[PATCH 4.4 013/112] parisc: Fix kernel memory layout regarding position of __gp

From: Greg Kroah-Hartman
Date: Wed Oct 26 2016 - 09:06:38 EST


4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Helge Deller <deller@xxxxxx>

commit f8850abb7ba68229838014b3409460e576751c6d upstream.

Architecturally we need to keep __gp below 0x1000000.

But because of ftrace and tracepoint support, the RO_DATA_SECTION now gets much
bigger than it was before. By moving the linkage tables before RO_DATA_SECTION
we can avoid that __gp gets positioned at a too high address.

Signed-off-by: Helge Deller <deller@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/parisc/kernel/vmlinux.lds.S | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

--- a/arch/parisc/kernel/vmlinux.lds.S
+++ b/arch/parisc/kernel/vmlinux.lds.S
@@ -88,8 +88,9 @@ SECTIONS
/* Start of data section */
_sdata = .;

- RO_DATA_SECTION(8)
-
+ /* Architecturally we need to keep __gp below 0x1000000 and thus
+ * in front of RO_DATA_SECTION() which stores lots of tracepoint
+ * and ftrace symbols. */
#ifdef CONFIG_64BIT
. = ALIGN(16);
/* Linkage tables */
@@ -104,6 +105,8 @@ SECTIONS
}
#endif

+ RO_DATA_SECTION(8)
+
/* unwind info */
.PARISC.unwind : {
__start___unwind = .;