[3/3] powerpc: link warning for orphan sections

Submitted by Nicholas Piggin on May 11, 2017, 5:40 p.m.

Details

Message ID 20170511174040.19728-4-npiggin@gmail.com
State Under Review
Headers show

Commit Message

Nicholas Piggin May 11, 2017, 5:40 p.m.
Add --orphan-handling=warn to final link flags. This ensures we can
handle all sections explicitly. This would have caught subtle breakage
such as 7de3b27bac47da9de08409df1d69664acbb72197 at build-time.

Also bring existing orphan sections into the fold:
- .text.hot and .text.unlikely are compiler generated sections.
- .sdata2, .dynsbss, .plt are used by PPC32
- We previously did not specify DWARF_DEBUG or STABS_DEBUG
- DWARF_DEBUG did not include all DWARF sections that can be emitted
- A number of sections are unused and can be discarded.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/Makefile             |  1 +
 arch/powerpc/kernel/vmlinux.lds.S | 16 ++++++++++++++--
 include/asm-generic/vmlinux.lds.h | 12 ++++++++++++
 3 files changed, 27 insertions(+), 2 deletions(-)

Patch hide | download patch | download mbox

diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index eaa1865e4a8d..8d4ed73d5490 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -98,6 +98,7 @@  endif
 LDFLAGS_vmlinux-y := -Bstatic
 LDFLAGS_vmlinux-$(CONFIG_RELOCATABLE) := -pie
 LDFLAGS_vmlinux	:= $(LDFLAGS_vmlinux-y)
+LDFLAGS_vmlinux += $(call ld-option,--orphan-handling=warn)
 
 ifeq ($(CONFIG_PPC64),y)
 ifeq ($(call cc-option-yn,-mcmodel=medium),y)
diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index 5aa434e84605..24a37e49d7fe 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -86,7 +86,7 @@  SECTIONS
 		ALIGN_FUNCTION();
 #endif
 		/* careful! __ftr_alt_* sections need to be close to .text */
-		*(.text .fixup __ftr_alt_* .ref.text)
+		*(.text.hot .text .text.fixup .text.unlikely .fixup __ftr_alt_* .ref.text);
 		SCHED_TEXT
 		CPUIDLE_TEXT
 		LOCK_TEXT
@@ -253,7 +253,9 @@  SECTIONS
 	.data : AT(ADDR(.data) - LOAD_OFFSET) {
 		DATA_DATA
 		*(.sdata)
+		*(.sdata2)
 		*(.got.plt) *(.got)
+		*(.plt)
 	}
 #else
 	.data : AT(ADDR(.data) - LOAD_OFFSET) {
@@ -316,6 +318,16 @@  SECTIONS
 	_end = . ;
 	PROVIDE32 (end = .);
 
-	/* Sections to be discarded. */
+	STABS_DEBUG
+
+	DWARF_DEBUG
+
 	DISCARDS
+	/DISCARD/ : {
+		*(*.EMB.apuinfo)
+		*(.glink .iplt .plt .rela* .comment)
+		*(.gnu.version*)
+		*(.gnu.attributes)
+		*(.eh_frame)
+	}
 }
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 3558f4eb1a86..b38ac26a82b3 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -596,6 +596,7 @@ 
 #define SBSS(sbss_align)						\
 	. = ALIGN(sbss_align);						\
 	.sbss : AT(ADDR(.sbss) - LOAD_OFFSET) {				\
+		*(.dynsbss)						\
 		*(.sbss)						\
 		*(.scommon)						\
 	}
@@ -642,11 +643,22 @@ 
 		.debug_str      0 : { *(.debug_str) }			\
 		.debug_loc      0 : { *(.debug_loc) }			\
 		.debug_macinfo  0 : { *(.debug_macinfo) }		\
+		.debug_pubtypes 0 : { *(.debug_pubtypes) }		\
+		/* DWARF 3 */						\
+		.debug_ranges	0 : { *(.debug_ranges) }		\
 		/* SGI/MIPS DWARF 2 extensions */			\
 		.debug_weaknames 0 : { *(.debug_weaknames) }		\
 		.debug_funcnames 0 : { *(.debug_funcnames) }		\
 		.debug_typenames 0 : { *(.debug_typenames) }		\
 		.debug_varnames  0 : { *(.debug_varnames) }		\
+		/* GNU DWARF 2 extensions */				\
+		.debug_gnu_pubnames 0 : { *(.debug_gnu_pubnames) }	\
+		.debug_gnu_pubtypes 0 : { *(.debug_gnu_pubtypes) }	\
+		/* DWARF 4 */						\
+		.debug_types	0 : { *(.debug_types) }			\
+		/* DWARF 5 */						\
+		.debug_macro	0 : { *(.debug_macro) }			\
+		.debug_addr	0 : { *(.debug_addr) }
 
 		/* Stabs debugging sections.  */
 #define STABS_DEBUG							\