Date: Sat, 19 Jul 2008 10:59:29 -0700 From: Marcel Moolenaar <xcllnt@mac.com> To: FreeBSD Arch <arch@freebsd.org> Subject: RFC: cross-libkvm/libthread_db/proc_service Message-ID: <34889018-8358-46AC-897E-32767FB84E14@mac.com>
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All,
We have a couple of interfaces/APIs that can't be used cross-platform.
Take for example libkvm. On a 32-bit platform, we can't typically use
libkvm on a 64-kernel, because the libkvm interface uses u_long for
the target address, which on 32-bit platforms is 32 bits wide.
Likewise, libthread_db and proc_service are designed for native use
only and need API tweaks to work in a cross-environment. Both use
psaddr_t to represent a target address, which is defined as a void*
in <sys/procfs.h>.
I'd like to change those interfaces/APIs to allow them to be used in
a cross-platform debugging environment. Basically, this means that a
target address will have to be defined as a uint64_t. Other datatypes
may also need to be retyped.
For libkvm in particular I don't want to redefine struct kinfo_proc,
struct nlist, etc. While it could be useful in a hybrid 32/64-bit
environment, the effect of such changes have too high a chance to
trickle down various other components/interfaces. Thus, for libkvm
the focus is on kvm_read() and kvm_write().
Suggested plan of attack:
o add kvm_xread() and kvm_xwrite() to the libkvm API to minimize
the overall impact. The new functions operate on a 64-bit target
address (psaddr_t).
o change psaddr_t from a void* to a 64-bit integral (sys/procfs.h)
This affects proc_service and libthread_db. And consequently our
threading support in GDB.
Comments/thoughts?
--
Marcel Moolenaar
xcllnt@mac.com
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