* [RFA] Ensure 'exec-file has changed' check has priority over 'exec-file-mismatch' check
@ 2020-05-23 13:08 Philippe Waroquiers
2020-06-04 13:28 ` Pedro Alves
0 siblings, 1 reply; 2+ messages in thread
From: Philippe Waroquiers @ 2020-05-23 13:08 UTC (permalink / raw)
To: gdb-patches
Following the implementation of exec-file-mismatch based on build-id,
an attach to a process that runs a modified exec-file was triggering
the exec-file-mismatch handling, giving a warning such as:
warning: Mismatch between current exec-file /bd/home/philippe/gdb/git/build_termours/gdb/testsuite/outputs/gdb.base/attach/attach
and automatically determined exec-file /bd/home/philippe/gdb/git/build_termours/gdb/testsuite/outputs/gdb.base/attach/attach
exec-file-mismatch handling is currently "ask"
as the build-ids differ when an exec-file is recompiled.
This patch ensures that the exec-file-mismatch check is done with an up to date
build-id. With this, exec-file-mismatch check will only trigger when the
PID file really differs from the (build-id refreshed) current exec-file.
Note that the additional check does not (yet) reload the symbols if
the exec-file is changed: this reload will happen later if needed.
gdb/ChangeLog
YYYY-MM-DD Philippe Waroquiers <philippe.waroquiers@skynet.be>
* exec.c (validate_exec_file): Ensure the build-id is up to
date by calling reopen_exec_file (that checks file timestamp
to decide to re-read the file).
gdb/testsuite/ChangeLog
YYYY-MM-DD Philippe Waroquiers <philippe.waroquiers@skynet.be>
* gdb.base/attach.exp: Test priority of 'exec-file' changed
over 'exec-file-mismatch'.
* gdb.base/attach.c: Mark should_exit volatile.
* gdb.base/attach2.c: Likewise. Add a comment explaining
why the sleep cannot be big.
* gdb.base/attach3.c: New file.
---
gdb/exec.c | 10 ++++++
gdb/testsuite/gdb.base/attach.c | 2 +-
gdb/testsuite/gdb.base/attach.exp | 56 +++++++++++++++++++++++++++++--
gdb/testsuite/gdb.base/attach2.c | 4 ++-
4 files changed, 68 insertions(+), 4 deletions(-)
diff --git a/gdb/exec.c b/gdb/exec.c
index 14c77495a3..021c9ea350 100644
--- a/gdb/exec.c
+++ b/gdb/exec.c
@@ -254,6 +254,16 @@ validate_exec_file (int from_tty)
if (current_exec_file == NULL || pid_exec_file == NULL)
return;
+ /* Try validating via build-id, if available. This is the most
+ reliable check. */
+
+ /* In case current_exec_file was changed, reopen_exec_file ensures
+ an up to date build_id (will do nothing if the file timestamp
+ did not change). If exec file changed, reopen_exec_file has
+ allocated another file name, so get_exec_file again. */
+ reopen_exec_file ();
+ current_exec_file = get_exec_file (0);
+
/* Try validating via build-id, if available. This is the most
reliable check. */
const bfd_build_id *exec_file_build_id = build_id_bfd_get (exec_bfd);
diff --git a/gdb/testsuite/gdb.base/attach.c b/gdb/testsuite/gdb.base/attach.c
index 2e87f9b710..b3c5498401 100644
--- a/gdb/testsuite/gdb.base/attach.c
+++ b/gdb/testsuite/gdb.base/attach.c
@@ -8,7 +8,7 @@
#include <unistd.h>
int bidule = 0;
-int should_exit = 0;
+volatile int should_exit = 0;
int main ()
{
diff --git a/gdb/testsuite/gdb.base/attach.exp b/gdb/testsuite/gdb.base/attach.exp
index 32f72e2a9a..84aede7e2a 100644
--- a/gdb/testsuite/gdb.base/attach.exp
+++ b/gdb/testsuite/gdb.base/attach.exp
@@ -17,12 +17,13 @@ if {![can_spawn_for_attach]} {
return 0
}
-standard_testfile attach.c attach2.c
+standard_testfile attach.c attach2.c attach3.c
set binfile2 ${binfile}2
+set binfile3 ${binfile}3
set escapedbinfile [string_to_regexp $binfile]
#execute_anywhere "rm -f ${binfile} ${binfile2}"
-remote_exec build "rm -f ${binfile} ${binfile2}"
+remote_exec build "rm -f ${binfile} ${binfile2} ${binfile3}"
# For debugging this test
#
#log_user 1
@@ -41,6 +42,13 @@ if { [gdb_compile "${srcdir}/${subdir}/${srcfile2}" "${binfile2}" executable {d
return -1
}
+# Build the third file, used to check attach when exec-file has changed.
+
+if { [gdb_compile "${srcdir}/${subdir}/${srcfile3}" "${binfile3}" executable {debug}] != "" } {
+ untested "failed to compile attach exec-file changed test"
+ return -1
+}
+
if [get_compiler_info] {
return -1
}
@@ -515,6 +523,7 @@ proc_with_prefix do_attach_exec_mismatch_handling_tests {} {
global gdb_prompt
global binfile
global binfile2
+ global binfile3
clean_restart $binfile
@@ -577,10 +586,53 @@ proc_with_prefix do_attach_exec_mismatch_handling_tests {} {
# Detach the process.
gdb_test "detach" "Detaching from program: .* detached\\\]" "$test detach attach"
+ # Test that the 'exec-file' changed is checked before exec-file-mismatch.
+ set test "mismatch exec-file changed has priority"
+ gdb_test_no_output "set exec-file-mismatch ask"
+ gdb_test_multiple "attach $testpid" "$test attach1 again, initial exec-file" {
+ -re "Attaching to program.*exec-file-mismatch handling is currently \"ask\".*Load new symbol table from .*attach\".*\(y or n\)" {
+ pass "$test attach1 again"
+ }
+ }
+ gdb_test "y" "Reading symbols from .*attach.*" "$test load attach1 again"
+
+ gdb_test "detach" "Detaching from program: .* detached\\\]" "$test detach attach initial exec-file"
+
+ # Change the exec-file and attach to a new process using the changed file.
+ remote_exec build "mv ${binfile} ${binfile}.initial"
+ remote_exec build "mv ${binfile3} ${binfile}"
+ # Ensure GDB detects ${binfile} has changed when checking timestamp.
+ sleep 1
+ remote_exec build "touch ${binfile}"
+ set test_spawn_id3 [spawn_wait_for_attach $binfile]
+ set testpid3 [spawn_id_get_pid $test_spawn_id3]
+
+ gdb_test "attach $testpid3" "Attaching to program.*attach' has changed; re-reading symbols.*" \
+ "$test attach1 again, after changing exec-file"
+ gdb_test "detach" "Detaching from program: .* detached\\\]" "$test detach after attach changed exec-file"
+
+ # Now, test the situation when current exec-file has changed
+ # and we attach to a pid using another file.
+ # Ensure GDB detects ${binfile} has changed when checking timestamp.
+ sleep 1
+ remote_exec build "touch ${binfile}"
+
+ gdb_test_multiple "attach $testpid2" "$test attach2" {
+ -re "Attaching to program.*exec-file-mismatch handling is currently \"ask\".*Load new symbol table from .*attach2\".*\(y or n\)" {
+ pass "$test attach2 with exec-file changed and need to load another exec-file"
+ }
+ }
+ gdb_test "y" "Reading symbols from .*attach2.*" \
+ "$test load attach2 exec-file changed and load another exec file"
+
+ # Restore initial build situation.
+ remote_exec build "mv ${binfile} ${binfile3}"
+ remote_exec build "mv ${binfile}.initial ${binfile}"
# Don't leave a process around
kill_wait_spawned_process $test_spawn_id
kill_wait_spawned_process $test_spawn_id2
+ kill_wait_spawned_process $test_spawn_id3
}
do_attach_tests
diff --git a/gdb/testsuite/gdb.base/attach2.c b/gdb/testsuite/gdb.base/attach2.c
index 44d37258fb..d070d933b0 100644
--- a/gdb/testsuite/gdb.base/attach2.c
+++ b/gdb/testsuite/gdb.base/attach2.c
@@ -9,12 +9,14 @@
#include <unistd.h>
float bidule = 0.0;
-int should_exit = 0;
+volatile int should_exit = 0;
int main ()
{
int local_i = 0;
+ /* Cannot sleep a very long time, as attach.exp assumes the
+ process will exit before the standard GDB timeout. */
sleep( 10 ); /* System call causes register fetch to fail */
/* This is a known HPUX "feature" */
while (! should_exit)
--
2.20.1
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [RFA] Ensure 'exec-file has changed' check has priority over 'exec-file-mismatch' check
2020-05-23 13:08 [RFA] Ensure 'exec-file has changed' check has priority over 'exec-file-mismatch' check Philippe Waroquiers
@ 2020-06-04 13:28 ` Pedro Alves
0 siblings, 0 replies; 2+ messages in thread
From: Pedro Alves @ 2020-06-04 13:28 UTC (permalink / raw)
To: Philippe Waroquiers, gdb-patches
Hi Philippe,
On 5/23/20 2:08 PM, Philippe Waroquiers via Gdb-patches wrote:
> YYYY-MM-DD Philippe Waroquiers <philippe.waroquiers@skynet.be>
>
> * gdb.base/attach.exp: Test priority of 'exec-file' changed
> over 'exec-file-mismatch'.
> * gdb.base/attach.c: Mark should_exit volatile.
> * gdb.base/attach2.c: Likewise. Add a comment explaining
> why the sleep cannot be big.
> * gdb.base/attach3.c: New file.
> ---
> gdb/exec.c | 10 ++++++
> gdb/testsuite/gdb.base/attach.c | 2 +-
> gdb/testsuite/gdb.base/attach.exp | 56 +++++++++++++++++++++++++++++--
> gdb/testsuite/gdb.base/attach2.c | 4 ++-
> 4 files changed, 68 insertions(+), 4 deletions(-)
attach3.c is missing from the patch.
Thanks,
Pedro Alves
^ permalink raw reply [flat|nested] 2+ messages in thread
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