On Tue, May 23, 2017 at 01:30:55PM +0900, AKASHI Takahiro wrote: > After entering kgdb mode, the first 'stepi' can succeed, but the following > 'stepi' never executes the next instruction. > > This is because a software step cannot get enabled as the software step > bit(SS) in SPSR, which is cleared by the first single stepping, will not > be set again for the following 's' commands.
For userspace, we have user_rewind_single_step to re-arm the state machine on an unhandled step exception. It sounds like we need the kernel version of that? > Please note that this bit, as well as the software step control bit(SS) > in MDSCR, must be set before resuming the execution. > kernel_active_single_step() called by kgdb_arch_handle_exception() checks > only for the bit in MDSCR, and so kgdb_enable_single_step() will never be > called. MDSCR.SS shouldn't get cleared by the hardware, so I don't understand your point here. Will ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Kgdb-bugreport mailing list Kgdb-bugreport@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kgdb-bugreport
