Re: [PATCH v4 mips-next 6/7] vmlinux.lds.h: catch compound literals into data and BSS

From: Kees Cook
Date: Thu Jan 07 2021 - 16:51:47 EST


On Thu, Jan 07, 2021 at 01:20:55PM +0000, Alexander Lobakin wrote:
> When building kernel with LD_DEAD_CODE_DATA_ELIMINATION, LLVM stack
> generates separate sections for compound literals, just like in case
> with enabled LTO [0]:
>
> ld.lld: warning: drivers/built-in.a(mtd/nand/spi/gigadevice.o):
> (.data..compoundliteral.14) is being placed in
> '.data..compoundliteral.14'
> ld.lld: warning: drivers/built-in.a(mtd/nand/spi/gigadevice.o):
> (.data..compoundliteral.15) is being placed in
> '.data..compoundliteral.15'
> ld.lld: warning: drivers/built-in.a(mtd/nand/spi/gigadevice.o):
> (.data..compoundliteral.16) is being placed in
> '.data..compoundliteral.16'
> ld.lld: warning: drivers/built-in.a(mtd/nand/spi/gigadevice.o):
> (.data..compoundliteral.17) is being placed in
> '.data..compoundliteral.17'
>
> [...]
>
> Handle this by adding the related sections to generic definitions
> as suggested by Sami [0].
>
> [0] https://lore.kernel.org/lkml/20201211184633.3213045-3-samitolvanen@xxxxxxxxxx
>
> Suggested-by: Kees Cook <keescook@xxxxxxxxxxxx>
> Signed-off-by: Alexander Lobakin <alobakin@xxxxx>

Suggested-by: Sami Tolvanen <samitolvanen@xxxxxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>

--
Kees Cook