binutils < 2.18 has a bug that makes it misbehave when taking an
ELF file with all segments at load address 0 as input. This
happens when running "strip" on vmlinux, because of the AT() magic
in this linker script. People using GCC >= 4.2 won't run into
this problem, because the "build-id" support will put some data
into the "notes" segment (at a non-zero load address).
To work around this, we force some data into both the "dummy"
segment and the kernel segment, so the dummy segment will get a
non-zero load address. It's not enough to always create the
"notes" segment, since if nothing gets assigned to it, its load
address will be zero.
Signed-off-by: Segher Boessenkool <[EMAIL PROTECTED]>
Tested-By: Milton Miller <[EMAIL PROTECTED]>
---
arch/powerpc/kernel/vmlinux.lds.S | 31 ++++++++++++++++++++++++++++---
1 files changed, 28 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/kernel/vmlinux.lds.S
b/arch/powerpc/kernel/vmlinux.lds.S
index 87a72c6..a914411 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -9,6 +9,25 @@
ENTRY(_stext)
+PHDRS {
+ kernel PT_LOAD FLAGS(7); /* RWX */
+ notes PT_NOTE FLAGS(0);
+ dummy PT_NOTE FLAGS(0);
+
+ /* binutils < 2.18 has a bug that makes it misbehave when taking an
+ ELF file with all segments at load address 0 as input. This
+ happens when running "strip" on vmlinux, because of the AT() magic
+ in this linker script. People using GCC >= 4.2 won't run into
+ this problem, because the "build-id" support will put some data
+ into the "notes" segment (at a non-zero load address).
+
+ To work around this, we force some data into both the "dummy"
+ segment and the kernel segment, so the dummy segment will get a
+ non-zero load address. It's not enough to always create the
+ "notes" segment, since if nothing gets assigned to it, its load
+ address will be zero. */
+}
+
#ifdef CONFIG_PPC64
OUTPUT_ARCH(powerpc:common64)
jiffies = jiffies_64;
@@ -50,7 +69,7 @@ SECTIONS
. = ALIGN(PAGE_SIZE);
_etext = .;
PROVIDE32 (etext = .);
- }
+ } :kernel
/* Read-only data */
RODATA
@@ -62,7 +81,13 @@ SECTIONS
__stop___ex_table = .;
}
- NOTES
+ NOTES :kernel :notes
+
+ /* The dummy segment contents for the bug workaround mentioned above
+ near PHDRS. */
+ .dummy : {
+ LONG(0xf177)
+ } :kernel :dummy
/*
* Init sections discarded at runtime
@@ -74,7 +99,7 @@ SECTIONS
_sinittext = .;
INIT_TEXT
_einittext = .;
- }
+ } :kernel
/* .exit.text is discarded at runtime, not link time,
* to deal with references from __bug_table
--
1.5.6.4.gf1ba5
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