On Tue, Jan 07, 2020 at 09:59:23AM -0800, Sargun Dhillon wrote: > This patchset introduces a mechanism (pidfd_getfd syscall) to get file > descriptors from other processes via pidfd. Although this can be achieved > using SCM_RIGHTS, and parasitic code injection, this offers a more > straightforward mechanism, with less overhead and complexity. The process > under manipulation's fd still remains valid, and unmodified by the > copy operation. > > It introduces a flags field. The flags field is reserved a the moment, > but the intent is to extend it with the following capabilities: > * Close the remote FD when copying it > * Drop the cgroup data if it's a fd pointing a socket when copying it > > The syscall numbers were chosen to be one greater than openat2. > > Summary of history: > This initially started as a ptrace command. It did not require the process > to be stopped, and felt like kind of an awkward fit for ptrace. After that, > it moved to an ioctl on the pidfd. Given the core functionality, it made > sense to make it a syscall which did not require the process to be stopped. > > Previous versions: > V8: https://lore.kernel.org/lkml/20200103162928.5271-1-sargun@xxxxxxxxx/ > V7: https://lore.kernel.org/lkml/20191226180227.GA29389@ircssh-2.c.rugged-nimbus-611.internal/ > V6: https://lore.kernel.org/lkml/20191223210823.GA25083@ircssh-2.c.rugged-nimbus-611.internal/ > V5: https://lore.kernel.org/lkml/20191220232746.GA20215@ircssh-2.c.rugged-nimbus-611.internal/ > V4: https://lore.kernel.org/lkml/20191218235310.GA17259@ircssh-2.c.rugged-nimbus-611.internal/ > V3: https://lore.kernel.org/lkml/20191217005842.GA14379@ircssh-2.c.rugged-nimbus-611.internal/ > V2: https://lore.kernel.org/lkml/20191209070446.GA32336@ircssh-2.c.rugged-nimbus-611.internal/ > RFC V1: https://lore.kernel.org/lkml/20191205234450.GA26369@ircssh-2.c.rugged-nimbus-611.internal/ I don't see anything wrong with this series anymore: Acked-by: Christian Brauner <christian.brauner@xxxxxxxxxx> Other Acked-bys/Reviewed-bys and reviews of course strongly encouraged! Christian
