Merge patch series "riscv: improve link and support ARCH_WANT_LD_ORPHAN_WARN"

Jisheng Zhang <jszhang@kernel.org> says:

This series tries to improve link time handling of riscv:
patch1 adds the missing RUNTIME_DISCARD_EXIT as suggested by Masahiro.

Similar as other architectures such as x86, arm64 and so on, enable
ARCH_WANT_LD_ORPHAN_WARN to enable linker orphan warnings to prevent
from missing any new sections in future. So the following two patches
are preparation ones, and the last patch finally selects
ARCH_WANT_LD_ORPHAN_WARN

* b4-shazam-merge:
  riscv: select ARCH_WANT_LD_ORPHAN_WARN for !XIP_KERNEL
  riscv: vmlinux.lds.S: explicitly catch .init.bss sections from EFI stub
  riscv: vmlinux.lds.S: explicitly catch .riscv.attributes sections
  riscv: vmlinux.lds.S: explicitly catch .rela.dyn symbols
  riscv: lds: define RUNTIME_DISCARD_EXIT

Link: https://lore.kernel.org/r/20230119155417.2600-1-jszhang@kernel.orgSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

arch/riscv/Kconfig

@@ -47,6 +47,7 @@ config RISCV
 	select ARCH_WANT_FRAME_POINTERS
 	select ARCH_WANT_GENERAL_HUGETLB
 	select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
+	select ARCH_WANT_LD_ORPHAN_WARN if !XIP_KERNEL
 	select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE
 	select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
 	select BUILDTIME_TABLE_SORT if MMU

arch/riscv/kernel/vmlinux.lds.S

@@ -5,6 +5,7 @@
  */
 
 #define RO_EXCEPTION_TABLE_ALIGN	4
+#define RUNTIME_DISCARD_EXIT
 
 #ifdef CONFIG_XIP_KERNEL
 #include "vmlinux-xip.lds.S"
@@ -86,6 +87,9 @@ SECTIONS
 	/* Start of init data section */
 	__init_data_begin = .;
 	INIT_DATA_SECTION(16)
+	.init.bss : {
+		*(.init.bss)	/* from the EFI stub */
+	}
 	.exit.data :
 	{
 		EXIT_DATA
@@ -96,6 +100,10 @@ SECTIONS
 		*(.rel.dyn*)
 	}
 
+	.rela.dyn : {
+		*(.rela*)
+	}
+
 	__init_data_end = .;
 
 	. = ALIGN(8);
@@ -141,6 +149,7 @@ SECTIONS
 	STABS_DEBUG
 	DWARF_DEBUG
 	ELF_DETAILS
+	.riscv.attributes 0 : { *(.riscv.attributes) }
 
 	DISCARDS
 }