From: Michael Ellerman mpe@ellerman.id.au
commit 4b9880dbf3bdba3a7c56445137c3d0e30aaa0a40 upstream.
The powerpc linker script explicitly includes .exit.text, because otherwise the link fails due to references from __bug_table and __ex_table. The code is freed (discarded) at runtime along with .init.text and data.
That has worked in the past despite powerpc not defining RUNTIME_DISCARD_EXIT because DISCARDS appears late in the powerpc linker script (line 410), and the explicit inclusion of .exit.text earlier (line 280) supersedes the discard.
However commit 99cb0d917ffa ("arch: fix broken BuildID for arm64 and riscv") introduced an earlier use of DISCARD as part of the RO_DATA macro (line 136). With binutils < 2.36 that causes the DISCARD directives later in the script to be applied earlier [1], causing .exit.text to actually be discarded at link time, leading to build errors:
'.exit.text' referenced in section '__bug_table' of crypto/algboss.o: defined in discarded section '.exit.text' of crypto/algboss.o '.exit.text' referenced in section '__ex_table' of drivers/nvdimm/core.o: defined in discarded section '.exit.text' of drivers/nvdimm/core.o
Fix it by defining RUNTIME_DISCARD_EXIT, which causes the generic DISCARDS macro to not include .exit.text at all.
1: https://lore.kernel.org/lkml/87fscp2v7k.fsf@igel.home/
Fixes: 99cb0d917ffa ("arch: fix broken BuildID for arm64 and riscv") Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://lore.kernel.org/r/20230105132349.384666-1-mpe@ellerman.id.au Signed-off-by: Tom Saeger tom.saeger@oracle.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/powerpc/kernel/vmlinux.lds.S | 1 + 1 file changed, 1 insertion(+)
--- a/arch/powerpc/kernel/vmlinux.lds.S +++ b/arch/powerpc/kernel/vmlinux.lds.S @@ -8,6 +8,7 @@ #define BSS_FIRST_SECTIONS *(.bss.prominit) #define EMITS_PT_NOTE #define RO_EXCEPTION_TABLE_ALIGN 0 +#define RUNTIME_DISCARD_EXIT
#define SOFT_MASK_TABLE(align) \ . = ALIGN(align); \