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| author | Tankut Baris Aktemur <tankut.baris.aktemur@intel.com> | 2020-05-14 13:59:53 +0200 |
|---|---|---|
| committer | Tankut Baris Aktemur <tankut.baris.aktemur@intel.com> | 2020-05-14 13:59:53 +0200 |
| commit | fc75c28ba1ea7353fb6e1e5904c5703a48504b67 (patch) | |
| tree | 5b1a59f1c2cb60a34c7ca6b34e7868aaac49c975 /gdb/infrun.c | |
| parent | 9d95b8e9d631e76eb152c86003db6b89e913bdd9 (diff) | |
| download | gdb-fc75c28ba1ea7353fb6e1e5904c5703a48504b67.zip gdb-fc75c28ba1ea7353fb6e1e5904c5703a48504b67.tar.gz gdb-fc75c28ba1ea7353fb6e1e5904c5703a48504b67.tar.bz2 | |
gdb: protect some 'regcache_read_pc' calls
It possible that a thread whose PC we attempt to read is already dead.
In this case, 'regcache_read_pc' errors out. This impacts the
"proceed" execution flow, where GDB quits early before having a chance
to check if there exists a pending event. To remedy, keep going with
a 0 value for the PC if 'regcache_read_pc' fails. Because the value
of PC before resuming a thread is mostly used for storing and checking
the next time the thread stops, this tolerance is expected to be
harmless for a dead thread/process.
gdb/ChangeLog:
2020-05-14 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
* regcache.c (regcache_read_pc_protected): New function
implementation that returns 0 if the PC cannot read via
'regcache_read_pc'.
* infrun.c (proceed): Call 'regcache_read_pc_protected'
instead of 'regcache_read_pc'.
(keep_going_pass_signal): Ditto.
gdbsupport/ChangeLog:
2020-05-14 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
* common-regcache.h (regcache_read_pc_protected): New function
declaration.
Diffstat (limited to 'gdb/infrun.c')
| -rw-r--r-- | gdb/infrun.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/gdb/infrun.c b/gdb/infrun.c index 3c6b201..5e01336 100644 --- a/gdb/infrun.c +++ b/gdb/infrun.c @@ -2995,7 +2995,8 @@ proceed (CORE_ADDR addr, enum gdb_signal siggnal) gdbarch = regcache->arch (); const address_space *aspace = regcache->aspace (); - pc = regcache_read_pc (regcache); + pc = regcache_read_pc_protected (regcache); + thread_info *cur_thr = inferior_thread (); /* Fill in with reasonable starting values. */ @@ -3122,7 +3123,7 @@ proceed (CORE_ADDR addr, enum gdb_signal siggnal) advanced. Must do this before resuming any thread, as in all-stop/remote, once we resume we can't send any other packet until the target stops again. */ - cur_thr->prev_pc = regcache_read_pc (regcache); + cur_thr->prev_pc = regcache_read_pc_protected (regcache); { scoped_restore save_defer_tc = make_scoped_defer_target_commit_resume (); @@ -7929,7 +7930,7 @@ keep_going_pass_signal (struct execution_control_state *ecs) /* Save the pc before execution, to compare with pc after stop. */ ecs->event_thread->prev_pc - = regcache_read_pc (get_thread_regcache (ecs->event_thread)); + = regcache_read_pc_protected (get_thread_regcache (ecs->event_thread)); if (ecs->event_thread->control.trap_expected) { |