Re: drivers/gpu/drm/i915/i915.prelink.o: warning: objtool: __intel_wait_for_register_fw.cold()+0xce: relocation to !ENDBR: vlv_allow_gt_wake.cold+0x0

Peter Zijlstra
2022-04-06T11:01:18Z

On Tue, Apr 05, 2022 at 10:32:51PM -0700, Josh Poimboeuf wrote:
> On Wed, Apr 06, 2022 at 02:46:22AM +0200, Thomas Gleixner wrote:
> > On Tue, Apr 05 2022 at 17:05, Josh Poimboeuf wrote:
> > > On Tue, Apr 05, 2022 at 04:01:15PM +0200, Peter Zijlstra wrote:
> > >
> > > But objtool is complaining about a real problem (albeit with a cryptic
> > > warning). I don't think we want to paper over that. See patch.
> > >
> > > Also, are in-tree users of trace_printk() even allowed??
> >
> > See the comment in the header file you are patching:
> >
> > * This is intended as a debugging tool for the developer only.
> > * Please refrain from leaving trace_printks scattered around in
> > * your code. (Extra memory is used for special buffers that are
> > * allocated when trace_printk() is used.)
>
> So what do we do ... send a nastygram?

Best would be for Steve to send a patch removing them all:

arch/powerpc/kvm/book3s_xics.c:#define XICS_DBG(fmt...) trace_printk(fmt)
drivers/gpu/drm/i915/gt/intel_gtt.h:#define DBG(...) trace_printk(__VA_ARGS__)
drivers/gpu/drm/i915/i915_gem.h:#define GEM_TRACE(...) trace_printk(__VA_ARGS__)
drivers/gpu/drm/i915/i915_gem.h: trace_printk(__VA_ARGS__); \
drivers/hwtracing/stm/dummy_stm.c: trace_printk("[%u:%u] [pkt: %x/%x] (%llx)\n", master, channel,
drivers/infiniband/hw/hfi1/trace_dbg.h: trace_printk(fmt, ##__VA_ARGS__)
drivers/tty/n_tty.c:# define n_tty_trace(f, args...) trace_printk(f, ##args)
drivers/usb/early/xhci-dbc.c:#define xdbc_trace trace_printk
fs/ext4/inline.c: trace_printk("inode %lu\n", dir->i_ino);
fs/ext4/inline.c: trace_printk("de: off %u rlen %u name %.*s nlen %u ino %u\n",

All except i915 use CPP tokens that don't exist, local developer really
has to take effort to enable it. i915 crud depends on a CONFIG_ symbols
that all{yes,mod}config will happily set for you,