p) + if ((stopped_by_random_signal && unwind_on_signal_p) + || (m_timed_out && unwind_on_timeout_p)) { infcall_debug_printf ("unwind-on-signal is on, don't notify"); return false; @@ -742,6 +774,9 @@ private: infcall_debug_printf ("Stopping thread %s", m_thread->ptid.to_string ().c_str ()); + call_thread_fsm *fsm + = gdb::checked_static_cast<call_thread_fsm *> (m_thread->thread_fsm ()); + fsm->timed_out (); target_stop (m_thread->ptid); } }; @@ -1749,14 +1784,27 @@ When the function is done executing, GDB will silently stop."), /* A timeout results in a signal being sent to the inferior. */ gdb_assert (stopped_by_random_signal); - /* Indentation is weird here. A later patch is going to move the - following block into an if/else, so I'm leaving the indentation - here to minimise the later patch. + if (unwind_on_timeout_p) + { + /* The user wants the context restored. */ + + /* We must get back to the frame we were before the + dummy call. */ + dummy_frame_pop (dummy_id, call_thread.get ()); - Also, the error message used below refers to 'set - unwind-on-timeout' which doesn't exist yet. This will be added - in a later commit, I'm leaving this in for now to minimise the - churn caused by the commit that adds unwind-on-timeout. */ + /* We also need to restore inferior status to that before the + dummy call. */ + restore_infcall_control_state (inf_status.release ()); + + error (_("\ +The program being debugged timed out while in a function called from GDB.\n\ +GDB has restored the context to what it was before the call.\n\ +To change this behavior use \"set unwind-on-timeout off\".\n\ +Evaluation of the expression containing the function\n\ +(%s) will be abandoned."), + name.c_str ()); + } + else { /* The user wants to stay in the frame where we stopped (default). Discard inferior status, we're not at the same @@ -1882,6 +1930,20 @@ The default is to unwind the frame."), show_unwind_on_terminating_exception_p, &setlist, &showlist); + add_setshow_boolean_cmd ("unwind-on-timeout", no_class, + &unwind_on_timeout_p, _("\ +Set unwinding of stack if a timeout occurs while in a call dummy."), _("\ +Show unwinding of stack if a timeout occurs while in a call dummy."), + _("\ +The unwind on timeout flag lets the user determine what gdb should do if\n\ +gdb times out while in a function called from gdb. If set, gdb unwinds\n\ +the stack and restores the context to what it was before the call. If\n\ +unset, gdb leaves the inferior in the frame where the timeout occurred.\n\ +The default is to stop in the frame where the timeout occurred."), + NULL, + show_unwind_on_timeout_p, + &setlist, &showlist); + add_setshow_uinteger_cmd ("direct-call-timeout", no_class, &direct_call_timeout, _("\ Set the timeout, for direct calls to inferior function calls."), _("\ diff --git a/gdb/testsuite/gdb.base/infcall-timeout.exp b/gdb/testsuite/gdb.base/infcall-timeout.exp index e6a03b2..ad4dbe3 100644 --- a/gdb/testsuite/gdb.base/infcall-timeout.exp +++ b/gdb/testsuite/gdb.base/infcall-timeout.exp @@ -28,7 +28,11 @@ if { [build_executable "failed to prepare" ${binfile} "${srcfile}" \ # then adjust the direct-call-timeout, and make an inferior function # call that will never return. GDB should eventually timeout and stop # the inferior. -proc run_test { target_async target_non_stop non_stop } { +# +# When UNWIND is "off" the inferior wil be left in the frame where the +# timeout occurs, otherwise, when UNWIND is "on", GDB should unwind +# back to the frame where the inferior call was made. +proc run_test { target_async target_non_stop non_stop unwind } { save_vars { ::GDBFLAGS } { append ::GDBFLAGS \ " -ex \"maint set target-non-stop $target_non_stop\"" @@ -45,28 +49,43 @@ proc run_test { target_async target_non_stop non_stop } { } gdb_test_no_output "set direct-call-timeout 5" + gdb_test_no_output "set unwind-on-timeout $unwind" + + if { $unwind } { + gdb_test "print function_that_never_returns ()" \ + [multi_line \ + "The program being debugged timed out while in a function called from GDB\\." \ + "GDB has restored the context to what it was before the call\\." \ + "To change this behavior use \"set unwind-on-timeout off\"\\." \ + "Evaluation of the expression containing the function" \ + "\\(function_that_never_returns\\) will be abandoned\\."] - # When non-stop mode is off we get slightly different output from GDB. - if { ([target_info gdb_protocol] == "remote" - || [target_info gdb_protocol] == "extended-remote") - && !$target_non_stop } { - set stopped_line_pattern "Program received signal SIGINT, Interrupt\\." + gdb_test "bt" \ + "#0\\s+main \\(\\).*" } else { - set stopped_line_pattern "Program stopped\\." - } + # When non-stop mode is off we get slightly different output from GDB. + if { ([target_info gdb_protocol] == "remote" + || [target_info gdb_protocol] == "extended-remote") + && !$target_non_stop } { + set stopped_line_pattern "Program received signal SIGINT, Interrupt\\." + } else { + set stopped_line_pattern "Program stopped\\." + } - gdb_test "print function_that_never_returns ()" \ - [multi_line \ - $stopped_line_pattern \ - ".*" \ - "The program being debugged timed out while in a function called from GDB\\." \ - "GDB remains in the frame where the timeout occurred\\." \ - "To change this behavior use \"set unwind-on-timeout on\"\\." \ - "Evaluation of the expression containing the function" \ - "\\(function_that_never_returns\\) will be abandoned\\." \ - "When the function is done executing, GDB will silently stop\\."] - - gdb_test "bt" ".* function_that_never_returns .*<function called from gdb>.*" + gdb_test "print function_that_never_returns ()" \ + [multi_line \ + $stopped_line_pattern \ + ".*" \ + "The program being debugged timed out while in a function called from GDB\\." \ + "GDB remains in the frame where the timeout occurred\\." \ + "To change this behavior use \"set unwind-on-timeout on\"\\." \ + "Evaluation of the expression containing the function" \ + "\\(function_that_never_returns\\) will be abandoned\\." \ + "When the function is done executing, GDB will silently stop\\."] + + gdb_test "bt" \ + ".* function_that_never_returns .*<function called from gdb>.*" + } } foreach_with_prefix target_async { "on" "off" } { @@ -88,7 +107,9 @@ foreach_with_prefix target_async { "on" "off" } { continue } - run_test $target_async $target_non_stop $non_stop + foreach_with_prefix unwind { "on" "off" } { + run_test $target_async $target_non_stop $non_stop $unwind + } } } } diff --git a/gdb/testsuite/gdb.threads/infcall-from-bp-cond-timeout.exp b/gdb/testsuite/gdb.threads/infcall-from-bp-cond-timeout.exp index 67dabce..8f17f13 100644 --- a/gdb/testsuite/gdb.threads/infcall-from-bp-cond-timeout.exp +++ b/gdb/testsuite/gdb.threads/infcall-from-bp-cond-timeout.exp @@ -41,7 +41,12 @@ set segfault_line [gdb_get_line_number "Segfault here"] # thread, on which the inferior call relies, either hits a breakpoint # (when OTHER_THREAD_BP is true), or crashes (when OTHER_THREAD_BP is # false). -proc run_test { target_async target_non_stop non_stop other_thread_bp } { +# +# When UNWIND is "on" GDB will unwind the thread which performed the +# inferior function call back to the state where the inferior call was +# made (when the inferior call times out). Otherwise, when UNWIND is +# "off", the inferior is left in the frame where the timeout occurred. +proc run_test { target_async target_non_stop non_stop other_thread_bp unwind } { save_vars { ::GDBFLAGS } { append ::GDBFLAGS " -ex \"maint set target-non-stop $target_non_stop\"" append ::GDBFLAGS " -ex \"maint non-stop $non_stop\"" @@ -72,6 +77,7 @@ proc run_test { target_async target_non_stop non_stop other_thread_bp } { # for this timeout. For now though, we just hope 5 seconds is # enough. gdb_test_no_output "set indirect-call-timeout 5" + gdb_test_no_output "set unwind-on-timeout $unwind" gdb_breakpoint \ "${::srcfile}:${::cond_bp_line} if (condition_func ())" @@ -92,27 +98,43 @@ proc run_test { target_async target_non_stop non_stop other_thread_bp } { "get number for segfault breakpoint"] } - # When non-stop mode is off we get slightly different output from GDB. - if { ([target_info gdb_protocol] == "remote" - || [target_info gdb_protocol] == "extended-remote") - && !$target_non_stop} { - set stopped_line_pattern "Thread ${::decimal} \"\[^\r\n\"\]+\" received signal SIGINT, Interrupt\\." + if { $unwind } { + gdb_test "continue" \ + [multi_line \ + "Error in testing condition for breakpoint ${bp_num}:" \ + "The program being debugged timed out while in a function called from GDB\\." \ + "GDB has restored the context to what it was before the call\\." \ + "To change this behavior use \"set unwind-on-timeout off\"\\." \ + "Evaluation of the expression containing the function" \ + "\\(condition_func\\) will be abandoned\\." \ + "" \ + "Thread ${::decimal}\[^\r\n\]*hit Breakpoint ${bp_num}, \[^\r\n\]+" \ + "\[^\r\n\]+ Conditional breakpoint here\\. \[^\r\n\]+"] \ + "expected timeout waiting for inferior call to complete" } else { - set stopped_line_pattern "Thread ${::decimal} \"\[^\r\n\"\]+\" stopped\\." - } + # When non-stop mode is off we get slightly different output from GDB. + if { ([target_info gdb_protocol] == "remote" + || [target_info gdb_protocol] == "extended-remote") + && !$target_non_stop} { + set stopped_line_pattern \ + "Thread ${::decimal} \"\[^\r\n\"\]+\" received signal SIGINT, Interrupt\\." + } else { + set stopped_line_pattern "Thread ${::decimal} \"\[^\r\n\"\]+\" stopped\\." + } - gdb_test "continue" \ - [multi_line \ - $stopped_line_pattern \ - ".*" \ - "Error in testing condition for breakpoint ${bp_num}:" \ - "The program being debugged timed out while in a function called from GDB\\." \ - "GDB remains in the frame where the timeout occurred\\." \ - "To change this behavior use \"set unwind-on-timeout on\"\\." \ - "Evaluation of the expression containing the function" \ - "\\(condition_func\\) will be abandoned\\." \ - "When the function is done executing, GDB will silently stop\\."] \ - "expected timeout waiting for inferior call to complete" + gdb_test "continue" \ + [multi_line \ + "$stopped_line_pattern" \ + ".*" \ + "Error in testing condition for breakpoint ${bp_num}:" \ + "The program being debugged timed out while in a function called from GDB\\." \ + "GDB remains in the frame where the timeout occurred\\." \ + "To change this behavior use \"set unwind-on-timeout on\"\\." \ + "Evaluation of the expression containing the function" \ + "\\(condition_func\\) will be abandoned\\." \ + "When the function is done executing, GDB will silently stop\\."] \ + "expected timeout waiting for inferior call to complete" + } # Remember that other thread that either crashed (with a segfault) # or hit a breakpoint? Now that the inferior call has timed out, @@ -158,8 +180,11 @@ foreach_with_prefix target_async {"on" "off" } { # disabled. continue } - foreach_with_prefix other_thread_bp { true false } { - run_test $target_async $target_non_stop $non_stop $other_thread_bp + foreach_with_prefix unwind {"off" "on"} { + foreach_with_prefix other_thread_bp { true false } { + run_test $target_async $target_non_stop $non_stop \ + $other_thread_bp $unwind + } } } } |