[PATCH 0/2] powerpc: Add to linker script discards

Joel Stanley (2):
  powerpc: Discard more sections in linker script
  powerpc: Discard dynsym section for !PPC32

 arch/powerpc/kernel/vmlinux.lds.S | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

-- 
2.19.1

Building the ppc64 kernel with a modern binutils results in this
warning:

 powerpc64le-linux-gnu-ld: warning: orphan section `.gnu.hash' from
 `linker stubs' being placed in section `.gnu.hash'

Alan Modra [off-list ref] explains:

 > .gnu.hash, like .hash, is used by glibc ld.so for dynamic symbol
 > lookup.  I imagine you don't need either section in a kernel, so
 > discarding both sounds reasonable.  Likely you could discard .interp
 > and .dynstr too, and .dynsym when !CONFIG_PPC32.

Reported-by: Stephen Rothwell <redacted>
Signed-off-by: Joel Stanley <joel@jms.id.au>
---
See https://lore.kernel.org/lkml/CACPK8Xft3n5KkpTjN3=7_VUCXHFcK7mxvZm2Rrqu7tppcBoyOg@mail.gmail.com/T/#m58532c86cf0c7b4fb01cc1fe724e48d4c7d8e4a7

 arch/powerpc/kernel/vmlinux.lds.S | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index 5c5d559a23fd..e14cde32b003 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S

@@ -279,8 +279,6 @@ SECTIONS
 		__dynamic_start = .;
 		*(.dynamic)
 	}
-	.hash : AT(ADDR(.hash) - LOAD_OFFSET) { *(.hash) }
-	.interp : AT(ADDR(.interp) - LOAD_OFFSET) { *(.interp) }
 	.rela.dyn : AT(ADDR(.rela.dyn) - LOAD_OFFSET)
 	{
 		__rela_dyn_start = .;

@@ -389,5 +387,8 @@ SECTIONS
 		*(.gnu.version*)
 		*(.gnu.attributes)
 		*(.eh_frame)
+		*(.hash .gnu.hash)
+		*(.interp)
+		*(.dynstr)
 	}
 }

-- 
2.19.1

Alan Modra [off-list ref] explains:

 > Likely you could discard .interp > and .dynstr too, and .dynsym when
 > !CONFIG_PPC32.

Discarding of interp and dynstr happened in a previous patch. The dynsym
cleanup was a bit less straightforward, so it gets it's own patch.

Signed-off-by: Joel Stanley <joel@jms.id.au>
---
See https://lore.kernel.org/lkml/CACPK8Xft3n5KkpTjN3=7_VUCXHFcK7mxvZm2Rrqu7tppcBoyOg@mail.gmail.com/T/#m58532c86cf0c7b4fb01cc1fe724e48d4c7d8e4a7

 arch/powerpc/kernel/vmlinux.lds.S | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index e14cde32b003..49dd678a2de4 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S

@@ -266,14 +266,13 @@ SECTIONS
 	}
 #ifdef CONFIG_RELOCATABLE
 	. = ALIGN(8);
+#ifdef CONFIG_PPC32
 	.dynsym : AT(ADDR(.dynsym) - LOAD_OFFSET)
 	{
-#ifdef CONFIG_PPC32
 		__dynamic_symtab = .;
-#endif
 		*(.dynsym)
 	}
-	.dynstr : AT(ADDR(.dynstr) - LOAD_OFFSET) { *(.dynstr) }
+#endif
 	.dynamic : AT(ADDR(.dynamic) - LOAD_OFFSET)
 	{
 		__dynamic_start = .;

@@ -390,5 +389,8 @@ SECTIONS
 		*(.hash .gnu.hash)
 		*(.interp)
 		*(.dynstr)
+#ifndef CONFIG_PPC32
+		*(.dynsym)
+#endif
 	}
 }

-- 
2.19.1