[PATCH] arm64/debug: don't duplicate filenames.

Jamie Iles jamie.iles at oracle.com
Thu Nov 9 05:08:51 PST 2017


Hi Dave,

On Thu, Nov 09, 2017 at 12:35:04PM +0000, Dave Martin wrote:
> On Thu, Nov 09, 2017 at 12:14:40PM +0000, Jamie Iles wrote:
> > Rather than explicitly pushing the filename into .rodata.str, use a
> > compiler generated string literal and use the address of that as an
> > input constraint to the inline assembly.  This allows the compiler to
> > emit only one version of the string without relying on the linker to
> > deduplicate.
> 
> But if the linker does deduplicate, why does it matter?

It's not broken, but at the moment we have multiple copies in the object 
file then we're relying on the linker.  If we use the same pattern as 
X86, we can let GCC assign sections+attributes for us and only get one 
copy in the object file.

> Or is the linker not removing duplicates that some from the same source
> file?

In my testing, yes, the linker is merging them.

Jamie



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