Re: [PATCH v6 14/17] [gdb/generic] corefile/bug: Use thread-specific gdbarch when dumping register state to core files

[Tom Tromey <tom@tromey.com>]

>>>>> "Luis" == Luis Machado via Gdb-patches <gdb-patches@sourceware.org> writes:

Luis> When we have a core file generated by gdb (via the gcore command), gdb dumps
Luis> the target description to a note.  During loading of that core file, gdb will
Luis> first try to load that saved target description.

Luis> This works fine for almost all architectures. But AArch64 has a few
Luis> dynamically-generated target descriptions/gdbarch depending on the vector
Luis> length that was in use at the time the core file was generated.

Luis> The target description gdb dumps to the core file note is the one generated
Luis> at the time of attachment/startup.  If, for example, the SVE vector length
Luis> changed during execution, this would not reflect on the core file, as gdb
Luis> would still dump the initial target description.

Luis> Another issue is that the gdbarch potentially doesn't match the thread's
Luis> real gdbarch, and so things like the register cache may have different formats
Luis> and sizes.

Luis> To address this, fetch the thread's architecture before dumping its register
Luis> state.  That way we will always use the correct target description/gdbarch.

FWIW this seems fine to me.
Approved-By: Tom Tromey <tom@tromey.com>

Tom