On Mon, 27 Feb 2017 13:41:13 -0800 David Daney <ddaney@xxxxxxxxxxxxxxxxxx> wrote: > On 02/27/2017 01:06 PM, Steven Rostedt wrote: > > On Mon, 27 Feb 2017 11:59:50 -0800 > > David Daney <ddaney@xxxxxxxxxxxxxxxxxx> wrote: > > > >> For me the size is not the important issue, it is the alignment of the > >> struct jump_entry entries in the table. I don't understand how your > >> patch helps, and I cannot Acked-by unless I understand what is being > >> done and can see that it is both correct and necessary. > > > > You brought up a very good point and I'm glad that I had Jason Cc all > > the arch maintainers in one patch. > > > > I think jump_labels may be much more broken than we think, and Jason's > > fix doesn't fix anything. We had this same issues with tracepoints. > > > > I'm looking at jump_label_init, and how we iterate over an array of > > struct jump_entry's that was put together by the linker. The problem is > > that jump_entry is not a power of 2 in size. > > > > ELF sections may have an ENTSIZE property exactly for arrays. Since > each jump_entry will have a unique value they cannot be merged, but we > can tell the assembler they are an array and get them properly packed. > Perhaps something like (untested): > > .pushsection __jump_table, \"awM\",@progbits,24 > FOO > .popsection > And the linker will honor this too? -- Steve
