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author | Tom de Vries <tdevries@suse.de> | 2024-05-08 14:13:11 +0200 |
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committer | Tom de Vries <tdevries@suse.de> | 2024-05-08 14:13:11 +0200 |
commit | 2236c5e384de20b0dd6b2fbc964a7269027cb2d9 (patch) | |
tree | d8e9d036c5294db37f90800496a00ebdfc076d6d /gdb | |
parent | c144f638337944101131d9fe6de4ab908f6d4c2d (diff) | |
download | gdb-2236c5e384de20b0dd6b2fbc964a7269027cb2d9.zip gdb-2236c5e384de20b0dd6b2fbc964a7269027cb2d9.tar.gz gdb-2236c5e384de20b0dd6b2fbc964a7269027cb2d9.tar.bz2 |
[gdb/python] Make gdb.UnwindInfo.add_saved_register more robust
On arm-linux, until commit bbb12eb9c84 ("gdb/arm: Remove tpidruro register
from non-FreeBSD target descriptions") I ran into:
...
FAIL: gdb.base/inline-frame-cycle-unwind.exp: cycle at level 5: \
backtrace when the unwind is broken at frame 5
...
What happens is the following:
- the TestUnwinder from inline-frame-cycle-unwind.py calls
gdb.UnwindInfo.add_saved_register with reg == tpidruro and value
"<unavailable>",
- pyuw_sniffer calls value->contents ().data () to access the value of the
register, which throws an UNAVAILABLE_ERROR,
- this causes the TestUnwinder unwinder to fail, after which another unwinder
succeeds and returns the correct frame, and
- the test-case fails because it's counting on the TestUnwinder to succeed and
return an incorrect frame.
Fix this by checking for !value::entirely_available as well as
valued::optimized_out in unwind_infopy_add_saved_register.
Tested on x86_64-linux and arm-linux.
Approved-By: Andrew Burgess <aburgess@redhat.com>
PR python/31437
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31437
Diffstat (limited to 'gdb')
-rw-r--r-- | gdb/python/py-unwind.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/gdb/python/py-unwind.c b/gdb/python/py-unwind.c index a86ccd2..18125e5 100644 --- a/gdb/python/py-unwind.c +++ b/gdb/python/py-unwind.c @@ -361,6 +361,18 @@ unwind_infopy_add_saved_register (PyObject *self, PyObject *args, PyObject *kw) return nullptr; } + if (value->optimized_out () || !value->entirely_available ()) + { + /* If we allow this value to be registered here, pyuw_sniffer is going + to run into an exception when trying to access its contents. + Throwing an exception here just puts a burden on the user to + implement the same checks on the user side. We could return False + here and True otherwise, but again that might require changes in user + code. So, handle this with minimal impact for the user, while + improving robustness: silently ignore the register/value pair. */ + Py_RETURN_NONE; + } + gdbpy_ref<> new_value = gdbpy_ref<>::new_reference (pyo_reg_value); bool found = false; for (saved_reg ® : *unwind_info->saved_regs) |