From aacbb8a556ab7e211763d285ae7b756329f902e2 Mon Sep 17 00:00:00 2001 From: Luis Machado Date: Tue, 7 May 2013 07:43:33 +0000 Subject: [PATCH] gdb/ * ppc-linux-nat.c (ppc_linux_new_thread): Clear the new thread's debug state prior to replicating existing hardware watchpoints or breakpoints. gdb/testsuite/ * gdb.threads/wp-replication.c: New file. * gdb.threads/wp-replication.exp: New file. --- gdb/ChangeLog | 6 + gdb/ppc-linux-nat.c | 13 ++- gdb/testsuite/ChangeLog | 5 + gdb/testsuite/gdb.threads/wp-replication.c | 163 +++++++++++++++++++++++++++ gdb/testsuite/gdb.threads/wp-replication.exp | 151 +++++++++++++++++++++++++ 5 files changed, 337 insertions(+), 1 deletion(-) create mode 100644 gdb/testsuite/gdb.threads/wp-replication.c create mode 100644 gdb/testsuite/gdb.threads/wp-replication.exp diff --git a/gdb/ChangeLog b/gdb/ChangeLog index b729ec1..880ec6c 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,9 @@ +2013-05-07 Luis Machado + + * ppc-linux-nat.c (ppc_linux_new_thread): Clear the new thread's + debug state prior to replicating existing hardware watchpoints or + breakpoints. + 2013-05-07 Jan Kratochvil * gcore.c (gcore_create_callback): Ignore sections with diff --git a/gdb/ppc-linux-nat.c b/gdb/ppc-linux-nat.c index edb16c0..280dcbe 100644 --- a/gdb/ppc-linux-nat.c +++ b/gdb/ppc-linux-nat.c @@ -2178,7 +2178,18 @@ ppc_linux_new_thread (struct lwp_info *lp) /* Copy that thread's breakpoints and watchpoints to the new thread. */ for (i = 0; i < max_slots_number; i++) if (hw_breaks[i].hw_break) - booke_insert_point (hw_breaks[i].hw_break, tid); + { + /* Older kernels did not make new threads inherit their parent + thread's debug state, so we always clear the slot and replicate + the debug state ourselves, ensuring compatibility with all + kernels. */ + + /* The ppc debug resource accounting is done through "slots". + Ask the kernel the deallocate this specific *point's slot. */ + ptrace (PPC_PTRACE_DELHWDEBUG, tid, 0, hw_breaks[i].slot); + + booke_insert_point (hw_breaks[i].hw_break, tid); + } } else ptrace (PTRACE_SET_DEBUGREG, tid, 0, saved_dabr_value); diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog index 3d928bb..a33d6d0 100644 --- a/gdb/testsuite/ChangeLog +++ b/gdb/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2013-05-07 Luis Machado + + * gdb.threads/wp-replication.c: New file. + * gdb.threads/wp-replication.exp: New file. + 2013-05-06 Sandra Loosemore * gdb.xml/tdesc-regs.exp: Add case for nios2. diff --git a/gdb/testsuite/gdb.threads/wp-replication.c b/gdb/testsuite/gdb.threads/wp-replication.c new file mode 100644 index 0000000..a0afab2 --- /dev/null +++ b/gdb/testsuite/gdb.threads/wp-replication.c @@ -0,0 +1,163 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2009-2013 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . + + Check that hardware watchpoints get correctly replicated to all + existing threads when hardware watchpoints are created. This test + creates one hardware watchpoint per thread until a maximum is + reached. It originally addresses a deficiency seen on embedded + powerpc targets with slotted hardware *point designs. +*/ + +#include +#include +#include +#include +#include + +#ifndef NR_THREADS +#define NR_THREADS 4 /* Set by the testcase. */ +#endif + +#ifndef X_INCR_COUNT +#define X_INCR_COUNT 10 /* Set by the testcase. */ +#endif + +void *thread_function (void *arg); /* Function executed by each thread. */ + +/* Used to hold threads back until wp-replication.exp is ready. */ +int test_ready = 0; + +/* Used to hold threads back until every thread has had a chance of causing + a watchpoint trigger. This prevents a situation in GDB where it may miss + watchpoint triggers when threads exit while other threads are causing + watchpoint triggers. */ +int can_terminate = 0; + +/* Used to push the program out of the waiting loop after the + testcase is done counting the number of hardware watchpoints + available for our target. */ +int watch_count_done = 0; + +/* Number of watchpoints GDB is capable of using (this is provided + by GDB during the test run). */ +int hw_watch_count = 0; + +/* Array with elements we can create watchpoints for. */ +static int watched_data[NR_THREADS]; +pthread_mutex_t data_mutex; + +/* Wait function to keep threads busy while the testcase does + what it needs to do. */ +void +empty_cycle (void) +{ + usleep (1); +} + +int +main () +{ + int res; + pthread_t threads[NR_THREADS]; + int i; + + while (watch_count_done == 0) + { + /* GDB will modify the value of "i" at runtime and we will + get past this point. */ + empty_cycle (); + } + + pthread_mutex_init (&data_mutex, NULL); + + for (i = 0; i < NR_THREADS; i++) + { + res = pthread_create (&threads[i], + NULL, thread_function, + (void *) (intptr_t) i); + if (res != 0) + { + fprintf (stderr, "error in thread %d create\n", i); + abort (); + } + } + + for (i = 0; i < NR_THREADS; ++i) + { + res = pthread_join (threads[i], NULL); + if (res != 0) + { + fprintf (stderr, "error in thread %d join\n", i); + abort (); + } + } + + exit (EXIT_SUCCESS); +} + +/* Easy place for a breakpoint. + wp-replication.exp uses this to track when all threads are running + instead of, for example, the program keeping track + because we don't need the program to know when all threads are running, + instead we need gdb to know when all threads are running. + There is a delay between when a thread has started and when the thread + has been registered with gdb. */ + +void +thread_started (void) +{ +} + +void * +thread_function (void *arg) +{ + int i, j; + long thread_number = (long) arg; + + thread_started (); + + /* Don't start incrementing X until wp-replication.exp is ready. */ + while (!test_ready) + usleep (1); + + pthread_mutex_lock (&data_mutex); + + for (i = 0; i < NR_TRIGGERS_PER_THREAD; i++) + { + for (j = 0; j < hw_watch_count; j++) + { + /* For debugging. */ + printf ("Thread %ld changing watch_thread[%d] data" + " from %d -> %d\n", thread_number, j, + watched_data[j], watched_data[j] + 1); + /* Increment the watched data field. */ + watched_data[j]++; + } + } + + pthread_mutex_unlock (&data_mutex); + + /* Hold the threads here to work around a problem GDB has evaluating + watchpoints right when a DSO event shows up (PR breakpoints/10116). + Sleep a little longer (than, say, 1, 5 or 10) to avoid consuming + lots of cycles while the other threads are trying to execute the + loop. */ + while (!can_terminate) + usleep (100); + + pthread_exit (NULL); +} diff --git a/gdb/testsuite/gdb.threads/wp-replication.exp b/gdb/testsuite/gdb.threads/wp-replication.exp new file mode 100644 index 0000000..8927a43 --- /dev/null +++ b/gdb/testsuite/gdb.threads/wp-replication.exp @@ -0,0 +1,151 @@ +# This testcase is part of GDB, the GNU debugger. + +# Copyright 2009-2013 Free Software Foundation, Inc. + +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 3 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see . + +# Check that hardware watchpoints get correctly replicated to all +# existing threads when hardware watchpoints are created. This test +# creates one hardware watchpoint per thread until a maximum is +# reached. It originally addresses a deficiency seen on embedded +# powerpc targets with slotted hardware *point designs. + +set NR_THREADS 10 +set NR_TRIGGERS_PER_THREAD 2 + +# This test verifies that a hardware watchpoint gets replicated to +# every existing thread and is detected properly. This test is +# only meaningful on a target with hardware watchpoint support. +if {[skip_hw_watchpoint_tests]} { + return 0 +} + +standard_testfile +if {[gdb_compile_pthreads "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable [list debug "additional_flags=-DNR_THREADS=$NR_THREADS -DNR_TRIGGERS_PER_THREAD=$NR_TRIGGERS_PER_THREAD"]] != "" } { + return -1 +} + +clean_restart ${binfile} + +# Force hardware watchpoints to be used. +gdb_test_no_output "set can-use-hw-watchpoints 1" "" + +# Run to `main' where we begin our tests. +if ![runto_main] then { + fail "Failed to run to main" + return 0 +} + +# First, break at empty_cycle. +gdb_test "break empty_cycle" \ + "Breakpoint 2 at .*: file .*${srcfile}, line .*" \ + "Breakpoint on empty_cycle" + +# Set some default values. +set hwatch_count 0 +set done 0 + +# Count the number of hardware watchpoints available on +# this target. +while { $done == 0 } { + + gdb_test "continue" \ + ".*Breakpoint 2, empty_cycle \\(\\) at .*${srcfile}.*" \ + "Continue to empty_cycle to insert watchpoint $hwatch_count" + + # Some targets do resource counting as we insert watchpoints. + # Such targets won't cause a watchpoint insertion failure, but + # will switch to software watchpoints silently. We check for + # both cases here. + gdb_test_multiple "watch watched_data\[$hwatch_count\]" \ + "watch watched_data\[$hwatch_count\]" { + -re "Hardware watchpoint .*$gdb_prompt $" { + } + -re "Watchpoint .*$gdb_prompt $" { + set done 1 + break + } + } + + gdb_test_multiple "continue" "watchpoint created successfully" { + -re ".*Breakpoint 2, empty_cycle \\(\\).*$gdb_prompt $" { + incr hwatch_count + } + -re ".*Could not insert hardware watchpoint.*$gdb_prompt $" { + set done 1 + break + } + } +} + +# Target cannot insert hardware watchpoints. It should have reported +# (through board settings) that it did not support them in the first place. +# Just exit. +if { $hwatch_count == 0} { + fail "No hardware watchpoints available" + return 0 +} + +# Set the testcase's internal variable indicating the number of +# hardware watchpoints the target supports. +gdb_test_no_output "set var hw_watch_count=${hwatch_count}" \ + "set var hw_watch_count=${hwatch_count}" + +# At this point, we know how many hardware watchpoints +# the target supports. Use that to do further testing. +delete_breakpoints + +# Break out of the empty_cycle loop by changing the +# controlling variable. +gdb_test_no_output "set var watch_count_done=1" \ + "set var watch_count_done=1" + +# Prepare to create all the threads. +gdb_test "break thread_started" \ + "Breakpoint \[0-9\]+ at .*: file .*${srcfile}, line .*" \ + "Breakpoint on thread_started" + +# Move all threads to where they're supposed to be for testing. +for { set i 0 } { $i < $NR_THREADS } { incr i } { + + # We want to set the maximum number of hardware watchpoints + # and make sure the target can handle that without an error. + # That will show us the watchpoints got replicated to all the + # threads correctly, and that no new watchpoints got created + # in the background for a specific thread. + if {$i < $hwatch_count} { + gdb_test "watch watched_data\[$i\]" \ + "Hardware watchpoint .*" \ + "watch watched_data\[$i\]" + } else { + verbose -log "Not setting watchpoint for watched_data\[$i\]\n" + } + + gdb_test continue "Continuing\\..*Breakpoint \[0-9\]+, thread_started \\(\\) at .*$srcfile.*" \ + "Thread $i hit breakpoint at thread_started" +} + +# Let the threads run and change the watched data, leading +# to watchpoint triggers. +gdb_test_no_output "set var test_ready=1" \ + "set var test_ready=1" + +# Set the number of expected watchpoint triggers. +set TRIGGERS [expr "$NR_THREADS * $hwatch_count * $NR_TRIGGERS_PER_THREAD"] + +# Move the threads and hit the watchpoints TRIGGERS times. +for { set i 1 } { $i <= $TRIGGERS } { incr i } { + gdb_test continue "Continuing\\..*Hardware watchpoint \[0-9\]+: watched_data\[\[0-9\]+\].*Old value = \[0-9\]+.*New value = \[0-9\]+.*thread_function \\(arg=$hex\\) at .*$srcfile.*" \ + "Continue to watchpoint trigger $i out of ${TRIGGERS} on watched_data" +} -- 2.7.4