Re: More trouble with i386 EFLAGS and ptrace

From: Daniel Jacobowitz
Date: Sun Mar 13 2005 - 15:09:39 EST

On Sun, Mar 13, 2005 at 12:27:58AM -0800, Roland McGrath wrote:
> This patch further cleans up the appearance of TF in eflags when ptrace is
> involved. With this, PTRACE_SINGLESTEP will not cause TF to appear in
> eflags as seen by PTRACE_GETREGS and the like, when the instruction faulted
> for some reason other than the single-step trap.
> This moves the check added by Dan's patch from setup_sigcontext to
> handle_signal. This is a cosmetic difference, but I think it makes more
> sense to consolidate all the "reset registers to canonical state" work in
> the same place (i.e. put it with the syscall rollback code), separate from
> the signal handler setup. The change that matters is moving the similar
> check out of do_debug, where it only covers the case of a single-step trap.
> Instead, it goes into the ptrace_signal_deliver macro, which is called
> before the ptrace stop for whatever signal results from whatever kind of
> fault in that instruction (or asynchronous signal). With that, the
> handle_signal check is still needed only for the case of PTRACE_SINGLESTEP
> with a handled signal.
> Thanks,
> Roland

Thanks, looks right to me!

Daniel Jacobowitz
CodeSourcery, LLC
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