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| author | Pedro Alves <palves@redhat.com> | 2015-02-10 19:13:31 +0000 |
|---|---|---|
| committer | Pedro Alves <palves@redhat.com> | 2015-02-10 19:13:31 +0000 |
| commit | b052c4fbf5e64a2e96452642adf433f60b185245 (patch) | |
| tree | 3c82670d102425aa50b6b1a2888825c1414aa521 | |
| parent | b05ec7a53f8a3b0cbcb2b42772ca0e70a319d2ab (diff) | |
| download | gdb-b052c4fbf5e64a2e96452642adf433f60b185245.zip gdb-b052c4fbf5e64a2e96452642adf433f60b185245.tar.gz gdb-b052c4fbf5e64a2e96452642adf433f60b185245.tar.bz2 | |
displaced_step_fixup may access memory from the wrong inferior/thread
displaced_step_fixup takes an thread to work with, as argument. OTOH,
gdbarch_displaced_step_fixup fixes up the current thread. The former
calls the latter without making sure the current thread is the one
that was passed in. If it is not, then gdbarch_displaced_step_fixup
may e.g., try reading from a running thread, which doesn't work on
some targets, or worse, read memory from the wrong inferior and
succeed.
This is mostly a latent problem currently, as non-stop switches the
current thread to the event thread early in fetch_inferior_event.
Tested on x86_64 Fedora 20.
gdb/
2015-02-10 Pedro Alves <palves@redhat.com>
* infrun.c (displaced_step_fixup): Switch to the event thread
before calling gdbarch_displaced_step_fixup.
| -rw-r--r-- | gdb/ChangeLog | 5 | ||||
| -rw-r--r-- | gdb/infrun.c | 4 |
2 files changed, 9 insertions, 0 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 08575ff..58df0ca 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,8 @@ +2015-02-10 Pedro Alves <palves@redhat.com> + + * infrun.c (displaced_step_fixup): Switch to the event thread + before calling gdbarch_displaced_step_fixup. + 2015-02-10 Antoine Tremblay <antoine.tremblay@ericsson.com> * MAINTAINERS (Write After Approval): Add Antoine Tremblay. diff --git a/gdb/infrun.c b/gdb/infrun.c index 11dcc0e..5770d77 100644 --- a/gdb/infrun.c +++ b/gdb/infrun.c @@ -1784,6 +1784,10 @@ displaced_step_fixup (ptid_t event_ptid, enum gdb_signal signal) /* Did the instruction complete successfully? */ if (signal == GDB_SIGNAL_TRAP) { + /* Fixup may need to read memory/registers. Switch to the + thread that we're fixing up. */ + switch_to_thread (event_ptid); + /* Fix up the resulting state. */ gdbarch_displaced_step_fixup (displaced->step_gdbarch, displaced->step_closure, |