From afa8d396f6a952d17b348a981dd2c56f83305611 Mon Sep 17 00:00:00 2001 From: Pedro Alves Date: Thu, 19 Feb 2015 20:48:54 +0000 Subject: [PATCH] fix gdbserver/linux-low'c's pending status handling Another fix I'm working made schedlock.exp fail with gdbserver frequently. Looking deeper, it turns out to be a pre-existing bug. status_pending_p_callback is filtering out LWPs incorrectly. The result is that that sometimes status_pending_p_callback returns a pending event for an LWP that isn't expected, and then GDBserver gets very confused. E.g,. when doing a step-over, linux_wait_for_event is called with a particular LWP's ptid, meaning events for all other LWPs should be left pending, but here we see it retuning an event for some other LWP: linux_wait_1: [] step_over_bkpt set [LWP 29577.29577], doing a blocking wait <-------- my_waitpid (-1, 0x40000001) my_waitpid (-1, 0x80000001): status(57f), 0 LWFE: waitpid(-1, ...) returned 0, ERRNO-OK pc is 0x4007a0 src/gdb/gdbserver/linux-low.c:2587: A problem internal to GDBserver has been detected. linux_wait_1: got event for 29581 <-------- Remote connection closed (gdb) FAIL: gdb.threads/schedlock.exp: continue to breakpoint: return to loop (initial) delete breakpoints Tested on x86_64 Fedora 20. gdb/gdbserver/ChangeLog: 2015-02-20 Pedro Alves * linux-low.c (status_pending_p_callback): Use ptid_match. --- gdb/gdbserver/ChangeLog | 4 ++++ gdb/gdbserver/linux-low.c | 5 ++--- 2 files changed, 6 insertions(+), 3 deletions(-) diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog index 06848e089c..cd79d75f79 100644 --- a/gdb/gdbserver/ChangeLog +++ b/gdb/gdbserver/ChangeLog @@ -1,3 +1,7 @@ +2015-02-20 Pedro Alves + + * linux-low.c (status_pending_p_callback): Use ptid_match. + 2015-02-19 Antoine Tremblay PR breakpoints/16812 diff --git a/gdb/gdbserver/linux-low.c b/gdb/gdbserver/linux-low.c index 1869857d59..a6e1e3dce5 100644 --- a/gdb/gdbserver/linux-low.c +++ b/gdb/gdbserver/linux-low.c @@ -1288,9 +1288,8 @@ status_pending_p_callback (struct inferior_list_entry *entry, void *arg) ptid_t ptid = * (ptid_t *) arg; /* Check if we're only interested in events from a specific process - or its lwps. */ - if (!ptid_equal (minus_one_ptid, ptid) - && ptid_get_pid (ptid) != ptid_get_pid (thread->entry.id)) + or a specific LWP. */ + if (!ptid_match (ptid_of (thread), ptid)) return 0; if (lp->status_pending_p