Messages in this thread | | | Subject | Re: [PREVIEW 10/10] linkage: add .cfi_{start/end}proc to ENTRY/ENDPROC | From | Jiri Slaby <> | Date | Fri, 17 Feb 2017 14:36:15 +0100 |
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On 02/17/2017, 02:16 PM, Josh Poimboeuf wrote: > On Fri, Feb 17, 2017 at 11:47:57AM +0100, Jiri Slaby wrote: >> This is just a preview, not to merged now, only later with DWARF >> unwinder series. This is what the series will serve for (aside from >> cleanup and unification). >> >> I am aware of CFI_STARTPROC and CFI_ENDPROC left defined in other archs >> in spite of cfi annotations removal ages ago. For simplicity. I am using >> DW_ prefix here. > > If objtool is going to be generating CFI instructions, why not have it > generate .cfi_startproc and .cfi_endproc too?
I tried that, but in many places it is very hard to recognize start and/or end of a function. Having .cfi_startproc and .cfi_endproc in place makes it rather easy, actually reduced to "emit dwarf instructions for this code between here and there". Plus pre-prepared .eh_frame only to be extended. (.eh_frame_hdr has to be rehashed of course.)
thanks, -- js suse labs
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