Re: [PATCH] Set TIF_IRET in more places

Ulrich Drepper (drepper@redhat.com)
Mon, 06 Jan 2003 10:42:11 -0800


Luca Barbieri wrote:

> 1. vfork seems to not set any TIF_ flags so a ptracer setting regs
> while a vforking task is stopped in ptrace_notify called from vfork
> would result in clobbered %ecx and %edx.

Just to be clear: the vfork syscall does not use sysenter. It's not
possible with the current implementation. The magic sysenter wrapping
code would have to recognize the syscall and handle it special by saving
the return address. From glibc's POV the %edx register would be free
but I consider this interface far to fragile.

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