On Sun, 2013-02-10 at 15:10 +0100, Frederic Weisbecker wrote: > 2013/2/1 Li Zhong <zh...@linux.vnet.ibm.com>: > > This is the exception hooks for context tracking subsystem, including > > data access, program check, single step, instruction breakpoint, machine > > check, > > alignment, fp unavailable, altivec assist, unknown exception, whose handlers > > might use RCU. > > > > This patch corresponds to > > [PATCH] x86: Exception hooks for userspace RCU extended QS > > commit 6ba3c97a38803883c2eee489505796cb0a727122 > > > > Signed-off-by: Li Zhong <zh...@linux.vnet.ibm.com> > > Looks good! > > I guess we should move exception_enter/exit definition to the generic > code. They should be the same for all archs after all.
Indeed. > Also we are > relying on user_mode(regs) but this may be buggy with some corner > cases. For example if an exception happen after a call to user_exit() I guess you mean user_enter() here, or am I confused? > (on syscall exit) but before we actually resume in userspace, the > exception will exit in kernel mode from the context tracking POV. > > So instead on relying on the regs, which are not sync with the context > tracking state, we should use something like: > > prev_state = exception_enter(); > ... > exception_exit(prev_state); > > Also preempt_schedule_irq() is concerned as well by this problem. So I > should convert it to that scheme as well. I'm going to prepare some > patches. > > Feel free to merge this patch in the powerpc tree, I'll do the > conversion along the way. Or if your patches gets merged earlier than these, I can update my code according to yours. Thanks, Zhong > > Thanks. > _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
