Messages in this thread | | | Date | Mon, 24 Apr 2023 13:07:50 +0200 | From | Oleg Nesterov <> | Subject | Re: [PATCH] MIPS: uprobes: Restore thread.trap_nr |
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On 04/23, Tiezhu Yang wrote: > > Cc: > Oleg Nesterov <oleg@redhat.com> > Srikar Dronamraju <srikar@linux.vnet.ibm.com> > > On 04/23/2023 11:08 AM, Bagas Sanjaya wrote: > >On Sun, Apr 23, 2023 at 09:38:03AM +0800, Tiezhu Yang wrote: > >>thread.trap_nr is saved in arch_uprobe_pre_xol(), it should be restored > >>in arch_uprobe_{post,abort}_xol() accordingly, actually it was only done > >>in the post function, just do it in the abort function too, this change > >>is similar with x86 and powerpc. > > > >I'm confused (please fix up grammar, spelling, and punctuation). Can you > >explain why thread.trap_nr should be restored somewhere else? Also, what > >x86/powerpc changes as reference? > > > > Here is the related first commit for x86 in 2012: > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0326f5a94dde > > When xol insn itself triggers the signal, restart the original insn, > in this case, UTASK_SSTEP_TRAPPED is set [1], it does *abort_xol() > instead of *post_xol() [2], then should do the restore operations.
Yes... for example, if the uprobed task was killed abort() should restore the state and (in particular) change ->trap_nr from UPROBE_TRAP_NR back to ->saved_trap_nr.
So the patch looks fine to me.
Oleg.
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